Practical hydroponics & Greenhouses

PRACTICAL

PONICS & GREENHOUSES The Commercial Growers’ Magazine

2016

SEPTEMB ER

ISSUE 171

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CITY FARMING: rise of urban agriculture AEROPONICS IN VANCOUVER

TOP END GREENING

Canada’s first commercial aeroponics farm

Hydroponics in Australia’s Northern Territory

NORTHERN EXPOSURE

OPTIMISING GREENHOUSE CONTROL

Greenhouse project in northern Canada

Avoiding plant stress in summer

Published by: Casper Publications Pty Ltd

From The Editor

(A.B.N. 67 064 029 303)

PO Box 225, Narrabeen, NSW 2101 Tel: (02) 9905-9933 info@hydroponics.com.au

Managing Editor Christine Brown-Paul c.brown.paul@gmail.com

Contributing Authors Steven Carruthers Rick Donnan

Advertising Sales Mark Lewis Tel: +613 9432-5428 Email: marklewis@hydroponics.com.au

Creative Direction & Design Steve (Gecko) Harrison Tel: +84 (0) 908 426-349 Email: sleepygecko@gmail.com

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The Rise Of Urban Agriculture

W

elcome to this new look issue of Practical Hydroponics & Greenhouses. We hope you like the new, refreshed design – thanks go to our new designer, Steve Harrison who has done a sterling job in giving PH&G an attractive makeover (Steve worked for the magazine about 15 years ago).

And on the subject of changes, I’ll be sitting in the editor’s chair while our trusty editor Steven Carruthers takes a long overdue and well-deserved break. Let me take this opportunity of saying hello to all our loyal readers and of course to new ones – many of you might recognise my byline, as I’ve been writing for the magazine for many years.

As populations increase and global resources become increasingly costly, market demand for local, fresh produce from sustainable sources is rapidly growing.

Addressing this situation has become a very popular pursuit across a range of industries, not least agriculture and sustainable horticulture.

In this issue we trace the rise of city farming – also known as urban agriculture – a phenomenon whose widespread uptake globally is at the vanguard of a silent revolution in the way our food is produced. Embracing practices such as rooftop farming, hydroponics, aquaponics, aeroponics and the like, city farming is the farming of the future.

One country in particular, which is championing the principles of urban agriculture and sustainability is Canada with one of its largest cities, Vancouver, working towards being the greenest city in the world by 2020.

Vancouver is also home to Canada’s first commercial aeroponics farm, using ’space-age’ tech to grow produce for local restaurants and markets.

Meanwhile, in a remote hamlet in northern Canada, an ambitious greenhouse project is helping to bring healthy fresh produce to the local community.

Finally, closer to home we head off to the Top End in Australia’s Northern Territory to check out an innovative project, which has seen a hydroponic greenhouse growing green leafy vegetables and herbs for the benefit of the local community.

Do you have a story for us? We welcome stories for publication with a focus on hydroponics, greenhouse, IPM, crop management and horticulture lighting technology. Let’s hear your ideas.

www.hydroponics.com.au ISSN 2202-1485

Enjoy this issue!

Christine Brown-Paul Practical Hydroponics & Greenhouses . September . 2016. 3

A Magazine for

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PONICS

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& GREENHOUSES ISSUE 171 :: SEPTEMBER 2016 :: THE COMMERCIAL GROWERS’ MAGAZINE

Features City Farming part one ..........................16 City farms are growing in significance throughout Australia and the rest of the world. To be continued next month.

Aeroponics in Vancouver ......................24 Canada’s first commercial aeroponics farm uses ‘space-age’ tech to grow produce for local restaurants and markets.

City Farming

Northern Exposure .............................42 An ambitious greenhouse project in northern Canada is bringing healthy fresh produce to the local community.

Top End Greening ...............................56 In Australia’s Northern Territory, a community initiative is growing fruit and vegetables in a hydroponics greenhouse.

Practical Iron: deficiency & toxicity ..................30 Recognising deficiencies or excesses of mineral elements is key to diagnosing nutritional disorders.

Aeroponics in Vancouver

Japanese Harvest ...............................36 Both pests and their natural enemies respond to the colour and intensity of light.

Optimising Greenhouse Control .........48 Control of the greenhouse climate during summer demands a different strategy to avoid plant stress.

Measuring Crop Temperature ...........50 Measuring temperatures of plants and fruit is important in achieving optimum production and quality.

Iron Deficiencies & Toxicity

whether in editorial matter or in feature articles or in advertisements is not published on the basis that the Publisher accepts or assumes liability or responsibility to any reader of the magazine for any loss or damage resulting from the correctness of such information.

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Departments From the Editor .....................................3 News & Products ...................................6 Reader Inquiries..................................12 Cover: Across the globe, rooftop gardens like this one are part of a silent revolution in the greening of our cities.

Japanese Harvest

Practical Hydroponics & Greenhouses . September . 2016. 5

News & Products BlUePRinT FOR gROwTH COUlD insPiRe veg inDUsTRy The vegetable industry has received a blueprint for growth, with a new report outlining key areas in which the Australian vegetable industry can tap into consumer and retail trends to increase consumption of fresh vegetables.

The report highlights innovations in the global fresh produce industry, including QR code shopping kiosks in the Philippines, “grazing areas” to let shoppers sample products in British supermarkets, AmazonFresh grocery home delivery in the USA, and shopping trolleys with interactive touchscreens in South Korea.

“This report will help Australian growers and retailers gain a new perspective on the Australian market by giving them insights into innovative developments in international industry,” said AUSVEG spokesperson Shaun Lindhe.

“It could inspire some fresh ideas on how to translate successful overseas initiatives into increasing vegetable consumption among Australian consumers, which in turn

could lead to growth in our industry.” AUSVEG is the leading horticultural body representing Australia’s 9,000 vegetable and potato growers. “Social factors like an increased focus on healthy eating have created a great opportunity to highlight the health and nutritional benefits that fresh Australian vegetables can bring to a wellbalanced diet,” said Mr Lindhe.

“Meanwhile, technological advancements are making it easier for vegetable growers and retailers to meet consumer needs, such as by offering pre-prepared product formats – like pre-cut veggie mixes or pre-packed lettuce leaves – so that consumers can grab and go.”

The report, part of the Project Harvest study commissioned by Horticulture Innovation Australia, brings together industry insights from consumer research group Colmar Brunton from February 2015 to May this year to offer vegetable growers bite-sized snapshots of consumer behaviour trends.“There are major social and technological factors driving changes to the

6 . Practical Hydroponics & Greenhouses . September . 2016

behaviour of modern consumers, and the insights in this report could help growers and retailers to get on the front foot and capitalise on the potential of these changes to increase fresh vegetable consumption,” said Mr Lindhe.

veRTiCAl FARming glOBAl mARkeT OUTlOOk (2015-2022) According to Stratistics MRC (Market Research Consulting), the Global Vertical Farming Market was estimated at $1.15 billion in 2015 and is poised to reach $6.31 billion by 2022, growing at a compound annual growth rate (CAGR) of 27.5%.

Increasing inclination towards healthy food without pesticides, rising urban population and no weather related crop failures are the factors favouring the market growth.

However, limited variety of crops, high initial investment and lack of technical insights are the restraining factors for the vertical farming market. Rapidly increasing city populations have made farmland inadequate for cultivation, so there is a need for alternative farming

FlOweR BOAT TO JAPAn

techniques, which acts as an opportunity for vertical farming.

Based on ‘functional devices’, the lighting segment is likely to dominate the vertical farming market during the forecast period, due to the replacement of traditional lighting systems by energy-efficient LEDs. Functional devices include elements such as climate control equipment, hydroponic components, sensors and other growth mechanisms.

Many advantages associated with hydroponics such as recycling of water and reduced nutrition costs, are expected to exhibit considerable growth over the forecast period. The Asia-Pacific region is projected to hold the largest share of the global vertical farming market due to increasing demand for high quality food, rising urban population and

government incentives in China, Singapore, and Japan.

Some of the key players in the global market include Aerofarms, Agrilution, American Hydroponics, Everlight Electronics, Farmedhere, Green Sense Farms, Hort Americas, Illumitex, Inc., Koninklijke Philips NV, Moflo Aeroponics, Nihon Advanced Agri Corporation, Pacific Group, Philips Horticulture Lamps, Sky Green and Spread Co. Stratistics MRC is a US-based research and consulting service with in-depth knowledge of different industries. The company explores market trends and draws insights with assessments and analytical views.

The full PDF-format report can be purchased at: www.strategymrc.com starting at USD $4,150 for a single user licence.

8 . Practical Hydroponics & Greenhouses . September . 2016

Shipping native flowers by sea instead of air could substantially reduce freight costs and add directly to grower returns.

More than 50 per cent of Australian production of native flowers and foliage is exported, mostly to the Japanese market – but presently by air. However, rising costs and increased competition threaten the industry’s viability.

Reductions in travel time to nine days have helped make sea freight a real option for the industry. Unlike airfreight, temperature can be accurately controlled during sea shipping.

NSW DPI, in co-operation with Maersk Sealand, recently conducted a trial shipment of Australian grown flowers and foliage to Japan. Quality was evaluated when the products arrived in Tokyo.

As with the shipment of vegetables by sea to Dubai, reported in the April edition of Agriculture Today, the product arrived fresh.

However, for flowers there are also some problems to overcome, including clear labelling, paperwork and shipping documentation.

According to DPI’s Gosford-based project leader, Jenny Ekman, the project highlighted a number of supply chain issues within the industry.

“There is a clear need for reliable product quality standards, standardised packaging and labelling, clear communication between supply chain members and

accurate market feedback to growers,” Dr Ekman said. Other trial results were positive.

