World Agriculture Vol.2 No.2 (Autumn 2011)

Front Cover

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Inside Front

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Dear readers,

If you wish to receive regular Issues of this Journal please complete the strip and post it to: Circulation Department, Script Media, 47 Church Street, Barnsley, South Yorkshire S70 2AS or fax it to the publishers on 01226 734478.

Or fill in the form online at www.world-agriculture.net If you wish to place an advertisement in future Issues please in the first instance contact the Publishers by e-mail editor@world-agriculture.net or by post: World Agriculture, Script Media, 47 Church Street, Barnsley, South Yorkshire, S70 2AS. If you wish to submit an article for consideration by the Editorial Board for inclusion in a Section of World Agriculture: a) Scientific b) Economic & Social c) Opinion & Comment, or d) a Letter to the Editor, please follow the Instructions to Contributors printed in this Issue and submit by e-mail to the Editor at the address given at the end of the Instructions.

For further information about World Agriculture please go to the following web address: www.world-agriculture.net Yours faithfully, David Frape

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editorial World Agriculture Editorial Board

Appointments to the Editorial Board The Editorial Board is very pleased to welcome: Professor Sir Brian Heap CBE, BSc, MA, PhD, ScD, FSB, FRSC, FRAgS, FRS and Professor Demis J Murphy BA, DPhil

Published by Script Media, 47 Church Street, Barnsley, South Yorkshire S70 2AS, UK

Patron Sir Crispin Tickell GCMG, KCVO Chairman Professor Sir Colin Spedding CBE, MSc, PhD, DSc, CBiol, Hon FSB, FRASE, FIHort, FRAgS, FRSA, Hon Assoc RCVS, Hon DSc Agriculturalist Deputy Chairman & Editor Dr David Frape BSc, PhD, PG Dip Agric, CBiol, FSB, FRCPath, RNutr Mammalian physiologist Email: David.L.Frape@btinternet.com Assistant Editors Robert Cook BSc, CBiol, FSB (UK) Plant pathologist and agronomist Dr Ben Aldiss BSc, PhD, CBiol, MSB, FRES (UK) Ecologist, entomologist and educationalist Members of the Editorial Board Professor Pramod Kumar Aggarwal B.Sc, M.Sc, Ph.D. (India), Ph.D. (Netherlands), FNAAS (India), FNASc (India) Crop ecologist Professor Phil Brookes BSc, PhD, DSc (UK) Soil microbial ecologist Professor Andrew Challinor BSc, PhD (UK) Agricultural meteorologist Professor J. Perry Gustafson BSc, MS, PhD (USA) Plant geneticist Professor Sir Brian Heap CBE BSc, MA, PhD, ScD, FSB, FRSC, FRAgS, FRS (UK) Animal physiologist Professor Paul Jarvis FRS, FRSE, FRSwedish Soc. Agric. & Forestry (UK) Silviculturalist Professor Brian Kerry MBE, BSc, PhD (UK) Soil microbial ecologist Professor Glen M. MacDonald BA, MSc, PhD (USA) Geographer Professor Sir John Marsh CBE, MA, PG Dip Ag Econ, CBiol, FSB, FRASE, FRAgS (UK) Agricultural economist Professor Ian McConnell BVMS, MRVS, MA, PhD, FRCPath, FRSE (UK) Animal immunologist Professor Denis J Murphy BA, DPhil (UK) Crop biotechnologist Dr Christie Peacock BSc, PhD, FRSA, FRAgS, Hon. DSc, FSB (UK) Tropical Agriculturalist Professor RH Richards C.B.E., M.A., Vet. M.B., Ph.D., C.Biol., F.S.B., F.R.S.M., M.R.C.V.S., F.R.Ag.S (UK) Aquaculturalist Professor Neil C. Turner FTSE, FAIAST, FNAAS (India), BSc, PhD, DSc (Australia) Crop physiologist Dr Roger Turner BSc PhD, MBPR (UK) Agronomist Professor John Snape BSc PhD (UK) Crop geneticist Editorial Assistants Dr Philip Taylor BSc, MSc, PhD Advisor to the board Ms Sofie Aldiss BSc Dr John Bingham Michael J.C. Crouch BSc MSc (Res) CBE, FRS, FRASE, ScD (UK) Rob Coleman BSc MSc Crop geneticist

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contents

In this Issue ...

Editorials: Sustaining World Food Supply using novel technologies NPK efficiency and ‘plowing’

Scientific: Developments in Rice Research: Visions and Pragmatism Dr John E. Sheehy & Dr Peter L. Mitchell Peak phosphorus: implications for agriculture Professor Peter S. Cornish Carbon, Conservation and Agricultural Development – the Coastal Peatlands of Sumatra, Indonesia John Bathgate & Dr Tony Greer

Economic & Social: A deficiency of idle land to expand food production Susie Roques, John Garstang, Dr Daniel Kindred, Dr Jeremy Wiltshire, Steven Tompkins and Professor Roger Sylvester-Bradley Intensive (farming) Agriculture Professor Sir Colin Spedding Sustainable Intensification Professor Sir John Marsh

Comment & Opinion Impact of Cultured Meat on Global Agriculture Professor Brian J. Ford

Books and Report Reviews: Hay on Wye Festival Reviewed by Robert Cook Good Food for Everyone Forever, Colin Tudge, Pari Publishing Reviewed by Professor Sean Rickard

Letters to the Editor Christopher Jones David Jenkins

Potential future articles Instructions to contributors Publisher’s Disclaimer No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise or from any use or operation of any methods, products, instructions or ideas contained in the material herein.

Although all advertising material is expected to conform to ethical standards, inclusion in this publication does not constitute a guarantee, or endorsement of the quality or value of such product by the Publisher, or of the claims made by the manufacturer.

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World Agriculture: A peer-reviewed, scientific review journal directed towards opinion formers, decision makers, policy makers and farmers

objectives and functions of the Journal The Journal will publish articles giving clear, unbiased and factual accounts of development in, or affecting, world agriculture. Articles will interpret the influence of related subjects (including climate, forestry, fisheries and human population, economics, transmissible disease, ecology) on these developments. Fully referenced, and reviewed, articles by scientists, economists and technologists will be included with editorial comment. Furthermore, a section for “Opinion & Comment” allows skilled individuals with considerable experience to express views with a rational basis that are argued logically.

References to papers that have been subject to peer-review will not be mandatory for this section. From time to time the Editor will invite individuals to prepare articles on important subjects of topical and international concern for publication in the Journal.

Articles will be independently refereed. Each article must create interest in the reader, pose a challenge to conventional thought and create discussion. Each will: 1) Explain likely consequences of the directions that policy, or development, is taking. This will include interactive effects of climate change, population growth and distribution, economic and social factors, food supplies, transmissible disease evolution, oceanic changes and forest cover. Opinion, in the “Opinion & Comment” Section must be based on sound deductions and indicated as such. Thus, an important objective is to assist decision-makers and to influence policies and methods that ensure development is evidence-based and proceeds in a more “sustainable” way. Without a clear understanding of the economic causes of the different rates of agricultural development in developing and developed countries and of migration rates between continents rational policies may not be developed. Hence, the role of economics must be understood and contribute an important part in the discussion of all subjects.

2) Provide independent and objective guidance to encourage the adoption of technical innovations and new knowledge.

3) Discourage false short-sighted policies and loose terminology, e.g. “organic”, “genetically modified”, “basic”, “sustainable”, “progress” and encourage informed comment on policies of governments and NGOs. 4) Indicate the essential role of wild-life and climate, not only in the context of agricultural and forestry development, but by maintaining environmental balance, to ensure the sustenance and enjoyment of all.

5) Summarise specific issues and draw objective conclusions concerning the way agriculture should develop and respond in the location/region of each enterprise, to evolving factors that inevitably affect development.

6) Promote expertise, for advising on world agricultural development and related subjects.

7) Allow interested readers to comment by “Letters to the Editor” and by “Opinion & Comment” columns.

8) Provide book and report reviews of selected works of major significance.

9) To include a wide range of commercial advertisements and personal advertisements from advisors and consultant groups.

Near drought conditions challenge spring soybean crops. (Glycine max)

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editorials

Sustaining World Food Supply using novel technologies J. Perry Gustafson1, and John W. Snape2 1. USDA-ARS, 206 Curtis Hall, University of Missouri, Columbia, Missouri 65211 2. John Innes Centre, Norwich Research Park, Coney, Norwich, NR4 7UH, UK

T

he UN projects that by 2050 World food production will need to increase by a minimum of 70% to feed a projected World population of more than 9 billion. It is clear that extraordinary improvements in agricultural productivity will be necessary. World food production has been steadily increasing from ~2.94 billon metric tonnes (Bt) in 1961 (plants ~2.45 Bt and ~0.49 animals Bt) to ~8.27 Bt in 2007 (plants ~7.36 Bt and animals ~1.22 Bt) (1). Most importantly, this massive increase in food production was produced on the same area of land, as a result of improved crop cultivars, crop technology advances, and better management practices (2). Projections suggest that increases in World food production between now and 2050 are feasible provided that existing and newly developed technology can genetically improve cultivars, and with improved crop management practices, will mitigate any adverse effects on the environment, whilst avoiding the cultivation of new land (3).

In creating new cultivars, plant breeders will have to pay increased attention to the effects of global warming on food production.

However, current advances in technology are capable of doing so and of dramatically decreasing the time to deliver genetic improvements into the

References

1. The United Nations Food and Agriculture Organization FAOSTAT (http://faostat.fao.org/site/368/Deskt opDefault.aspx?PageID=368#ancor) (2010).

2. World Bank World Development Report: Agriculture for Development (The World Bank, Washington,

field. These include tissue and anther culture techniques, which bypass some traditional approaches to seed production; modern approaches to mutation technology and the utilization of molecular biology technologies, such as marker-assisted selection.

Introducing gene complexes by genetic manipulation from related species has a long history (4) and will continue into the future. Arguably, the technology of high future impact is likely to be plant transformation, currently defined as involving the transfer of genes from one organism to another bypassing any sexual process. The coordinated application of all existing and new technologies will be required to sustain the productivity of arable lands and to maintain our fragile environment.

Quantum increases in yield, and a reduction in production costs by better management will come about through the application of genetic manipulation in novel ways. Clearly, innovative thinking and long-term research are needed for current ideas to reach practice. Two promising, but theoretical, approaches are improving 1) photosynthesis in C3 cereal species by making them ‘C4-like’, and 2) nitrogen fixation in cereals. There is optimism that these goals can be achieved; but the obstacles to success are formidable and the chances of success in the short-term are low. A proj-

D.C., 2008).

3. Gustafson, J.P., Borlaug, N.E., and Raven, P.H. (2010). World Food Supply and Biodiversity. World Agriculture. 1:37-41.

4. Sears, E.R. (1954). The transfer of leaf-rust resistance from Aegilops umbellulata to wheat. Brookhaven Symp. Biol. 9:1-22.

ect to develop C4 like photosynthesis in rice is already underway (5 – see current Issue), and routes for N fixation are being explored (6). However, considering the development time for cultivar production involving the world’s crops, we must keep in mind that most of the cultivars to be released in the next 10-20 years are already in development, or will need to be within the next 5 years. These novel challenges of N fixation and C-4 like crops are still theoretical and some time away from implementation, so are unlikely to be available to farmers until well into the future. The process of nitrogen fixation requires the coordinated action of many genes, and the manipulation of such a complex system is beyond current technology.

However, creating symbiotic relationships with N-fixing bacteria in plant roots, may be a viable alternative route.

Continued long-term improvement in world food production is fundamental to World security. A future reduction in human conflict, the environment, and our biodiversity are intimately tied to the increase of crop production. Feeding the growing human population is clearly the most important challenge facing the world today and we will need to use creative thinking in any approach to applied/basic research problems to increase food production.

5. Sheehy, J.E., and Mitchell, P.L. (2011). Developments in Rice Research: Visions and Pragmatism.

ThisIssue 6. Perrin H. Beatty and Allen G. (2011). Good Future Prospects for Cereals That Fix Nitrogen Science 22-July-2011: 416-417.

[DOI:10.1126/science.1209467]

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editorials

NPK efficiency and “plowing” David Frape

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he world population is approximately 6.5 billion (6.5 x 109) and it is expected to rise to 9.5 x 109 within the next few decades.

This rise will greatly increase the likelihood of mass starvation on a scale not previously witnessed, unless there are increases in both the annual output of fertilisers and the efficiency of their use, especially with respect to nitrogen and phosphorus (N & P).

World Agriculture has published two papers on the roles of N and P fertilisers. The difficulties confronted by each of these elements are quite different.

There is a limitless supply of N, as it is cycled from the atmosphere (78 % N2) to the soil and back. It is fixed in a reactive form by blue-green bacteria (Cyanobacteria), root nodule bacteria, lightning and as NH3 in the HaberBosch process for industrial and fertiliser use. The industrial fixation of N2 currently consumes 4 % of the world’s supply of natural gas, as a source of hydrogen, and 1-2 % of total energy production, mostly as electricity, some of which is generated by natural gas (Smil 2011).

The situation with P is different. The world’s available reserves of P are limited and predictions of their life range

References Cornish, P.S. (2011) Peak phosphorus: implications for agriculture.

World Agriculture, 2, this Issue.

Faulkner, E. (1945) Plowman’s Folly.

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from 50 years to centuries (Cornish, this issue). As world population increases, use of both N and P fertilisers will also increase. A major improvement in the efficiency with which both N and P are used in agricultural rotations is essential. At present, this is measured as the amount in an edible crop expressed as a percentage of that in the fertiliser. Experimental evidence from 15N studies indicates that, for wheat, the efficiency of N use can be very high:85-90 % (Smil 2011); but in agriculture as a whole it is of the order of only 30-35 % for both N and P, although a reliable estimate for P is at present questioned, owing to the difficulty of estimating the slow release of some of the residual P, which is fixed in soil. The value for organic fertilisers is no greater and their greenhouse gas production is worse (Goulding et al. 2011), although organic crop waste should, nevertheless, be returned to the soil to maintain levels of organic matter, whenever possible.

Meat consumption is increasing and this causes further stresses on the agricultural use of N. Not only is the yield of metabolisable energy (ME) produced per ha lower in meat products compared with field crops but, in addition, N efficiency is much poorer

University of Oklahoma Press, OUPRESS.Com, Amazon.co.uk.

Ford, B. (2011) Synthetic meat.

World Agriculture, 2, This issue.

Goulding, K.W.T., Trewavas, A.J. & Giller, K.E. (2011) Feeding the

as a consequence, in particular, of the high losses of N in excreta. This is reflected in a very low world-wide N efficiency of only 15 % for total food products (Ford, this issue, Smil 2011).

In order to improve the efficiency of use for both N and P by precision soil management, a detailed knowledge of top-soil status and climatic conditions is urgently needed on a field/area basis (Cornish, this issue), so that losses and pollution caused by their run-off can be reduced. For this purpose appropriate crop rotations and management are needed , as these also improve soil nutrient use. An important factor in this may be the introduction of zero tillage, where soils and crops are suitable (Cornish, this issue, Goulding et al. 2011); but have we not heard of this before? Faulkner (1945), wrote.

“The truth is that no one has ever advanced a scientific reason for plowing. ----- it seems logical to suggest the wisdom of trying to devise implements which negotiate the trashy surface!” Ah well, ‘is there nothing new under the sun?’ There is and a purpose of this Journal is to present reliable evidence, to draw conclusions from it and to indicate possible consequences of alternative courses of action based on those conclusions.

World: A contribution to the debate.

World Agriculture, 2, 32-38.

Smil, V. (2011) Nitrogen cycle and world food production. World Agriculture, 2, 9-13.

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Developments in Rice Research: Visions and Pragmatism Dr John E Sheehy1 and Dr Peter L Mitchell2 1 Consultant, International Rice Research Institute, 12 Barley Way, Marlow, Bucks, SL7 2UG, UK 2 Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK

Summary

Rice research concerns the development of new products, concepts and technologies to improve the yield and quality of rice in ways that do not damage the environment. Over the next 40 years, the predicted 2.2 billion (32%) increase in the number of human beings on the planet threatens the ability of agricultural technologies to produce sufficient food to meet the demand. Billions of people eat rice every day and it is the main source of energy and protein for hundreds of millions of poor people. Almost all of the world’s production of rice, 690 million tonnes, is consumed by humans and over the past half century, there has been a linear relationship between population in Asia and rice production. The population in Asia, where sixty percent of the world’s population live, will increase by about a billion over the next half century and rice production may have to double to keep pace, whilst overcoming some of the negative effects of climate change. Additional research to protect yields from high temperature damage will require further research on heat tolerance and on breeding rice cultivars that flower in cooler parts of the day. Unfortunately, the elite rice cultivars of the Green Revolution have approached a yield barrier and the increase in yield/ha is slowing. There is rising competition for water between agriculture, human consumption and industry. Given the abundant use of water for most rice production, availability could be a significant future constraint. The yield barrier would be broken by changing the photosynthesis of rice from the C3 to the C4 metabolic pathway. Such a change would be accompanied by a near doubling of water-use efficiency and an improvement in nitrogen-use efficiency. Protecting yields from losses caused by pests and weeds requires investment in integrated pest management and weed research. We argue that there is an urgent need for transformative research aimed at breaking existing yield barriers and improving nutritional quality of the grain. We describe the objectives of an international effort aimed at producing C4 rice. There is an urgent need for funding the high-risk, high-return research that will enable us to dissipate the problems facing humanity before those problems engulf us.

Keywords: Rice, photosynthesis, molecular biology, water, pests, weeds, climate change, biofortification, funding, C4 rice

Introduction Today, 75% of the world’s 6.8 billion people live in the developing world, where most of the world’s poverty is concentrated. A billion people live on about a dollar a day and spend half their income on food.

Some 854 million people are hungry and each day about 25 000 people die from hungerrelated causes (Sheehy and Mitchell 2011). Rice, wheat, maize, millet and sorghum provide 70% of the food energy of the world. About half the world's population has rice as the staple cereal, and almost all of the world production, 690 million tonnes in 2010, is consumed directly as food , particularly in Asia, where 90% of rice production is grown and eaten (Rice Almanac 2002).

Clearly rice has a key role in global food security and in efforts to reduce hunger and poverty. Rice production is supported by research around

the world, much of it now coordinated in the Global Rice Science Partnership (GRiSP 2010).

Rice research contributes to poverty-alleviation through several direct and indirect mechanisms (Dawe 2000).

In his acceptance speech for the Nobel Peace Prize in 1970, Norman Borlaug warned that if the frightening power of human reproduction was not curbed, the success of the Green Revolution would be ephemeral. Since then, world population has already increased by 75% and is continuing to rise. In the 21st century the population of Asia will rise by about 27% to 5.2 billion and that of Africa will almost double to nearly 2 billion.

At the same time the urban fraction of the population is predicted to reach 70% by 2050.

Each year, a city of a million people consumes about 0.75 million tons of food and 117 million tons of water (Stanners and Bourdeau 1995). In addition, about 1.5 billion tons of water

(rainfall or irrigation) are also used in producing the food for that city. By 2050, the urban population will require about 4.7 billion tons of food annually and the rural population, upon whom the urban population depends for its food, will require about 2.0 billion tons annually.

How to feed the rapidly growing population of the world in a sustainable manner would be a daunting challenge for world agriculture even in the absence of climate change. Global food security and the need to eliminate hunger and poverty have become topics of general conversation and the subject of several recent reports (Royal Society 2009; Godfray et al. 2010; Foresight 2011). The combination of increasing population, rapid economic development in Asia and South America, climate change, and neglect of funding for agricultural research threatens food security and therefore the

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scientific stability of society. The question arises: what proportion of the world's population has to be hungry before civilization as we know it ceases? We do not wish to find out the answer to this question; instead efforts must be concentrated on increasing food production and improving distribution to meet the demand, doing this sustainablywhilst achieving resilience in response to climate change.

The situation can be summarised in a sentence. We must produce more rice, of higher quality, from less land, using less water, less labour, less fertiliser, less pesticide, and with a smaller carbon footprint during an era of climate change.

It is worth noting that this eclectic set of criteria includes some of the classical economic factors of production (land, labour, capital) and some of the biological resources needed by plants (solar radiation, carbon dioxide, water, mineral nutrients). However, business as usual will not be good enough in the pursuit of increased rice production. In the early nineties it was recognised that elite rice cultivars had a yield barrier (Kropff et al. 1994); this is the reason that the gains of the

Glossary

Activation tagging: Insertion of activation vectors carrying strong promoters causing mutagenesis; designed to generate novel phenotypes.

Aerobic rice: Rice varieties that would normally be grown flooded shallowly, instead being grown in soil without flooding, i.e. with irrigation merely to maintain a moist but aerobic soil.Alternate wetting and drying: A technique to minimize use of irrigation water by flooding the rice field followed by drainage until the soil is at field capacity and then reflooding.

Backcrossing: In genetics, crossing the hybrid between two varieties with one of the parent varieties, and repeating this to obtain all the characteristics of the backcross parent plus one or more characteristics from the other parent.

Biofortification: Production of staple food crops that contain a selected micronutrient in concentrations higher than normal.

Bioinformatics: Use of databases and associated tools to store, manipulate

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Figure 1: The average yield of paddy rice for Asia between 1961 and 2004. The curve shown is y = 1.78+2.40/(1+exp(-(x-1981)/8.12)) with r2 = 0.99 (data from D. Dawe, personal communication). The curve gives a lower asymptotic yield value of about 1.8 t/ha and an upper asymptotic yield value of about 4.2 t/ha.

Green Revolution are largely exhausted (Fig. 1; Sheehy 2001a; Sheehy and Mitchell 2011).

Between 1961 and 2001 the production of rice kept pace with Asia's population, but to keep up in the face of climate change over the next 40 years will require breaking this yield barrier. An option is to install a C4 photosynthetic system in rice (Mitchell and Sheehy 2006). In this paper, we urge the

beginning of a new era of highrisk, high-return, transformative research, a large part of which should be focused on a substantial increase in yield.

We concentrate on biological research topics, selected because they derive from systems analysis, or rigorous quantitative assessment, and are intended to be transformative rather than simply incremental.

and analyse biological data, in particular sequences of DNA and genetic information.

Biological nitrogen fixation: Capture of gaseous nitrogen from the atmosphere into biological compounds; carried out by certain bacteria either living freely in soil or in symbiotic association with a green plant.

Bund: A low earth bank to retain irrigation water on a field; such a field or section of a field is bunded.

Bundle sheath cell: Cells forming a sheath around the vascular bundles (veins) of vascular plants. In C4 plants these cells become highly specialized for part of C4 photosynthesis.

C3 (photosynthesis, plant): The basic mechanism of photosynthesis where the first detectable compound in which CO2 is fixed has three carbon atoms.

C4 (photosynthesis, plant): The kind of photosynthesis where the first detectable compound in which CO2 is fixed has four carbon atoms; the CO2 is released and refixed by the C3 process in a different cell.

Compensation point (for CO2): The

concentration of CO2 at which photosynthesis balances respiration by a leaf, in defined conditions.

Cultivar: A named and registered variety of cultivated plant, the product of plant breeding.

Dry deposition: Gases or particles in the atmosphere arriving at a surface without involvement of water; opposite of wet deposition where rain or snow is involved.

Evapotranspiration: Loss of water to the atmosphere from vegetated ground from a combination of evaporation from the soil and transpiration through the plants.

Field capacity: The water content of a soil when water stops draining from it under the influence of gravity alone.

Germplasm: Generic term for any source of genetic variation for use in plant breeding, whether existing varieties, landraces or related species.

Greenhouse gas: Any gas in the atmosphere that absorbs infra-red radiation emitted by the surface of the earth and thereby keeps the earth warmer than it would be if the radiation Continued

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scientific Glossary

Continued escaped directly to space. This includes water vapour, carbon dioxide, methane, nitrous oxide and several other compounds. Given that water vapour is universally present it is carbon dioxide, methane and nitrous oxide that attract most attention from the point of view of climate change because their concentrations have been measurably changed during the last 250 years since the start of the Industrial Revolution.

Harvest index: The harvested portion of a crop as a proportion of all the crop above ground, each measured as dry weight.

Husk leaves (of maize): The leaves that surround the cob, as opposed to the foliar leaves borne on the stem.

Indica: The tropical subspecies of rice, as opposed to the temperate one (japonica).

Kranz anatomy: The characteristic pattern seen in transverse section of the leaf of a C4 plant where there is a dark green halo around each vein, standing out from the paler green colour of the rest of the leaf; from the German word (curiously retaining its Germanic capital after nearly a century of usage) for a wreath.

El Niño and La Niña: are the names given to periodic climatic patterns that occur across the tropical Pacific Ocean; El Niño is associated with very low rainfall and high radiation conditions in the Philippines, La Niña is associated with high rainfall and low radiation.

Landrace: Variety of a crop plant that has not been consciously selected or bred but arisen from continuous selection and use by farmers in a particular place.

Lodging: The toppling over of a cereal plant to a near horizontal position by heavy rain or wind or both.

Logistic growth: A pattern of growth which is slow at first, then rapidly

increases and then levels off to a plateau; that can be described by a logistic equation.

Marker-assisted (backcrossing, breeding): The ability to select plants with the desired characteristic before that characteristic becomes apparent by using biotechnological techniques to identify a piece of DNA, the marker, that is closely associated with the gene for the characteristic.

Mesophyll cell: The cells in the middle of a leaf, containing chloroplasts. In C3 plants all photosynthesis is carried out in these cells. In C4 plants only the first part of C4 photosynthesis occurs in the mesophyll cells.

Micronutrient: An essential nutrient required in small amounts in the diet, of the order of micrograms or milligrams daily, as opposed to protein, carbohydrates and fats required in bulk.

Mid-season drainage: The practice in managing irrigated rice of draining the field completely in the middle of the growth of the crop and then reflooding.

Nitrogen use efficiency: A measure, variously defined, of the proportion of nitrogen in a crop relative to what was supplied as fertilizer or what was derived from the soil or both.

Panicle: The much branched inflorescence of the rice plant (and many other grasses) with grains borne on the tips of the branches.

Phenology: The study of the timing of biological events such as flowering, in relation to environmental factors.

Promoter: A length of DNA that switches on a gene next to it.

Quantitative trait locus: The location of the DNA (locus) that contributes genetically to a characteristic (trait) that is variable in amount (quantitative) instead of qualitative; loosely, one of the genes for the characteristic.