Products such as NSW Christmas bush and Tasmanian rice flower suffered little quality loss during shipping and received good prices.

All of the foliages trialled looked as fresh when they came out of the container as when they were packed.

Kangaroo paws benefited from being shipped upright in containers of water.

Flowers are normally packed dry in cartons for export. However, according to Dr Ekman, kangaroo paws could well arrive in the Japanese market in better condition after nine days cool storage in water, than after two days dry storage under warmer temperatures, as occurs during air freight.

Sea freight was approximately 61pc of the cost of airfreight.

Returns at auction were reduced by approximately 10pc compared to air

freighted products, suggesting that this shipping method could improve returns to growers.

For further information contact: Dr Jenny Ekman, Gosford, 02 4348 1942.

eATing mORe veggies wOUlD BRing $100m in HeAlTH sAvings: RePORT A report released recently has found if Australians ate just 10 per cent more vegetables per day, all levels of government could reap $100 million per year combined in health savings.

Commissioned by Horticulture Innovation Australia (Hort Innovation) and delivered by Deloitte Access Economics, the report also revealed that more than 90 per cent of Australians fail to eat the recommended intake of vegetables per day.

Currently, the average Australian is eating just 2.3 serves of vegetables per day, far short of the recommended five serves or 375

grams. Hort Innovation Chief Executive John Lloyd said the research indicates the nation could benefit significantly if the current intake of 174 grams was boosted to just 190 grams.

“If Australians ate just a handful more of broccoli or two extra carrots per week they would reduce their risk of some cancers and cardiovascular disease,” he said.

“In economic terms, based on detailed modelling, all levels of government would also stand to benefit through an estimated $100 million in health expenditure savings per year combined.

“On top of this, a 10 per cent increase in national vegetable consumption would further support vegetable growers nationally with an estimated $23 million per year in additional profit.”

The report also showed: Men eat fewer vegetables than women, with 3.8 per cent of males consuming

Practical Hydroponics & Greenhouses . September . 2016. 9

adequate vegetables compared to 10.2 per cent of females.

Internationally, Australia was ranked 63rd in the world by apparent consumption of vegetables per capita.

Tasmanians are Australia’s highest vegetable consumers but still only 12 per cent of the local population are consuming the recommended daily intake.

Vegetable consumption generally increases with age, peaking among 75-84-year-olds.

‘Fruiting vegetables’ such as corn and pumpkin are the top vegetables consumed by most Australians (excluding potatoes).

gROw UP TO 15 FisH AnD 20+ vegeTABle PlAnTs in yOUR BACk yARD Suburban Farmer is a Perth-based, family-run business that promotes self-sufficiency in your backyard with fresh vegetables, eggs and fish amongst the produce you can grow with their help.

The company installs quality aquaponics systems of various sizes capable of growing species such as barramundi, marron, trout, yabbies, black bream and silver perch.

“We can also retrofit your existing water feature or pond by adding a water-wise vegetable garden filter (growbed),” said managing director Jason Cleary.

“With a tested simple design, our

systems are easy to maintain, inexpensive to run and can fit in the corner of the patio or backyard. You only need three square metres in order to grow 25 fish and 30 to 50 vegetable plants.

“Systems come complete with everything you need to raise fish and grow vegetables. “ For further information contact: Jason Cleary PO Box here 0414 752 576 E: jason@suburbanfarmer.com.au

AUsTRAliA AnD inDiA JOin FORCes in $7m eFFORT TO sAve Bees Australian and Indian researchers are pooling efforts – and funding – to safeguard fruit and vegetable crops, and insect pollinators, in the face of challenges such as honeybee habitat loss and disease.

The $7 million five-year program will be delivered by some of the country’s top researchers from Western Sydney University, Bayer CropScience, Syngenta Asia-Pacific and Greening Australia, and executed with support from Horticulture Innovation Australia through its strategic co-investment Pollination Fund. The multifaceted project will operate in parallel to the All India Coordinated Research Program (AICRP) of the Indian Council of Agricultural Research on Honey Bee Health and Training, which is being conducted through 26

10 . Practical Hydroponics & Greenhouses . September . 2016

research centres across India.

AICRP India project coordinator Professor RK Thakur said the research will help conserve diverse pollinator resources and enhance the productivity of agricultural and horticultural crops in both India and Australia.

“Increased floral biodiversity on farms can stabilise pollinator populations and contribute to resilience and profitability of farm operations,” he said.

Western Sydney University project leader Professor James Cook said the research will develop new strategies to help landowners and growers safeguard the health of pollinating insects.

“Given the fundamental importance of bees and other pollinators to successful crop harvests and the health of natural ecosystems, there is a significant lack of detailed knowledge about their overall health and wellbeing,” he said.

“Researchers will map the health of pollinating insects such as honeybees, native stingless and solitary bees, and outline the resources needed to support them.”

Prof Cook said protecting the future of bee colonies and sourcing other pollinators has never been more important.

“Australia is the last country in the world that is free of the parasitic Varroa mite that is thought to be a major factor behind widespread colony collapses in the United States, Canada, Europe and Japan,” he said.

“These tiny mites attach themselves to bees inside hives and feed from the bees, causing open wounds and transmitting viral diseases. If Varroa takes hold in Australia, it will decimate populations of both managed and wild European honey bees, and we will then be far

more reliant on native pollinators.”

Horticulture Innovation Australia Chief Executive Officer John Lloyd said the project will help give growers, and the general population, increased certainty about the future of Australian fruit and vegetable production.

“This exciting $7 million project will deliver ground-breaking research that will ultimately, help position Australia as a world-leader in bee health and pollination research and development,” he said.

“For this reason, it is crucial that we put practical measures in place to support honey bee health and identify and develop new pollination opportunities and techniques.”

For further information contact: Horticulture Innovation Australia Ltd Level 8, 1 Chifley Square NSW 2000 Aust.

T: 61 2 8295 2300 F: 61 2 8295 2399 www.horticulture.com.au

mODUlAiR gReenHOUses UnDeR COnsTRUCTiOn in FRAnCe For decades Netherlands-based company, Van der Hoeven has proven to be a leading player in the field of complete solutions for horticulture projects. With its new ModulAIR concept, Van der Hoeven introduces a flexible, modular climate system for a variety of climate conditions.

ModulAIR is a product in development. In the last couple of years, areas such as light, efficiency of the fans and integration of the components have been optimised.

A collaboration between Van der Hoeven and HortiNed began in 2013 and is now starting to bear fruit.

Currently, 250,000 m² of ModulAIR greenhouses are under construction, including a CATE research station, with various climate solutions in the Marmande region of France. Most of the projects are located in the South of France, from the Bordeaux region and further south, however, the company is also working to find an appropriate solution for the market in Brittany. Here, environmentally friendly cultivation, pesticide-free cultivation, energy efficiency and higher production outputs play a role in finding the best solution.

The first project is expected to be achieved next year. Besides ModulAIR greenhouses, HortiNed and Van der Hoeven are also building many traditional greenhouses in France.

For further information contact: Van der Hoeven Horticultural projects T: +31 88 262 66 66 info@vanderhoeven.nl www.vanderhoeven.nl b

Practical Hydroponics & Greenhouses . September . 2016. 11

Reader Inquiries Thanks for your letters

Rick Donnan

I have a few suggestions to help us better identify your problems, and hence give the most appropriate answers: • Some of your letters are very long. This is not a problem, but they will have to be edited down before publishing.

• Please keep your actual questions short, and limit yourself to one, or at most two, questions.

• Please comment as to whether you are a hobbyist or a commercial grower, and what crop you are growing.

• Please describe at least the basics of your system, especially whether you recirculate or not.

This is vital information, but often overlooked. Other useful information, if known, would be: media type, container size and depth, channel size, length and slope, solution volume per plant.

• For irrigation and nutrient questions, please describe your typical irrigation pattern over a day, plus how and when your solutions are made up. If you have had any analysis done, such as your raw water, please attach a copy.

• Include any extra information you wish.

Address your inquiry to: PH&G PO Box 225, Narrabeen, NSW 2101 AUSTRALIA Int: +612 9905 9030 Email: info@hydroponics.com.au

QUesTiOn should i use twin skins if building a polythene greenhouse?

I am considering building a single span poly house to grow speciality cucumbers. I have a friend who says twin skins are essential if I plan to heat the greenhouse, but others warn that the twin skin loses light. What do you recommend?

AnsweR Twin skin greenhouses The main reason for using twin layers of flexible plastic covering in a greenhouse is to reduce the heat loss through the greenhouse cover. Two sheets of plastic are installed plus a fan to pump air to inflate the space between the two sheets. This gives a layer of air, which acts as an insulating blanket. It performs better if thin. If too thick a layer of air, convection currents will ensue and this air movement will increase heat loss.

It is important to find a balance between energy saving and maximum light distribution.

12 . Practical Hydroponics & Greenhouses . September . 2016

The fan needs to use outside air because the air inside the greenhouse usually has a higher absolute humidity than outside air because of plant transpiration. This means that the inside air has a higher dew point and consequently, fogging and condensation could occur within the enclosed envelope. Fan pressure should be low at between five and 15mm of water. Higher pressures can lead to the plastic stretching and weakening, and lower pressures lead to the skins flapping and potentially being damaged.

It is possible to use double skins on the roof of the greenhouse and/or walls. The best type of structure would also have roof vents, and depending upon the design, these would also be double skin, but may be single skin. The full job would be to twin skin everything, that is, the roof, the roof vents and all the sidewalls.

The downside to twin skins is the reduction of light coming into the greenhouse. The common rule of thumb is that 1% loss of light = 1% loss of yield. Say the plastic in your

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Because there is already enough uncertainty.

Against the number of advantages of twin skin covers, must be weighed the extra reduction in light.

greenhouse has a high light transmission of 90%. In a twin layer this is reduced to 90% x 90% = 81% transmission. That is, the loss of an additional 9% light compared to single skin.

The result is a significant loss in photosynthesis and hence, a 9% loss in yield.

Thermal screens Another alternative to twin skins is to keep a single skin, but to add a movable thermal screen, which is closed at night.

This has the advantage that the screen remains retracted during the day and hence, doesn’t reduce light transmission (other than the extra shading of a few per cent because of the space taken up by the retracted screen). Its other advantage is that the screen reduces the volume of greenhouse air that needs to be heated.

Note that there are a wide range of screen types, some of which can operate as both a shade and a thermal screen.

Energy requirement single and twin skin We need to calculate the difference in heat energy required for each of the three major options. These are: Single skin polythene only Single skin polythene + thermal screen Twin skin polythene.

Twin skin polythene The annual heat loss from a greenhouse can be calculated from the climatic data for the location of the greenhouse.

The measure used is ‘degree hours’, that is, the total differences between the minimum required greenhouse temperature and all lower outside temperatures each hour for the whole year. These have been converted to give the energy required for the year for 14 climate zones within Australia. I have used graphs of this data published in Greenhouses edited by Dr Keith Garzoli, AGPS 1988.

Available from Casper Publications.

14 . Practical Hydroponics & Greenhouses . September . 2016

As examples, I have taken the locations as Brisbane and Hobart (latitudes 270 S and 430 S, respectively). I have also taken the minimum greenhouse temperature to be 190 C. BRISBANE (warmer climate) annual heating requirement: Single skin = 240 MJ/m2.

Single skin + thermal screen = 150 MJ/m2.

Twin skin = 150 MJ/m2.

HOBART (colder climate) annual heating requirement: Single skin = 1250 MJ/m2.

Single skin + thermal screen = 800 MJ/m2.

Twin skin = 850 MJ/m2.

Financial evaluation Notice that there is virtually no difference between the heat losses between twin skin and the single skin plus thermal screen.

A simple financial evaluation comes down to evaluating the additional costs associated with each of the different options. That is: Single skin: The cost of the additional heat energy required.

Single screen + thermal screen: The cost of installing and maintaining the thermal screen.

Twin skin: The extra cost of installing the second skin plus the associated 9% loss in yield.

Sidewalls Even if using single skins on the roof of the greenhouse, with or without thermal screens, the use of twin skins on sidewalls can be effective. This is because they reduce heat loss without significantly reducing the light input into the greenhouse. This especially applies to smaller greenhouses where the sidewall area is a significant proportion of the heat loss surface.

It is important to find a balance between energy saving and maximum light distribution. b

This single skin greenhouse features ridge venting.

Practical Hydroponics & Greenhouses . September . 2016. 15

CiTy FARms ARe gROwing in signiFiCAnCe THROUgHOUT AUsTRAliA AnD THe ResT OF THe wORlD. THey ARe seen As PART OF A glOBAl sHiFT TOwARDs sUsTAinABle lOCAl COmmUniTies COmmiTTeD TO sOURCing FResH FOOD AnD ACTively PARTiCiPATing in eDUCATiOnAl PROgRAms THAT ReinFORCe THe COnneCTiOn BeTween PADDOCk AnD PlATe. HyDROPOniCs is PlAying A key ROle in THis gROwTH.

By CHrIsTIne Brown-PAul Worldwide, city farming (or urban agriculture) is growing in profile with a recent landmark study finding that areas of land in and around cities are becoming increasingly important as centres of food production.

The study, which was published in the November 2014 issue of the journal Environmental Research Letters, is the first global assessment to quantify urban croplands and

document the resources they consume, namely water, which has both environmental and food safety implications.

The analysis was a collaboration between the International Water Management Institute (IWMI,) under the CGIAR Research Program on Water Land and Ecosystems, the University of California-Berkeley, and Stanford University.

CGIAR (the Consultative Group for International Agricultural Research) is a global partnership that unites organisations engaged in research for a food secure future.

According to the study, food production worldwide is taking on an increasingly urban flavour, with 456 million hectares— an area about the size of the European Union— currently under cultivation in and around the world’s cities, challenging the rural orientation of most agriculture research and development work.

The study is the first global assessment to quantify

CiTy FARming Part One

Vancouver aims to be the world’s greenest city by 2020.

16 . Practical Hydroponics & Greenhouses . September . 2016

urban croplands and document the resources they consume, namely water, which has both environmental and food safety implications.

“This is the first study to document the global scale of food production in and around urban settings and it is surprising to see how much the farm is definitely getting closer and closer to the table,” said Pay Drechsel, a scientist at the IWMI and co-author of the study.

The authors said their goal was to highlight the role of urban farming in the quest for food security and sustainable development, given the largely rural focus of most agriculture research and policy work. In addition, they wanted to spotlight the starkly different view of urban farming one finds in the developed and developing world.

“We see this dichotomy where urban farming

in wealthy countries is praised for reducing emissions and enhancing a green economy, while in developing countries, it can be regarded as an inconvenient vestige of rural life that stands in the way of modernisation,” Mr Drechsel said.

“That’s an attitude that needs to change.”

Co-author of the study, Eric Lambin, is a Stanford Woods Institute senior fellow and the George and Setsuko Ishiyama Provostial Professor in environmental Earth system science at Stanford.

“The geographic boundary between urban and rural areas is more fuzzy than often assumed: within and around cities, one finds highly intensive forms of agriculture that benefit from the labour availability in cities and the close proximity to urban markets,” Professor Lambin said.

Practical Hydroponics & Greenhouses . September . 2016. 17

URBAn AgRiCUlTURe AnD FOOD seCURiTy Pay Drechsel and his colleagues note that urban agriculture, in addition to contributing to food security, puts marginal lands into productive use, assists in flood control, increases income opportunities for the poor and strengthens urban biodiversity.

Overall, the researchers found that of the 456 million hectares of land (about 1.1 billion acres) being farmed in urban proximity, most lies just outside the city proper— within 20 kilometres. However, 67 million hectares (around 166 million acres) is being farmed in open spaces in the urban core. These findings reinforce previous studies documenting that up to 70% of households in developing countries are engaged in some type of farming and food production.

Related studies also have revealed that urban farms do not typically grow ‘calorie rich’ cereals such as wheat or rice. Instead, they most often produce high-value and nutritionally important perishable crops like fresh vegetables. In sub-Saharan Africa, for example, urban farmers supply up to 90% of the leafy salad greens

consumed in the region’s rapidly growing cities.

“In urban areas of Ghana, every day there are about 2,000 urban vegetable farmers supplying greens to 800,000 people,” Mr Drechsel said.

Moreover, most of these farmers irrigate their fields with highly polluted water. In Accra, for example, up to 10% of household wastewater is indirectly recycled by urban vegetable farms.

“These farms are now recycling more wastewater than local treatment plants,” Mr Drechsel said.

iRRigATiOn AnD wATeR UsAge On URBAn FARms The study finds that within cities alone there are roughly 24 million hectares of land under irrigation, and 44 million hectares that are rain fed. Those numbers are larger than respective total area under rice in South Asia, the cultivated area under maize in sub-Saharan Africa, or the cultivated croplands of the cerrados and llanos in Latin America and the Caribbean.

The researchers note that in the not-too-distant future, the prospect of irrigated urban croplands will play a

The Pocket Farm west Philadelphia

18 . Practical Hydroponics & Greenhouses . September . 2016

Chicago is home to the world’s first airport aeroponic garden at Terminal 3 at o’Hare International Airport.

larger role in more densely populated and/or increasingly water scarce regions such as South Asia.

The study observed that water usage by urban farms is not just a water recycling opportunity, it also can potentially become a food safety concern. For example, while irrigation allows consumers to get vegetables in the dry (lean) season, it also potentially exposes them to pathogens that can be present in the poorly treated water. However, the researchers said the food safety issues, while important, can be addressed to maintain the many valuable and under-appreciated contributions of urban farms.

DATA PAinTs THe PiCTURe The richly detailed portrait of urban farming presented in the study was derived in part from new data and maps generated by researchers at the University of Frankfurt and at the US National Aeronautics and Space Administration (NASA), which use satellite imagery and other sources to provide greater insights into the distribution of croplands globally. The authors say their study may have actually underestimated urban

croplands, as they focused on farmed areas in and around cities with at least 50,000 residents, even though many countries define areas with smaller populations as ‘urban’.

“This is an important first step toward better understanding urban crop production at the global and regional scales,” said Anne Thebo, an environmental engineer at the University of California-Berkeley, who was the lead author of the study.

“In particular, by including farmlands in areas just outside of cities we can begin to see what these croplands really mean for urban water management and food production.”

Researchers say further study is warranted, exploring how crop production in and around cities affects ecosystem services in the rural-urban corridor and, in particular, what it means for managing water resources and improving food safety.

gReening THe wORlD’s CiTies The importance of ‘living green’ was brought to the attention of 16 countries at an International Practical Hydroponics & Greenhouses . September . 2016. 19

Farmed Here In Bedford Park, Chicago is not only the first organically certified indoor but also the largest indoor farm in north America.

Green City Conference in March this year. Organised by the International Association of Horticultural Producers (AIPH) and the Canadian Nursery Landscape Association (CNLA), the event was held in Vancouver, Canada. Since 1948, AIPH has united horticultural producers in an international community that thrives to this day.

Topics on the agenda included: Becoming the greenest city in the world, Using plants to manage stormwater threats, How to implement greening and change the public mindset, How buildings need to be able to ‘heal people’ and The benefits of a ‘Green City’.