Radiation use efficiency: The amount of dry weight of a crop (usually, but could be the energy content of the dry

weight for a true efficiency) that is produced from unit amount of radiation on the crop. Numerical values must have precise definitions of the parts of the crop measured, the part of solar radiation considered, and whether the radiation was absorbed or intercepted by the crop.

Tiller: A branch of a grass plant, hence of cereal crops, arising from a bud near the ground.

Transcriptome: is the set of all RNA molecules produced in one, or a population of cells.

Transgenic: A plant containing a gene from a different species moved into it by genetic engineering.

Transpiration: Loss of water from the leaves of a plant as a continuous flow from the roots.

Up-regulate: Adjustment of metabolism upwards or increased in some way in response to change in an environmental factor.

Variety: Loosely, a cultivar; technically in botanical nomenclature a named variant of a species of plant which occurs in the wild and breeds true.

Vein (in leaf): The feature on a leaf visible with the naked eye that marks the presence of a vascular bundle, the transport system of the plant for water and sap.

Water use efficiency: A measure, variously defined, of the proportion of water used by a crop relative to what arrived as rainfall or was supplied as irrigation or both. The numerical value is strongly dependent on the scale of measurement and time period, whether for a leaf, a plant, a crop or field, or a catchment; and whether instantaneous, for 24 hours, for crop duration or for a year.

Yield potential: The yield of a variety in an optimal physical environment (solar radiation, temperature, water, mineral nutrients) and with complete protection from weeds, pests and diseases.

Abbreviations BS bundle sheath, CGIAR Consultative Group on International Agricultural Research, DW dry weight, GHG greenhouse gas, GRiSP Global Rice Science Partnership, HI harvest index, IPM integrated pest management, IRRI International Rice Research Institute, M mesophyll cell in C4 plant, MJ megajoules, i.e. 106 joules, NOAA – ESRL National Oceanic and Atmospheric Administration – Earth System Research Laboratory, Rubisco ribulose 1,5-bisphosphate carboxylase–oxygenase, RUE radiation use efficiency.

Rice ecosystems

A

little over a third of the world’s land is suitable for agriculture; the rest is ice, desert, forest or mountains unsuitable for farming. In 1950, the world’s population was about 2.3 billion and there were about 2 ha of farmland available to meet the food requirements of each person. By 2050 the available farmland will have fallen to less than 0.6 ha/person, assuming forests and wetlands remain

free of agriculture. Rice is grown on every inhabited continent, in a wide range of climates, in four ecosystems characterised by the presence or absence of surface water (from flooded to dry land) for all or parts of its growing season. The contributions of the four ecosystems to the world totals are shown in Fig. 2. The area available for rice cultivation is likely to decrease as land is taken out of cultivation for industry and housing as

urbanisation proceeds. One consequence of the very unequal distribution of rice production among the ecosystems is the different emphasis of research in each ecosystem for either food security or for alleviating hunger.

From the point of view of food security, the bulk of world rice production comes from the irrigated system and must continue to do so. Rainfed lowland rice in favourable locations and

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Figure 2: Contributions of the four rice ecosystems to world rice production. The percentage area and production are from the Rice Almanac (2002). The total area of rice harvested is 157 million hectares and the total production is 677 million tonnes (average of the three years 2007–2009; FAOSTAT 2011) which gives an average yield overall of 4.31 t/ha.

Research here concentrates on improving productivity from larger farms with good access to inputs, information and markets. In contrast, rice-eating communities that tend to grow rice in the upland, flood-prone or in unfavourable rainfed lowland ecosystems are vulnerable to hunger.

Supporting smallholder agriculture is vital for these communities and is the focus of research for direct application in these situations, and also the object of much attention from charitable organisations. Research from bottomupwards or farmer-led initiatives have a role here because small interventions carefully identified can produce critical improvements in crop survival, reliability and yield. Local solutions and lowinput systems may be entirely appropriate in these cases.

Constraints Water

Only 1% of water on the planet is fresh and there is rising competition between agriculture, human consumption and industry. Given the abundant use of water for most rice production, water availability could be a significant constraint. Bouman et al. (2007) review the use of water for rice, from field to catchment scale, present and future.

Water vapour moves from inside leaves to the atmosphere (transpiration) while carbon dioxide takes the reverse path (photosynthesis). Since the gaseous diffusion pathways are the same, there is a near-linear relationship between transpiration and photosynthesis (deWit 1958). Evaporation from the soil, or water surface, is described mathematically in terms of vapour pressure deficit, wind speed and radiation (Penman 1948); these factors also affect transpiration. As the crop canopy develops, the balance between evaporation and transpiration changes, but,not surprisingly, there are close

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empirical relationships between yield of biomass and evapotranspiration (Tanner and Sinclair 1983; deWit 1958; Connor et al. 1985).

Improvements in the productivity of current terrestrial crops must be accompanied by proportionate increases in the use of water.

Chapagain and Hoekstra (2011) estimate the global requirement of water for rice to be 784 km3 year-1 of which 44% is from direct rainfall. In Asia, irrigated rice accounts for 50% of the water diverted for irrigation (Tabbal et al. 2002). Future demands for irrigation water for rice will compete with an increased use of water by industry and urban development. Despite the components of the water balance being well understood, it is not easy to calculate accurately the amount of water required for global rice production because of variability in soils, weather and climates. Irrigated rice requires about 150–250 mm water for land preparation, 50 mm for seedling growth in the nursery, and 5–15 mm day-1 for evapotranspiration from transplanting to harvest (Guerra et al.

1998; De Datta 1981). In addition, there are losses from percolation through the puddled soil, varying between 1 and 30 mm day-1 depending on soil type (Bouman and Tuong 2001). A certain minimum percolation is required to ensure that toxins do not accumulate in the rooting zone, but the quantity is neither well defined nor is it easily controlled (Aimrun et al.

2010; De Datta 1981). It can be seen that there is great variation in the estimates of the components of water use for rice (Shashidhar 2007; Zwart and Bastiaansen 2004). It is clear that more site-specific reliable measurements of all the components of the water balance are required before estimates of future demands for the irrigated system can be made with confidence.

Many areas of the world grow rice

without irrigation in bunded fields that capture and retain rainwater (rainfed lowland rice), or in unbunded fields (upland rice). These regions often receive near adequate rainfall for maximising rice production during the growing season (Thiyagarajan 2001).

Indeed, in many countries the water used for rice farming comes mainly from rainfall in the wet season , so surprisingly, the contribution of rice to water scarcity is relatively small (Chapagain and Hoekstra 2011).

Major problems in rainfed lowland and upland systems are usually unpredictable rainfall, infertile soils and weeds. Even in bunded fields, and with uniformly distributed rainfall, water shortage can occur and reduce yields significantly. Under such circumstances it is the magnitude of the decrease in water use efficiency which should become the focus of research attention. Yields are severely restricted when soils fall below field capacity or when there is no standing water during reproductive growth, a growth phase especially sensitive to water shortage. It is unlikely that the major advances in yield production required in the next 50 years will come from rainfed environments unless a large improvement in transpirational wateruse efficiency can be made. Sheehy and Michell (2006) showed that a change from C3 to C4 rice would increase transpirational water-use efficiency by 89%.

The near doubling of the transpirational water-use efficiency of rice associated with a change from the C3 to C4 pathway would be advantageous in both the irrigated and non-irrigated systems. Possible improvements in water use efficiency resulting from increases in crop photosynthesis, caused by increases in atmospheric CO2 concentrations, are likely to be limited by increases in evapotranspiration driven by increased atmospheric temperatures (Allen et al. 2003). Rice does not use more water in transpiration than comparable crops and it can be grown with much less water (rainfall and irrigation) as aerobic rice or with alternate wetting and drying (Bouman et al. 2007). These techniques can save 15–45% of water compared with normal flooded growth but yields are reduced by about 20%.

The management of water is likely to remain a complex issue during the next 50 years and ways of raising water-use efficiency at all scales in the farming system will remain important (Bouman et al. 2007). For irrigated rice this will require better irrigation engineering and better use of water at the farm to catchment scales, possibly by assigning a cost to water, thus

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scientific helping farmers make better decisions about water use, and ensuring high rates of reuse from field to field.

Deep water and submergence Although rice roots are adapted to anaerobic soils, the above-ground parts cannot tolerate submergence for long, so that too much water on the field can be as damaging as too little.

Recent research has been remarkably successful in tackling this problem.

Four to nine million hectares are cultivated with deepwater and floating rice types that are highly elongated plants which thrive in paddies with water up to 4 m deep (Catling 1992); they yield about 1.5–3.5 t ha-1 grain.

Pronounced elongation growth (up to 25 cm day-1) in response to submergence maintains sufficient aerial tissue above the water for efficient photosynthesis and oxygen exchange with submerged organs (Bailey-Serres and Voesenek 2008). The rapid elongation response of deepwater varieties has been shown to depend on two genes named SNORKEL1 and SNORKEL2, that are absent from nondeepwater rice.

About 20 million ha of rainfed lowland rice are adversely affected by monsoon flash floods each year which cause the plants to be totally submerged. When partially or completely submerged, most rice varieties display a moderate capacity to elongate leaves and the portion of the stems that are trapped underwater. This elongation growth leads to a spindly plant that easily lodges when floodwaters recede.

If the flood is deep, underwater elongation growth can exhaust energy reserves, causing death within a matter of days. The development of highyielding submergence-tolerant lines largely spans the 50 years of research at the International Rice Research Institute (1960–2010).

Landraces with unusual flooding and submergence tolerance but low yields were first reported in the early 1950s and systematically screened in the 1970s (Vergara and Mazaredo 1975; Mackill et al. 1996). Until the development of molecular tools in the mid1990s, the genetic control of submergence tolerance remained unclear. The fine mapping of SUBMERGENCE 1 (SUB1), a robust quantitative trait locus in a submergence- tolerant landrace from India, enabled markerassisted breeding of high-yielding rice capable of enduring transient complete submergence (Mackill et al.

1993; Mishra et al. 1996). This enabled its transfer by marker-assisted backcrossing into cultivars preferred by farmers (Xu et al. 2004; Mackill 2006).

The SNORKEL and SUB1 genes are very similar in sequence (Hattori et al.

2009), but SUB1 inhibits elongation of leaves and internodes when induced during submergence. This enables survival by reducing carbohydrate consumption, thus allowing the plants to recover from submergence (Fukao and Bailey-Serres 2008a). Ideally, rice varieties with tolerance during the entire life cycle should be developed, because flooding can cause damage at all growth stages. However, there are no known varieties with tolerance to submergence at flowering or later. In flood-prone tidal areas, farmers would benefit from rice that is tolerant of saline floodwaters.

Pests, diseases and weeds Integrated pest management (IPM) in rice can be achieved by using in combination cultural practices including varietal resistance, conservation of natural predators and parasites of pest species, and pesticides only when ecological and economic considerations indicate their value <http://www.knowledgebank.irri.org/i pm, 11th August 2011>. Biological pest control is a population-levelling process in which one speciesâ&#x20AC;&#x2122; population lowers the numbers of another species by mechanisms such as predation, parasitism, pathogenicity or competition. Biological control has proved relatively successful and safe. It can be an economical and environmentally benign solution to severe pest problems. If the value of the yield loss is less than the cost of the chemical control methods then biological control should be the management system of choice. The economics of yield losses in relation to the costs of pesticides and their potential damage to human health will always require scrutiny and every new rice cv needs to be thoroughly tested for susceptibility to pests and diseases. The large germplasm collections maintained at IRRI have been screened to identify resistance genes and these are being incorporated in most breeding programmes and many modern varieties have multiple resistance. It is certain that as new higher yielding cultivars are bred, issues surrounding the appropriate way of keeping yield losses to pests and diseases at a minimum will continue to be an essential part of the development process (Rubia and Penning 1990; Heong and Hardy 2008; Heong et al. 1998).

Successful weed management aims to minimise the impact of weeds in the short term and simultaneously to ensure that yield losses will not increase in the long term as a result of practices that are implemented.

Currently, water management plays an important role in weed control in rice so shortage of water leads to weedy and low-yielding crops or to use of other methods of weed control. Weed rice (types of rice that have evolved from varieties grown in much earlier times) pose two problems. First, because many of their characteristics are so close to rice varieties being cultivated now, they are difficult to eliminate by cultural methods or by herbicides. Secondly, they could conceivably be recipients through gene flow for characteristics bred into modern cultivars if these convey an advantage to weed rice. Tolerance to herbicides derived from genetically engineered rice varieties is a commonly expressed concern. Molecular methods are required to identify the weed rice types and to assist in the ecological studies of gene flow.

Relatively little is known about patterns of phenological development in weeds of rice crops in relation to elements of climate change such as temperature and CO2 concentration (Rodenberg et al. 2011) . Flowering can be faster, slower, or unchanged at elevated CO2 concentrations depending on species (Patterson 1995), and a more rapid emergence of weed seedlings at an elevated CO2 has been documented under field conditions (Ziska and Bunce 1993). In common with pest management, the challenge for weed management research is to develop control strategies at a molecular and crop management level that sustain and enhance farm profits while safeguarding the biological environment and human health.

Climate change Climate change is a contentious and complex issue; in rice science we would not wish to increase contributions to potential climate change or avoid taking its possible consequences into account in our research. The two principal areas of rice research in relation to climate change are: mitigation of greenhouse gas emissions from rice systems (Wassman et al. 2000) and discovering and adding adaptive features so that increases in production can continue if significant changes in climate occur (Sheehy et al. 2005a).

Rice fields are a source and a sink for environmentally significant gases (Khalil et al. 1990). Estimates of methane emissions from rice fields have improved as measurements across Asia have been made (Wassmann et al. 2000). Methane from rice accounts for about 10% of global methane emissions and in 2010 <http://www.globalmethane.org, 11th August 2011> was about 27.5 Mt CH4 yr-1 and emissions of N2O are

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scientific probably less than 0.5% (by weight) of the value for methane. Mid-season drainage in irrigated rice is one of the most effective tools for decreasing methane emissions and a single midseason aeration can reduce average seasonal emissions by 40% (Wassmann et al. 2010). However, N2O is released from drained fields and mid-season drainage must be managed so as not to induce yield depressions caused by water shortage. Furthermore, the antagonism between CH4 and N2O emissions is a major impediment for devising effective mitigation strategies in the rice–wheat system: measures to reduce the emission of one GHG often intensify the emission of the other GHG (Wassmann et al. 2004). In rainfed and deepwater rice, mitigation options are very limited in both number and potential gains (Wassmann et al. 2000; Wassmann et al. 2009a; Wassmann et al. 2009b; Haefele et al.

2010). However, there is no reason to suspect that increasing grain yields will lead to an increase in CH4 emissions (Denier van der Gon et al. 2002).

Little thought has been given to the consequences of gaseous ammonia (NH3) emissions from rice. In many rice systems more than 50% of the nitrogen fertiliser applied can be lost through volatilisation (Vlek and Byrnes 1986; De Datta 1995). The total emission of NH3 from rice can be estimated theoretically from the current global annual production of 690 million tonnes (593 million tonnes dry matter) containing 1.4% N plus 890 million tonnes of straw with 0.6% N. Global rice biomass thus contains 13.6 million tonnes N, and an equal amount will have been lost by volatilisation from fertiliser, which is equivalent to 16.5 million tonnes NH3. The residence time of NH3 in the atmosphere is 10–30 d (Tsunogai and Ikeuchi 1968) and most of it is returned to the soil by precipitation and dry deposition within a few kilometres of its source.

The effects of deposition are complex, but it can be damaging to natural vegetation (Krupa 2003).

Over the past 25 years, minimum temperatures increased (0.04 °C yr-1) during both the dry and wet seasons at IRRI and maximum temperatures increased in the wet (0.02 °C yr-1), but not the dry season (Sheehy et al.

2005a). Over the 50 years of IRRI’s history atmospheric CO2 concentrations have risen from about 317 to 390 ppm (NOAA ESRL data). It has been shown that temperature increases in the range 22–32 °C reduced rice yields by 0.6 t ha-1 °C-1 (Baker and Allen 1993; Sheehy et al. 2006), whereas yield increases by about 0.5 t ha-1 for every 75 ppm increase in atmospheric CO2. Overall, it is likely

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Table 1: Modelled percentage increases in rice yields required by 2050 relative to 2004 resulting from population increases, the combination of increases in temperature and CO2. The increase in yield to allow for disasters (extreme weather events) in four Asian countries is calculated from the data for rice production over the past 40 years from the FAOSTAT database (2005) (after Sheehy et al. 2007a). that over the next 50 years increases in daily average temperatures will have a greater negative effect on yield than the positive benefit of increasing CO2 (Sheehy et al. 2007a). However, the yield-depressing effects of high temperatures caused by weather extremes in the range 35–40 °C during flowering are a more serious threat to yield.

Rice is self-pollinated and pollination normally occurs in late morning.

Permanent thermal damage to the reproductive mechanisms in that temperature range reduces grain yield by approximately 20% at 35 °C rising to 95% at 40 °C during flowering (Satake and Yoshida 1978; Horie et al. 1995; Prasad et al. 2006; Sheehy et al.

2005a, 2006). In theory, yield losses owing to infertility caused by high temperature during flowering can be minimised, but not completely eliminated, by changing the time of day at which the crop flowers to the cooler parts of the day (Sheehy et al. 2005a).

It is vital that clock genes be identified that allow rice to flower in the coolest part of the day or at night so as to avoid thermal infertility (Sheehy et al.

2007b). Other possible solutions are to discover mechanisms that confer tolerance of high temperatures for vulnerable processes during the reproductive phase ( Prasad et al. 2006). Going from an El Niño year to a La Niña year in the Philippines decreases potential yield by 28% (Sheehy et al. 2005a); the damaging effects of weather extremes of all types are large (Table 1).

Developing rice resilient to climate change presents plant breeders with a

substantial challenge; it should be storm-resistant, submergent-tolerant, flowering in early morning, salt-tolerant, fast-growing and high-yielding.

The bioengineering of biological nitrogen fixation into rice would reduce significantly the requirement for nitrogen fertilisers (Fischer 2000) and significantly reduce ammonia volatilisation. Managing rice to reduce gaseous emissions will remain important.

Farmers must learn how to adapt to the consequences of climate change through choice of variety and appropriate agronomy, which will be a challenge and no easy matter.

Nutrients Plant growth depends on the uptake of a range of mineral elements from the soil and increased yield depends on increased uptake. The large amounts of nutrients required in high yielding crops (Table 2) far exceeds the capacity of the soil to supply them without the application of fertilisers.

The proportion of an applied fertiliser element that appears in the crop (fertiliser use efficiency for each mineral element) is highly variable depending on soil type and other environmental factors. Thus, site specific nutrient management is recommended for increasing yield (Cassman et al. 1996; Olk et al. 1999; Dobermann et al.

2004). Of particular concern is the negative K balance in about 80% of the intensive rice fields in Asia.

Dobermann et al. (1998) suggested that it was only a matter of time before the indigenous supply becomes a limiting factor on the most fertile

Table 2: The mineral element content (kg.ha-1) of a rice crop (grain and straw) yielding grain at 12 t.ha-1 (14% moisture content) with a harvest index of 0.5 (after Sheehy et al. 2001a). Latshaw and Miller (1924) showed that carbon, oxygen and hydrogen made up about 95% of the dry weight of corn. The carbon content of rice plants is approximately 40%; rice straw = 38 % (Jimenez and Ladh, IRRI 2000) and mineral elements comprise about 8%.

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scientific complex and as new stress-tolerant cultivars are developed, novel nutrient management systems are required (Haefele and Hijmans, 2007; Haefele et al. 2009). Greenwood et al. (1990) showed that C4 crops contained about 72% of the nitrogen of C3 crops at the same value of biomass. Mitchell and Sheehy (2006) estimated that the photosynthetic N- use efficiency of C4 rice would be about two and a half times greater than for C3 rice.

In rice, the rate at which the developing panicle acquires N exceeds the rate at which the crop acquires it through its roots during grain filling (Sheehy et al. 1998). The requirement for a large N ‘reservoir’ in the leaf and other vegetative tissues was emphasised by Sinclair and Sheehy (1999).

Using the critical N model of Greenwood et al. (1990), crops can be managed to ensure that their N content is optimal for maximum yield.

However, yield potential is set by weather and the optimum N fertiliser required will be lower in a La Niña year than in an El Niño year. As an example, at IRRI, assuming 50% volatilisation, 415 kg N ha1 needs to be supplied to enable the critical N content in an El Niño year and 250 kg N ha1 in a La Niña year (Sheehy et al. 2005a,b). How is a poor farmer in the developing world to access seasonal weather forecasts and predictions of optimum N rates? The quantity of fertiliser N required to support maximum yields and the large losses into the environment lead to the conclusion that replacing fertiliser N by biologically fixed N via a nodular sym-

biotic system should be a high priority for continued research (Sheehy et al.

2005b). However, the anaerobic environment of the roots of irrigated rice are not best suited to the oxygen requirements of root nodules and novel ways of water management in terms of raised beds may benefit attempts to nodulate rice roots.

Improving rice quality The first semi-dwarf rice of the Green Revolution, IR8, did not have good grain quality but it demonstrated that high yields were possible. Apart from the importance to the consumer of desirable cooking and eating properties, it has been recognised that rice with concentrations of micronutrients higher than normal could make an effective contribution to reducing deficiencies in poor communities where rice forms a large part of the diet.

Biofortification has several components: breeding micronutrient-dense varieties of staple food crops; determining the availability to consumers of micronutrients in cooked foods and that they relieve deficiency; and ensuring general acceptability of new varieties to both farmers and consumers (Bouis et al. 2011). The advantage of biofortification is that the benefits are enduring with no further inputs, whereas providing food supplements or fortification of food incurs continuing costs. Ultimately, economic development and diversification of diets will ensure adequate intake of micronutrients but until that occurs biofortification has a role to play. Existing varieties, or landraces, with high concen-

trations of micronutrient must be sought or created by genetic engineering, so that this attribute can be transferred to elite cultivars (adapted to local conditions, high-yielding, resistant to pests and diseases) using marker-assisted backcrossing.

Biofortification of rice is carried out at IRRI and in the HarvestPlus research programme of the CGIAR (www.harvestplus.org) which has been operating since 2004. Rice varieties with high concentrations of iron or zinc have been identified and used in breeding programmes. Rice high in zinc is expected to be released in India and Bangladesh in 2013.

Vitamin A is acquired direct from meat and dairy sources, but foods of plant origin provide ‚-carotene (provitamin A) which is converted to vitamin A in the body. Rice plants produce ‚-carotene (pro-vitamin A) in the green tissues but not in the edible part of the seed so natural variation is not available to be exploited in plant breeding. Three genes for enzymes of the biochemical pathway for ‚carotene were introduced to rice by genetic engineering (Ye et al. 2000).

The ‚-carotene made in the grains gave a strong yellow colour prompting the name Golden Rice for this initiative. An improved version of Golden Rice with higher concentration of ‚carotene was produced five years later (Paine et al. 2005). Experiments have confirmed that the ‚-carotene in dietary rice is absorbed into the blood (Tang et al. 2009). The Golden Rice project at IRRI (www.irri.org/goldenrice) with partners in Bangladesh and the Philippines is using the transgenic rice in breeding programmes to produce locally adapted varieties. Data for safety and regulatory processes are being generated now and release to farmers should follow in several years.

Rice contains little or no folate (B9). In recent years transgenic rice plants producing measurable amounts of folate have been produced, but this work is still at an experimental stage (Storozhenko et al. 2007).

C4 Rice

Figure 3: Diagrams of C3 and C4 photosynthesis to summarize the biochemistry and show the two types of cell in C4 photosynthesis. The mechanism in the C4 mesophyll cell acts as a pump, supercharging the basic mechanism of carbon assimilation which is restricted to the bundle sheath cell. The pump is always operating, like a supercharger, so there is a permanent running cost in metabolic energy which is easy to afford in hot, sunny environments where C4 plants thrive. Rubisco is ribulose 1,5-bisphosphate carboxylase–oxygenase; CA is the enzyme carbonic anhydrase; RuBP is ribulose 1,5-bisphosphate; PEP is phosphoenolpyruvate; the Calvin cycle is a set of reactions that regenerates the acceptor molecule, RuBP, and adds one unit of fixed carbon in the form of carbohydrate (CH2O) on each turn.

Carbon dioxide is first fixed into a compound in rice with three carbons (C3) by the photosynthetic enzyme ribulose bisphosphate carboxylase oxygenase (Rubisco) in mesophyll cells— this is known as C3 photosynthesis (Fig. 3). Rubisco also reacts with oxygen (O2) which results in a cycle of reactions known as photorespiration (rather than photosynthesis) because there is uptake of O2 and output of CO2 as occurs in normal respiration.

At temperatures in excess of 20°C, O2 begins to out-compete CO2 and dramatic reductions in photosynthetic efficiency result. The C4 pathway has two spatially separated parts connect-

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Figure 4: The final dry weights of C4 crops (y = 0·20 x, r2 = 0.85, blue line) and C3 crops (y = 0·12 x, r2 = 0.75, red line) are related to the length of the growing season but with different slopes, i.e. dry weights of C4 crops are 1.7 times those of C3 crops (data from Monteith, 1978). Recent results from maize and rice (Sheehy et al., 2007a) have been added to the original set of points on the graph. ed by a “CO2 pump”; the first part involves the initial fixation of CO2 into C4 acids using an enzyme that is insensitive to O2. In the second part, CO2 is released from the C4 acid at a rate which creates a region of high CO2 concentration where it is fixed by Rubisco free of competition from O2.

The build-up of CO2 by the “CO2 pump” requires extra energy from sunlight and therefore it is only in hot, sunny climates that the C4 pathway is beneficial.

Most C4 plants, and certainly all known C4 grasses, compartmentalise the two parts of the photosynthetic pathway between mesophyll (M) cells and bundle sheath (BS) cells which are morphologically distinct cell types that are arranged in concentric circles around veins (Nelson and Langdale 1992). Enlarged BS cells surround the veins (V) and the BS cells are surrounded by M cells. Each pair of veins is thus separated by two bundle sheath and two mesophyll cells in a VBS-M-M-BS-V pattern, as seen in transverse section of the leaf, referred to as Kranz anatomy. The two-cell arrangement facilitates the development of a high concentration of CO2 in the BS cells which suppresses photorespira-

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tion. The separation of metabolism is achieved by restricting the expression of a small number of genes to either the BS or M cells (Brown et al. 2005).

Genes encoding all of these enzymes are present in C3 plants, but expressionis much lower than in C4 species.

Despite the apparent biochemical and morphological complexity of the C4 mechanism, it is remarkably found independently in over 45 groups of unrelated species in 19 families of vascular plants including several different types of grass plant (Kellogg 1999).

This repeated presence of a complex trait indicates that it is relatively easy to generate. Indeed some plants are able to switch between C3 and C4 photosynthesis (Ueno 1998), indicating that the processes governing the function of these apparently complex systems must be flexible (Hibberd, et al. 2008).

The link between the efficiency of photosynthesis and yield was made by Monteith (1978) who compared the yields of a number of C3 and C4 crops growing over a range of crop durations. He showed that C4 crops in subtropical and tropical climates could produce about 66% more biomass

than C3 crops (Fig. 4). The attraction of the full C4 system is not only its high yield, but also the doubled wateruse efficiency and higher nitrogen-use efficiency that accompanies the trait.

At the end of record breaking yield (~11 t ha1) experiments for IRRI in 1997 and 1998 with an elite indica and lines of a new plant type it was proposed that further yield increases were probably beyond the capacity of rice with its C3 photosynthetic system (Sheehy et al. 2000). Mitchell and Sheehy (1998) investigated radiation use efficiency (defined by Monteith, 1977) and showed that it was strongly related to photosynthesis. The hypothesis that an increase in radiation use efficiency (RUE) would result in an increase in yield was tested experimentally. Rice and maize were grown simultaneously at IRRI in 2006 without limitations of water and nutrients and the yields were 8.3 tha1 and 13.9 t ha1; the RUE values were 2.9 g DW MJ1 and 4.4 g DW MJ1, respectively (Sheehy et al. 2007a). It was recognised that to increase maximum yields by 50%, the RUE of rice would have to rise to that of maize and to make that possible the C3 photosynthetic system of rice would have to be converted to a C4 system (Mitchell and Sheehy 2006; Sheehy et al. 2008).

Although controversial to some people, genetic engineering has proved indispensable for transferring genes between sexually incompatible species to produce transgenic plants for agriculture (Mitchell and Sheehy 2000).

Furthermore, attempts have been made to engineer novel multigene pathways to increase photosynthesis in leaves (Suzuki et al. 2006) and to recapture CO2 from photorespiration (Kebish et al. 2007). Arabidopsis is often used as a tool for understanding the molecular biology of the plant partly because it has a small and well documented genome. Brown et al.

(2005) suggested using Cleome gynandra, the C4 plant most closely related to Arabidopsis, to accelerate an understanding of the anatomical aspects of the C4 syndrome.

However, when considering such a radical change to the photosynthetic system the possibility of confounding factors such as resource rejection by plants is often overlooked (Thomas and Sadras 2001). Also not all plants are able to up-regulate their photosynthetic activity when grown at high concentrations of CO2 (Allen 1994) indicating there may be sink limitations which feed back to prevent increases in photosynthesis. Ingram et al. (1997) and Baker and Allen (1993) concluded that rice photosynthesis and yield did not increase at CO2 concentrations above 500 ppm. It is of vital importance to consider the relative importance of source strength and

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Figure 5: The objectives of the C4 project are shown in two groups: those involving gene discovery (direct) and those concerned with technical developments underpinning the direct approaches (support). sink capacity when programmes aimed at increasing yields are planned.

Harvest index (HI) relates grain yield and biomass, with grain yield being expressed as a proportion of the total above-ground dry matter. Sheehy et al. (1998) showed that the HI of well managed rice crops was nearly constant at 0.5 and so improvements in yield via improvements in HI were most unlikely. A C4 rice crop must have a larger vegetative biomass to deliver a larger grain yield.

How could C4 rice be constructed?

Let us consider what type of rice might have the sink capacity to use a supercharged photosynthetic apparatus in order to increase substantially both photosynthesis and growth rate.

Rice is a weak perennial with two strong phases of logistic growth: vegetative growth followed by reproductive growth (Sheehy et al. 2004). First let us deal with the vegetative phase of growth and imagine that it is possible to increase the maximum grain yields of irrigated rice growing over 100 days in the tropics by 50% e.g. to about 15 t ha-1. Given a HI of 0.5, the total vegetative biomass would have to increase by 50%, therefore the masses of leaves and stems would have to increase by the same amount.

The HI concept provides no indication of the individual units of production, the tillers, but stem mass and stem strength (to prevent lodging) would have to increase. However, it is clear that the Green Revolution varieties of dwarf indica rice do not possess the stems that characterize maize, sorghum or many of the wild relatives of rice. Consequently, it is unlikely that dwarf indicas could produce the required increase in stem biomass and therefore the 50% increase in vegetative biomass needed for C4 rice.

Furthermore, we speculate that the suppression of the stem sink for assimilation is what ultimately limits the upregulation of photosynthesis in response to increasing CO2 concentrations in dwarf indicas. Indeed, we suggest that the wild relatives of rice and landraces should be screened for the ability to up-regulate leaf photosynthesis at high concentrations of CO2.

In contrast, in the reproductive phase, rice has unused sink capacity for spikelet development and the evidence (Sheehy et al. 2001b) indicates that less than half the available spikelets are converted into grain. This is why in experiments with elevated CO2 concentrations increases in grain yield were observed (Baker and Allen 1993; Ziska et al. 1997; Kobayashi et al. 2005). Sink strength has two components and it is the vegetative, rather than the reproductive one that requires additional attention.

Let us now turn to the issues surrounding source strength. The rapid development of molecular tools and technologies encouraged IRRI to invest in a â&#x20AC;&#x2DC;high-risk high-returnâ&#x20AC;&#x2122; C4 rice project. The first priority was to build a team of multidisciplinary partners with complementary skills from advanced institutions across the world and so IRRI formed a Global Consortium for C4 rice. Once formed, the Consortium agreed a strategy, which was to install a maize-like photosynthesis mechanism in rice. The tactics and operational approaches would centre on discovering the cassette of genes necessary to make this a reality. Given the complexity of the required genetic transformation, it was thought unwise at the early stage to prioritise a single research route to developing C4 rice and the consortium decided to pursue several paths in par-

allel. The objectives can be divided into two groups as shown in Fig. 5: those involving gene discovery (direct) and those concerning technical developments underpinning the direct approaches (support).

It was obvious from the outset that there was a lack of understanding of the genetic control of leaf development, particularly the key feature of close vein spacingâ&#x20AC;&#x201D;the starting point for Kranz anatomy. To fill this gap a number of approaches are being actively pursued.

The development of screening tools for changes in leaf anatomy and CO2 compensation point.

Mutagenising sorghum, a C4 plant, and screening for C3-like reversions.

Using molecular tools to investigate cell-specific aspects of maize husk leaves which have leaf.anatomy and carbon fixation more like rice and that differ from foliar leaves which have Kranz anatomy and C4 function .

Establishing transcriptome atlases of maize, sorghum and rice leaf mesophyll and bundle sheath cells and using it as the foundation for a systems biology approach to the understanding of photosynthetic development and the discovery of C4 genes (Pinghua et al. 2010).

Screening available rice activation tagging lines for C4-like traits.

Screening mutants of the rice cultivar IR64 for any tendency towards C4 characteristics.

A molecular tool box is being built that allows the expression of genes specifically in mesophyll cells (M) or bundle sheath cells (BS) of rice.

Molecular approaches used to generate a comprehensive understanding of which maize proteins are needed for the C4 pathway to be active in M or BS cells of rice.

To make lines of rice containing substantial parts of the C4 pathway.

This will determine whether compartmentation of biochemistry required for C4 photosynthesis into M and BS cells leads to alterations in leaf anatomy associated with the pathway.

To develop a set of promoters of varying strength and specific for M or BS cells of rice.

Apply bioinformatics methodology in support of gene discovery.

To search for wild rice types containing any tendency towards C4 characteristics.

To use wild types to uncover genes crucial in the formation of a suitable platform for the expression of a C4 rice cassette of genes.

The timeline of the C4 initiative can be conveniently divided into three phases that are estimated at current

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scientific rates of funding to demand 15 years of coordinated research carried out at IRRI and in the laboratories of the C4 Rice Consortium. Phase I is largely about proving the concept and assembling the components required to construct C4 rice. Phase II is about constructing prototypes of C4 rice using the genes, tools and knowledge generated in Phase I. Phase III will be concerned with optimising C4 rice in locally adapted cultivars and delivering its benefits to consumers.

Funding The success of the first Green Revolution over the past three decades diverted the worldâ&#x20AC;&#x2122;s attention from agriculture. This resulted in lower support for agricultural research so that for some centres, such as the International Rice Research Institute (IRRI), the downward trend in funding continued until 2006 with the budget

Conclusions The breeding of semi-dwarf cultivars in the 1960s was an example of transformative research: a change of plant height, unimportant in itself, led to substantially higher yields because the plants could take up more nitrogen and carry heavier panicles without lodging. This made investments in irrigation and crop protection worthwhile. The cultivars of the Green Revolution more than doubled the food supply in Asia in 25 years, with an increase of only 4% in net cropped area (Lipton 2007; Rosegrant and Hazell 2000).

However, population growth is generating a demand for increased grain production that is beyond the delivery capacity of the current

Growing rice plants

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in real dollars falling to the 1978 figure. Furthermore, developed nations reduced their investments in agricultural research and turned their remaining research investments away from productivity gains (Pardey et al. 2006).

The slowing in the rate of increase in rice production has been accompanied by a doubling of rice prices during the past five years. Sheehy (2003) calculated the benefit accruing from a C4 rice replacing C3 rice could be as high as 43.7 billion US dollars a year; that figure would now be closer to 100 billion US dollars. Furthermore, Sheehy et al.

(2007c) suggested that the money spent annually on research aimed at preventing malaria or HIV/AIDS far exceeds that spent each year on cutting edge research such as C4 rice despite 25,000 people dying each day from causes related to hunger. Significant progress in yield enhancement research will require the integration of efforts from those engaged in fundarice genome.

The tools of molecular biology provide us with opportunities unavailable to plant breeders of the past: they enable us to identify the genes responsible for desirable traits (such as SUB1) and then to transfer them efficiently into new cultivars. The tools can also be used to transfer genes between sexually incompatible species such as maize and rice. A maize-like C4 photosynthetic pathway in rice would have the potential to deliver a very large improvement in yield; it would double water-use efficiency and increase nitrogen-use efficiency (Sheehy and Mitchell 2006). The combination of advantages peculiar to C4 rice means the syndrome could be used in all of the

mental and applied research. All forms of research require a funding flow and it is only in the more affluent societies that curiosity-driven research can prosper. Curiosity and demand for products are the engines of research and one form of research can stimulate the other. However, funding mechanisms to integrate the research required for C4 rice, across national and disciplinary boundaries, are almost non-existent with the exception of that of the Bill & Melinda Gates Foundation.

Since 2000, the funding situation has improved for the CGIAR Centres, but almost all the increase comes from grants earmarked for specific research projects. This trend is to be regretted as it seems it will not be possible for the Centres to embark on the innovative, risky but visionary research which, if successful, is most likely to transform agricultural productivity in the face of climate change. rice ecosystems to improve yields. It is easy to suggest that the construction of C4 rice will be especially difficult given current knowledge, or that the cost might be unusually high for agricultural research. But the need is correspondingly high: global population continues to increase, climate change will alter cropping patterns and probably reduce yields, and water available for agriculture will become scarce or more expensive.

Constructing C4 rice is a highreward, high-risk venture, and with current funding is likely to take about 15 years to complete. It will require the ingenuity and skills of researchers from institutions in many countries, hence the formation of a Consortium for C4 Rice.

Continued

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scientific

Terrace rice fields, Bali, Indonesia Continued Future climates are expected to be more variable with frequent episodes of high temperatures during the growing season (Prasad et al. 2006). High temperature during flowering decreases spikelet fertility and yield. However, there is potential for genetic improvement of heat tolerance and for changing the time of flowering to the cooler parts of the day. Breeding rice crops that are heat tolerant must continue to be a priority. Protecting yields from losses caused by pests, diseases and weeds means integrated pest management and weed research need to benefit from continuing research investment. The genetic diversity of rice is conserved in the IRRI Gene Bank and it provides researchers with germplasm for screening. It is a highly valued asset without which progress in many research projects could not be made.

Farmers have to deliver the benefits of new science, yet in the developing world crops are often grown on land areas of a few hectares, or less, using the simplest of tools and traditional knowledge. High performance technologies, such as the C4 syndrome or submergence tolerance, delivered in seeds would give

poor farmers an opportunity to improve their livelihoods without reeducation or the need for other equipment. The new management systems that could help mitigate the emission of greenhouse gases require education and access to information produced by weather forecasts and predictive modeling tools. To take advantage fully of such opportunities there is a need to develop and deliver decision support systems for crop management for which the growing and widespread use SMS text on mobile phones and specialized â&#x20AC;&#x2DC;Appsâ&#x20AC;&#x2122; offer great potential.

In our opinion at least half of the budget of the CGIAR should be directed to transformative research aimed at producing a large increase in the yields of all its agricultural systems in an environmentally acceptable manner. Biofortification is also another area which can be systemwide and has the potential to make a permanent and widespread change in rice quality. The newly formed Global Rice Science Partnership (GRiSP) has 900 research partners worldwide and represents, for the first time, a single strategic plan for global rice research. It remains to be seen if this

and similar initiatives will generate even more acronyms and largely fund low-risk research or stimulate the investment needed for the highrisk, innovative and transformative science needed to tackle the massive problems discussed in this paper.

The economic benefits that would flow from rice, wheat and legumes using supercharged photosynthesis and biological nitrogen fixation would be many billions of dollars annually (Sheehy 2003). The cost of discovering the cassettes of genes responsible for both of those syndromes would probably be of the order of a several hundred million dollars; the cost-benefit ratio is enormous. It must be remembered that expensive is different to impossible.

Acknowledgements We are grateful to Anaida Ferrer at IRRI for preparing figures for publication and to Gene Hettel for allowing us access to the photographic resources at IRRI. Use of facilities at the Department of Animal and Plant Sciences and support from Professor F.I. Woodward are gratefully acknowledged by P.L.M.

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scientific References Allen, L.H. Jr. (1994) Carbon Dioxide Increase: Direct impacts of crops and indirect effects mediated through anticipated climate changes. In Physiology and Determination of crop Yield. Eds. K.J. Boote, J.M. Bennett, T.R. Sinclair and G.M. Paulsen. ASA-CSSA-SSA: Maidison, Wisconsin. pp.

425-459.

Allen Jr., L.H., Vu, J.C.V. and Sheehy, J. (2003) Carbon dioxide, plants and transpiration. In Encyclopedia of Water Science. Eds. S.W. Trimble, B.A. Stewart and T.A.Howell. Taylor and Francis. pp. 57-61.

Aimrun, W., Amin, M.S.M. and Gholizadeh, A. (2010) Spatial Variability of Irrigation Water Percolation Rates and its Relation to Rice Productivity. American Journal of Applied Sciences, 7 (1), 51-55.

Bailey-Serres, J., Voesenek, LA.C. (2008) Flooding stress: acclimations and genetic diversity.

Ann Rev Plant Biol. 59, 313–39.

Baker, J.T. and Allen, Jr., L.H. (1993) Effects of CO2 and temperature on rice: a summary of five growing seasons. J. Agric. Meteorol. 48, 575-582.

Bouis, H.E., Hotz, C., McClafferty, B., Meenakshi, J.V. and Pfeiffer, W.H. (2011) Biofortification: A new tool to reduce micronutrient malnutrition. Food and Nutrition Bulletin 32: Supplement 1, 31S-40S. Bouman, B.A.M. and Tuong, T.P., (2001) Field water management to save water and increase its productivity in irrigated lowland rice. Agric. Water Management. 49, 11–30.

Bouman, B., Barker, R., Humphreys, E. and Tuong, T.P. 2007. Rice: feeding the billions. In Water for Food, Water for Life. Ed. D. Molden.

London (Earthscan). pp. 515–549.

Brown, N., Parsley, K. and Hibberd, J.M. (2005) The future of C4 research— maize, flaveria or cleome? Trends Plant Sci. 10, 215-221.

Cassman, K.G., Dobermann, A., Sta Cruz, P.C., Gines, G.C., Samson, M.I., Descalsota, J.P., Alcantara, J.M., Dizon, M.A. and Olk, D.C. (1996) Soil organic matter and the indigenous nitrogen supply of intensive irrigated rice systems in the tropics. Plant and Soil 182, 267-278.

Catling ,D. (1992) Rice in deep water. London: MacMillan Press Ltd. Chapagain, A.K. and Hoekstra, A.Y. (2011) The blue, green and grey water footprint of rice from production and consumption perspectives, Ecological Economics, 70 (4): 749-758.

Connor, D.J., Jones, T.J. and Palta, J.A. (1985) Response of sunflower to strategies of irrigation. I. Growth, yield and the efficiency of water use.

Field Crops Research, 10, 15-26.

Dawe, D. (2000) The contribution of rice research to poverty alleviation. In Redesigning rice photosynthesis to increase yield. Eds. J.E. Sheehy, P.L. Mitchell and Hardy B. (2000) Proceedings of the Workshop on The Quest to Reduce Hunger: Redesigning Rice Photosynthesis, 30 Nov.-3 Dec. 1999, Los Baños, Philippines. Makati City (Philippines): International Rice Research Institute and Amsterdam (The Netherlands): Elsevier Science B.V. pp. 293.

De Datta, S.K., (1981) Principles and Practices of Rice Production. IRRI, Los Baños, Philippines. pp. 618.

De Datta, S.K. (1995) Nitrogen transformations in wetland rice ecosystems. Fert. Res. 42, 193203.

Denier van der Gon, H.A.C., Kropff, M.J., van Breemen, N., Wassmann, R., Lantin, R.S., Aduna,E.A., Metra-Corton, T., and van Laar, H.H. (2002) Optimising grain yields reduces CH4 emissions from rice paddy fields. Proceedings of the National Academy of Sciences USA 99, 1202112024. de Wit, C.T. (1958) Transpiration and crop yields. Versl. Landbouwk. Onderz. No. 64.6. 88 p.

Dobermann, A., Cassman, K.G., Mamaril, C.P. and Sheehy, J.E. (1998) Management of phosphorus, potassium, and sulfur in intensive, irrigated lowland rice. Field Crops Research 56, 113-138.

Dobermann, A., Abdulrachman, S., Gines, H.C., Nagarajan, R., Satawathananont, S., Son, T.T., Tan, P.S., Wang, G.H., Simbahan, G., Adviento, M.A. and Witt, C. (2004) Agronomic performance of site-specific nutrient management in intensive rice cropping systems in Asia. In Increasing the productivity of intensive rice systems through sitespecific nutrient management. Eds. A. Dobermann, C. Witt and D. Dawe. Enfield, N.H. (USA) and Los Baños (Philippines): Science Publishers, Inc., and International Rice Research Institute (IRRI). pp. 307-336.

FAOSTAT. (2011) Website for data on world crop production (updated 17th May 2011),

18 WORLD AGRICULTURE

accessed on 30th June 2011, at http://faostat.fao.org/site/567/default.aspx.

Fischer, K.S. (2000) Frontier project on nitrogen fixation in rice: looking ahead. In The quest for nitrogen fixation in rice. Eds. J.K. Ladha and P.M. Reddy. Proceedings of the Third Working Group meeting on assessing opportunities for nitrogen fixation in rice, 9-12 Aug. 1999. International Rice Research Institute, Laguna, Philippines, pp. 25-31.

Foresight (2011) The Future of Food and Farming: Challenges and Choices for Global Sustainability. London (Government Office for Science).

Fukao, T. and Bailey-Serres, J. (2008a) Ethylene-a key regulator of submergence responses in rice. Plant Sci. 175, 43-51.

Godfray, H.C.J., Beddington, J.R., Crute, I.R., Haddad, L., Lawrence, D., Muir, J.F., Pretty, J., Robinson, S., Thomas, S.M. & Toulmin, C. (2010) Food security: the challenge of feeding 9 billion people. Science 327: 812–818.

Greenwood, D.J., Lemaire, G., Gosse, G., Cruz, P., Draycott, A., Neeteson, J.J. (1990) Decline in percentage N of C3 and C4 crops with increasing plant mass. Annals of Botany 66, 425-436.

GRiSP (2010) Global Rice Science Partnership.

Available at http://irri.org/our-science/global-ricescience-partnership-grisp (accessed on 8th July 2011).

Guerra, L.C, Bhuiyan, S.I., Tuong, T.P. & Barker, R. (1998) Producing more rice with less water from irrigated systems. SWIM Paper No. 5, Colombo, International Water Management Institute.

Haefele, S.M. and Hijmans, R.J. (2007) Soil quality in rice-based rainfed lowlands of Asia: characterization and distribution. In Science, technology, and trade for peace and prosperity. Eds. P.K. Aggarwal, J.K. Ladha, R.K. Singh, C. Devakumar and B. Hardy. Proceedings of the 26th International Rice Research Conference, 9-12 Oct 2006, New Delhi, India. Los Baños (Philippines): International Rice Research Institute, Indian Council of Agricultural Research, and National Academy of Agricultural Sciences. pp. 297-308.

Haefele SM, Knoblauch C, Gummert M, Konboon Y, Koyama S. (2009) Black carbon (biochar) in rice-based systems: characteristics and opportunities. In Amazonian dark earths: Wim Sombroek’s vision. Eds. W.I. Woods, W.G. Teixeira, J. Lehmann, C. Steiner, A. WinklerPrins, L. Rebellato, Springer Science + Business Media B.V. pp. 445-463.

Haefele, S.M., Ismail, A.M., Johnson, D.E. , Vera Cruz, C. and Samson, B. (2010) Crop and natural resource management for climate-ready rice in unfavorable environments: coping with adverse conditions and creating opportunities. http://irri.org/climatedocs/presentation_Lists/Docs /2_Haefele.pdf Hattori, Y. Nagai, K., Furukawa, S., Song, X.J., Kawano, R., Sakakibara, H., Wu, J.Z., Matsumoto, T., Yoshimura, A., Kitano, H., Matsuoka, M., Mori, H. and Ashikari, M. (2009) The ethylene response factors SNORKEL1 and SNORKEL2 allow rice to adapt to deep water. Nature 460, 10261031.

Heong, K.L. and Hardy, B. (2008) Planthoppers – New threats to the sustainability of intensive rice production systems in Asia. International Rice Research Institute, Los Banos, Philippines. pp.

460.

Heong, K.L., Escalada, M.M., Huan, N.H. and Mai, V. 1998. Use of communication media in changing rice farmers' pest management in South Vietnam. Crop Protection, 17 (5), 413 – 425.

Hibberd, J.M., Langdale, J.A. and Sheehy, J. (2008) Using C4 photosynthesis to increase the yield of rice-rationale and feasibility. Current Opinion in Plant Biology 228-231.

Horie, T., Nakagawa, H., Centeno, H.G.S.and Kropff, M.J. (1995) The rice crop simulation model SIMRIW and its testing. In Modeling the impact of climate change on rice production in Asia. Eds. Matthews R.B., Kropff, M.J., Bachelet, D. and van Laar, H.H. Wallingford (UK): CAB International, and Manila (Philippines): International Rice Research Institute. pp. 51-66.

Ingram, K.T., Manalo, P.A. and Pamplona, R.R. (1997) Carbon dioxide and temperature: effects on Growth and development of rice cultivars. In Advances in carbon dioxide effects research ASA Special Publication no. 61.

Jimenez, R.R., and Ladha, J.K. (1993) Automated elemental analysis: a rapid and reliable but expensive measurement of total carbon and nitrogen in plant and soil samples. Commun.

Soil Sci. Plant Anal. 24 (15&16):1897-1924.

Kebeish R, Niessen M, Thiruveedhi K, Bari R, Hirsch H-J, Rosenkranz R, Stäbler N, Schönfeld B, Kreuzaler F, Peterhänsel C. (2007). Chloroplastic

photorespiratory bypass increases photosynthesis and biomass production in Arabidopsis thaliana.

Nature Biotechnology 25, 593-599.

Kellogg, E.A. (1999) Phylogenetic aspects of the evolution of C4 photosynthesis. In C4 Plant Biology. Eds. Sage R.F. and Monson R.K. Academic Press; pp. 411-444.

Khalil, M.A.K., Rasmussen, R.A., and Wang M.X. (1990) Emissions of Trace Gases from Chinese Rice Fields and Biogas Generators: CH4, N2O, CO, CO2, Chlorocarbons and Hydrocarbons. Chemosphere 20, 207-226.

Kobayashi, K., Kim, H., Lieffering, M., Miura, S. and Okada, M. (2005) Paddy rice response to free-air CO2 enrichment. Journal of Agricultural Meteorology 60, 475–479.

Kropff, M.J., Cassman, K.G., Peng, S., Matthews, R.B., and Setter, T.L. (1994) Quantitative understanding of yield potential. In Breaking the Yield Barrier. Ed. Cassman, K. G. Proceedings of a Workshop on Rice Yield Potential in Favorable Environments, International Rice Research Institute, Philippines, pp. 21-38.

Krupa, S. V. (2003). Effects of atmospheric ammonia (NH3) on terrestrial vegetation: A review.

Environmental Pollution, 124, 179–221.

Latshaw, W.L. and Miller, E.C. (1924) Elemental Composition of the Corn Plant. J. Agric. Res. 27 (11),845-861.

Lipton, M. (2007) Plant breeding and poverty: Can transgenic seeds replicate the 'green revolution' as a source of gains for the poor? Journal of Development Studies 43, 31-62.

Mackill, D.J., Amante, M.M., Vergara. B.S. and Sarkarung. S. (1993) Improved semidwarf rice lines with tolerance to submergence of seedlings.

Crop Sci. 33, 749–75.

Mackill , D.J., Coffman, W.R. and Garrity, D.P. (1966) Rainfed lowland rice improvement. Los Banos, The Philippines: International Rice Research Institute.

Mackill, D.J. (2006) Breeding for resistance to abiotic stresses in rice: the value of quantitative trait loci. In Plant breeding: the Arnel R Hallauer International Symposium Ames. Eds. Lamkey K.R. and Lee M. Blackwell Publishing. pp. 201–12.

Mishra, S.B., Senadhira, D. And Manigbas, N.L. (1996) Genetics of submergence tolerance in rice (Oryza sativa L.). Field Crops Res. 46, 177–81.