Vancouver is working towards being the greenest city in the world by 2020. The former Mayor of Vancouver and Premier of British Columbia, Mike Harcourt, opened the conference by demonstrating that Vancouver has had an environmental focus since the 1980s when back then they were already looking at alternatives to cars and different energy sources as well as planning the city to be more sustainable. For a long time it has been a philosophy of Vancouver that there is a close link between greening the city, economic sustainability and liveability. Vancouver Urban Forest Strategy, which has a target of achieving 22% tree coverage in the city by 2050, was introduced by Bill Stephen from the City of Vancouver. In a densely populated city this is a big challenge as growing space has reduced with city development, but initiatives such as ‘Street tree cooling networks’, the ‘citizen forester’ and planting 150,000 trees by 2020, will all help in reaching the goal. Local examples of green city projects were provided from the University of British Columbia, including the East Clayton 20 . Practical Hydroponics & Greenhouses . September . 2016

Neighbourhood Project, introduced by Patrick Condon and Sara Barron, and how plants have been used to manage stormwater threats presented by Daniel Roehr.

A ‘Living Garden’ concept, integrating plants with water and biodiversity, along with other practical examples of how to implement greening and change the public mindset towards the subject was discussed by Egbert Roozen, Director of the Dutch Landscape and Garden Contractors Association from The Netherlands. A powerful case for ‘living buildings’ and ‘living green infrastructure’ and how buildings need to be able to ‘heal people’ was given by Steven Peck, President of Green Roofs for Healthy Cities. His organisation is aiming to secure one billion square feet of green roofs in North America by 2022. Many cities across China have invested billions of dollars in becoming greener at a scale that vastly exceeds other countries. Professor Li Xiong, Dean of the School of Landscape Architecture at Beijing Forestry University, China, has been closely involved in developing the standards for Chinese Garden Cities. The standard for garden cities is tough and implemented firmly, but the social, environmental, health and economic benefits in China’s Garden Cities are plain to see. Examples of cities around the world that have used an International Horticultural Exhibition to stimulate city greening, were presented by Karen Tambayong from Indonesia who is Chair of the AIPH Green City Committee. Such exhibitions are a great way for any city to distinguish itself as green and reap much broader benefits too. A tool to measure and quantify living green infrastructure assets was illustrated by Paul Ronan from Ontario Parks. Once you can measure and value green infrastructure then the argument for having it becomes much stronger. During the conference CNLA (Connecticut Nursery & Landscape Association) also launched its new Landscape Standard.

Summarising his thoughts on the conference, the chairman, Bill Hardy, commented: “I am delighted that this event has been so successful. We have brought together a truly international audience to debate these critical issues for the future of our cities. We want this conference to be a part of the process of getting more cities to embrace living green. I was pleased that we could also tour the best green examples around the city and that Vancouver can provide real inspiration for cities everywhere.”AIPH Secretary General, Tim Briercliffe commented: “In an increasingly urbanised world the importance of city greening just keeps getting bigger. The intelligent use of plants in the urban landscape can address so many problems that cities face

Chicago- based company urban Till supplies herbs and microgreens to more than 200 clients in the area.

and this conference has illustrated that so well. We will continue our work to promote the benefits of city greening as we prepare for the next AIPH International Green City conference, which will take place in Antalya, Turkey in September this year.”

CHiCAgO: URBAn AgRiCUlTURe CAPiTAl OF THe Us Chicago boasts many small community gardens and multi-million dollar indoor farms, and is leading urban farming renaissance in the US. With 821 growing sites across the city, Chicago is also home to the world’s first airport aeroponic garden at Terminal 3 at O’Hare International Airport.

In 2011, the Chicago Department of Aviation (CDA) installed an aeroponic garden in the mezzanine level of the O’Hare Rotunda Building.

Ticketed airport visitors can view the garden while relaxing or enjoying a meal in the comfortable lounge area—often, the meal will contain some vegetables and herbs grown just a few feet away.

O’Hare’s aeroponic garden features plant roots suspended in 26 towers that house over 1,100 planting spots. A nutrient solution is regularly cycled through the towers using pumps so that no water evaporates or is wasted, making the process self-sustaining. No fertilisers or chemicals are used in the garden.

“Producing and purchasing locally grown foods supports the CDA’s commitment to sustainability by strengthening the local economy and job market, providing a unique learning opportunity for travellers, and reducing urban sprawl, traffic congestion, habitat

loss, and pollution from the transportation of produce,” said a CDA spokesperson.

In Bedford Park in Chicago, Farmed Here is not only the first organically certified indoor vertical aquaponic farm in Illinois, but also the largest indoor farm in North America. The two-storey facility currently sits on a 90,000-square-foor site of a formerly abandoned warehouse in the outskirts of Chicago.

Farmed Here’s produce is grown in a sustainable environment where 97% of fresh water is reused and plants are grown without the use of herbicides or pesticides.

The farm’s LED lighting system obviates the need for natural sunlight to grow.

Farmed Here CEO Nate Laurell says that investors are becoming increasingly interested in indoor farming as LED lighting and solar energy drive operation costs “cheaper and cheaper.”

Projections show that the global vertical farming market is expected reach $3.88 billion by 2020; a figure that Nate Laurell says is lower than what it actually might be.

“The greens market for Chicago land alone is $400 million dollars,” he said.

“Given the market is so big, and it’s so top of mind for people where their food came from and how it was grown, even if only some fraction of that food grew in an indoor environment, when you extrapolate to other cities in the US and abroad, you’d easily reach $4 billion; $4 billion seems light.”

Mr Laurell explained that vertical farming is ideal

Practical Hydroponics & Greenhouses . September . 2016. 21

compared to outdoor agriculture, as it produces local food year-round, has a small geographic footprint, a high yield per cubic foot ratio and slashes food miles.

“On the consumer side, there is a large demand for local food, food grown close to the city. People want to know where their food comes from and cut out transportation miles to get more freshness,” he added.

Farmed Here plans to expand to up to 15 cities within the next decade.

Another indoor hydroponic farm is Urban Till. Located on the west side of Chicago, the company supplies herbs and microgreens to more than 200 clients in the area.

CEO Brock Leach says that Urban Till will expand nationally and internationally with its proprietary hydroponics this year.

“We have an intellectual property to produce more water from the air than what we use in the farm at no additional cost of electricity, and we’re able to produce 22 . Practical Hydroponics & Greenhouses . September . 2016

agricultural goods without water supply to do so,” he said.

“When I looked at the other people doing hydroponics, it was all R&D hydroponics. There was nobody really focused on cost control, and that’s why I thought it was a good business. That’s my background, that’s where I’ve been successful in my career in the past.”

In Chicago’s Pullman Park district, the largest rooftop greenhouse in the world, measuring 75,000 square feet was built and opened by Gotham Greens in 2015.

“Our Pullman facility annually grows up to 10 million heads of leafy greens and herbs, year-round, for the finest retailers and restaurants across the greater Chicago land area,” said Viraj Puri, Gotham Greens’ CEO and co-founder.

The climate controlled greenhouse facility also sits on top of an already environmentally friendly factory occupied by eco-soap company, Method.

In Chicago’s Pullman Park district, the largest rooftop greenhouse in the world, measuring 75,000 square feet was built and opened by Gotham Greens in 2015.

Gotham Greens has three existing greenhouses in New York.

“Chicago was a logical expansion because it is a large city—by market the third largest—a cold weather place with a short growing season and a limited supply of year-round local produce,” Mr Puri said.

“The traditional farmer in Illinois turns a head of lettuce twice a year, every 60 days, maybe a third turn if they’re lucky. We do 25 crop turns per year, and a lot of that has to do with controlling climate, temperature, humidity, light and carbon dioxide.”

Part 2 to be continued next issue. b

About the author Christine Brown-Paul is a Sydney-based journalist and a regular contributor to PH&G, with a special interest in the environment and sustainable technology. Email: c.brown.paul@gmail.

Practical Hydroponics & Greenhouses . September . 2016. 23

AeROPOniCs in vAnCOUveR in vAnCOUveR, CAnADA’s FiRsT COmmeRCiAl AeROPOniCs FARm Uses ‘sPACe-Age’ TeCH TO gROw PRODUCe FOR lOCAl ResTAURAnTs AnD mARkeTs.

By CHRisTine BROwn-PAUl

Aeroponically grown produce Harvest urban Farms is Canada’s first commercial farm to use aeroponics, a process in which plants are grown in an environment of air or mist.

24 . Practical Hydroponics & Greenhouses . September . 2016

Vancouver in British Columbia, Canada is working towards being the greenest city in the world by 2020 (see previous article, 'City Farming' this issue page 16) and features many local examples of green city projects.

Vancouver also boasts Canada’s first commercial aeroponics farm, a new urban farm growing food for local restaurants and markets without soil, or any other growing medium. To grow produce, Harvest Urban Farms (HUF) uses aeroponics, a process in which plants are grown in an environment of air or mist — from which the plants receive nutrients.

“The roots are literally suspended in mid-air and by doing that they have a lot more oxygen that’s available to them so they can grow a lot faster,” said Aaron Ferguson, CEO of Harvest Urban Farms.

In aeroponics, plants are grown in a misted environment to transmit nutrients so aeroponics is considered a form of hydroponics, as it does use water although to a minimal degree. Aeroponic systems and biocontrols proven by NASA for rapid aeroponic food production on earth and space to grow pesticide-free food and crops anywhere.

“It is kind of Space Age. Much of modern aeroponics was developed on the International Space Station,” said Aaron.

“Part of our development process was actually working with some folks who had NASA grants to do that, and we took it from there and made it more commercially viable.”

Harvest Urban Farms was founded in 2012 by Aaron Ferguson, Shaun Juncal and Michael Berruti (the latter is now the company’s Director of Technology).