Mitchell, P.L., Sheehy, J.E. and Woodward, F.I. (1998) Potential yields and the efficiency of radiation use in rice. IRRI Discussion Paper Series No. 32. Manila (Philippines). pp. 62.

Mitchell, P.L. and Sheehy, J.E. (2000) Genetic modification and agriculture. In Redesigning rice photosynthesis to increase yield. Eds. J.E. Sheehy, P.L. Mitchell and B. Hardy. (2000) Proceedings of the Workshop on The Quest to Reduce Hunger: Redesigning Rice Photosynthesis, 30 Nov.-3 Dec. 1999, Los Baños, Philippines. Makati City (Philippines): International Rice Research Institute and Amsterdam (The Netherlands): Elsevier Science B.V. pp. 293.

Mitchell, P.L. and Sheehy, J.E. (2006) Supercharging rice photosynthesis to increase yield. New Phytologist 171, 688–693.

Monteith, J.L. (1977) Climate and the efficiency of crop production in Britain. Philos. Trans. Royal Soc. London B, 277-294.

Monteith, J.L. (1978) Reassessment of maximum growth rates for C3 and C4 crops.

Experimental Agriculture 14, 1-5.

Nelson, T., Langdale, J.A. (1992) Developmental genetics of C4 photosynthesis.

Ann. Rev. Plant Physiol. Plant Mol. Biol. 43, 25-47.

Olk, D.C., Cassman, K.G., Simbahan, G., Sta. Cruz, P.C., Abdulrachman, S., Nagarajan, R., Pham Sy, T. and Satawathananont, S. (1999) Interpreting fertilizer-use efficiency in relation to soil nutrient-supplying capacity, factor productivity, and agronomic efficiency. Nutrient Cycling in Agroecosystems 53, 35-41.

Paine, J.A., Shipton, C.A., Chaggar, S., Howells, R.M., Kennedy, M.J., Vernon, G., Wright, S.Y., Hinchliffe, E., Adams, J.L., Silverstone, A.L. and Drake, R. (2005) A new version of Golden Rice with increased pro-vitamin A content. Nature Biotechnology 23, 482-487.

Pardey, P.G., Alston, J.M. and Piggott, R.R. (eds) (2006) Agricultural R&D in the developing world.

International Food Policy Research Institute, Washington, D.C. pp. 372 Patterson, D. T. (1995). Weeds in a changing climate. Weed Sci. 43, 685–701.

Penman, H.L. (1948) Natural evaporation from open water, bare soil, and grass. Proc. R. Soc. Lond. A193, 120-45.

Pinghua , P., Ponnala, L., Gandotra, N., Wang, L., Si, Y., Tausta, S.L., Tesfamichael, H.K., Provart, N., Patel, R., Myers, C.R., Reidel, E.J., Turgeon,

19

12/10/11

14:09

Page 1

R., Liu, P., Sun, Q., Nelson,T. and Brutnell, T.P. (2010) The developmental dynamics of the maize leaf transcriptome. Nature Genetics, 42, 10601067.

Prasad, P.V.V., Boote, K.J., Allen, L.H., Jr., Sheehy, J.E. and Thomas, J.M.G. (2006) Species, ecotype and cultivar differences in spikelet fertility and harvest index of rice in response to high temperature stress. Field Crops Research 95, 398-411.

Rice Almanac. (2002) Rice Almanac (third edition). Manila, Philippines (International Rice Research Institute; edited by J.L. Maclean, D.C. Dawe, B. Hardy and G.P. Hettel. pp. 253.

Rodenburg, J., Meinke, H., Johnson, D. (2011) Challenges for weed management in African rice systems in a changing climate. J. Agric. Science (Cambridge), 149, 427-435.

Rosegrant, M. and Hazell, P. (2000) Transforming the rural Asian economy: The unfinished revolution. Oxford University Press, Hong Kong, for the Asian Development Bank. pp. 512.

Royal Society. 2009. Reaping the Benefits: Science and the Sustainable Intensification of Global Agriculture. London (The Royal Society; Policy Document 11/09).

Rubia, F.G. and Penning de Vries, F.W.T. (1990) Simulation of rice yield reductions caused by stem borer (SB). Int. Rice Res. Newsl. 15 (1), 34-35.

Satake, T. and Yoshida, S. (1978) High temperature-induced sterility in indica rices at flowering.

Jpn. J. Crop Sci. 47 (1), 6-17.

Shashidhar, H.E. (2007) Aerobic rice –An efficient water management strategy for rice production. In Food and Water Security Eds. U. Aswathanarayana, Taylor & Francis. pp. 360.

Sheehy, J.E., Dionora, M.J.A., Mitchell, P.L., Peng, S., Cassman, K.G., Lemaire, G. and Williams, R.L. (1998) Critical nitrogen concentrations: implications for high yielding rice (Oryza sativa L.) cultivars in the tropics. Field Crops Res. 59, 31-41.

Sheehy, J.E., Mitchell, P.L,. Dionora, M.J.A., Tsukaguchi, T., Peng, S. and Khush, G.S. (2000) Unlocking the yield barrier in rice through a nitrogen-led improvement in the radiation conversion factor. Plant Prod. Sci. 3, 372-374.

Sheehy, J.E. (2001a). Will yield barriers limit future rice production? In Crop science: progress and prospects. Eds. J. Nösberger, H.H. Geiger and P.C. Struik. Hamburg (Germany): CAB International. pp. 281-305.

Sheehy, J.E., Dionora, M.J.A. and Mitchell, P.L. (2001b) Spikelet numbers, sink size and potential yield in rice. Field Crops Res. 71, 77-85.

Sheehy, J.E. (2003) Plant design: concepts and constraints. Indian J. Plant Physiol. Special Issue. pp. 36-48.

Sheehy, J.E., Mitchell, P.L. and Ferrer, A.B. (2004) Bi-phasic growth patterns in rice. Ann. Bot. 94, 811-817.

Sheehy, J., Elmido, A.E., Centeno, G. And Pablico, P. (2005a) Searching for new plants for climate change. J..Agric. Meteorol. 60 (5), 463468.

Sheehy, J.E., Mitchell, P.L., Kirk, G.J.D. and Ferrer, A.B. (2005b) Can smarter nitrogen fertilizers be designed? Matching nitrogen supply to crop requirements at high yields using a simple model. Field Crops Res. 94, 54-66.

Sheehy, J.E., Mitchell, P.L., Allen, L.H. and Ferrer, A.B. (2006) Mathematical consequences of using various empirical expressions of crop yield as a function of temperature. Field Crops Res. 98, 216-221.

Sheehy, J.E., Ferrer, A.B., Mitchell, P.L., ElmidoMabilangan, A., Pablico, P. and Dionora, M.J.A .

(2007a) How the rice crop works and why it needs a new engine. In Charting new pathways to C4 rice. Eds. J.E. Sheehy, P.L. Mitchell and B. Hardy. International Rice Research Institute, Los Baños, Philippines. pp. 3-26.

Sheehy, J.E., Mabilangan, A.E., Dionora, M.J.A . and Pablico, P. (2007b) Time of day of flowering in wild species of the genus Oryza. International Rice Research Notes, 32 (1), 12-13.

Sheehy, J.E., Ferrer, A.B, and Mitchell, P.L .

(2007c): Harnessing photosynthesis in tomorrow’s world: Humans, crop production and poverty alleviation. In Energy from the sun. Proceedings of the 14th International Congress of Photosynthesis Glasgow. Eds. J.F. Allen, E. Gantt, J.H. Golbeck and B. Osmond. Heidelberg: Springer. pp. 12371242.

Sheehy, J.E., Gunawardana, D., Ferrer, A.B., Danila, F., Tan, K.G. and Mitchell, P.L. (2008) Systems biology or the the biology of systems: routes to reducing hunger. New Phytologist 179, 579–582.

Sheehy, J.E. and Mitchell, P.L. (2011). Rice and global food security: the race between scientific discovery and catastrophe. In Access not Excess,

Eds. C. Pasternak. Smith-Gordon & Co. ISBN 9781-85463-245-6. pp. 81-90.

Sinclair, T.R. and Sheehy, J.E. (1999) Erect leaves and photosynthesis in rice. Science 283, 1456-1457.

Stanners, D. and Bourdeau, P. (1995) Europe's environment. Statistical compendium for the Dobris assessment. ECSC-EC-EAEC, Brussels and Luxembourg.

Storozhenko, S., De Brouwer, V., Volckaert, M., Navarrete, O., Blancquaert, D., Zhang, G.F.,Lambert, W., Van Der Straeten, D. (2007) Folate fortification of rice by metabolic engineering. Nat. Biotechnol. 25, 1277-1279.

Suzuki, S., Murai, N., Kasaoka, K., Hiyoshi, T., Imaseki, H., Burnell, J.N. and Arai, M. (2006) Carbon metabolism in transgenic rice plants that express phosphoenolpyruvate carboxylase and/or phosphoenolpyruvate carboxykinase. Plant Science 170, 1010-1019.

Tabbal, D. F., Bouman, B. A. M., Bhuiyan, S. I., Sibayan E. B. and Sattar, M. A. (2002) On farm strategies for reducing water input in irrigated rice; case studies in the Philippines. Agricultural Water Management. 56 (2), 93-112.

Tang, G., Qin, J., Dolnikowski, G.D., Russell, R.M. & Grusak, M.A. (2009) Golden Rice is an effective source of vitamin A. American Journal of Clinical Nutrition 89, 1776–1783.

Tanner, C.B. and Sinclair, T.R. (1983) Efficient water use in crop production: research or research?. In Limitations to efficient water use in crop production. Eds. H.M. Taylor, W.R. Jordan and T.R. Sinclair. Am. Soc. Agron., Madison, WI. pp. 128.

Thiyagarajan, T.M. (2001) Water-saving rice cultivation in India. In Water-saving rice production systems. Eds. H. Hengsdijk and P.S. Bindraban. Proceedings of an international symposium on water-saving rice production systems at Nanjing University, China, April 2-4, 2001. pp.

15-45.

Thomas, H. and Sadras, V.O. (2001) The capture and gratuitous disposal of resources by plants. Functional Ecology 15, 3–12.

Tsunogai, S. and Ikeuchi, K. (1968) Ammonia in the atmosphere. The Geochemical Society of Japan, Geochemical Journal 2, 157-166.

Ueno, O. (1988) Induction of Kranz anatomy and C4-like biochemical characteristics in a submerged amphibious plant by abscisic acid. Plant Cell 10, 571-583.

Vergara, B.S., and Mazaredo, A. (1975) Screening for resistance to submergence under greenhouse conditions. In Proceedings of the International Seminar on Deepwater Rice August 1974. Bangladesh Rice Res. Inst., Dhaka,

Bangladesh. pp.67-70.

Vlek, P.L.G. and Byrnes, B.H. (1986) The efficacy and loss of fertilizer N in lowland rice. Fert.

Res. 9, 131-147.

Wassmann, R., Lantin, R.S., Neue, H.U., Buendia, L.V., Corton, T.M. and Lu, Y. (2000) Characterization of methane emissions from rice fields in Asia. III. Mitigation options and future research needs. Nutr. Cycl. Agroecosyst. 58, 2336.

Wassmann, R., Neue, H.H., Ladha, J. K. and Aulakh, M.S. (2004) Greenhouse gas emissions from rice-wheat cropping systems in Asia.

Environment, Development and Sustainability, 6, 65–90.

Wassmann R, Jagadish, S.V.K., Heuer, S., Ismail, A., Redona, E., Serraj, R., Singh, R.K., Howell, G., Pathak, H., Sumfleth, K. And Donald, L.S. (2009a) Climate change affecting rice production: the physiological and agronomic basis for possible adaptation strategies. Adv. Agron. 101, 59-122.

Wassmann R, Jagadish, S.V.K., Sumfleth, K., Pathak, H., Howell, G., Ismail, A., Serraj, R., Redona, E., Singh, R.K.,and Heuer, S. (2009b) Regional vulnerability of climate change impacts on Asian rice production and Agronomy. Adv Agron 102, 91-133.

Wassmann R, Jagadish, S.V.K., Sumfleth, K., Hosen,Y. and Sander, B.O. (2010) Rice production and global climate change: scope for adaptation and mitigation activities. In Advanced technologies for coping with climate change ‘no regret’ options for adaptation and mitigation and their potential uptake. Ed. R. Wassmann. IRRI Limited Proceedings No. 16. Los Baños (Philippines). pp 67-76.

Xu, K.N., Deb, R, and Mackill, D.J. ( 2004) A microsatellite marker and a codominant PCRbased marker for marker-assisted selection of submergence tolerance in rice. Crop Sci. 44, 248–53.

Ye, X., Al-Babili, S., Klöti, A., Zhang, J., Lucca, P., Beyer, P. and Potrykus, I. (2000) Engineering the provitamin A (beta-carotene) biosynthetic pathway into (carotenoid-free) rice endosperm.

Science 287, 303-305.

Ziska, L. H., and Bunce, J. A. (1993). The influence of elevated CO2 and temperature on seed germination and emergence from the soil. Field Crops Res. 34, 147–157.

Ziska, L.H., Namuco, O., Moya, T. and Quilang, J. (1997) Growth and yield response of fieldgrown rice to increasing carbon dioxide and air temperature. Agronomy Journal 89, 45-53.

Zwart, S.J. and Bastiaanssen, W.G.M. (2004) Review of measured crop water productivity values for irrigated wheat, rice, cotton and maize.

Agr. Water Management, 69, 115-133.

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Peak phosphorus: implications for agriculture Peter S Cornish University of Western Sydney, Locked Bag 1790, Penrith DC, 1790, NSW Australia

Summary Phosphorus (P) is as essential to agriculture as it is to life. Contrary to predictions of ‘peak P’ and a looming crisis in P supply, recent studies show that rock phosphate (RP) reserves will last for centuries. Mine production capacity is approaching the long-term demand for P, which is expected to plateau mid-century and then decline as global population stabilises and the demand for P in developing countries declines, as it has in many developed countries in recent decades. Nevertheless, there is no room for complacency about RP supply, as major reserves are held by only a few countries and there are significant geopolitical and trade issues to be managed if all farmers are to have equitable access to P-fertilizer. Despite plentiful reserves, careful stewardship is needed to ensure P supplies into the distant future. Global P budgets identify possible areas for reducing consumption, but the potential for on-farm actions to reduce long-term use of RP-based fertiliser are limited, other than by reducing P losses from soil erosion through implementing reduced or zero tillage (for all of its other benefits). Significant P losses in surface runoff will be minimised by balancing fertilizer inputs with farm outputs once soil P has been raised to near the critical concentrations for economic production. Most strategies to improve fertilizer efficiency will improve profitability without reducing long-term P demand.

Keywords: Rock phosphate, phosphorus, P-fertiliser, Peak P, P-efficiency, agronomy

Abbreviations

Phosphorus (P), rock phosphate (RP), International Fertiliser Development Centre (IFDC), Global Phosphorus Research Initiative (GPRI), US Geological Survey (USGS)

Introduction The price of rock phosphate (RP) briefly shot up 8-fold in 2007/08, appearing to vindicate claims that the world had passed “Peak P” and that reserves would be exhausted within decades (Déry and Anderson 2007). The term ‘Peak P’ (or Peak oil) refers to the maximum rate of resource extraction, said to occur when half the total reserve has been depleted (Hubbert, 1949) and to herald great price volatility as the resource becomes more difficult and expensive to extract. In a widely-cited but different approach to Peak P analysis, Cordell et al. (2009) provided only slightly less pessimistic forecasts, calling for urgent action to reduce consumption of RP and the threat to world food supplies.

The life of RP reserves is

undeniably important, given that P is essential for all life and Pfertilizer is essential to sustain food production. P is nonsubstitutable and reserves are finite and essentially nonrenewable.

The story of P may not be as clear-cut as the pessimists portray. Déry and Anderson (2007) believed that RP production had peaked at 150 Mt in 1989, yet it rose to 176 Mt in 2010 and the USGS predicts it will reach 228 Mt by 2015 (Jasinski 2011). The 2007/08 price spike had nothing to do with peak P, but other events affecting both supply and demand (Cornish 2010). Supply was constrained by temporary fertilizer factory closures and China imposing a 175% tax on P exports (now removed). Demand was fuelled by population growth, rising affluence and growing demand for meat, and

crop area expansion in response to shrinking world grain stocks and a rising demand for biofuels.

Further uncertainties about the forecasts of ‘Peak P’ arise from uncertainties about the values used for the size of the global reserve, which were USGS estimates made before a recent fourfold increase to 65 000 Mt (Jasinski 2011).

The prospect of exhausting RP reserves raises critical questions for agriculture that are considered in this paper. Is the reserve of high grade RP really diminishing so fast that a shortage of P will impact on farmers and global food security in the foreseeable future, or are there other more urgent drivers of P-efficiency? How might P efficiency be improved if this is an imperative, both at the farm level and in relation to the global P-balance?

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scientific Rock phosphate reserves and reserve life Supply considerations

The size of the reserve

T

he total resource comprises the ‘reserve’ that can be mined economically with existing technology, and the ‘reserve base’ that is now marginally economic or subeconomic but likely to be mined with new technology or at greater economic and/or environmental cost.

There are environmental issues to be addressed when exploiting lowergrade reserves (Cordell et al. 2009).

The USGS has discontinued publication of reserve base estimates, but last reported it was around three times the reserve (Jasinski 2009). The total resource also includes the ‘inferred reserve base’, an additional less well-proven resource including large deposits of low grade ore that are technically accessible with new technology. The average estimate of the total resource is around six times the economic ‘reserve’ (Van Vuuren et al. 2010), excluding vast seabed deposits. Uncertainty about these estimates makes it difficult to confidently forecast reserve life. The USGS increased their ‘reserve’ estimate from 16 000 Mt in 2009 to 65 000 Mt in 2010 (Jasinski 2011). This followed a study by Kauwenbergh (2010) that now seems a defensible foundation for estimating reserve life.

In the most recent estimates of economic reserves, three-quarters are in Morocco/Western Sahara and the rest is distributed amongst only seven

countries (Table 1). Neither Western Europe nor South Asia has useful reserves, making them particularly vulnerable to any interruption in supply.

Morocco/Western Sahara now meets 15% of global demand for RP. This share will grow as other reserves are depleted over coming decades.

Questions have been raised about the legality of Morocco’s occupation of Western Sahara and the longer-term security of this supply. Apart from geopolitics, there are trade issues.

China has become a significant supplier of P-fertilizer to world markets, but has already shown a propensity to impose tariffs to manage P-exports for its own purposes.

political uncertainties, or trade manipulation.

Mine production capacity and RP price

Over the past 35 years, global demand for RP has doubled, outstripping population growth of 65%.

Growth in demand has been confined to developing countries, where P-fertiliser usage now far exceeds the developed world (Table 2). P use in developing countries increased 5-fold in the last 20 years, reflecting low initial soil fertility due to previously inadequate fertilizer use, rising populations and food demand, changing diets, and the economic capacity to apply more fertilizer. That rate of increase over the next 20 years would critically stress the capacity to supply fertilizer P, but this is unlikely as the evidence from developed countries shows.

Global production of RP in 2010 was 176 Mt (Table 1). Major new mines opened in 2010-2011 in Peru (3.9 Mt RP/year) and Saudi Arabia (5 Mt/year).

By 2015, production and processing capacity is expected to exceed 228 Mt (Jasinski 2011). This suggests global production capacity will be adequate for the foreseeable future, but does not rule out regional deficits, geo-

Adequate production capacity takes some pressure off RP price, but the quality of known deposits is falling, so rising processing costs will apply upward pressure. Price forecasts are very uncertain, although von Horn and Sartorius (2009) predict that RP will be in the range US$100-120/t by 2030 (indexed to 2009). If so, then rising prices are unlikely to threaten food security within the next 20-30 years, but as recent events show, future short-term price/supply problems can’t be ruled out.

The demand for P

In developed countries, P-fertiliser use tends to have fallen over three decades, and in the EU to have fallen quite sharply (Fig. 1). The EU and the USA together make up almost 80% of the P demand of developed economies. Even in Australia where much of the arable land was inherently infertile, demand peaked at ~500 kt fertilizer-P in 1998 and has fallen since to <400 kt P/year. Stable or declining demand in developed economies reflects past high P rates and raised fertility levels. Environmental concerns about P in water runoff associated with excessive P in soils has also moderated demand. For example, water quality targets under the ‘Water

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scientific mid 21st century and for economic reserves to “last for at least 100 years” (Steen 1998).

The striking point to emerge from these forecasts, regardless of their approach, is that all say economically recoverable reserves will be effectively used by the end of this century.

Agricultural scientists have warned of P shortages for many years and sought improved P-efficiency for this very reason (e.g. Lazenby 1976).

quality targets under the ‘Water Framework Directive’ (Directive 2000/60/EC of the European Parliament) have led to reduced applications of P fertilizer and manure in much of the EU. Improved technology for fertilizer management has also reduced demand for fertilizer, as farmers use P more efficiently.

most from past excessive fertilizer use, and reduced P use will provide environmental and economic benefits, possibly without compromising further intensification of production.

Vitousek et al. (2009) show that application rates in developed economies have followed a trajectory over time from too little, to (apparently) too much, and then to a more balanced fertilizer regime.

Peak P prediction uses a simple statistical model based on the observation that extractive industries grow exponentially early in development but production falls as extraction becomes more difficult. A critical assumption is that peak supply is reached when half the total reserve remains. A Gaussian (bell-shaped) curve is fitted to historical data for mine extraction, constrained so that the area under the curve equals the estimated total resource (depleted + remaining). The future date of ‘Peak P’ and the peak rate of mine production can be predicted from mine output from first production to the present. A Peak P analysis was conducted by Cordell et al. (2009). It shows a supply peak in 2030 of ~28 Mt P/year (~215 MT RP).

By extrapolation, reserves are forecast to run out around 2150.

Predicted demand Most short-term forecasts indicate growth of ~2% in E and SE Asia, 4% in S Asia and Latin America, and a disappointing 1% in Africa. The developed world should remain stable or to continue a slow decline. In an earlier long-term prediction which has so far been close to the mark, Steen (1998) forecast demand to grow by 2% pa to the year 2030 and then plateau at ~30 Mt P/yr by 2040 (230 Mt RP) as population stabilises and soil-P requirements start to fall. This is close to the mine production capacity expected by 2015. Vitousek et al. (2009) show that fertiliser use in China appears to be following the trajectory of developed economies, lending weight to the projection that world P demand will plateau then decline.

Future demand could increase in some sub-Saharan African countries that are considering using subsidies to encourage P application. In coming decades, increased P use in Africa and rainfed agriculture in South Asia and China ideally should drive any increase in P demand. Internationally, the greatest yield gaps (actual v. potential) are in rainfed areas where increased P application may provide the greatest benefit. Irrigated areas have suffered

Forecasts of reserve life The ‘Peak P’ method

Forecasts compared Most of the recent attention to reserve life has focused on Peak P forecasts, although the USGS has made annual forecasts by simply dividing the size of the known by the annual rate of mine production. In 2009, before increasing the estimated size of the reserve, the USGS forecast that economic reserves would be depleted by 2100.

These forecasts, like most others, take no account of important factors determining supply and demand. The ‘most likely’ scenario in a more sophisticated forecast was for half the remaining reserve to be depleted by

The above analyses used a variety of data for the size of the reserve, but all were much lower than the recent IFDC figure (Kauwenbergh 2010). By using the simple USGS approach to forecasting, the IFDC estimated a reserve life of 300-400 years. If broadly correct, then whilst resource stewardship for future generations is an important responsibility for humanity, the size of the reserve per se is hardly an urgent driver for improving P-efficiency.

Upon release of the IFDC report, the GPRI, a small group of concerned academics, stated that even if the revised estimates were ‘accurate’ it would delay Peak P by only ‘several decades’.

A revised Peak P analysis (Cordell et al.

2011) was used to discredit the IFDC prediction of a 300-400 year reserve life. Unlike the previous Peak P analysis of Cordell et al. (2009), in this analysis the y-axis for predicted mine production was dimensionless.

However, the predicted peak in RP production (in ~60 years) shown in the graph was almost double the actual 2010 production used in the modelling (176 Mt). Without saying so, they predicted peak mine production of >310 Mt/year without considering demand, which is likely to plateau at around 230 Mt/yr by mid-century and then possibly decline.

Peak P is not an appropriate tool for forecasting reserve life because it fails to take account of demand. Clearly, the simplistic approach of the IFDC and USGS is also inadequate. A more comprehensive updated forecast is overdue.

Summary data for the size of the economic RP reserve and the present and predicted supply and demand are given in Table 3. Whilst they make a case for agriculture to manage with reduced inputs of P to maintain reserves for the very long-term, as human-kind must do, any urgency for action must come from legitimate drivers other than the global RP supply and processing capacity.

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scientific of subsistence farmers yields at all after decades with little or no P-fertilizer.

Management of uplands to reduce soil erosion has implications for future Pfertilizer requirement of crops in areas of sediment deposition.

Losses from manure applied to non-arable land and landfill

A global perspective on improving P-efficiency Global P balances indicate where P efficiencies might be gained. They also suggest other drivers to reduce P use. A concerted effort to improve the data used in P balances and subsequent estimates of P stocks and flows would be valuable, although without intensive data the global budgets hide important variation between regions, farms, and even between fields within farms. A recent global P balance showed that 14.9 Mt P (115 Mt RP at an average 13% P) was mined for fertilizer in 2005 but only 3 Mt was consumed by humans (Cordell et al., 2009). The following discussion considers where the apparent ‘losses’ occur and how they might be reduced, using the data in Table 3 that were synthesized from Cordell et al.

(2009). They conceptualized a food producing system based on arable, fertilized land (presumably crops and pastures). Domestic animals were part of the food system, but any unfertilized vegetation they grazed was treated as the ‘natural environment’ and not part of the system. Total P inputs to the system of 27 Mt P/yr comprised 14 Mt P in RP-based fertilizer (0.9 Mt was lost in distribution), 0.9 Mt P in feed supplements, and 12.1 Mt P transferred into the arable system from animals grazing the natural environment. As P passed through the food producing-consuming system, losses to the natural environment totaling 22.6 Mt P were accounted for. The data suggest that 4 Mt P accumulated in soil, which is discussed below with the apparent losses.

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Soil erosion The 8 Mt P/year P ‘lost’ in water-erosion from arable land is 30% of all P ‘lost’ from food-related human activity, although some of this will be subsoil P associated with gully and stream bank erosion (Rustomji et al., 2008). Gully erosion takes land area from food production, and is a serious matter, but the P ‘lost’ does not need to be replaced to maintain crop productivity on the remaining land. So in global P budgets, some of the P input that appears to replace P lost in erosion will actually contribute to P build up in surface soil.

Severe surface erosion (and nutrient loss) undoubtedly occurs in some agricultural landscapes, but in most developed economies the adoption of reduced or no-tillage has dramatically reduced this erosion in what is arguably the most important although largely unheralded agricultural advance since the Green Revolution (Freebairn et al., 2006; Cornish, 2011).

Clearly, the further adaptation and adoption of these techniques, especially in the developing world, will reduce soil loss and, with that, the loss of P. But the incentive to adopt these techniques will likely be the timely planting, more intensive cropping, and improved rainfall-use efficiency reported in many countries.

The soil and P eroded from local hillslopes or the uplands of drainage basins is not necessarily lost to agricultural production. For example, ~70 M ha rainfed rice is mostly terraced and bunded, retaining much of the sediment (and P) eroded either from nearby hillslopes or more distant uplands, helping to explain why the rainfed rice

Domestic animals produce 15 Mt P/year in manure, derived partly from crops (2.6 Mt P) but largely from grazing non-arable areas (12.1 Mt P). Of this, 8 Mt is applied to arable land and 7 Mt P is said to be ‘lost’, but some must be returned to non-arable land and replace P consumed by grazing animals. The real P ‘loss’ is hard to determine, although some will be transported in water runoff potentially incurring environmental costs.

Soil-P accumulation This was not explicitly estimated by Cordell et al. (2009), but can be deduced from their data. P inputs to arable land totaled 22 Mt P/year, comprising RP-based fertilizer (14 Mt P) and animal manure (8 Mt P). Plant removal from arable land was 10 Mt P (from the source data) and ‘loss’ in soil erosion was 8 Mt P/year. So there is a net apparent accumulation in soil of 4 Mt P, or greater if some of the P input that appears to replace P lost in erosion actually accumulates in surface soil. This accumulation is often said to reflect ‘inefficiency’, a point considered later. Average accumulation covers a range of situations from fields that are high in P and getting higher (e.g. sites of animal waste disposal) through to fields that are low in P and getting lower (e.g. many subsistence smallholders).

Crop losses – pests and diseases Loss of 3 Mt P/year may be an illusion of P accounting, as yield loss to the farmer does not necessarily translate to P loss to the food producing system.

Any P that is not truly lost from the system must be accounted for as additional P accumulation in soil. The driver here is improved plant protection to raise productivity and profitability, even if less crop area needs to be sown and fertilized.

The vegetarian diet Of the 3 Mt P consumed annually by humans, only 0.6 Mt is derived from

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scientific domestic animals (Cordell et al. 2009), showing that whilst vegetarians consume less P than omnivores, the saving in total P is small. Moreover, reducing animal product in the diet may inadvertently increase demand for P fertilizer. The reason is that although 2.6 Mt P in harvested crops goes to domestic animals, the 8 Mt they return to arable land as manure represents a transfer of P from nonarable land to arable land, reducing the need for P-fertilizer on crops. Of course, this comes at the cost of P depletion in non-arable land.

Recycling from urban consumers to rural producers Of the 3 Mt P/year produced in human excreta, 1.2 Mt P is ‘lost’ to landfill and application to non-arable land (some of which may be grazed or forested). Some 1.5 Mt P is lost in sewage discharge to surface water, often with adverse environmental impacts. Only the remaining 0.3 Mt P is recycled to arable land, and this could be usefully increased. Safe, effective nutrient recycling or recovery from sewage and other organic waste streams is a relatively mature research area, with recovery using struvite (MgNH4PO4) crystallization being especially promising (eg Ali et al.

2003). Market forces, if not regulation, will determine how quickly such nutrient recovery is implemented.

Globally, though, any saving in RP from recycling human waste will be so small that reducing P discharge to surface water will remain the stronger driver for recycling.

Improving on-farm P-efficiency From the analysis above, seemingly the biggest global opportunity to reduce fertilizer consumption is to manage soil erosion, which removes native soil P and the P accumulation from fertilizer and manure application.

Presumably there are also opportunities to manage ‘losses’ in animal waste, but the real magnitude of this loss is unclear. The on-farm opportunity most often referred to is the apparent inefficiency leading to P accumulating in soil. The following section teases out some of the thinking behind this inefficiency to indicate where it might be improved through agricultural management or breeding.

Fertilizer efficiency To increase P-use efficiency in agriculture we first need to be clear about how to measure it. The following definitions follow Syers et al. (2008).

Agronomic P efficiency: (Yield+P -Yield-P)/Papplied Apparent recovery or efficiency: (P uptake+P - P uptake-P)/Papplied These measures suit nutrients such as nitrogen that, if managed well, leave little residual; but P uptake from fertilizer rarely exceeds 25% in the year of application although eventual recovery may be as high as 90% over appropriate timescales (Syers et al. 2008). So P-balance efficiency is also needed at the level of a field or whole-farm over a sequence of crops, or years.

P-balance efficiency: Poutput/Pinput (applied) Plant physiologists and breeders are more interested in: Physiological efficiency: (Yield+P -Yield-P)/(P uptake+P -P uptake-P) The ideal farm would have fields with balanced P budgets and soil P near the critical concentration for the plants in the production system. In this state, P-balance efficiency over time would be high even though agronomic P efficiency would be low.

Realistically though, a balanced farm P budget is much more attainable than a balanced budget and optimal soil P on all parts of all fields – that is the future of precision agriculture or at least more-precise agriculture, and it depends on having relevant measures of soil or plant P status and the knowledge and confidence to use them.

Research on precision management of P nutrition is lagging behind nitrogen because both real-time soil P analysis at the time of fertilizer application and remote sensing of plant P status are more difficult.

The P status of agricultural soils Some soils receive insufficient P inputs to replace outputs, so P status declines over time. This may be a deliberate strategy to exploit high fertility (giving high yields with high agronomic efficiency), or because farmers can’t afford enough fertilizer on soils of lower fertility. Or it may reflect an approach to organic farming that precludes imports of P to a farm that is exporting P in product (Burkitt et al.

2007). More generally, long-term use of fertilizer raises the organic and inorganic P status above their native states. Economic plant production requires P inputs to exceed P outputs until soil P approaches the agronomic threshold for production, because soluble P fertilizers are readily “fixed” in soil as adsorbed P, sparingly-soluble precipitates of P, and as organic P which is recalcitrant to mineralisation, collectively labelled ‘slowly-available P’ in Fig. 2.

When P application exceeds plant uptake it is often interpreted as fertilizer inefficiency, although it may really be low apparent recovery. In P-deficient soils it is better seen as the necessary accumulation of soil P to the point where inputs can more closely balance outputs at a high level of productivity. The fact that P-fertilizer use is falling in many developed countries is a sign that soil P levels are high enough for farmers to attempt to balance P budgets or in some cases to run negative P budgets.

Available P in agricultural soils obviously lies on a continuum from deficiency through to and above the critical concentration for economic production. The strategy to improve P efficiency on any field or farm depends on its P status and related economic and environmental considerations, as well as the objectives of the farmer.

Fig 2: Conceptual framework to consider options for reducing dependency on RP-based fertilizer at farm scale. Boxes with broken lines denote P stocks, solid lines denote flows. Bold italic text denotes where farm-level P efficiency can be improved. Uptake efficiency includes genetic and agronomic methods. The framework excludes environmental losses by assuming that surface erosion is minimized with soil-conserving tillage.

Soil P can also be managed to reduce environmental losses (see text).

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scientific The options for reducing dependency on RP-based fertilizer are shown in Fig. 2, where it is assumed that soilconserving tillage practices have minimised erosion losses.

Improving on-farm P-efficiency – soils with excess P In soils with excess P inputs may be reduced to improve farm profitability and reduce environmental risk. A large body of research has led to international acceptance that soils with plant-available P concentrations significantly above the agronomic threshold are at increased risk of ‘leaking’ P to the environment. It remains unclear whether or not there is a threshold for environmental-P risk similar to the agronomic threshold, but it ought to be possible on most soils to temporarily halt or reduce P application without sacrificing productivity when soil P is above the agronomic threshold.

Difficulties arise where farm/field soil P concentrations are heterogeneous and it is not feasible to either detect or manage the localised areas of greatest risk. Further difficulties arise where land managers are reluctant to reduce fertilizer use when this has been one of the foundations for raising productivity.

Soils used for intensive horticulture and dairy production commonly have strongly positive farm and/or field P balances, resulting in soil P concentrations that are well above the agronomic threshold as well as runoff water with greatly elevated P concentrations (Australian examples include Nash and Murdoch 1997; Hollinger et al. 2001).

Excessive use of P is not necessarily confined to intensive industries. In southern Australia where agriculture is regarded as ‘extensive’ compared to Western Europe, a recent survey found that over half the soils with fertilized crops and/or pastures had plant-available P concentrations at or above critical values, yet these farms generally had small positive farm P-balances (D Weaver and M Wong, pers. comm.).

Farmers are continuing to apply P at rates greater than replacement, even though 'losses' to the slowly-available pool of soil P should be small. It is pertinent to ask why these farmers do this, but there is no easy answer.

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Improving on-farm P-efficiency – soils near or below the agronomic threshold In these soils, apart from managing soil erosion, there are four long-term options (or combinations of them) for using less RP-based fertilizer (Fig. 2).

1. Draw on ‘alternative’ P sources (e.g. sewage or reclaimed P) 2. Reduce RP-based inputs, maintain the same enterprise, draw down soil P, and accept lower production as P outputs fall to balance inputs (become less intensive) 3. Reduce RP-based inputs, switch enterprise to one exporting less P (e.g. grain to fibre) 4. Maintain the same enterprise, reduce P concentration in the exported product whilst maintaining productivity (e.g. breed low phytate-P grain, Bowen et al. 2006) Regarding option 2, if P-fertilizer inputs are reduced and outputs exceed inputs, then available soil P must eventually fall even if ‘slowlyavailable’ P or other ‘available but lessaccessible’ resources on the farm maintain the available P and productivity for a time. This period may be prolonged if soil P reserves are high or intra-farm P transfers are large, although productivity (not necessarily profitability) must inevitably fall, even on organic farms (Burkitt et al. 2007; Cornish 2009). This period can also be extended by improving fertilizer efficiency.

In higher-P soils below the agronomic threshold, improved fertilizer efficiency would mean that slowly available P could be drawn down further than is otherwise possible when P outputs exceed P inputs (in option 2); but eventually inputs need to balance outputs to maintain productivity.

Increasing fertilizer efficiency alone cannot reduce the long-term demand for fertilizer. The reasons for seeking fertilizer efficiency are economic.

In lower-P soils, improved fertilizer efficiency reduces the amount of P ‘lost’ to the slowly available pool as fertility is built up, again providing an economic benefit whilst tying up less P unproductively in soil.

Substantial current research aims to

improve fertilizer efficiency or apparent recovery by managing interactions between pools of P and retaining less P in the slowly-available pool (see Syers et al. 2008; Special Issue of Crop and Pasture Science (60), 2009). The strategies mostly focus on (i) improving P uptake efficiency or (ii) modifying roots or using microbial inoculants to explore greater soil volumes or access less-available forms of P. None of them yet allows high production from low-P soils.

Of the tools available to scientists to maintain current enterprises with high production, only physiological P efficiency (option 4) will improve longterm farm P efficiency, allowing high productivity of existing enterprises with reduced P inputs to the farm.

Improving soil P testing Reliable soil testing underpins most strategies for improved P management. It is easy to criticise farmers for not using soil tests more, but perhaps they justifiably lack confidence in soil testing (and associated advisory services). In graphs of soil P v. crop or pasture yield there is usually large uncertainty around ‘critical’ values that leads to uncertainty in the interpretation of soil test values (cf. Figs. 2 and 3 in Gourley et al. 2009). There are many reasons for this variation. Australian experience may hold a clue for other low-rainfall or seasonally dry areas.

Here, dry surface soils have long been known to increase fertiliser requirement (Cornish 2011), yet this is rarely considered when interpreting soil test values and making fertiliser recommendations, except to place fertiliser deeper into moist soil if surface drying is expected (e.g. Rose et al., 2009).

New soil tests are being developed with improved predictive power over a range of soil types (Mason et al., 2010) although interpretation will still need to account for surface soil drying.

Soil acidity, soil acidification and lime The availability of P is reduced in soils with acid soil reaction (pH). Liming of excessively acid agricultural soil (< pH 5) has long been practiced, bringing sparingly soluble precipitates of P into soil solution (Fig. 2). Since the 1980’s the concern has not so much been with soil acidity per se as with soil

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scientific acidification. This occurs slowly and naturally in many soils, but the rate is accelerated by agriculture, a process described by Helyar and Porter (1989).

Vast global areas of neutral to acid arable soils are becoming more acid.

Amongst other effects, this increases fertilizer-P requirements. Whilst liming can correct soil acidity, it is more important to reduce the rates of acidification in the first place. Some acidification is unavoidable, but rates are increased by certain nitrogenous fertilizers.

Ammonium-based fertilizers are worst, including the widely used diammonium phosphate (DAP) and mono-ammonium phosphate (MAP).

Urea is less acidifying, and potassium nitrate and superphosphate fertilizers do not acidify soil. Another major cause of acidification is nitrate leaching from soils, which can be addressed through fertilizer and crop management.

References Ali, M.I., Schneider, P.A. and Hudson, N. (2003) Assessing nutrient recovery from piggery effluents. MODSIM03 NZ. Bowen, D.E., Guttieri, M.J., Peterson, K., Raboy, V. and Souza, E.J. (2006) Phosphorus fractions in developing seeds of four low-phytate barley (H. vulgare L.) genotypes. Crop Science 46, 24682473.

Burkitt, L.L., Small, D.R., McDonald, J.W., Wales, W.J. and Jenkin, M.L (2007) Comparing irrigated biodynamic and conventionally managed dairy farms. 1. Soil and pasture properties.

Australian Journal of Experimental Agriculture 47, 479–488.

Cordell, D., Drangert, Jan-Olof and White, S. (2009) The story of phosphorus: Global food security and food for thought. Global Environmental Change, 19, 292–305.

Cordell D., White, S. and Lindstrom, T. (2011) Peak phosphorus: the crunch time for humanity?

The Sustainability Review, April 4, 2011.

Cornish, P.S. (2009) Phosphorus management of organic and low-input farms. Crop and Pasture Science, 60, 105-115.

Cornish, P.S. (2010) A postscript to Peak P – an agronomist’s response to diminishing P reserves. Proc. Of the New Zealand Grasslands Association 72: XXVII-XXXIV. Cornish, P.S. (2011) Donald Oration: On farming systems and the importance of partnerships between farmers and researchers. Agricultural Science 23, 26-35.

Déry, P. and Anderson, B. (2007) Peak phosphorus. Energy Bulletin. August, 2007 energybulletin.net/node/33164.

Freebairn, DM, Cornish, PS, Anderson, WK, Walker, SR, Robinson, JB and Beswick, AR (2006) Management Systems in Climate Regions of the World – Australia. In ‘Dryland Agriculture’ 2nd ed.

Agronomy Monograph 23. (American Society of Agronomy, Crop Science Society of America, Soil Science Society of America: Madison, Wisconsin USA.) Chapter 20: 837-878.

Grimm, K.A., (1998) There's no substitute for phosphate: Looming fertilizer ore problems threaten our food security. Monitor 7(4), 18-21.

Gourley, C.J.P., Melland, A., Waller, R., Awty, I., Smith, A.P., Peverill, K. and Hannah, M. (2009) Making better fertiliser decisions for grazed pastures in Australia. Bulletin DPI, Victoria.

Helyar K.R. and Porter W.M. (1989). ‘Soil acidification, its measurement and the processes involved’. In A.D. Robson (ed.), Soil Acidity and Plant Growth, Academic Press, Sydney, NSW. Hollinger, E., Cornish, P.S., Baginska, B., Mann, R. and Kuczera, G. ( 2001) Farm-scale stormwater losses of sediment and nutrients from a market garden near Sydney. Agricultural Water

Conclusions There will not be a supply-constrained peak in RP mine production in coming decades. Any shortage of RP is more likely to be related to geopolitical and trade issues. Peak P is not an appropriate tool for predicting the life of RP reserves because it takes no account of demand, which is expected to plateau mid-century and then decline as population stabilizes and soil P concentrations rise in developing countries.

Although the global P budget suggests there is significant inefficiency on farms, much of this apparent inefficiency is associated with soil erosion. This can be managed through soil-conserving cultural practices which will be adopted increasingly for a range of benefits other than reduced loss of P. There

are also strong economic and environmental reasons to reduce P inputs where soil P is already high.

There are few other on-farm options for reducing long-term demand for RP. Inputs must replace outputs once soil P concentrations are high enough for economic production. A range of agronomic and plant breeding approaches to improve agronomic efficiency will improve farm profitability and may reduce the amount of P tied up in slowly available forms in soil, but they will not reduce the long-term demand for RP. Soil P testing is central to many of the strategies for using P more efficiently (and profitably), but farmers in rainfed Australia (at least) seem to lack confidence in the tests.

Research that leads to wider, effective use of soil tests is recommended.

Guano quarry, Chincha Islands in Peru, during the 1890s

Management, 47, 227-241.

Hubbert, M.K. (1949) Energy from fossil fuels.

Science, 109, 103.

Jasinski S.M. (2009) U.S. Geological Survey, Mineral Commodity Summaries, January 2009, p 121.

Jasinski, S.M. (2011) U.S. Geological Survey, Mineral Commodity Summaries, January 2011, p 119.

Kauwenbergh, S. (2010) World Phosphate Rock Reserves & Resources. IFDC, Sept. 2010.

Lazenby, A. (1976) Fertilizer resources and the sub and super philosophy. (In) Reviews in Rural Science 3, Ed. G Blair (UNE), Aug. 1976.

Mason, S., McNeill, A. and McLaughlin, M.J. (2010) Expanding the use of Diffusive Gradients in Thin-Films (DGT) for assessing phosphorus requirements of different crop types. "Food Security from Sustainable Agriculture" Ed. H. Dove and R. A. Culvenor Proc. 15th Agronomy Conference, 15-18 November 2010, Lincoln, New Zealand.

Rose, T.J., Rengel, Z., Ma, Q. and Bowden, J.W. (2009) Phosphorus accumulation by field-grown canola crops and the potential for deep phosphorus placement in a Mediterranean-type climate.

Crop and Pasture Science 60, 987–994.

Steen, Ingrid (1998) Phosphorus availability in the 21st century: Management of a non-renewable resource. Phosphorus and Potassium, 217,

25-31.

Syers, J.K., Johnston, A.E. and Curtin, D. (2008) Efficiency of soil and fertilizer phosphorus use.

FAO Fertilizer and Plant Nutrition Bulletin 18, Rome, 2008.

Nash, D. and Murdoch, C. (1997) Phosphorus ni runoff from a fertile dairy pasture. Australian Journal of Soil Research 35, 419-29.

Rustomji, P., Caitcheon, G. and Hairsine, P. (2008) Combining a spatial budget with geochemical tracers and river station data to construct a catchment sediment budget. Water Resources Research, 44: 10.1029/2007WR006112.

Van Vuuren, D.P., Bouwen, A.F. and Beusen, A.H.W. (2010) Phosphorus demand for the 1970-2100 period: A scenario analysis of resource depletion. Global Environmental Change 20, 428-439.

Vitousek, P.M., Naylor, R., Crews, T., David, M.B., Drinkwater, L.E., Holland, E., Johnes, P.J., Katzenberger, J., Martinelli, L. A., Matson, P. A., Nziguheba, G.. Ojima, D., Palm, C.A., Robertson, G.P., Sanchez, P.A., Townsend, A. R. and Zhang, F.S. (2009) Nutrient imbalances in agricultural development. Science 324, 1519-1520.

Von Horn, J. and Sartorius, C. (2009) International conference on nutrient recovery from wastewater streams. Eds Ashley, K., Mavinic, D. and Koch, F. ISBN: 9781843392323 (IWA Publishing, London).

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Carbon, Conservation and Agricultural Development – the Coastal Peatlands of Sumatra, Indonesia John Bathgate (lewisbathgate@hotmail.com); Tony Greer (tony_greer@hotmail.com); Reddy Rachmady (raptor_javanhawkeagle@yahoo.com) Summary This paper examines the issue of continued and increased pressure on carbon conservation in the peatlands of Indonesia – with a specific focus on the coastal peatlands of Riau Province, Sumatra and the current development on those lands. What can be realistically expected to be conserved is considered alongside the mechanisms available to do so. Land use development and, therefore, deforestation in Riau started in the early 1980s when major clearing began for the establishment of large palm oil plantations. This was quickly followed by the widespread establishment of smaller oil palm holdings by small holders. The 1990s saw the emergence of the pulp and paper industry in the Province and public sector lands were converted to industrial tree plantations for fibre. Initially most of the forest conversion took place on the more accessible mineral soil lands. Development of the peat swamp environment followed later; requiring more intensive investment in capital and technology to expand at a large scale.

At the small scale of the individual householder, peat is difficult to develop as the surrounding hydrology cannot be controlled.

Practical options for carbon conservation and development alternatives in this setting are limited.

Large areas of peatland are already degraded and the forest removed. Rehabilitation of peatlands for carbon and biodiversity conservation is one option but in practice it is entirely unproven and would require enormous long-term funding for outcomes that could never match those from pristine forest.

Integrated development is examined as the only proven option for maintaining some natural forest alongside a commodity crop. Such an environment stores up to 50% of the ecosystem carbon that successful rehabilitation might store. The other 50% of carbon drives agricultural commodity markets that pay for the benefits for as long as there are strong markets for palm oil and fibre pulp. The time scale of estate concession license periods of up to 100 years along with the business corporate model, are appropriate for mitigation attempts of the extended time of the carbon cycle. .

Key words: Peat swamp forest, soil carbon, climate change, deforestation, agriculture, livelihoods, palm oil, fibre plantations, drainage, Riau, Indonesia

Glossary Atmospheric haze – dust, smoke or other dry particles that obscure clarity of the sky.

Biomass – biological material from living or recently living organisms of flora and fauna.

Biodiversity – the degree of variation of life forms within a given ecosystem or region.

Beyond compliance – conducting

business with environmental protection more than required by law.

Carbon cycle – the movement of carbon atoms, originating as CO2 through various organic and other molecular combinations in nature, returning as CO2.

Integrated development – crop production and conservation are delivered from a common area of land.

Palm oil – cultivated crop that pro-

duces edible oil from fruits of the palm.

Peat swamp forest – tropical moist forests where water-logging produces thick deposits of organic soil.

Plantation fibre – cultivated hardwood trees that produce short-fibre pulpwood.

Selection logging – practice of harvesting a portion of natural forest stands while retaining a forest structure on that area of land.

Abbreviations BAPPENAS Indonesian National Development Planning Agency; CO2 carbon dioxide; CO2e

carbon dioxide equivalent; FSC Forest Stewardship Council; GDP gross domestic product; GHG green house gases; ha hectare; M million; RSPO Roundtable for Sustainable Palm Oil; t tonne, metric

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scientific Background

this could become reality.

Carbon Conservation and Development

First the time frame. The global carbon cycle has a long feedback and stabilization period during which carbon stocks must be kept out of the atmosphere to effect climate mitigation. Project funding and project management need to stay in place throughout this process, which is likely to be at least a century?

There is increasing international interest and pressure from concerned stakeholders that tropical peatlands be managed for the purpose of environmental services alone. The rational is that if the vast stores of soil carbon to be found in peat swamps are left intact, then global climate will benefit. In coastal Riau, Sumatra, Indonesia, commentators have taken this to mean that current land use development trends involving deforestation must be halted (Verchot et al. 2010). A secondary benefit of such an intervention would be the maintenance of biodiversity within these forests.

In principle the climate mitigation concept is simple enough. Local participants, opportunistic loggers and farmers, would forego imminent deforestation and their loss of livelihood would be compensated by beneficiaries of climate mitigation.

This list would also have to include plantation companies with rights to develop licensed land areas, although the principles and mechanism for compensation here are less clear. There are, however, many questions that need to be answered before

The Political Setting

I

ndonesia’s democratic awakening since the 1990s has been accompanied by much opening up of forested state lands for the production of agricultural commodities. Decentralization of resource control has been a key driver of this land use change (Poulter & Badcock, 2001). Coastal Riau is no

Second, criteria for peat carbon conservation need to be determined. Most carbon in peat lands is soil carbon that was accumulated under a climate dissimilar from that of today (see for example Page et al. 2004). Waterlogged swamp conditions have been a key requirement for tropical peat soil carbon to accumulate. It is often assumed that by maintaining peat swamp forest conditions under the current climatic conditions that carbon stocks will be maintained; although there is no evidence of this, it is possible carbon investors would require proof.

Third is the necessity to maintain the present healthy economic growth that mirrors the population growth of Riau province. To halt deforestation, mechanisms will need to be developed that secure livelihoods and economic benefits for the many people who depend for livelihood on informal logging, shifting cultivation and plantation agriculture.

exception; its peat swamp forests are now almost the last source of additional productive lands in that province. An estimated 0.62 Mha of intact peat swamp forest and 0.67 Mha of degraded peat swamp forest remained in 2009, with another 2.11 M ha of peat that is developed or totally deforested (Figure 1).

Peat swamp forest has been reduced

by selection logging, village agriculture and conversion to oil and tree plantations and the accompanying side effects of drainage and fire. While some of this development is planned and can be controlled i.e. the larger estate plantations, much is not. This uncontrolled development becomes the agricultural frontier - the rural poor’s last chance to share in income from rich natural resources. The chaotic initial process produces much deforestation and atmospheric haze for small initial output of agriculture. The environment is paying for the rapid transition to a devolved market economy. Indeed, the government estimates that all Indonesia’s peatlands contribute 50% of national GHG emissions for just 1% of GDP (BAPPENAS, 2009).

Central Government, under international pressure on its peat carbon record, has announced a ban on new development of peat swamp forest and tighter compliance with existing legislation.

Figure 1: Approximate extent and condition of peatlands, Riau Province, Sumatra, Indonesia

Deforestation in Riau has resulted in massive losses in biodiversity with the most visible and tragic impacts being to the mega fauna – Sumatran Elephant and Tiger. However, the remaining forested peatland landscape cannot be conserved no matter how much the world would like it to be.