“We all came from diverse backgrounds (tech, engineering, management consulting), but shared a common vision for tackling what we saw as one of the biggest global challenges on the horizon: food production for urban environments,” said Shaun Juncal, HUF’s VP Marketing.

“Aaron introduced me and Mike to Dickson Despommier’s book, The Vertical Farm: Feeding the World in the 21st Century, and we started exploring the world of commercially viable vertical farming. We spent three years developing our patented technology and forming important partnerships before beginning work on our flagship farm in Vancouver BC. “Our current facility in Vancouver, British Columbia, is a large-scale, high-pressure aeroponic farm. The farm is located is a warehouse in the Strathcona neighbourhood of Vancouver and is an example of controlled environment agriculture,” he said.

Aaron Ferguson said aeroponic techniques enable the farm to get a seed to germinate and sprout within 24 hours. He said they could produce lettuce plants, for example, ready for harvest within 28 to 35 days.

“Lettuce plants out in the field take about 45 days to be mature,” he said.

The environment the plants are kept in is humid, and the plants are kept under LED lights with a pink-purple glow — a part of the spectrum that specifically gives plants the light they need. The farm uses ultra-efficient LEDs throughout its operations, recycles all water and manages temperature, CO2 and humidity levels through a centralised control.

“Our initial focus is on leafy greens,” Shaun said.

“Our salad mixes are very popular; we also sell mustards, arugula, mizuna, kale, basil sorrel and more.

As we move into winter we will also be growing strawberries.

“Our weekly yield at full capacity is between 400-800 pounds per week, depending on the crops being harvested,” he said.

lOCAl AnD sUsTAinABle According to Shaun, two important values of Harvest Urban Farms are being local and sustainable.

“We see the technology behind our farm chiefly as a

Plants are kept under a light with a pink-purple glow — a part of the spectrum that specifically gives the plants the light they need.

Practical Hydroponics & Greenhouses . September . 2016. 25

Aeroponics tour and workshop at Harvest urban Farms.

Photographer: David Arias (http://arias.ca).

Harvest urban Farms is located in a warehouse in the strathcona area of Vancouver.

26 . Practical Hydroponics & Greenhouses . September . 2016

mechanism to provide local produce year-round to urban areas,” Shaun said.

“The focus for us is less on the ‘space age tech’ and more on the fact that consumers in cities can buy their produce from a farm located in their neighbourhood. We want to be your local, neighbourhood farmer.

“In terms of sustainability, HUF was born out of the realisation that we need to change the way we think about food-production in the 21st century. The current methods of ‘big ag’ are simply not sustainable,” he said.

“At HUF, we want to build a company that is not only environmentally sustainable [using 2% of the water required by traditional agriculture and 2.5% of the footprint] but also economically sustainable [creating jobs and triple bottom line franchises in cities around the world].”

Harvest Urban Farms supplies their produce to restaurants and markets within close vicinity to the farm.

“We serve a hyper-local market, focusing on restaurants and grocery stores within a 10-kilometre radius. Given our central location, even in such a localised market the demand far exceeds our supply,” Shaun said.

The HUF team recently ran a workshop on aeroponics at the Vancouver Urban Farming Society (VUFS), which drew considerable interest and attendance locally and

further afield The society was launched in 2010, with an aim to grow urban farming as a viable, thriving and vibrant sector in Vancouver and beyond.

“VUFS is an organisation that supports the shared interests of urban farmers. The group strengthens and grows the urban farming sector through education, advocacy, networking and business support,” said a spokesperson.

“VUFS began as an informal group of urban farmers, entrepreneurs, urban farming supporters, food security advocates, and consumers dedicated to increasing the sustainability of urban farming in Vancouver and throughout BC.” Aaron Ferguson said he hopes to see the use of aeroponics grow in Vancouver, as he believes growing food locally, as opposed to importing it, improves the quality and eliminates supply chain costs.

“Vancouver still gets a lot of its food in the wintertime from California, and part of what we’re trying to do is eliminate that,” he said.

“California food is great, but it should be for people in California, not for people in Vancouver. It’s more sustainable in general not spending that fuel to cart food around.” b

Aaron Ferguson, Ceo of Harvest urban Farms says he would like to see more aeroponics farms in Vancouver.

Practical Hydroponics & Greenhouses . September . 2016. 27

WHERE THERE IS WATER THERE IS LIFE!

Chloritic rose leaves.

(Image lindsay stoddard)

IRONfe: DEFICIENCY & TOXICITY Deficiencies or excesses of mineral elements show in a number of ways: in colour, density, size and shape of leaves; in the thickness and colour of stems and the length of internodes; in the colour, fibrousness and thickness of roots; in the abundance and timing of flowers; and in the size, colour, hardness and flavour of fruit. Recognising those particular effects is the key to diagnosing nutritional disorders.

By sTeven CARRUTHeRs Iron (chemical symbol Fe) is one of the six micronutrients

ferri. Of the many special properties of iron, its ability to

or trace elements essential for plant growth and

readily undergo valency changes or be readily oxidised

reproduction. With the atomic number 26, it is a transition

and reduced, is the essence of its biological importance.

element with an atomic weight of 55.84 and a specific

Most scientific literature and studies discuss iron in soil

gravity of 7.87. Iron is by mass the most common element

where it is present as minerals (e.g. haematite), inorganic

on Earth, forming much of Earth’s outer and inner core –

precipitates (e.g. iron oxides), organic complexes (e.g.

it is the fourth most abundant element after oxygen,

humates), and ions in the soil solution. Chemically, it

silicon and aluminium. Iron is present in all soils and is

occurs in two forms or oxidation states; ferric (Fe3+), the

often responsible for its red or brown colour.

oxidised state, and ferrous (Fe2+), the reduced state.

The chemical symbol Fe originates from the Latin, ferrum, as is the origin of the familiar prefixes, ferro and 30 . Practical Hydroponics & Greenhouses . September . 2016

Ferrous iron is readily oxidised to ferric, which is extremely insoluble in water. In normal, well-aerated,

agricultural soils, oxidation is favoured and therefore ferric iron predominates. These phenomena are the crux of the iron deficiency problem in crops.

In common with all plant nutrients, iron must be in aqueous solution before roots can take it up. Any factor, which reduces the activity, or concentration, of dissolved iron (Fe ions) will detrimentally affect uptake.

By and large, the solubility of iron in soil is dictated by the dissolution and precipitation of ferric oxides and hence the aqueous activity of ferric ions. This reaction is highly pH dependent—the activity of soluble iron decreases 1,000-fold for each unit increase in pH. Naturally, the reaction is also affected by the redox conditions in the soil. For these reasons, a well-aerated, acid soil will have a higher soluble ferric iron content than an alkaline soil. Under reducing conditions, ferrous iron (Fe2+) is favoured. This is an important source of soluble iron in anaerobic conditions such as flooded rice fields. However, the much greater solubility of ferrous iron can cause iron toxicity problems in some situations.

For example, ‘bronzing’ in rice.

phenolic-based exudates. At the root hair surface (plasmalemma), ferric chelate is reduced to ferrous chelate, which readily exchanges, thus freeing Fe2+ for absorption by the root hair.

Once it has passed into the root hair the Fe2+ is oxidised to Fe3+ and then chelated by citrate ions. The ferric-citrate chelate is then transported via the xylem to the actively growing regions of the plant. Following translocation, iron tends to become fixed and is unable to be re-translocated from organ to organ. For this reason, iron deficiency symptoms tend to only affect new growth.

Most of this knowledge comes from experiments using the radiotracer technique, which is worthy of a brief mention here. Radioactive isotopes (e.g. Fe-59) can be used to trace the path and fate of substances from the soil to final destination.

Figure 1. Distribution of Fe-59 in tomato leaves.

FUnCTiOns OF iROn Iron is required by plants to produce chlorophyll and to activate several enzymes, especially those involved in photosynthesis and respiration. It is also involved in protein synthesis and developing fruit colour.

Although the exact role of chlorophyll production is still not clear, a definite relationship between iron and chlorophyll content in plant leaves has been demonstrated. Interruption of chlorophyll production in iron deficient plants is, of course, the cause of the universal visual symptom, chlorosis.

Iron is primarily taken up by plants in soil as the ferrous (Fe2+) iron. However, because most agricultural soils contain iron in the ferric (Fe3+) form, plants must somehow first solubilise the Fe3+ and then reduce it to Fe2+ so that it can pass through the root hair plasma membrane (plasmalemma).

The exact mechanism that achieves this is still poorly understood. It appears to vary between plant species and there is a definite difference between dicotyledenous plants and gramminaceous monocots. Since the latter are only of minor importance, they are not considered here.

In dicotyledoneous species (i.e. most crops), iron uptake is an active energy requiring process. The plant root hairs release protons (H+ ions) and exudates into the surrounding soil. The protons help solubilise Fe3+, by reducing pH, and promote the chelation of Fe3+ ions by

Figure 1 above: shows the pattern of uptake of Fe-59 by a chlorotic tomato leaf. On the left is a normal photograph (black = green), and the right an autoradiograph of the same leaf.

The distribution of iron 59 corresponds exactly with the areas of re-greening.

To date, iron has been found to be essential for some 14 different enzyme or protein systems involved in various metabolic pathways. Some of the more important functions are summarised in Table 1.

Table 1 below: Enzyme or protein systems and various metabolic pathways. Source: Ciba Specialty Chemicals Water Treatment Ltd.

Practical Hydroponics & Greenhouses . September . 2016. 31

iROn DeFiCienCy Almost without exception, iron deficiency results in chlorosis of the young, rapidly growing leaves; older leaves remain dark green. The chlorosis is characteristically interveinal. The veins remain starkly green in contrast to the yellow interveinal areas.