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scientific in a modified condition and said to be a major contributor of GHG (Proforest 2005, Hooijer et al. 2006). A similar situation exists in Kalimantan, but is not discussed here.

Tropical peat swamp is a raised ground water dome. The swamp forest cover maintains its own essential environment by retarding runoff, in part by surface roughness of soil, roots and vegetation (Figure 4). Continuous inputs of forest debris, particularly tree roots (Brady, 1981) have built and maintained the huge stores of peat soil carbon over the last 5-6,000 years (Supardi et al. 1993). In the last 12000 years the area of tropical peat deposits has shrunk and now there are concerns for the effects of global warming on existing deposits.

Figure 2: Conservation status of peatlands, Riau Province, Sumatra, Indonesia Maintenance of the formal protected area network, that government endorses and gazettes, must be of the highest priority for national as well as international national strategies on forest and biodiversity conservation in Indonesia â&#x20AC;&#x201C; as these areas are not exempt from development pressures (Figure 2). The formal agricultural sector while still impacting on the environment is and can be driven further to control more of its impact. The informal sector will unavoidably lag behind in terms of being able to mitigate impacts on environment.

The Geographical and Economic Setting Riau is currently one of the richest provinces in Indonesia, with abundant natural resources: petroleum, natural gas, palm oil and fibre. Extensive logging has led to a massive decline of

forest cover from an estimated 78 % of land area in 1982 to just 33 % in 2005 (Central Bureau of Statistics, 2011) (Figure 3). Since the 1970s, the majority of Indonesia has experienced declining population growth rates that currently stand at about 1.5 % annual.

Riau is a significant exception, with increasing rates every decade since 1970, reaching a peak in the 1990s at 4.3 % annual with a population of 5.55 M in 2010 (Central Bureau of Statistics, 2011). The economy of Riau expanded faster at 8.6 %, than the Indonesian average of 6.04 %, for 2006. Local government benefits from an increased share of tax revenue due to decentralization. The economy is natural resource-based, led by crude oil.

Topography Coastal peatlands make up around 3.4 Mha of the province with much of it

Figure 3: Natural forest cover remaining, Riau Province, Sumatra, Indonesia

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Figure 4: Undisturbed peat swamp forest floor is characterized by having water levels at, or above, the ground surface for most of the year. Various aerial root adaptations facilitate gas exchange in addition to maintaining high water levels.

Riauâ&#x20AC;&#x2122;s coastal peat swamps 30 years ago were almost exclusively a public owned landscape of pristine forest.

Government zoning of the land was mostly present as permanent production forest (by selection logging) with minor areas for conservation and conversion to agriculture. Community lands were confined to small enclaves.

Today, land zone is no guarantee of condition. Uncertainty is linked to ownership and the competing interests and claims among government agencies, communities and developers. Forests may be physically removed and lost, or often they may be altered, perhaps permanently, by the peripheral impacts of neighbouring developments such as drainage (Figure 5).

There is little agreement on definition of what constitutes viable forest that will recover in time if the natural hydrology is restored â&#x20AC;&#x201C; as opposed to that damaged beyond a point of no return. In the Kampar Peninsular, Page et al. (2008), estimated from satellite

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scientific This widespread illegal logging and accompanying drainage often starts irreversible decline and loss of forest cover.

Figure 5: Following repeated cycles of logging and burning, within a period of 20 years or so, little is left of the original peat swamp environment. The forest has disappeared and water tables are lowered.

Restoring water levels across the peat dome would almost certainly provide a huge technical challenge – requiring at the very least, that the forest is restored. Given the extent and severity of the forest degredation, restoration at scale is unlikely. The forest environment is replaced by pioneer shrubs and ferns that continue to be destroyed at regular intervals by burning. images that 6 % of the forest cover was good. That figure is in agreement with an assessment of forest cover made from the 2009 images for this present paper (Figure 1). The Kampar Peninsular core is the largest tract of intact peat swamp forest remaining in Riau. Deterioration at margins of peat swamp forests is affected by ground water drainage and other edge effects, but the exact mechanisms are unclear.

Following repeated cylcles of logging and burning, within a period of twenty years or so, little is left of the original peat swamp environment. The forest has disappeared and water tables are lowered. Restoring water levels across the peat dome would almost certainly provide a huge technical challenge – requiring at the very least, that the forest is restored. Given the extent and severity of the forest degredation, restoration at scale is unlikely. The forest environment is replaced by pioneer shrubs and ferns that continue to be destroyed at regular intervals by buring.

transforming closed-canopy peat swamp forest to agriculture are: Stage 1: Concession Selection Logging.

Typically this is several rounds of selection cutting on a 20 year cycle. Most logs are extracted by manually pushed carts on portable light rail systems that can be relocated as the logging front moves. This system does not require drainage of the surrounding land to operate. Canopy opening leads to lowered humidity and forest drying; in exceptional dry spells fire can spread.

But if selection cutting is controlled and other impacts are minor, the forest can recover.

Stage 2: Illegal Logging. Often this is organized around a local community.

Since ca 1990 tracked excavators have been used widely to dig narrow ditches about 1 km apart that connect to the nearest small river or canal, for log extraction (Figure 6). These ‘wild’ drains are never closed after their brief use and flow continuously, slowly reducing ground water levels in porous soils of surrounding peatlands.

The Agricultural Frontier The agricultural frontier has not been government policy. It is an outcome of pressure on land since the political reform of the 1990s that has seen the population of the province and contribution to national GDP grow. The initial pressure for farm land is from rural people who need a source of income from low-investment slash and burn agriculture - low yielding and unsustainable as it may be (Figures 5, 6 & 7). Although not always sequential, some of the steps in the process of

Stage 3: Slash & Burn Encroachment.

Drainage of peat is essential for any agricultural crop (except for sago on the coast). Small ditches left from previous illegal logging are often the initial source of ‘borrowed’ drainage.

Encroachment is opportunistic and follows available access - extending up to 0.5 km on each side of ditches, canals, and floating roads. Fire is always used to clear the land as there is no other means available (Figure 7). Peat can smolder for weeks until rains arrive; farmers have no capacity or motivation to douse fires. Burnt peat ash is the cheap fertilizer that greatly raises the scarce mineral content of peat soil (Figure 8).

Figure 6: Abandoned logging canals cut across a degraded peat swamp forest landscape.

Figure 7: Dry periods often trigger opportunistic burning of former peat swamp forest land in preparation for agriculture. The blackened bole of a remnant forest tree remains in the centre forground.

Figure 8: In the absence of heavy machinery for land clearing, fire is the only accessible tool for many people seeking to develop land. Fire also brings the additional benefit of a pulse of nutrient inputs.

Initial planting is patchy. Clumps of fruit trees, oil palm or rubber trees are planted at strategic points to claim the land boundaries, and simple thatched structures erected for shelter or temporary habitation. Often the process is repeated several, or many, times as dry periods allow; later fires take a toll on earlier plantings. A patchwork emerges of scattered remnants of degraded

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scientific integrated (Figure 10 & 11).

Peatland Carbon Reserves A review by BAPPENAS (2009) concluded that annual emissions from all Indonesian peatlands are about 500 M t of CO2. This is lower than estimates made previously, e.g. Hooijer (2006).

Recent monitoring of soil respiration from drained agricultural peat indicates rates in the range 30-60 t CO2 /ha/year when root respiration gas exchange is excluded (Hatano 2009; Hooijer et al. 2009). Monitoring of local atmospheric CO2 levels has commenced in Sarawak Malaysia (AsiaFlux, 2010) and is now planned for Riau, to provide better estimates peat soil emissions.

Figure 9: The agricultureal frontier comprises of a mosaic of remnant natural forest, tree and fruit crops and newly cleared lands – cleared by fire in preparation for planting forest, scrub, fern, grassland and seasonal agriculture (Figure 9). Corn, chili and pineapple are common initial crops. Rice is cultivated in a few riverside places offering tidal irrigation.

Investment in tree or palm crops tends to increase as the fire phase passes.

These frontier activities bring temporary benefits but yields are often low and the system inefficient for the amount of soil carbon emitted. The frontier produces degraded and poorly utilized forest land that does strengthen the case for organized development to be given access to these now degraded public lands.

Stage 4: Productive Agriculture. Over a decade the frontier patchwork of forest, re-growth and subsistence crops is transformed into organized plantations of palm oil and rubber Whereas the agricultural frontier was mostly informal slash-burn driven by individual farmers, in the new landscape dominated by organized plantations only small enclaves of individuals’ gardens remain. The initial pioneers are bought or pushed out by larger schemes with land titles. Most plantations are developed on public land of either Agriculture or Forest status. Legal requirement to conserve the original forest is different for each but in general are minimal – the focus being at most – legal compliance.

Stage 5: Integrated Land Use. In the last few years the emerging green markets for commodities have led some national and international owned estates to voluntarily set aside

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larger areas of conservation in order to demonstrate commitment to a business model that extends ‘beyond compliance’. Such schemes include the Round Table for Sustainable Palm Oil (RSPO) and the Forest Stewardship Council (FSC) for wood origin certification. Legal and voluntary constraints can result in 30 % or more of concession land being set aside from development as natural forest - in various states of original structure and function. However, to implement such standards, no matter how desirable, is proving to be a challenge in the present development setting. This model is termed here Integrated Development as conservation and development outcomes are

Figure 10: Large scale estate crops – in this case tree crops for fibre - impact their environment in similar ways to what? but with the advantage of being able to control and manage the environment to a greater extent. In this picture - tree plantations make up the background – the white boles of remnant swamp forest in the foreground.

Despite uncertainty over the values, where water tables have been lowered, there is no doubt that peatlands are emitting large quantities of CO2.

This is where Indonesia’s reputation as a major contributor to global carbon emissions and climate change warming has originated – owing to the deforestation and the drainage based agricultural systems that follow. A key question to be asked is: what are the main factors that could be controlled to reduce peatland emissions, and by how much?

One integrated development project in Riau has monitored soil and biomass carbon stocks and fluxes in plantations and conservation set asides in its concessions, (Bathgate 2010). In the last 5 years, soil carbon is being lost at significant rates from both these dominant land use types. It is possible that in the conservation areas, previous deterioration has not had time to respond to the recent mitigation of logging and drainage impacts. A much

Figure 11: Large scale estate crop land preparation use a network of canals for transport and some drainage. Traces of old logging canals can still be seen on the recently cleared land surface.

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scientific longer monitoring period is required to understand the expected recovery process. However, at this stage several tentative conclusions may be drawn.

The pristine state is rare and soil carbon accumulation expected of pristine peat has not been found (or reported in Indonesia). Deterioration in peat swamp forest is difficult to recognize without intensive monitoring on the ground; therefore it may be widespread and largely unreported. The forest recovery expected to follow mitigation of disturbing factors may take several or many decades to happen.

Mindful of uncertainties, indicative carbon stock projections for peatland development in Riau are reproduced here, from Bathgate (2010). Carbon fluxes measured over the previous five years have been used, with modifying assumptions on rising water tables and declining production, to project long term trends in stored carbon. While the projections are speculative, they suggest that outcomes for peatland carbon storage and hence climate could be very different depending on the development scenarios implemented.

An horizon of a century is used in order to better reflect the carbon cycle and the maximum term of formal licenses (Figure 12). A start date of 1975 is when coastal swamp forest was pristine. Vegetation removal, e.g. forest clearance for plantation, is treated as an immediate release of carbon.

An initial value for stored carbon in the peat swamp system of around 10,000 t CO2/ha is based on values of peat soil and biomass volume and density and carbon content that have been measured in Kampar Peninsular

interior peatland.

1. ‘Society’s default’; informal development that results in a landscape entirely of small agriculture holdings.

2. ‘Integrated development; environmental ‘green’ certification with voluntary best practice that sets one third of the landscape aside for conservation management.

3. ‘Integrated development with product’; this accounts for carbon in products like palm oil or pulp fibre that is transferred out of the peatland.

Transferred carbon while no longer in stored form is an important transaction for development and merits inclusion in this carbon account.

4. Rehabilitation; in theory with sufficient funds and technical input all remaining degraded forest areas could be rehabilitated to being largely forested areas storing carbon. It should be noted that most international assistance projects provide funding for 3 to 5 years. These funding cycles would need to be extended in order to impact the carbon cycle.

5. ‘Undisturbed nature’; an option that remains for the estimated 0.62 Mha, of Riau peatland forests that are still intact.

In the case of intact forest, clearly total conservation delivers the optimum outcome for carbon storage. It makes little difference whether soil carbon stocks continue to build slowly, as modeled, or not. What is important for climate is that soil stocks do not decline.

By today’s understanding this requires the landscape to remain pristine. Such a change to the status quo requires a substantial and sustained

intervention – that in turn requires that society reaches a consensus to do so.

In theory one option for conserving carbon in degraded forest and scrub is rehabilitation. As modeled here it retains, and even increases existing stores of biogenic carbon. In practice it is entirely unproven and would require enormous funds for results that might not equal those achieved by conservation; both in terms of carbon and biodiversity.

So, the only effective option for modified forests is likely to be the integrated development option. It has the potential to store up to 50 % of the ecosystem carbon that, rehabilitation, the best theoretical option, can store (Bathgate, 2010).

The other 50% drives agricultural commodity markets that pay for the benefits – carbon, conservation and development. Some of the consumed carbon is immediately released to the atmosphere and some is transferred in commodities that may stay intact for some years, e.g. timber and writing paper. The latter, at least in Asian markets, provides further benefit of energy or recycling at end of life.

Importantly, society is not asked to find more funds – provided the planet continues to have a strong market for agricultural commodities like palm oil and short fibre pulp. In addition, concession license periods of up to 100 years along with the business corporate model, are appropriate to the long run of the carbon cycle.

In peatland frontier areas, integrated development has done more for conservation than any other land use.

While each district of coastal Riau has created its own landuse plan, integrated development is the only spatial model in practice across all (Figure 13).

Figure 12: Carbon stock changes in peatlands over time. Five idealized environments are presented as choices for the estimated 1.3 M ha of Riau peat swamps that remain.

This model has a conservation core often located on a central peat dome, buffered by a controlled activity zone giving way to an outer zone of intensive production and then on the outmost periphery to permanent settlement even by local communities.

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Figure 13: Schematic diagram of the Integrated Development model Calls for widespread conservation of all remaining forest areas as a direct alternative to development, whilst desirable, are idealistic. Most land being converted to agriculture is far from pristine and in some cases is continuing to deteriorate. While enclaves in the development landscape are valuable to conserve, for most of the non-pristine forests the conservation option foreclosed some time ago. The carbon storage trends shown in Figure 7 may be used to provide guidance on the most effective way of integrating land use and carbon charging to optimize society needs.

Carbon Finance Attention is drawn here to some fundamental issues that need to be considered before carbon funding could be made to work for peatlands. Large scale agricultural projects are funded on long term projected benefits – identified at design stage. The benefits produced from a project would have to track its stocks of carbon reliably over an extended period and accommodate human development factors.

Unfortunately at present there is insufficient confidence in estimates of carbon emissions, and hence in relative savings from various alternative land uses.

If agriculture uses soil carbon stocks less rapidly than the informal frontier operating alongside, should society pay? If the agriculture producer has promised to deliver climate benefits, for which consumers pay, should the producer be paid extra for what has already been ‘sold’ i.e. reductions in carbon emissions?

Protecting a resource from development in one locality should not transfer pressure to resources elsewhere.

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Ultimately that means the poverty underlying the frontier must be eliminated. Conservation incentives must provide alternative livelihoods for the rural poor, the loggers and cultivators.

At the same time incentives must give good value and remain affordable to investors; but society should not pay for what would have happened without incentives.

A fundamental issue is society’s trust in institutions to have the necessary legal and structural stability to reduce carbon emissions over 100 years.

Funds need to be dispensed now, on trust, that future generations will continue to withhold peat development, and that carbon emission reduction and climate benefits will accrue. There are spatial and temporal issues of who pays and who benefits. Climate mitigation benefits are global and very long term – so should all society contribute payment, perhaps on the basis of consumption of exported commodities.

The rates of annual emissions being reported from drained agricultural land, multiplied by today’s trading values of biomass carbon, roughly match values of agricultural production.

Compensation to forego agriculture might be payable from carbon income. In the long term society may well demand a reduction in public land emissions, in which case payments to forego emitting carbon would become affordable.

Toward Solutions The outcomes that this paper examines for coastal peatlands – agricultural production, conservation and carbon – are bound up in a complex process of political, social and geographical developments. A key question is:

development and progress for whom?

For the world the priority is conservation. An urgent and obvious solution to conserve Riau’s peat soil carbon, forest and unique biodiversity is to stop deforestation. For Riau, a halt to economic and social development now could be disastrous and might lead to even more environmental destruction. At this ‘just-emerging stage’ Indonesia cannot be expected to curtail economic growth significantly for the benefit of global climate. It would appear that the expectations of concerned international environmentalists clash with local demands.

Democracy, reform and a market led economy in Indonesia are still fragile.

As one study of Indonesian rural poor farmers noted, being in geographically remote locations means being out of reach of institutional health, education and economic assistance to the poor (Yurisinthae, 2010); farmers have little choice but to diversify their subsistence income according to opportunity. The ordinary individual’s needs of providing for his household’s livelihood should be realized. While high rates of economic growth in Indonesia are maintained with social and political stability, outside assistance with interventions could be entertained. This is surely unlikely if the economy were to stagnate nationally or internationally.

An estimated 1.3 M ha of undeveloped peatland remains in Riau. Its careful development following the integrated model could deliver perhaps 0.6 M ha of secure additional conservation and 0.7 M ha of agriculture inside a decade. This area of agriculture when fully developed could potentially add about 7 % to today’s regional economy.

Even with support of the international community the Indonesian government does not have the resources to manage the existing commitments on conservation. So, adding large areas of peatland to the existing conservation burden is not a way forward.

The proven way is to use the integrated development of agricultural estates in which embedded conservation areas are protected by zones of development that buffer against drainage, illegal logging and fire. Markets for products pay for this integrated conservation. For example, the conservation set-aside legal minimum today for industrial tree plantations is about 10 % of concession land. Government has signaled tougher regulation of the formal sector. If legal minima for setasides were raised to 20 or 25 % of

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scientific holdings, which a few extreme concessions have set aside, the green-end of growth-demand markets for commodities like palm oil and fibre pulp may well accept this extra cost.

However, if nearly half of the remaining area of undeveloped peat swamp is to be conserved, a larger more inclusive model is required. To achieve an expanded protected area network centered on the least accessible peat domes, buffered by integrated development on the periphery, concession holders and local communities would need to be compensated.

This indicates a role for international finance. Carbon and biodiversity can be protected in a well planned and managed integrated landscape, where local development and poverty alleviation are fulfilled, providing outcomes from both a business-as-usual “greener” agriculture and from new business in carbon conservation credits.

Government has targeted lowering carbon emissions from public lands, particularly those from drained agriculture. This will remain problematic

References AsiaFlux Steering Committee (2010).

Practice of flux observations in terrestrial ecosystems; edited from CGER Report 13414356 in Japanese BAPENAS, Dec (2009). Reducing carbon emissions from Indonesia’s peat lands; study commissioned by Indonesia national Development Planning Agency, Jakarta Indonesia Bathgate J. (2010). Reducing peatland carbon emissions through forest management; Proceedings of Palangkaraya International Symposium & Workshop on Tropical Peatland, p.42-46; edited Suwardi et al.

Brady M.A. (1981). Organic matter dynamics of coastal peat deposits in Sumatra, Indonesia. Doctoral thesis, Department of Forestry, University of British Columbia Central Bureau of Statistics (2011). www.bps.go.id 24 July 2011, Jakarta Indonesia Hatano R, Yamada H, Satos S, Inoue T (2010). Controlling factors of greenhouse gas emissions of tropical peat soils; Proceedings of Palangkaraya International Symposium &

while the science on peat soil emissions is so unclear. A network of GHG emission monitoring stations is needed to establish the climate outcomes of land use alternatives: degraded peatlands for formal agriculture versus informal agriculture and pristine peat land conservation. At present there is no rehabilitation to monitor.

More difficult to envisage is how to close completely the informal agriculture frontier. Unless this is achieved, the production and development benefits referred to above will be degraded and conservation options will be permanently lost. Rural communities are the forest gatekeepers with traditional rights of use, and a presence in the otherwise unoccupied public lands. There is a need to break the dependence of communities on informal logging. Local communities could be paid to forego frontier activities – from carbon funds administered through government. How this would work is, however, far from clear.

Payment of annual rent on the value of carbon tied up in standing biomass

Workshop on Tropical Peatland; edited Suwardi et al.

Hooijer A., Silvius M., Woosten H, Page S. (2006). Peat-CO2, Assessment of CO2 emissions from drained peatland in SE Asia: Wetlands International Hooijer A., Page S., Jauhiainen J. (2009).

Kampar Peninsular Science Based Management Support Project, Summary interim report 2007-08; Delft Hydraulics Netherlands Page, S. E., Wust, R.A., Weiss, D., Rieley, J., Shotyk, W. & Limin, S.H. (2004). A record of Late Pleistocene and Holocene carbon accumulation and climate change from an equatorial peat bog (Kalimantan, Indonesia): implications for past and present and future carbon dynamics. Journal of Quaternary Science, V19: Issue7; 625-635 Page S., Hoscilo A, Tansey A, Hooijer A (2008). Kampar Peninsular Science Based Management Support Project, draft report: development of a recommended land use zoning map ProForest (2005). Landscape-level assessment of hydrological & ecological values in the Kampar Peninsular; A study of HCVF assessment commissioned by Asia Pacific Resources International Limited, Dec 2005

is small. Annual rent based on the value of stored carbon in peat soil is some 10 fold higher. Another payment option is on the value of soil carbon that would be emitted annually under drainage based agriculture practices.

But another question remains: what would these individuals then do in order that they might generate marginal wealth?

If a way forward is found in time, the informal frontier will cease, carbon stocks in conservation lands will stabilize and agricultural emissions will be in the spotlight. Society at large will insist on lowered GHG emissions in future – and will accordingly need to be prepared to pay through a variety of market transactions in what is, increasingly, a global market based economy. How rapidly this can occur is unknown. Meanwhile, inevitably the environmental costs will mount with the inclusion of climate change impacts from developing peatlands;– but for conservation to be successful economic development is a necessary condition for peat swamp forest.

Poulter L., Badcock S. (2001). The effects of Indonesia’s decentralization on forests and estate crops in Riau Province; CIFOR case studies series, Bogor, Jakarta Supardi, Subeky A.D., Neuzil S.G. (1993).

General geology and peat resources of the Siak Kanan and Bengkalis Island peat deposits, Sumatra, Indonesia: Geological Soc of America, special paper 286 Verchot, L.V., Petkova, E., Obidzinski, K., Atmadja, S., Yuliani, E.L., Dermawan, A., Murdiyarso, D. and Amira, S. (2010).

Reducing forestry emissions in Indonesia; Center for International Forestry Research, Jl. CIFOR, Situ Gede, Bogor Indonesia WWF Indonesia (2010). Sumatra’s Forests, their Wildlife and the Climate: Windows in Time: 1985,1990, 2000 and 2009. Jakarta, Indonesia, (www.wwf.or.id/ accessed July 2011) Yurisinthae, E. (2010). Poor household characterization and design of resource based on productive activities of local economy in alleviating poverty efforts at West Kalimantan province: Proceedings of Palangkaraya International Symposium & Workshop on Tropical Peatland, p.184-187; edited Suwardi et al.

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economic & social

Intensive (farming) Agriculture Colin Spedding

S

ince people often hold quite strong views for or against what they call “intensive” farming, it is important to clarify the meanings that can be attached to the term.

Agriculture uses a vast range of resources and each one can be used intensively (or not), often related to output (but not always).

Thus labour can be used intensively in terms of output per man but sometimes meaning a large number of men per unit of some other resource (e.g. space or time).

Capital can be used intensively in a similar way, getting high output from it or using a lot per operation.

Space is used intensively in terms of a high stocking rate of animals per ha

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over time (=stocking rate) or at an instant in time (= stocking density).

Public concern tends to concentrate on the intensity of use of indoor space (especially for poultry and pigs) with assumptions made about the impact on animal welfare.

Individual animals can be used intensively, usually meaning obtaining high output/performance per animal per unit of time (e.g. growth rate per day or eggs per hen per year).

In this context it is worth noting that a well-fed animal is being used intensively relative to a poorly-fed one.

So there are degrees of intensity as well as a great many expressions of it, related to resource use.

It follows that the word “intensity” is

meaningless and confusing unless accompanied by details as to the particular form of intensity that is being referred to and the resource being used.

Without this specification it is quite impossible to attribute good or bad qualities and it is often the case that any particular intensity may have good consequences in one direction and poor in another.

This is well illustrated in the contrast between “outdoor” systems (animals free to move about but exposed to disease and the weather) and “indoor” systems (where movement may be restricted but animals are protected from the weather and, for example, parasites).

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economic & social

Sustainable intensification John Marsh Summary There is the prospect of a global population of 9 billion by mid 21st Century. Rising real levels of income, growing constraints on food production from climate change and alternative land use together with an accelerating rate of consumption of non-renewable natural resources in all sectors are likely to restrict food production. This has led commentators to say that the only way to feed the future population is a move towards sustainable intensification.

However, this is more a description of a desirable goal than a means of securing it.

To explore the complex issues that arise it is useful to examine in more detail what is meant by sustainablity and intensity and how they are influenced by other factors.

What is Sustainability?

1. A sustainable economic system is one that can repeat its cycle of production an infinite number of times without any loss of output.

Irrespective of the definition we use,the sustainability of the food and agricultural system depends upon the functioning of the economic and political system as a whole. The supply of food, fibre and biofuels involve a wide range of economic and ecological systems. It depends not only on what is produced on farms but also the activity of input industries that supply equipment, seeds, fertiliser and crop protection. The performance of a wide range of downstream businesses from food and cloth processing to retailers and fast food outlets also influence sustainability. It involves, too, the behaviour of people in their homes, where a significant part of the food bought is wasted, and raw material costs for clothes and other consumables. To secure the resources needed to continue production businesses have to compete with other users of the same resources – for food this includes directly the demand for fuel, for urban land uses and for leisure activities.