In plants with parallel veined leaves (e.g. graminae) a tramline effect is seen. In broad-leaved plants a fine reticulate pattern is evident (see Figures 2 and Figure 3).

Initially, the veins remain green, which gives a net-like pattern. In advanced stages, the veins also become chlorotic and may collapse, and the whole leaf appears bleached. Necrosis does not usually occur until the final stages of symptom development.

Visual symptoms are sufficiently characteristic for

accurate diagnosis of iron deficiency. There are no completely reliable methods for soil or plant tissue analysis available. If there is doubt, test spraying with iron compounds can be carried out—response is usually very quick.

The overall effect of iron deficiency chlorosis is a reduction in the photosynthetic activity necessary for growth and development. This, in turn, reduces the productivity of crops and their economic use by man.

Magnesium deficiency shows chlorosis in the interveinal areas, but these symptoms start on the older leaves, and the chlorosis has a more yellow-orange colour. Manganese deficiency also shows chlorosis on younger leaves, but the veins remain green even at severe deficiency.

youngest leaves (left and centre) are pale green to yellow with green veins. In severe cases (centre) of iron deficiency the minor veins also fade, and affected leaves appear light yellow to white. Compare with healthy leaf (right).

(Image nsw DPI)

Iron deficiency in cucumber.

Pale green symptoms first appear on young leaves. A faint green network of veins develops.

(Image nsw DPI)

32 . Practical Hydroponics & Greenhouses . September . 2016

Iron deficiency causes interveinal yellowing in strawberry. (Image Crop Diagnostic Centre, Manitoba Agriculture)

severe iron deficiency in gerbera.

(Image Haifa)

Interveinal chlorosis in which main veins remain green.

High levels of available molybdenum can reduce the uptake of Fe by causing the precipitation of iron molybdate on the root surfaces.

The most common reason for iron deficiency in plants is a high pH – iron availability decreases when the pH is above 7. Iron deficiency can be caused by poor substrate drainage, or high concentrations of metallic ions in the substrate or nutrient solution.

Iron deficiency can also be induced by too much manganese.

For most hydroponically grown vine crops, the nutrient solution should contain 2-3 ppm Fe.

TOxiCiTy Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. It can act catalytically to generate hydroxyl radicals, which can damage lipids, proteins and DNA. Because of the potential for toxicity associated with high iron levels, cells store iron with the intracellular protein ferritin, which releases iron in a controlled fashion. This protein is produced by almost all living organisms, including algae, bacteria, higher plants, and animals.

Iron toxicity is primarily pH related and occurs where the pH has dropped sufficiently to create an excess of

Practical Hydroponics & Greenhouses . September . 2016. 33

available Iron. As with some other nutrients, the visible symptoms of iron toxicity are likely to be a deficiency of another nutrient. Iron toxicity can also occur when zinc is deficient.

Excess iron can result in dark green foliage, stunted growth of tops and roots, and dark brown to purple leaves on some plants (e.g. bronzing disease of rice).

iROn CHelATes For hydroponics, iron sulphate or iron chelate compounds are used in nutrient formulations. Iron chelates are generally less likely to precipitate under alkaline conditions and are normally preferred in hydroponic solutions.

With regard to iron sulphate, its solubility is very low and the iron will subsequently precipitate to the bottom of the tank. Once precipitated, the metal irons are no longer available to plant roots and iron deficiency can occur. By comparison, iron chelates grip the metal ions tightly. As a result of this strong bond, the metal ions are protected from reacting with phosphates and sulphates and precipitating. Iron chelates are a soluble complex of iron, sodium and a chelating agent such as ethylenediaminetetraacetate, to make the iron soluble in water and accessible to plants. Three common iron chelates used in hydroponic solutions are Fe-EDTA, FeDTPA and Fe-EDDHA. The iron chelate commonly used in hydroponics is Fe-

Iron deficiency in tomato Chlorosis of intercostal areas of young tomato leaves, followed by yellowing of whole shoot tips. (Image yara us) 34 . Practical Hydroponics & Greenhouses . September . 2016

EDTA, however, it is only stable under acidic conditions (pH 6 and lower). Above pH 6, Fe-EDTA starts to become insoluble, resulting in the formation and precipitation of iron phosphate or iron oxide.

This may cause blockages of drippers, resulting in plant chlorosis. Fe-EDTA can be used as a foliar spray (foliar feeding).

As neutral and alkaline conditions (pH7 and above) are quite normal in the root zone environment, two other chelating agents have been designed specifically for use with iron for these conditions. These are DTPA (ethylenediaminepentaacetic acid) and EDDHA (ethylenediaminedi [2-ydroxyphenyl]-acetic acid). By using Fe-DTPA instead of Fe-EDTA, the grower’s crop is insured, in both acid and neutral pH conditions, from the risk of precipitation, dripper blockage and plant chlorosis—Fe-DTPA is stable under both pH conditions.

The iron metal chelate derived from EDDHA is stable under acidic, neutral and alkaline conditions and is recommended in situations where the pH of the nutrient solution in the root zone climbs above pH7, which may occur during periods of strong growth—strong growth boosts the pH upwards due to fast uptake of nitrates—or at the start of a new crop where the large water volume compared with the small root size make pH steering more difficult. EDDHA can be used in combination and mixed with Fe DTPA at all times. b

Iron deficiency in chrysanthemum Interveinal chlorosis starting at the top and progressing downwards.

Crop-specific quality substrates Call Cultilene for a free advice

Zeusstraat 2, 5048 CA, Tilburg, The Netherlands t + 31 (0)13 578 00 57 - e info@cultilene.nl - i www.cultilene.com

Japanese harvest

reaping the benefits of vertical farming with special leD lighting from Phillips.

36 . Practical Hydroponics & Greenhouses . September . 2016

FOOD PRODUCeRs in JAPAn ARe ReAPing THe BeneFiTs OF veRTiCAl FARming wiTH sPeCiAl leD ligHTing.

Philips Lighting has launched the latest in its indoor vertical farming experiments with trials at two Japanese facilities—with one growing 12,000 heads of lettuce a day under horticultural LED lighting technology. Indoor farming is a growing trend in urban centres in Japan where farmland is not prevalent.

A wide variety of herbs and greens can be cultivated in climate-controlled environments under LED lighting, for an energy efficient food production method that connects the local community to freshly grown produce.

Tokyo consumers have welcomed pesticide-free, wash-free lettuce grown with horticultural LED lighting

by Innovatus Inc., one of the world’s largest vertical farms. Also, convenience stores in the Kanto area, which holds around one-third of Japan’s population, now can buy processed foods with fresher, tastier vegetables and herbs grown with horticultural LED light from Delicious Cook Co., Ltd. This follows respective 14-month and 10-month trials at Innovatus Inc., and Delicious Cook Co., Ltd. Fresh, safe produce grown locally. A vertical farm is a fully

controlled facility where vegetables and herbs are grown in stacked layers without the use of daylight. Growing conditions are controlled carefully using tailored growth recipes. They provide everything to grow high-quality plants: the right light recipe, the ideal temperature, amount of water, CO2 and the best growing medium.

This farming method leads to cleaner, pesticide-free crops with a consistently great taste and maximum nutrition. Growers achieve higher yields and less waste thanks to the strictly controlled growing environment.

FAsT gROwing JAPAnese mARkeT “Increasingly, Japanese consumers are interested in a diverse variety of foods that have superior taste, are safe and nutritious as well as being offered at a reasonable price, “ said Udo van Slooten, business leader for Philips Lighting’s Horticulture business.

“Vertical farms are an ideal way to meet this growing demand for safe, fresh food especially in a country with highly-urbanised areas where space is at a premium.

“Philips’ first commercial vertical farming project was opened at Osaka University in Japan in 2014. Now, Japan is one of the fastest growing markets for our horticultural LED systems. Our collaboration with Japanese growers and partners has helped us further

Japanese consumers are interested in a diverse variety of foods that have superior taste, are safe and nutritious as well as being offered at a reasonable price

Practical Hydroponics & Greenhouses . September . 2016. 37

A wide variety of herbs and greens can be cultivated in climate-controlled environments under Phillips Green Power leD lighting

The new leD production module enables lettuce crops to get to Tokyo supermarkets in just two hours after shipment.

38 . Practical Hydroponics & Greenhouses . September . 2016

refine our LED installations and light recipes to better meet the requirement of the Japanese market,” Mr van Slooten said.

FROm gROwBeD TO sUPeRmARkeT wiTHin TwO HOURs After a trial starting in March 2015 at its Fuji Farm with a total floor area of 1,851 m2, Innovatus, from a standing start, now produces 12,000 heads of lettuce a day. This is one of the largest completely closedenvironment, vertical farms in the world using horticultural LED lighting.

“The trial using Philips GreenPower LED production module, has allowed us to grow five varieties of lettuces, mainly frilled lettuce, green leaf and romaine that are of a consistent quality and locally-produced, using only a fraction of the water compared to lettuces grown in open fields,” said Hitoshi Wada, director at Innovatus.

“Also, the quality and control it has given us with our lettuce crops has enabled us to get lettuces to Tokyo supermarkets in just two hours after shipment.

“Furthermore, as the lettuces are grown and packaged in an extremely hygienic environment, there is no need to wash them before eating,” he said.

Consistent quality herbs year round while reducing costs. In October 2015, Delicious Cook created a new city farm in Narashino City in the Chiba Prefecture of the urbanised Kanto region of Japan.

During a 10-month trial led by Philips Lighting business partner, CCS, Delicious Cook has used Philips GreenPower LED production module in three layers in a total cultivation area of roughly 80m2 on a footprint of 80m2 to grow relatively uncommon herbs. These include edible chrysanthemums and coriander for the company’s processed foods.

The Philips GreenPower LED production module gives Delicious Cook the flexibility to try out horticultural LED light recipes, opening up new possibilities for them to differentiate crop taste and increase yield.

Delicious Cook’s facilities manager, Katsuhiro Takahashi commented: “It is Delicious Cook’s strategy to transition from externally-produced food to food grown safely indoors.

“No one imagined that Philips Lighting and CCS would be able to help us with horticultural LED light to deliver results so quickly”. Now, Delicious Cook can rely upon its own high-quality produce, home-grown indoors all year round and avoid sourcing it from external suppliers, Mr Takahashi said. b Practical Hydroponics & Greenhouses . September . 2016. 39

ABOUT PHiliPs ligHTing Philips Lighting, a global leader in lighting products, systems and services, delivers innovations that unlock business value, providing rich user experiences that help improve lives. Serving professional and consumer markets, the company leads the industry in leveraging the Internet of Things to transform homes, buildings and urban spaces.

With 2015 sales of EUR 7.5 billion, Philips Lighting has approximately 36,000 employees in over 70 countries.

News from Philips Lighting is located at http://www.newsroom.lighting.philips.com For further information contact: Philips Lighting Daniel Bausor, Global Integrated Communications Tel: +44 (0) 7701 094980 Email: daniel.bausor@philips.com Philips Horticulture LED Solutions Daniela Damoiseaux, Global Marcom Manager Horticulture Tel: +31 6 31 65 29 69 Email: daniela.damoiseaux@philips.com www.philips.com/horti

40 . Practical Hydroponics & Greenhouses . September . 2016

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Practical Hydroponics & Greenhouses . September . 2016. 41

Northern Exposure 42 . Practical Hydroponics & Greenhouses . September . 2016

nunavut is the newest, largest, northernmost, and least populous territory of Canada.

AXEL HEIBERG ISLAND

ELLESMERE ISLAND

Grise Fiord

DEVON ISLAND

Clyde River

Pond Inlet

Nanisivik

Qikiqtarjuaq Pangnirtung

Repulse Bay

VICTORIA ISLAND

NUNAVUT INUIT

Baker Lake

Iqaluit Cape Dorset

SOUTHAMPTON ISLAND

HUDSON BAY

NEW FOUND LAND

CANADA

in A smAll HAmleT in nORTHeRn CAnADA An AmBiTiOUs gReenHOUse PROJeCT is HelPing TO BRing HeAlTHy FResH PRODUCe TO THe lOCAl COmmUniTy.

By CHRisTine BROwn-PAUl

Practical Hydroponics & Greenhouses . September . 2016. 43

nUnAvUT is THe newesT, lARgesT, nORTHeRnmOsT, AnD leAsT POPUlOUs TeRRiTORy OF CAnADA. iT wAs sePARATeD OFFiCiAlly FROm THe nORTHwesT TeRRiTORies On APRil 1, 1999, viA THe nunAVuT ACT AnD THe nunAVuT lAnD ClAIMs AGreeMenT ACT THOUgH THe BOUnDARies HAD Been COnTemPlATively DRAwn in 1993. THe CReATiOn OF nUnAvUT ResUlTeD in THe FiRsT mAJOR CHAnge TO CAnADA’s POliTiCAl mAP sinCe THe inCORPORATiOn OF THe new PROvinCe OF newFOUnDlAnD AnD lABRADOR in 1949.

A massive, sparsely populated territory of northern Canada, Nunavut forms most of the Canadian Arctic Archipelago. Its islands have expanses of tundra, craggy mountains and remote villages accessible only by plane or boat. It’s known for its indigenous Inuit people’s artwork, carvings and handmade clothing. Inuit art is displayed at the Nunatta Sunakkutaangit Museum in the capital, Iqaluit, on Baffin Island.

Located on the western shore of Hudson Bay in the Kivalliq Region of Nunavut, Arviat is a predominantly Inuit hamlet with the word “Arviat” derived from the Inuktitut word arviq meaning “Bowhead Whale” Arviat is the southernmost community on the Nunavut mainland and is close to the geographical centre of Canada.

The hamlet of just over 2,000 people on the shores of Hudson Bay has two grocery stores, and fresh food, which has to be flown in from southern Canada, is expensive.

Many vegetables, like lettuce, don’t keep for very long, and community educator Shirley Tagalik says this makes them even less appealing.

“If you buy something and it’s wilted and goes bad the next day, [you] don’t want to waste your money,” Ms Tagalik said.

However, the community now has a research greenhouse, a venture she hopes can not only help solve the community’s food insecurity problem, but also gain people’s interest in eating healthier.

“We want people to experience the taste of freshly grown produce,” Ms Tagalik said.

“They’re used to lettuce from the store that doesn’t have any taste.”

BeneFiTs FOR THe COmmUniTy In a small glass structure set up outside Arviat’s John Arnalukjuak high school, a hydroponic greenhouse project was set up by the Arviat Wellness Society in 2013.

Peppers, lettuce, tomatoes, radishes, spinach are beets 44 . Practical Hydroponics & Greenhouses . September . 2015

are some of the hydroponically grown vegetables that are thriving in the greenhouse under LED lights.

After testing a number of local fertilisers, like seaweed and caribou stomach, the greenhouse group looked to the abundance of goose excrement in and around the Kivalliq community, finding it the most effective.

Greenhouse project co-ordinators Keenan Lindell and Megan Gavin, a Grade 12 student at John Arnalujuak high school say they are very impressed with the how healthy and abundant growth of the vegetables.

“We had a bunch of kids help us plant seeds and they kept coming back to see how the plants are growing,” Mr Lindell said.

“It’s a great feeling to see how excited they get. We hope that this will encourage people to eat more vegetables.”

Once the produce is ready, the group announces it on radio and posts photos to a local Facebook page, so residents can come by to pick some up. The group usually saves some produce to deliver to the local elders centre.

This year, however, the greenhouse project is outgrowing its walls.

When the project first launched, the Arviat Wellness Society had distributed grow boxes to locally families, with the goal of encouraging small home gardens. This aspect of the project received a boost this year, when a Memorial University-based program called SucSEED donated 12 hydroponic bins to the initiative. The compact bins use a LED light so crops can grow year-round.

Keenan Lindell said there are now 12 Arviat households growing vegetables.

“Once they start to harvest that produce, the SucSEED program can help those growers sell their produce to Arviat stores,” he said.

Mr Lindell estimates the bins cost about $3 a week in power, and use 90 per cent less water than regular soilgrown produce.

“If these bins work out then the potential impact they could have is enormous,” he said.

“Imagine if every community in Nunavut had several [households] growing produce that they sold to the local stores?

“This will be a source of income for the growers as well as be less cost for the stores to buy locally, which also means the produce would cost less for consumers,” Mr Lindell said.

While lettuce might not be the most sought-after food item in Inuit communities, Arviat’s Wellness Society surveyed the community to find out what they wanted as

An elder of Arviat, an Inuit hamlet of nunavut.

Practical Hydroponics & Greenhouses . September . 2016. 45

far as access to produce.

“Community members responded by saying they don’t buy produce because it’s expensive and often not fresh,” Mr Lindell said.

“People also said that they would buy more produce if they knew it was grown locally and by people they know. I would love to see these bins in every community in Nunavut.”

CHAllenges Many people might be surprised that vegetables could grow at all up north, however, Keenan Lindell says the summers are getting longer, which means a longer growing season.

“Everybody was seeing all the negatives of climate change ... we wanted to try to focus on the positives of climate change,” he said.

Mixed flowers add colour, texture and flavour to salad products.

An Arctic summer, while more tolerable in Arviat than more remote settlements, is still unpredictable. While light is almost constant and temperatures can reach up to 30 degrees Celsius, harsh winds or even hail or snow are still a possibility.

Two-thirds of Arviat’s population is under the age of

16, and while teens aren’t known for their love of leafy greens, Shirley Tagalik says they’re the target audience for programming about nutrition. She hopes people in Arviat can lose weight and start eating better.

“I want people to eat more healthy food,” she said.

“We only cook fast food.”

The initiative is also giving Arviat’s young people a coveted summer job.

“Many families rely on their young people having jobs through the summer to help their family through,” Ms Tagalik said.

“This initiative gives them a chance to earn some money while learning and giving back to the community at the same time.” b

Compact bins use leD light so crops can grow year-round.

Arviat greenhouse coordinators Keenan lindell (l) and Megan Gavin measure plants in their community operation.

46 . Practical Hydroponics & Greenhouses . September . 2016

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NEW ONLINE COURSE

Proudly supported by

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www.gotafe.vic.edu.au | 1300 GOTAFE (468 233)

GOTAFE ŝƐ Ă ďƵƐŝŶĞƐƐ ŶĂŵĞ ŽĨ 'ŽƵůďƵƌŶ KǀĞŶƐ /ŶƐƟƚƵƚĞ ŽĨ d & ;ZdK ϯϬϵϰͿ͘ TŚŝƐ ƚƌĂŝŶŝŶŐ ŝƐ ĚĞůŝǀĞƌĞĚ ǁŝƚŚ sŝĐƚŽƌŝĂŶ ĂŶĚ ŽŵŵŽŶǁĞĂůƚŚ 'ŽǀĞƌŶŵĞŶƚ ĨƵŶĚŝŶŐ͘

OPTimising gReenHOUse COnTROl DURing sUmmeR The user-friendly isii compact from Hoogendoorn controls irrigation in greenhouses and open field and manages greenhouse climate.

in THe sUmmeR mOnTHs, COnTROl OF THe gReenHOUse ClimATe DemAnDs A DiFFeRenT sTRATegy TO AvOiD PlAnT sTRess CAUseD, FOR exAmPle By An inCReAse in TemPeRATURe & RADiATiOn. With offices in The Netherlands, France, Russia, China, Canada and Mexico Hoogendoorn started as a small technical installation company in 1967 and has grown into an international automation company active worldwide. In 1974, Hoogendoorn was the first in the world to bring a digital horticultural computer to market.