2. Some relief may be found by using resources more efficiently. Within any system there is always scope for improvements that can add to output without any increase in the volume of inputs used. This process can result in a persistent increase in production without increasing the quantity of inputs used. Such improvements may postpone crises but cannot finally avoid them. Significant extension of the time before resource scarcity makes progress impossible depends not only on using current systems bet-

ter but also on designing, across the whole food/farming system, new less resource consuming systems.

3. Inescapably some resources are fixed in supply so that no system that depends upon them can be regarded as sustainable. This would not matter if the fixed resource were sufficient to meet the needs of the system for millennia ahead. If that were the case the issue would be of intellectual curiosity but no practical significance. Sadly the reality is that some of the resources upon which our society depends are not only fixed in supply but in danger of being exhausted. Amongst these are fossil fuels, especially oil and mineral fertilisers. Less prominent but equally constraining, is the ability of the natural eco-system to support the food producing systems that are involved. Concerns about bio-diversity, about desertification and about the impact of changing climate indicate not only a loss of richness in eco-system services and the aesthetic values of the countryside but also of its capacity to support current levels of food production.

4. Known systems that do not depend on fixed resources deliver low output.

Thus the impact of many earlier societies and the Kalahari tribesmen of today on the environment may be minimal and their food system capable of producing current outputs indefinitely, as their use of land and natural resources allows these to be renewable and their system sustainable.

However, the standard of living that results falls far short of that demanded by the majority of the world’s population.

Intensification 1. Intensification implies a change in

systems of production to increase overall output by using a resource that is limiting supply – often simplified to land – more productively. Economic systems tend to do this autonomously for resources that can be bought in the market. As a resource becomes scarce its price is forced up and people look for systems that will increase output by making more use of other sorts of resource – in effect seeking a new technology to deliver the same, more or better outputs without greater use of the limiting resource.

2. However, markets do not recognise the values of what cannot be traded to communities. There are ‘external costs and benefits’ that do not figure in the decision making process of businesses as they commit resources to production. Such costs include not only matters such as impact on wildlife and landscape but also on the value to the communities that exist at remoter future dates of fixed resources consumed now. Thus, for economic systems to optimise resource use for the community, users should face prices that represent social values as well as the clearing price in today’s market place. This might include a value for environmental goods such as habitat and biodiversity. At this level some policy intervention via incentives, or regulation, becomes essential if an acceptable form of intensification is to be applied.

3. The politics are complicated.

Intensive farm systems have a bad public press. The popular images are of densely housed animal systems with animals bred and fed solely to minimise the cost per unit of saleable output and arable fields drenched with pesticides and fertilisers devoid of any

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economic & social output and arable fields drenched with pesticides and fertilisers devoid of any wildlife. The image includes distrust of the use of farm chemicals, whether as pesticides or fertiliser that ‘force the land to deliver higher yields than are natural’, with perceived adverse impacts on soil condition and on biodiversity. It is therefore important to understand how intensification to secure the output needs of future generations is to become acceptable.

In principle we can intensify the ways in which we use labour, land or capital. The resulting system will be more or less labour, land or capital intensive.

Labour 1 Farming systems that use a high proportion of labour in relation to other inputs are characterised by low levels of income. As economies grow opportunities for labour to earn more in other sectors tend to drive up its cost to farmers and lead to their exit from farming. Farming systems become less labour intensive. Output is maintained by increased use of capital and bought in inputs.

2 Similar pressures exist throughout agricultural and food chains system; both manufacturers and retail food businesses have sought to increase their competitiveness by shedding workers. This is recorded in national statistics as a rise in labour productivity. In the food service sector much of the business is done by concerns that achieve low labour costs. The number of boutique businesses may multiply, partly to offer differentiated products to consumers and partly to provide an income generating activity for unemployed former workers. However they constitute a very small part of the total food system.

3 Even where real incomes are stagnating there is often little scope to use more labour productively. Population increases in rural areas can result in an added burden the farm household has to carry and under employed workers tend to drift to urban areas in search of work.

Rising population implies that more labour will be available –- although it will include a growing number of old people who cannot cope with hard physical work. Attempts to substitute labour for capital, or purchased inputs, are likely to lead to a fall in production as crop protection and cultivation is less thorough by that means. Thus, although the real cost of manpower

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may fall, there is little prospect of greatly increasing output by making farming or its related industries more labour intensive.

Land The purchase of land as an investment has often been justified in terms of ‘they are not making any more of it’.

In practice the land available for agriculture declines as the demands of urban communities for housing, for transport and to sustain environmental and leisure needs grow. In a world of rising population and growing real income such pressures can only grow. b. Even against this background there are situations in mountainous and hilly areas where land once used for farming can no longer compete with the products of farms in more favoured areas. The failure of traditional systems creates problems for local communities and in maintaining the traditional eco-services that such land use provided. c. The language can be confusing.

Adopting productive systems that use more land in relation to other inputs, amounts to adopting more ‘land intensive’ system but this would be described by most people as moving towards extensive farming. In principle it could happen where the costs of converting unused, or little used land, to agricultural production were offset by the value of output. However, in most farming systems output can be expanded more certainly by applying more ‘other’ inputs to existing farmed land. In parts of Brazil and on the margin of farming in areas elsewhere in the world there may be profit in taking land into farming. However, for this the full costs and benefits need to take full account of the social and environmental costs of converting land to agricultural production. These would often make such a move unprofitable. d. In practical terms, whilst there may be scope for more land intensive systems in some low productivity areas of the world, it is improbable that such changes could contribute significantly to the overall goal of systems that both feed the world and are sustainable.

Capital Capital includes all the outputs of the economy that are not directly consumed or wasted. It is used in producing other goods and services. It origi-

nates in the unconsumed part of total production so, as economies grow, the available capital increases. The amount of capital available at any time is determined by the level of income and the savings ratio. The higher they are the more capital is available for use in future productive activities. b. Since it is useful, and always limited in supply, capital has a market price that represents the amount needed to compensate the recipients of income for not consuming all they receive in the current period and the risks they face in allowing other people to make use of their asset. Conventionally this is described as a rate of interest but in addition to the overt financial transactions, substantial amounts of capital are generated by farmers who set aside part of the current years output to provide seed or breeding stock for future use in production. c. Capital takes an infinite variety of forms. It is embodied in buildings and machinery that may contribute to several cycles of production. As working capital it provides inputs such as feed or animal health and crop protection and used up in each cycle. It is embodied in the accumulated skills of all those engaged in production, ranging from those of the farm labourer to the director of research institutions and the CEOs of multinational companies. This intellectual capital is embodied in the goods and services that are produced but it can be carried forward and developed through records and education. d. As understanding of the fundamental processes involved in production, both physical and social, grows, new ways of using capital to increase or improve the output derived from available resources aredeveloped. In a simplified view we can regard the capacity of the food and farming system to sustain output as a race between the run down of fixed resources and the capacity of capital investment to improve the rate of yield of those resources that remain or to discover new resources.

In the past 200 years investment has hugely increased the productive capacity of the food, fibre, biofuels and farming systems but using systems that have resulted in a deceleration of the available supply of some fixed resources. In the process science has also converted some substances that were regarded as non-productive into resources that contribute greatly

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economic & social to current output.

Sustainable intensification is attainable only in terms of injections of capital that raise productivity at a rate equal to, or greater than, the declining availability of fixed resources.

Ultimately this process must be limited, but it extends the ability of humanity to generate a sufficiency of food and other products from the resources that are available. Doomsday is postponed if not eliminated, or world population must decline.

Rows of bamboo canes support young tomato plants. This is rich agricultural land and is used for intensive farming.

Conclusions The immediate task and major challenge is to increase output from existing resources by applying known technologies more effectively. In developed countries there is a growing potential for ‘precision farming’, targeting both pesticides and fertilisers more accurately and breeding animals that generate a higher proportion of useful output in relation to the feed they consume. In developing countries major improvements may be made by using techniques that can more profitably employ the available rural labour. Some of these may relate to the presentation and processing of crops not just to their production.

Everywhere economic systems can be used to ensure a better match between consumer demand and the plans of producers. These developments may ease the immediate problems of resource constraint but in the long run more radical changes will be needed if we are to exploit fully our capacity to cope with the challenges of finite resources and a seemingly unlimited growth of population.

The implication of this analysis is that if we want to turn sustainable intensification from a slogan to a practicality we have to focus on maintaining the flow of capital into innovation in the food, fibre and farming systems. Some of this is a matter for risk bearing entrepreneurs who have the capacity to accumulate the funds needed to invest and the courage to take the risks involved. Such entrepreneurs exist at all levels of the food and farming systems.

Our understanding and exploitation of basic physical, biological, ecological and social systems is a fundamental energiser of the production system. Improvements through research and development enable us to match more closely the uses we make of the resources we control to their value to consumers and society as a whole. Those values include not only the market prices, but also the social costs and benefits.. The potential here is effectively limitless as each advance in knowledge prompts a deeper understanding and new questions.

Such advances can only be

applied where there is effective communication. Those who control the use of resources, in government and the private sector need to be aware of what possibilities are emerging. The system of communication should also enable the public to understand the potential of the advances, so as to influence decisions in ways that reflect the true value of those advances. There is no easy solution. History tells us of many cases where public hostility has frustrated progress, often fanned by the vested interests of companies or pressure groups. The press often seems to trivialise areas of conflicting views and uncertainty into a contest between the ‘good guys’ and ‘ruthless predatory business men’. This has reduced its ability to act as an effective informer of the public and thus facilitate the attainment of sustainable integration.

If we are to make progress we need a communication system that is inclusive, that encourages new ideas and is more focused on truth than sensation.

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economic & social

Idle land for future crop production Susie Roques, John Garstang, Daniel Kindred, Jeremy Wiltshire, Steven Tompkins and Roger Sylvester-Bradley ADAS, Boxworth, Cambridge CB23 4NN, UK

Abstract Cultivated land can only be left ‘idle’ temporarily; after a time the carbon sequestered by land left idle renders it unviable for re-cultivation without excessive carbon dioxide emissions. Depending on the increase in carbon footprints of crop products deemed to be acceptable, estimates from FAO cropping data appear to indicate that there were 1948 Mha of idle land suitable for return to cultivation in 2007. This represents 1.3 – 3.3% of the global arable area, which could provide over half of the extra cropland estimated by FAO to be needed by 2050. Alternatively, cropping of the 5.3 Mha idle land available in the EU27 could support >40% of the transport energy targeted to come from renewable sources by the EC. These are useful reserves, notwithstanding that improved crop productivity will also be vital in meeting future demands for both food and non-food products.

Keywords: Idle land; carbon sequestration; crop production

Glossary Carbon intensity: the quantity of greenhouse gas emissions, assessed as carbon dioxide equivalents, attrib-

utable to one tonne of crop produce.

Carbon dioxide equivalents: greenhouse gas emissions, summed

according to the global warming potential of each gas as it relates to carbon dioxide (CO2): methane, 21 x CO2; nitrous oxide, 298 x CO2.

Abbreviations EU, European Union (EU15 refers to members states up to 2004; EU27 refers to all current member states); EC, European Commission; FAO, Food & Agriculture Organisation; FSU, countries of the former Soviet Union; MPI, maximum periods of idleness; ECY, expected crop yield; MES, maximum acceptable carbon emissions from land use change.

More land for cropping?

The spread of famine across the globe will be avoided most feasibly by an increase in crop production of 70% (FAO, 2008), yet crop yields particularly in developed countries are becoming increasingly ‘stagnant’ (Brisson et al. 2010). Thus, attention turns inevitably to land where cultivation might expand. Deforestation and cultivation of grasslands are not desirable because they cause large emissions of carbon dioxide through destruction of vegetation or of soil organic matter (Dawson & Smith 2007). So how much other land is available? Despite a recent trend to high world prices, previous low crop prices, political and social change and decreased support for farming released some significant tracts of land around the world. For example, the breakup of the Soviet Union and a fall in grain prices caused large tracts of land to be idled in Eastern Europe. It seems possible that much of this uncropped land could be brought back into cultivation without

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causing excessive carbon dioxide emissions. And how much more food might this land grow?

Here we provide some headline conclusions from a study of FAO cropping data that indicates idle land available in Europe and globally, according to the level of carbon emissions that might prove acceptable. It is intended to submit a full and updated study for review and publication in the next Issue.

Estimating idle cropland with low carbon stocks Land is never truly ‘idle’. Cultivation may stop but, with re-establishment and growth of vegetation, carbon sequestration soon begins, both in the vegetation and the soil, and as time passes it becomes increasingly undesirable to bring the idled land back into production. Thus, for the purposes of this study ‘idle land’ is defined as land that has been cultivated previously and can be returned to cultivation

without excessive carbon emissions.

Fallow land is excluded because it represents part of a cropping system, for instance to conserve water and / or build soil fertility for subsequent crops.

Defined in this way, availability of idle cropland across the world is by no means straightforward or certain.

There are two essential criteria: to be evidently cultivable (indicated here by previous cultivation, but adjusted for ‘urbanisation’) and to have insubstantial sequestered carbon (due to a sufficiently short period of idleness). Few statistical resources report both criteria. Repeated aerial and satellite images may be most accurate (e.g.

Campbell et al., 2008), but are very incomplete. National statistics as collated by the FAO are also indicative, if idling of land can be presumed an infrequent act. We take this approach in our study, and apply a typical rate of carbon sequestration from a recent review (0.6 t/ha/year; Dawson & Smith, 2007) to deduce a more comprehensive, if less exact, summary.

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economic & social Idle land was estimated for each country in the world by subtracting the arable land in 2007 from the maximum area of arable land recorded between 1961 and 2007, and then adjusting for urbanisation. The analysis was not sensitive to desertification of previous agricultural land, but an element of verification was included through two case studies for the UK and USA, using alternative data sources and methods.

Estimates of idle land were limited to areas with low carbon stocks by calculating ‘maximum periods of idleness’ (MPI, in years) as given by the equation: MPI = MES x ECY x 20 / RSCA Thus for each region, estimates of idle land were calculated using three maximum emission scenarios (MES, tC/t), set according to three levels of additional emissions (kg CO2e per tonne of crop produce) that might be deemed acceptable due to land use change; 100, 200 & 300 – the largest level being sufficient to approximately double the carbon intensity of cereals grown intensively (400 kg CO2e/t; Kindred et al. 2008). Division by 3667 converts from kg of CO2e to tonnes of carbon. Multiplication by the expected crop yield (ECY), as t/ha/year, and by 20 years accounts for land productivity over a standard period over which one-off emissions are discounted1, and division by the rate of soil carbon accumulation (RSCA), as 0.6 tC/ ha/year, results in the number of years taken to reach a particular MES. ECY was set for the average annual yield of the dominant crop by area in each region from 2006-2008 (sourced from FAOSTAT).

Idle land across the globe The resulting MPI values varied between 1 and 16 years, giving global idle land totals in 2007 of between 19 and 48 Mha, depending on the MES considered acceptable. These areas are of the same order as estimates made previously by Searchinger et al.

(2008) when examining US biofuel expansion and much smaller than estimates exceeding 200 Mha (e.g.

Ramankutty & Foley, 1999; Campbell et al., 2008) that did not acknowledge carbon emissions. They represent possible increases of 1.3 – 3.3% on the 2007 global arable area. Interestingly, these areas have developed over a period when global population and

Figure 1: Estimated changes in availability of idle land for global regions assuming maximum acceptable emissions of 200 kg CO2e/t.

FSU = former Soviet Union; EU15 = European Union food production have also been increasing. The regions with most idle land are North America, Asia, the FSU and EU15, and those with least are in Africa and South America. Past changes in areas of idle land are shown in Figure 1 for a MES of 200 kg CO2e/t. Apparent decreases in idle land in the 1970s and 80s resulted from both the return of idle land to cultivation and the accumulation of soil carbon making idle land unsuitable for use. The global total of idle land has been high for the past decade following rapid increases in the 1990s, particularly in the former Soviet Union.

Recent data show that land is still becoming idle in major regions of the world (Europe, Asia and North America).

Contribution of idle land to future crop production This analysis supports the hypothesis that there are significant areas of idle cropland across the world, and that these might be returned to cultivation without excessive carbon emissions.

Ideally re-cultivation of this land should be prioritised over destruction for cultivation of virgin forests, grasslands and other land with high carbon stocks. Our mid-estimate of 37 Mha idle land (Figure 1) can be related to the FAO’s estimate of 70 Mha extra cropland required globally by 2050 (Bruinsma 2009). Alternatively, our mid-estimate of 5.3 Mha idle land in

the EU27 (MES 200 kg CO2e/t) is 44% of the land required (as calculated by Özdemir et al. 2009) to support the EC 2020 target of 10% transport energy from renewable sources.

However, for idle land to become recultivated, it will be important to recognise that some past drivers of land abandonment and idling will need to be reversed. Causes of land idling in Europe have been summarised by Rounsevell et al. (2005) as reduced world prices driven by supply surpluses and decreasing trade barriers, decoupling of market support from agricultural production, policies to diversify rural businesses, enhancement of environmental services, EU enlargement, competition for land for instance for bio-energy crops, and climate change (through reduced crop yields). Globally, other drivers are land degradation through drought, fire (Rico & Masedo, 2008), soil erosion (Bakker et al. 2005) or salinisation; also through major political changes (Muller & Munroe, 2008; Muller et al.

2009) and age, health and other sociological problems of farmers and landowners (Azima & Ismail, 2009; Rico & Masedo, 2008). As further data become available, it will be interesting to see the extent to which recent world shortages of cereals, and increases in prices, are causing idle land to be re-used.

The most dramatic period of cropland abandonment in recent times, as alluded to above, occurred in the former Soviet, Yugoslav and Eastern Bloc

1 Standard procedure in carbon footprinting guidelines such as PAS2050 (BSI 2008)

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economic & social states between 1992 and 1999, following the collapse of the Soviet Union. This led to abandonment of isolated and less accessible parcels of cropland (Muller et al. 2009), largely owing to changes in land ownership and the switch to a market-orientated agricultural industry. Our analysis of FAOSTAT data indicates that little of this abandoned land had been returned to cultivation by 2007.

Sudden peaks of idled land in Oceania correspond to periods of drought in

Australia; however, unlike changes in Europe, these areas are often returned to cultivation when conditions have improved.

Our analysis indicates that many reserves of idle land exist that may be cultivated without excessive carbon dioxide release. It seems likely that the most significant areas of former cropland that could be returned to cultivation are in the EU, the former Soviet Union and North America. With pres-

sure mounting to feed a global population, the importance of this land for future production cannot be understated. However, ultimate avoidance of famine must also depend on other options: changing diets, improving crop productivity, or possibly cultivating some grasslands and forests.

Hopefully a balance can be struck between these, acknowledging their very different effects on carbon intensities of food and other crop products.

References

5794.

Dawson, J.J.C., Smith, P. (2007). Carbon losses from soil and its consequences for land-use management. Science of the Total Environment 382, 165-190.

FAO. (2008). High Level Expert Forum – How to Feed the World in 2050. Rome, Italy: Office of the Director, Agricultural Development Economics Division, Economic and Social Development Department, FAO, Viale delle Terme di Caracalla, 00153 Rome.

Kindred, D., Berry, P., Burch, O., SylvesterBradley, R. (2008). Effects of nitrogen fertiliser use on green house gas emissions and land use change. Aspects of Applied Biology 88, 53 56.

Muller, D. & Munroe, D.K. (2008). Changing rural landscapes in Albania: Cropland abandonment and forest clearing in the postsocialist transition. Ann. Assoc. Am. Geogr. 98, 855-876.

Muller, D., Kuemmerle, T., Rusu, M., Griffiths, P. (2009). Lost in transition: Determinants of postsocialist cropland abandonment in Romania.

Journal of Land Use Science 4, 109-129. Özdemir, E.D., Härdtlein, M., Ludger, E.

(2009). Land substitution effects of biofuel side products and implications on the land area requirement for EU 2020 biofuel targets, Energy Policy 37, 2986 2996.

Ramankutty, N. & Foley, J.A. (1999), ‘Estimating historical changes in global land cover: croplands from 1700 to 1992’, Global Biogeochemical Cycles 13, 997-1027.

Rico, E.C., Maseda, R.C. (2008). Land abandonment: Concept and consequences [El abandono de tierras: Concepto teorico y consecuencias]. Revista Galega de Economia 17 (2).

Rounsevell, M.D.A., Ewert, F., Reginster, I., Leemans, R., Carter, T.R. (2005). Future scenarios of European agricultural land use: II. Projecting changes in cropland and grassland. Agricultural Ecosystems & Environment 107, 117-135.

Searchinger, T., Heimlich, R., Houghton, R.A., Dong, F., Elobeid, A., Fabiosa, J., Tokgoz, A., Hayes, D., Yu, T-H. (2008). Use of US Croplands for biofuels increases greenhouse gases through emissions from land use change. Science 319, 1238-1240.

Azima, A.M., Ismail, O. (2009). Challenges of idle agricultural land management – an institutional perspective in Malaysia. European Journal of Social Science 9, 39-47.

Bakker, M.M., Govers, G., Kosmas, C., Vanacker, V., Oost, K.V., Rounsevell, M., (2005).

Soil erosion as a driver of land-use change.

Agricultural Ecosystems and Environment 105, 467-481.

Brisson, N., Gate, P., Gouache, D., Charmet, G., Oury, F. and Huard, F. (2010). Why are wheat yields stagnating in Europe? A comprehensive data analysis for France. Field Crops Research 119, 201-212.

BSI (2008). PAS 2050:2008 Specification for the assessment of the life cycle greenhouse gas emissions of goods and services. British Standards Institution, London.

Campbell, E., Lobell, D.B., Genova, R.C. & Field, C.B. (2008). ‘The global potential of bioenergy on abandoned agricultural lands’.

Environmental Science and Technology 42, 5791-

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comment & opinion

Impact of Cultured Meat on Global Agriculture Brian J Ford Gonville & Caius College, University of Cambridge CB2 1TA. Rothay House, Mayfield Road, Eastrea, Cambridge PE7 2AY E-mail: fordbj:@cardiff.ac.uk

Summary Ideas on cultured meat have appeared in print for over a century, yet research has commenced only in recent years and surprisingly little progress has been made. This is an area in which the European Community has played a more prominent role than the United States of America. Culturing meat ex vivo proposes unique problems, yet the pressures on demand make this a priority area of concern. Even when cultured meat becomes popular and easily available, the rearing of livestock will continue. Conventional agriculture is a crucial component of land management, and our environment will depend upon the raising of grazing animals as much in the future as it has done in the past. Cultured muscle can never entirely supplant meat from conventional sources.

Keywords: meat, cultured, in vitro, mycoprotein, quorn, beef, muscle, Netherlands, United States, biofabrication.

Glossary Axolotl: an amphibian newt-like creature allied to the salamander.

Pressure on resources

M

eat production is exerting unsustainable pressures upon the environment. This form of agriculture has caused more species to become extinct than any other (Myers and Kent, 2005). In Central America since 1960 more than a quarter of rain-forest has been cleared for raising cattle and 70 per cent in Costa Rica and Panama has been destroyed in conversion to rearing livestock, while in Brazil 40 per cent of the land has been cleared for beef production (Caulfield,1985). This single agricultural sector consumes 8 per cent of all the fresh water in the world and it occupies almost one-third of the worldâ&#x20AC;&#x2122;s surface that is not covered by ice and permafrost. Raising meat currently contributes 18 per cent of greenhouse gases to the atmosphere. (FAO, 2006). This is greater than that produced by the entire world-wide transportation network.

People are regularly encouraged to limit their use of cars to help maintain the climate; they are far less likely to be pressed to cut down on meat consumption for a similar reason. As this journal has emphasised there are other

Mycoprotein: a growth of fungi which is rich in protein and suitable for human consumption

examples of disproportionality in our sense of urgency â&#x20AC;&#x201C; similarly, although much attention focusses on the venting of waste carbon dioxide into the atmosphere, there is far less attention paid to surplus nitrate in the environment (Smil, 2011). As we contemplate the future provision of meat, these are issues that demand a more balanced assessment.

Meat production is highly inefficient.

A steer requires 100 kg of hay and 4 kg of grain to produce 1 kg of beef.

American estimates of the amount of water needed to produce 1 pound of beef vary from 2,500 gallons of water to an industry estimate 450 gallons, but even the lower estimate is arguably unsustainable. The amount of crops that supply the average world inhabitant is 613 kg per capita annually. In China it is as low as 466 kg, but in the USA, by comparison, the figure is 1,480 kg (Pimentel 2001). This will change, since the emerging nations are now rapidly increasing their consumption of meat as they seek to emulate the inhabitants of western nations.

The conclusion is clear â&#x20AC;&#x201C; humans will not be able to consume meat as such a high proportion of a global diet

Biofabrication: producing complex products from separate ingredients that are artificially produced

in future. Meat substitutes have been widely available for some 2,000 years and some of these will increase in importance to compensate for a reduced per capita meat supply. In Indonesia, tempeh is a traditional highprotein meat substitute that is produced by fermenting cooked soya beans with the common pin-mould Rhizopus. The result is an appetising foodstuff that is amenable to a wide range of culinary applications. Bean curd made from soy is well known as tofu in Japan, though it originated as doufo in China and it is produced from the curds made by coagulating soy milk. These foods are claimed to lower the blood levels of low-density lipids by some 30 per cent (Ford, 2009).

More recent arrivals include ascomycete fungi of the genus Fusarium. Many species of this genus produce mycotoxins of economic importance in agriculture, but Fusarium venenatum has been successfully cultured to produce a mycoprotein meat substitute. This is marketed as Quorn and, although it is a profoundly unnatural and high-technology product, it is proving to be increasingly popular with devotees of health foods.

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comment & opinion Culturing meat The ultimate answer would be to culture meat. In this way, commercial continuous-process production of beefsteak would replace an agricultural sector (or, if not replace, at least substitute for much of the time). The idea is of considerable antiquity. The first mention of cultured meat was in a book written by a German writer who often wrote under the pseudonym of Velatus, in reality a scientist named Kurd Laßwitz. His pioneering science fiction novel entitled Auf Zwei Planeten of 1897 had Martian invaders bringing a range of novelties to earth, including synthetic foodstuffs. One of their innovations was cultured meat.

The idea was not further discussed until 1930, when the writer and politician Frederick Edwin Smith, First Earl of Birkenhead, wrote this description of ‘life in 2030’ in The Strand magazine: “It will no longer be necessary to go to the extravagant length of rearing a bullock in order to eat its steak.

From one ‘parent’ steak of choice tenderness it will be possible to grow as large and as juicy a steak as can be desired.” (Smith, 1930). Smith was a close friend of Winston Churchill, and he discussed his ideas with him. It will come as no surprise to anyone accustomed to the self-interest of politicians to find that Churchill took up the cause and wrote about the concept, though without attributing the source.

In 1932 he wrote: “With a greater knowledge of what are called hormones, i.e. the chemical messengers in our blood, it will be possible to control growth. We shall escape the absurdity of growing a whole chicken in order to eat the breast or wing, by growing these parts separately under a suitable medium. Synthetic food will, of course, also be used in the future.”

(Churchill, 1932). It is interesting to reflect that Smith had peered 100 years into the future; Churchill was looking a mere half-century and his prognostication has not come true as, for the following seventy years, little progress was made towards cultured meat.

Reasons for slow progress Why has research into cultured meat proved to be so slow to progress, whereas cultured non-meat cells (like F. venenatum) have been so much more easily exploited? The fundamental reason lies in the complex nature of meat. Although taught as being com-

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F. E. Smith, who became First Earl of Birkenhead, was a prominent politician and author who published a prediction of meat produced in culture for his book entitled Life in 2030. It was published in London by Brewer and Warren in 1930. posed of striated muscle, meat is composed of a complex and interrelated system of tissue types. Striated muscle coexists with connective tissue (itself a complex community of fibrocytes and other cell types), adipocytes, tendons, nerve fibres, lymph and blood vessels.

Not only are these different tissues structurally important, but striated muscle itself is relatively tasteless: steak depends on the ‘marbling’, the extent and distribution of fatty tissues, and it is the fat that confers much of the taste on roast meat (McGee 2004, Ford 2011).

These facts are often overlooked. A patent registered in the Netherlands in 1999 described the production of cultured muscle cells in a three-dimensional structure that would be ‘free of fat, tendon, bone and gristle’.

Freedom from bone would be an advantage, whereas freedom from fat would give a bland and unappetising product. Publications on the possibility of producing animal cells in bulk frequently confined themselves to the culture of a single cell type (Varley and Birch, 1999). This is not a viable approach for the perfection of a meat product. Parallel research has been devoted to systems of producing nutriment on a large scale, and it is now clear that cyanobacteria are clear candidates as they have a protein content in dry matter of up to 70 per cent and can easily be grown in culture.

Photobioreactors would allow us to raise pure cultures of such organisms in large amounts as a feedstock for cultures of animal cells (Ugwu, Aoyagi

Two years after F. E. Smith’s account, the young Winston Churchill was asked to write on life 50 years in the future. He took his friend’s idea and rewrote it with chicken, instead, as the food source. The article appeared in The Strand magazine in London in 1932.

Professor Bernard Roelen of the Faculty of Veterinary Medicine at Utrecht University provides this low-power phase micrograph of images of porcine muscle stem cells cultured in vitro. No striated muscle is yet visible, so these cells are early in differentiation. and Uchiyama, 2008).

Within the last decade, research has begun in a few locations, notably in the Netherlands (at Utrecht, Eindhoven, Amsterdam and Wageningen) and also in the United States (South Dakota, South Carolina and Maryland). In 2005 the first comprehensive paper on cultured meat appeared (Edelman, McFarland, Mironov and Matheny, 2005). Progress has generally been slow, though in 2007 the Netherlands authorities announced an investment of 2m Euros in cultured meat; this remains the largest single funding for this area of research. In April 2008 the Food Research Institute of Norway organised a conference on cultured meat.

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comment & opinion ally better seen as reflections of the recent past, rather than indicators of what lies ahead. In particular, our reliance on current trends as indicators of the future is deeply flawed (Spedding, 1996). Can we confidently look to a near future in which cultured meat makes livestock farming obsolete? There are two reasons to suggest that this will not come to pass.

Oron Catts and Ionat Zurr are artists with the SymbioticA project at the Centre of Excellence in Biological Arts at the School of Anatomy and Human Biology, University of Western Australia. They have cultured sheep cells in vitro as a novel art-form.

However, when the National New Biology Initiative was announced by the National Academies in the USA in September 2009, there was no support for cultured meat. The pressures on conventional agriculture continued to grow; that same year, beef farming became so unprofitable in Ireland that the entire agricultural sector was said to be ‘near collapse’ (Ryan, 2009). If there is any time to press on with the development of cultured meat, it is surely now.

Environmental concerns Recent research suggests that the environmental benefits of cultured meat would be considerable. Research from Oxford and Amsterdam suggests that greenhouse gas emissions could be reduced by as much as 96 per cent,

compared to raising beef through conventional agriculture. Energy input could be cut by up to 45 per cent, using up to 96 per cent less water, and 99 per cent less land (Anon, 2011).

There are thus clear incentives from economic and environmental perspectives that should drive research ahead.

Yet there remains an agricultural dimension that we cannot ignore. We may be able to look to a future where energy could be tapped with high efficiency, and thus water supplies can be extended (through desalination) virtually without limit. It is possible to contemplate a future where the efficiency of agriculture is optimised, and where nitrogen, pesticide and carbon dioxide pollution are better controlled. Our ability to predict such changes is limited, and our prognostications are usu-

The author has recently discussed cultured meat for the BBC on The One Show with food critic Jay Rayner. After writing the first book chapter on the topic in 2009, he has been interviewed about the potential importance of cultured meat on radio and TV.

First is the sheer complexity of the research. As I have emphasised, the intricate structure of meat, as a product, makes it difficult to recreate ex vivo. There have been experiments to create a collagen lattice on which cells might grow, and even talk of mechanical systems to exercise muscle cells in culture so that they become stronger and more like those found in nature. It may be that the answer will take us towards the harnessing of stem cells and embryonic tissues. Since an axolotl (Ambystoma mexicanum) can regrow an entire limb, it is clear that the potential may exist in more highly evolved animal species. Furthermore, we know that stem cells generate meat within the embryonic calf, and it must be possible to reprise this process in vitro. Since meat develops – in all its histological complexity – in natural animals, it must surely be possible to recreate such conditions in the laboratory. Creating the entire system may be easier than turning to biofabrication (Ford, 2011).

The second reason to doubt the abandonment of rearing livestock is the importance of grazing animals in maintaining the environment. The countryside largely owes its appearance and its equilibrium to the grazing of herbivores, and the rearing of sheep and cattle with (to a lesser extent) goats and pigs in maintaining this environment in a form to which our civilisation has become accustomed.

Although we think of areas like the lush meadows of Germany and the wild vistas of the English Lake District as ‘natural and unspoiled’, they are entirely artificial. These romantic landscapes are the result of land management and grazing of farm animals over thousands of years. The alternative – re-forestation – would deny the public open landscapes for recreational purposes and the cover of widespread woodland could even pose a security problem.

Long-term importance of livestock It can thus be seen that the impact of cultured meat on agriculture will be

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comment & opinion less than one might at first envisage.

Progress in research has proved to be perilously slow. We need to step back from looking at ways of synthesising the structure of meat, and regard the system instead from the standpoint of the single cell from which complex tissues naturally arise. It may well be that mycoprotein will prove easier to produce in a meat-like form for many decades before cultured meat becomes a reality. Furthermore, even when cultured meat and meat substitutes are widely and inexpensively available, the role of conventional agriculture will remain of paramount importance. It is not simply to produce meat that we raise livestock, but also to manage the land. No matter how research proceeds, and even if the consumption of meat becomes a costly luxury rather than being seen as a birthright, livestock will remain of fundamental importance.

In time, cultured meat may become an essential part of our daily diet. Its importance will increase as the pressures upon food supply by a mushrooming population outstrip availability. It will certainly ameliorate the demands placed upon finite resources of land and inputs. But, no matter how much this industrial sector expands, it will not replace agriculture.

It is to the farming of livestock that we owe our surroundings, and no foreseeable research can change that fundamental fact.

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References Anon (2011) Reduced emissions from laboratory-grown meat, Laboratory News: 4, July.

Caulfield, Catherine (1985) The Rain Forests. New Yorker magazine pp 49, 79, 14 January.

Churchill, W. S. (1932) Fifty years hence, Strand magazine, December.

Edelman, P. D., McFarland, D. C., Mironov, V. A. and Matheny, J. G. (2005) In Vitro Cultured Meat Production, Tissue Engineering 11 (5/6): 659-662.

FAO (2006) Livestockâ&#x20AC;&#x2122;s long shadow â&#x20AC;&#x201C; environmental issues and options. Food and Agricultural Organization of the United Nations, Rome, 2006.

Ford, Brian J. (2009) Culturing Meat for the Future: Anti-death versus anti-life, [chapter in] Tandy, Charles (editor) Death And Anti-Death, 7, Palo Alto: Ria University Press.

Ford, Brian J. (2011) Critical Focus (6): Cultured meat; food for the future, The Microscope 59 (2): 7381.

McGee, Harold (2004) Food and Cooking. London: Hodder & Stoughton, pp 129-130.

Myers, Norman, and Kent, Jennifer (2005) The New Atlas of Plant Management. Berkeley and Los Angeles: University of California Press.

Pimentel, David (2001) Ecological Integrity: Integrating Environment, Conservation and Health.

Washington DC: Island Press.

Ryan, Ray (2009) ICSMA demands urgent action to avoid collapse in beef production, Irish Examiner, 23 September.

Smil, V. (2011) Nitrogen cycle and world food production. World Agriculture, 2 (1) 9-13.

Smith, F. E. (1930) The World in 2030, London: Brewer and Warren.

Spedding, Sir Colin (1996) Agriculture and the Citizen, London: Chapman and Hall.

Ugwu, C., Aoyagi, H., and Uchiyama, H. (2008) Photobio-reactors for mass cultivation of algae.

Bioresource Technology 99: 4021-4028.

Varley, J., and Birch, J. (1999) Reactor design for large scale suspension animal cell culture.

Cytotechnology 29: 177-205.

Various soy products used in vegetarian cooking

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book & report reviews Reviewed by Robert Cook The Hay on Wye Literary Festival, 2011

T

he festival is an annual event held in late spring. This year the main sponsor was the Daily Telegraph, a leading UK newspaper.

The festival format allows presentation and discussion of a wide range of topics from historical, social and financial events to books and literature.

In recent years there has been an increasing level of interest in how and where our food is produced. To reflect these trends, in 2011, the Festival organisers included topics on food production and public concerns about the use of certain agricultural practices, such as the debate, chaired by the Daily Telegraph's environment correspondent Louise Gray, on GM crops.

There has also been a series of farm walks, which were frequently over subscribed, and well attended by people who have no experience of agriculture.

World Agriculture was represented in a panel discussion supported by R M Jones, a Hay on Wye agricultural merchant and veterinary distributor. The panel comprised three members of the editorial board of World Agriculture (Professor Sir Colin Spedding, Professor Denis Murphy and Dr Christie Peacock) and Rosie Boycott, Chairman of the London Food Commission. The aim was to explore the primary issues around food security and the challenges associated with meeting mankindâ&#x20AC;&#x2122;s need for food and living space, without destroying the environment.

The event was attended by about 400 people. Each of the speakers outlined their expertise and views on how appropriate technology and production methods can influence and support more sustainable food production throughout the world. The session was ably chaired by Jonathon Harrington, who also organised the debate. The common theme of the speakers was the need to exploit appropriate technology while involving society in novel approaches to food production. Ideas were well pre-

sented to be readily understood, by the audience and all who seek a better understanding of the pressures and opportunities that face us all, wherever we live.

Questions and discussion from the floor raised many issues including those of agricultural biotechnology, production methods, oil and fertiliser resource depletion, food distribution and infrastructure. In less developed parts of the world such as Africa, the need to enable poor farming families to generate additional income, from the sale of surplus production, was recognized as a way to improve life standards.

A number of excellent questions were asked from the floor. Concerns about genetic engineering of crop plant were raised by many and it was clear there was antagonism, not only to the technology but also the way it is perceived to be exploited. Some of these views were at variance with the panel specialists, who said that appropriate plant techniques would facilitate improved use of natural resources, reduce pesticide use and allow for more efficient production systems for food and energy crops.

The key challenge of increasing food and biofuel production without destroying the environment seemed to pass some of the audience by.

Following this debate it is clear that potential solutions to these challenges are largely unrecognised. The facts are not generally understood by many citizens, while others reject new technologies. The reasons are complex.

In part this may be because man has evolved to suspect and sometimes reject new information, especially when it has been generated outside the defined social group. There are sound evolutionary and societal reasons why this may be the case, but these do not help us solve the problems.

We have a rapidly increasing population demanding high quality food, which needs an increased area for production. In addition there are increasing needs for housing and infrastructure. Increasing wealth allows more opportunity for leisure. That creates

an associated demand for and exploitation of wilderness areas in which people can relax and enjoy the natural environment. The challenge of global agriculture is to meet these conflicting needs without increasing the land area under cultivation. This requires an increase in output per unit area without further degradation of the environment; effectively we must increase the area of land available for wildlife both in the farmed and unfarmed environment. This has to be achieved whilst preventing further destruction of habitat and species loss.

These primary concerns were obviously behind many of the questions from the floor. They define the problem agriculture has throughout the world. We have a lot of information which will help the industry become more environmentally benign and reduce adverse effects on the environment. Appropriate and relevant information must be applied to production systems to improve habitat and biodiversity management.

Clearly, there is a need for open minds and consideration of how best to exploit the available technologies and to base these developments on sound science. That requires good quality research, where it is necessary, and for the results to be articulated precisely in a comprehensible way.

The potential benefits and disadvantages of new technologies must be identified and the problems minimised. It is urgent and essential that both the agricultural industry and society recognize they both have responsibilities to ensure this happens - it needs not just mutual respect and good communications, but also for results of good quality research to be respected and sound evidence accepted.

The editorial team of World Agriculture believe that the journal has a key role to play in identifying the problems and presenting and explaining potential solutions. This must be done in a manner that can be readily understood by all those who seek to gain a better understanding of the pressures and opportunities that face us all, wherever we live.

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book & report reviews Reviewed by Professor Séan Rickard, Cranfield School of Management,Cranfield, Bedford MK43 0AL, UK. Good Food for Everyone Forever Colin Tudge, Pari Publishing. paperback, 176pp, ISBN: 978-8895604-13-8

T

he main message of this book, declares Colin Tudge with a focus on the world’s growing population, is that we, … can feed ourselves to the highest standards both of nutrition and gastronomy; that we can do so forever … without cruelty to livestock, without wrecking the rest of the world and driving other species to extinction. This is no small claim, the more so as food production is not the major source of pressure on the world’s ecology and biodiversity. Leaving the hyperbole aside for the moment, this objective, according to Colin, is to be achieved by turning away from science-based industrialised farming to science assisted craft farming.

Unfortunately the book lacks an index, so one has to search hard to find a definition of science-assisted farming, which appears to be traditional early twentieth century farming or, as Colin grandly describes it, enlightened farming.

In order to convince at least this reviewer that his vision is practical, Colin needed to demonstrate that his scienceassisted craft farming would, when compared to modern industrialised farming, better feed the world’s enlarging and increasingly affluent population. To my mind this means it must be superior not only in terms of ecological sustainability, but also in terms of economic and social sustainability. Put simply, businesses producing food must, without subsidy, not only be profitable and capable of producing an acceptable standard of living for all engaged, but also they must deliver to society both the quantity and variety of food it desires at affordable prices. I am afraid that on this test Colin’s vision is not superior and I’m sorry to say that despite working for some eminent scientific institutions in his career, his arguments have more in common with Romanticism than the scientific rationalism associated with the word enlightenment.

The book, not particularly long at 173 pages, devotes far too much time to irrelevant considerations such as the risible

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observation that modern farming is all about profit, not food, and the irrational claims such as nasty people are in charge of the food system. According to Colin, enlightened farming eschews high-tech solutions, large-scale mechanical power, artificial fertilisers and pesticides. Note the use of the word artificial rather than the more correct, but less emotive inorganic. Paradoxically, the rather vague, if not vacuous description of enlightened farming is revealed in Colin’s attempt to differentiate it from organic farming.

Admitting that organic farming could not … provide good food for everyone forever … we are told that enlightened farming does not … ban technology a priori on first principles. Sometimes artificial fertilisers … can give a crop just the boost it needs to make full use of transient sunshine or rain.

Sometimes particularly recalcitrant pests can be controlled most efficiently, and with least collateral damage to other wild creatures, with pesticides.

This statement not only appears in conflict with his criticisms of modern farming, but also is ironically a description that could be accurately applied to modern, large scale industrial farming. Colin attempts to get round this contradiction by implying that the laws of economics do not apply to large-scale industrial farms which are the product of the flawed economic system in which businesses in developed nations operate.

Colin argues – without any supporting evidence – that the prevailing economic framework ensures that … the highest of technologies are deployed primarily or even exclusively by corporates, who in turn workhand-in-hand with powerful governments, so that in practice they become agents of social and political control.

This is fairly typical of the book’s approach, which I believe is devalued by such outlandish claims. In effect, the book is more a criticism of modernity and the democratic systems that govern advanced economies than a serious study of future food production, backed-up by data capable of supporting the viability of his vision. And it makes it difficult to take the author seriously; at best it reflects a breath-taking ignorance of even basic economic forces. At the very heart of a sustainable system must be sustainable i.e. profitable businesses. The high standards of living achieved by modern economies are based ultimately on the profit incentive that under the constraints imposed by competition ensure that rational

businesses only invest in technologies and production systems that they believe will provide a return on their investment; any other approach threatens the longer term viability of their businesses.

In this respect farming is a business, like any other, and this seems to be the nub of Colin’s criticisms. He argues that farming is special and it is undeniable that food is primus inter pares when it comes to the basic necessities of life. But to my mind, this is all the more reason for researching and applying scientific techniques – including modern scales of operation – that collectively lower the price of food and increase food security. And although the world has experimented with other systems we have yet to find one that is superior to competitive industries in rewarding market leaders with sufficient profits to finance continued improvements in productivity and quality.

The adoption of science-based modernity gave the world the Green Revolution in the 1960s which is generally credited with keeping food production growing faster than the world’s population. But with breath-taking audacity Colin claims that there was … a lot wrong with the Green Revolution. For one thing it put a lot of farmers out of work. And he goes on by increasing output it lowers agricultural prices. So now we have it. Colin’s idea of enlightened farming is one where the individual farmer, however efficient and costly, becomes the ultimate beneficiary and consumers are expected to pay for this in the form of higher prices and, as we shall see, reduced choice. This approach to business and its customers, as demonstrated by the former Soviet Union, is a recipe for inefficiency, lower living standards and ultimately collapse.

Colin seems to think that modern farming only leads to gluts. Well tell that to the one billion people who go to bed hungry and malnourished in our world today and nearer home, with levels of food inflation not seen for over a generation, I imagine most consumers would take strong exception to being asked to pay more.

In a free society individuals can spend their money on what they believe will give them the highest satisfaction. For some people this means devoting part of their income to high-priced speciality food products. That’s their choice, but to force high prices on the population, not to mention the unemployed, single parent families and pensioners, is both morally wrong and highly inefficient.

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book & report reviews What happens to the people employed in other industries if the population were forced to divert more of its income to food? Choice also brings us to the issue of meat consumption and this is central to Colin’s vision. He seems to imagine that in pre-history humanity lived mainly on plants and that the consumption of meat is mainly the result of farmers realising that … far more cash can be generated overall if wheat is … fed to pigs and poultry … as well as … cattle. But we were hunter-gatherers before we learnt to farm and more to the point, for most people the consumption of meat is a natural choice -its consumption improves their welfare and it is an important source of nourishment.

In truth Colin’s vision of providing good food for everyone is based on denying them the diets they can currently

afford and freely choose. His vision is to turn the clock back to some mythical rural idyll where populations are required to devote a much larger share of their income to food while suffering a dramatic reduction in the availability of meat and presumably dairy products. Just how Colin arrives at the conclusion that society would be better off i.e. happier, under his restrictive regime is not explained. I’m pretty certain that the many millions of people now being released from abject poverty in the world’s developing nations who are freely and willingly increasing their consumption of meat and dairy products would need some convincing.

Closer to home, he seems to fail to grasp that the welfare of populations rests to a large extent on the provision and exercise of choice.

Overall my sense in reading this book is

one of disappointment and this reviewer was not convinced that Colin’s vision of enlightened farming is credible. To my mind this book does not practically contribute to the increasing problem of feeding a growing and developing world in the twenty-first century. I will continue to put my faith in science and technology to feed the world to the highest possible standards at affordable prices. In the absence of scientific and statistical evidence that at least offers scope for testable hypotheses, Colin’s vision of enlightened farming remains just that; indeed, it is a dangerous vision that not only rejects modernity but would, like Pol Pot, impose a version of agrarian socialism whereby many urban dwellers would be required to relocate to the countryside to work on small-scale farms as labourers.

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letters Dear Editor Thank you for the copy of World Agriculture which I have been reading with interest – including the editorial, which resonated with my own thoughts.

One or two comments on the articles, which in places rather underlines your points, unintentionally I think.

I wish Vaclav Smil had gone on to say more about the uptake on Nitrogen Fertiliser in plants - why it is so inefficient and what might be done about it? Also, something about the actual carbon emissions involved in its production. Perhaps he could have a second innings?

I was a little puzzled by David Hughes’ article. I thought one of the grounds for unease was that people do not ingest traces of individual pesticides but rather a cocktail of many traces. He does not seem to address this issue.

The article about wheat yields and feeding the world rings true in what it says about wheat yields. However, wheat is primarily a crop of the ‘developed’ world which is not where the outcome of attempts to ‘feed the world’ will be decided.

There does seem to be considerable evidence that yields starting from a much lower plateua can, in many cases, be substantially raised by improved organic practices – without the issues of cost and indebtedness and unreliability of inputs often associated with the use of fertiliser and other inputs.

Christopher Jones, Agricultural Fellowship, Manor Farm, West Haddon, Northampton

Dear Editor Tony Greer’s paper “Planting Paradise –is there an option? brought back many memories of Sabah East Malaysia, where I was from 1969 to 1979 and where I worked in forestry and conservation.

Throughout the 1960’s and 70’s forestry was the main revenue earner

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for the States’ Treasury and forest reserves formed the greater part of the States land. Felling concessions were handed out with little regard for their future management and vast areas were felled. Managing a forest district, the largest role for myself and staff was to ensure the collection of the correct amount of royalty due and to fine those logging companies that left non-merchantable trees standing. No seed trees of the valuable species were retained to restock the forest. As a forester, this was a concern to me, but may now be unfounded as timber is no longer the main source of revenue for the State.

As a country develops and its road infrastructure increases and develops, new opportunities arise with the inevitable increase in population.

Whatever one may feel about that, the first charge on land in any country, must be the provision of food for its people.

I note from Greer’s map –Fig 2 – the considerable reduction to forest reserves, the expansion of areas available for agriculture and development and a welcome increase in the areas of land having protected status.

The potential for agriculture in Sabah was evident during the 1970’s when the Padi Board, the Sabah Land Development Board and the Agriculture Department was improving agricultural techniques and introducing new crops. I well remember collecting excellent tea from Kundasang, avocado pears and other fruit from Ranau. Temperate vegetables were grown at Bundu Tuhan –an all-year enterprise in the hinterland of Mt Kinabalu. Cocoa was introduced and coffee grown for village consumption.

Tropical fruit was abundant, but not grown in commercial quantities. There were also experimental fish ponds using tilapia – a species now found in our supermarkets and emanating from South East Asia. Rubber was tapped on old smallholding plantations, but demand was dropping.

Oil palm was the crop shown to have the best economic return and was being introduced. From an ecological

point of view, the plantations were sterile dark and dank, an environment enjoyed by rats who ate the fallen fruit and by snakes that ate the rats. I agree with Greer, that large oil palm plantations which cut off areas of forest from other areas, must have green corridors provided so as to allow fauna to travel between areas of forest to breed and seek food. Sadly some small animals will not cross roadways and tunnels may have to be provided. Not difficult when roads are being built as culverts could be placed in suitable places. Co operation between developers and ecologists would solve that problem.

I worked for most of my time in Sabah with the National Park service and the increase in protected areas is to be applauded. I am particularly pleased that many of the areas that I recommended for protection under the Parks law have been so gazetted.

Conservation areas must be respected and kept sacrosanct not only for obvious botanical and zoological purposes but especially in mountainous and steep regions to facilitate the regular supply of clear, clean water. This is necessary for the increasing population and for the country’s padi fields.

Rice will not flourish in silt laden water.

There is one other important reason for the protection of the Bornean forest. Plants provide the basis for many drugs and will continue to do so in the future. Lose the forest and lose the potential for discovering new life enhancing medicines. Hopefully, the exploitation of the crude oil reserves discovered in the South China Sea in the 70’s will provide sufficient revenue for Sabah’s advancement without the need for any further exploitation of that wonderful treasure house that is the forests of Borneo.

David Jenkins, previously “Assistant Conservator of Forests” and “Park Warden”, Sabah.

56 The Street, Barton Mills, Suffolk, IP28 6AA, England.

Reference: Tony Greer (2010) World Agriculture 1 (2) 18-22, Planting Paradise – Is there an Option?

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looking ahead

World Agriculture: potential future articles Professor Allan Buckwell The Future of British Agriculture Dr Martin Christie BP Biofuels, Biofuels and Industry Dr Andrea Graham NFU, British Agriculture Pauline Fitzgerald Australian GM Canola Dr Julian Little Bayer Crop Science, Agrochemicals Drs D Powlson, A. Whitmore & Professor K Goulding, Rothamsted Soil carbon sequestration to mitigate climate change: a critical re-examination to identify the true and the false Professor Swinbank Reading, Common Agricultural Reforms James Neville Volac International, Milk products Dr Helen Wallace Genewatch, GM crops Dr Derek Yach Vegetable oil production and health

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instructions

World Agriculture: problems and potential Instruction to contributors

W

e have made a change to the guidance for citations in the text. In future, references should be numbered sequentially in the text and listed in the Reference section in numerical order. We have made this change as we consider it makes articles easier to read and simplifies the text. In this Issue there is inconsistency in the way references are presented, but we hope to adopt the new system with effect from the Issue due in early 2012.

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4. Regan, D & Smith, A (1979) Electrical responses evoked from the human brain. Scientific American, 241, 134-52.

5. Smil, V (2011) Nitrogen cycle and world food production. World Agriculture, 2 (1) 9-13.

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