Since then, the company has produced the most advanced process computers and cultivation and business registration systems that contribute to a sustainable approach to water, climate and energy.

With a partner network distributed across each continent, Hoogendoorn has trained specialists to support customers with knowledgeable product recommendations, training and customer service.

Hoogendoorn provides tips to control temperature and radiation and optimise your greenhouse control during summer:

TiP 1: OPTimise yOUR sCReening sTRATegy During the summer period a high level of radiation has a large effect on the crops. When plants start to feel

48 . Practical Hydroponics & Greenhouses . September . 2016

stressed, it is necessary to reduce the energy supply by closing the climate screen.

There are three ways to do this: The easiest way is to close the screen, based on a set level of radiation. However, usually this measure is often taken very ‘prudently’ which unnecessary limits growth.

The second method is to adjust the set point to the level of greenhouse humidity. In most cases this is done based on Relative Humidity (RH). This means that the screen closes when the RH is too low combined with a certain level of radiation. In the case that the RH level is correct, the screen remains open. Plant stress is measurable with a plant temperature meter. In the case that the plant temperature exceeds the greenhouse temperature, it is a sign that plants can’t cool down – because plants cool down due to evaporation, this means the risk of water stress increases. With this knowledge you can increase the light level when the greenhouse climate is correct. On days that plants struggle more to retain the photosynthetic process, you reduce the light level. On average, this increases crop growth.

TiP 2: OPTimise gReenHOUse TemPeRATURe COnTROl Temperature control has a large influence on the speed of growth. High temperatures can cause an unbalanced

A plant temperature camera such as this one from Hoogendoorn can detect high temperatures that can cause an unbalanced plant and even water stress.

plant and even water stress. During summer, you as a grower, face a dilemma: do you need to reduce temperature by ventilation, or do you need to close vents to maintain the right level of humidity and reduce CO2 loss?

Research shows that water stress in the late afternoon is caused by a low level of humidity. This means that a high temperature has less influence. On the contrary, a high temperature combined with a high level of radiation increases the photosynthesis. This benefit only applies when the stomata of the plants are opened for uptake of CO2.

To create a win-win situation for the plant, Hoogendoorn advises growers to increase the set point of the ventilation. This prevents a low level of humidity: the temperature increase is much less as expected.

TRAining With over 49 years of experience in horticultural automation, Hoogendoorn has considerable in-house knowledge. Via (customised) training, knowledge is shared about safe, efficient, and environmentally friendly production with advisors, students, customers and partners.

Training sessions are provided online or in-company, either on an individual basis or in groups. Moreover, in every e-newsletter Hoogendoorn includes growing tips and other relevant information that helps you to optimise your greenhouse climate.

Hoogendoorn provides tailor-made training at its offices, in-company or online through a webinar.

For more information on training or to sign up for Hoogendoorn’s newsletter visit: www.hoogendoorn.nl/en/ b Practical Hydroponics & Greenhouses . September . 2016. 49

Measuring crop temperatures in greenhouse cultivation, we normally measure the greenhouse temperature.

However, the temperatures of the plant and fruit are also very important in achieving optimum production and quality.

50 . Practical Hydroponics & Greenhouses . September . 2016

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This manual has been produced to give an easy guide to the basics of growing greenhouse cucumbers. It provides a simple reference point by having information in a easyto-find format. This publication represents the final extension output of HAL Project V00081, (Development & Extension of Improved Horticultural Practices to Increase Profitability in the Greenhouse Cucumber Industry).

www.hydroponics.com.au/buynow Practical Hydroponics & Greenhouses . September . 2016. 51

InFrAreD lIGHT everything on earth radiates infrared light, which is detected in the form of heat.

The warmer the crop, the more infrared light it radiates.

mAny gROweRs AlReADy wORk wiTH An inFRAReD CROP TemPeRATURe meTeR, wHiCH is COnneCTeD TO A ClimATe COmPUTeR. THis enABles THem TO BUilD UP A gOOD UnDeRsTAnDing OF THe TemPeRATURe AT THe TOP OF THe CROP. THe ReADings ARe sUBseQUenTly PlOTTeD in gRAPHs AnD COmPAReD wiTH, FOR exAmPle, THe gReenHOUse TemPeRATURe AnD inCiDenT RADiATiOn. There are also other possibilities for measuring the temperature at various places in the greenhouse and at different heights in the crop, for example, using a handheld infrared meter. These meters vary from simple models for measuring at one spot to advanced equipment that can measure temperature variations over a large surface area.

HOw DOes An inFRAReD THeRmOmeTeR wORk? Everything on earth radiates infrared light, which is detected in the form of heat. The warmer the crop, the more infrared light it radiates. An infrared thermometer measures the strength of the radiation between 7,500 and 13,000 nanometers. The hand-held meter converts this value and displays it as a temperature.

A professional thermal imaging camera also displays these temperatures as a normal photograph of the crop in a graduation of colours. Affordable thermal imaging cameras have recently come onto the market, which can be mounted on a smartphone. The resolutions of these cameras are fairly similar to those of professional cameras and they are subsequently suitable for measuring the temperature of crops.

Why is it important to measure crop temperatures?

Direct incident radiation may cause the temperature of plants and fruit to rise considerably in localised spots

52 . Practical Hydroponics & Greenhouses . September . 2016

because the plant collects more energy than it can process by photosynthesis. The plant has various ways of processing this superfluous energy, but these methods all have their limits. If the plant receives excessive radiation, it may burn.

Measuring the temperature of the crop with a thermal imaging camera clearly shows that large temperature differences can arise, both vertically and horizontally.

Based on this information, decisions can be taken regarding the closing of shading screens, application of a coating to the roof, or alteration of the position of the vents with regard to the sun.

Diffuse light improves the vertical and horizontal distribution of light and, furthermore, crops are less likely to burn at a specific light intensity if the light is diffuse. There is, however, always a risk that, despite the use of a diffuse coating or diffuse glass, the incidence of direct light through the vents on clear days will cause fruit and leaf burn.

This can be avoided by closing the shading screens far enough to prevent direct light from falling on the crop, or by closing the vents relative to the position of the sun.

Plant and fruit temperatures will, generally speaking, be lower with diffuse light than with direct light. This has advantages in summer because excessive temperatures can lead to crops burning.

In spring, with diffuse light, the temperature of the crop may be much lower than that of the greenhouse itself, which can be detrimental for growth rate and production.

So keep an eye on the temperature of your crop and, if necessary, raise the greenhouse temperature in the morning and/or ventilate less during the day. b For more information contact Mardenkro in The Netherlands Ph: +31 (0)13 507 70 69 Email: sales@redusystems.com Website: www.redusystems.com

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lying 320 kilometres southeast of Darwin, just below the “Top end”, Katherine is the fourth largest settlement in the northern Territory.

in THe CenTRe OF kATHeRine in AUsTRAliA’s nORTHeRn TeRRiTORy, A HyDROPOniC gReenHOUse HAs sTARTeD gROwing gReen leAFy vegeTABles AnD HeRBs.

By CHRisTine BROwn-PAUl Lying 320 kilometres southeast of Darwin, just below the “Top End”, Katherine is the fourth largest settlement in the Northern Territory. The township began as an outpost established with the Australian Overland Telegraph Line on the North-South transport route between Darwin and Adelaide.

Since that time, Katherine has grown with the development of transport and local industries including mining – especially gold mining. The town is a tourism gateway to the attractions of nearby Nitmiluk National 56 . Practical Hydroponics & Greenhouses . September . 2016

Park, which embraces the dramatic Katherine Gorge and its many ancient rock paintings. The region is known to experience heavy flooding during “the wet season”.

Katherine today is a modern thriving regional centre that offers a wide range of services to communities from the Western Australian border to the Gulf of Carpentaria on the Queensland border. Covering an area of 7,421 square kilometres, the Municipality of Katherine is located on the beautiful Katherine River, offering excellent fishing, walking and cycling.

The township has a population of over 10,766 people – the wider region boasting a population of just over 24,000, 60 per cent of whom identify as Indigenous.

COmmUniTy gARDen On a vacant block in the centre of town, the Katherine Indigenous Women’s Association, has teamed together with Jobfind and the not-for-profit organisation Food

Ladder to develop a community garden and hydroponics greenhouse centre.

The project has backing from the local council and preapproval for funding from the Territory Government.

Director and co-founder of Food Ladder, Kelly McJannett, said that the focus for the project is on “produce you just can’t get up here in regional and remote communities.”

“That is, typically leafy greens, the kind of produce that is very nutrient rich, high in iron and incorporating that into the diet of local people,” Ms McJannett said.

“We are really excited to be growing leafy green vegetables, but we would love to be doing strawberries as well.

“Having a walk through the local shop, it is really expensive to get really good local produce, so we want to bring all those costs down and make it really easy for

people to buy really good quality veggies,” she said.

Ms McJannett said the hydroponic setup uses town water to irrigate plants in the greenhouse.

“It is a very sustainable model, it is all closed-loop reticulation, so none of the water is wasted,” she said.

“We filter [the water], we put nutrient in, so no pesticides. We are not certified organic but we are certainly chemical free.”

The greenhouse is currently growing English spinach, broccoli, kale, garlic, Swiss chard, coriander, parsley, beetroot and lettuce.

The plants are grown in trays of small, round clay pellets known as hydroton.

Food Ladder’s Lina Challita said the hydroton replaced the need for soil.

“They serve as anchorage and something to keep the plants moist and retain the water as we irrigate [the Practical Hydroponics & Greenhouses . September . 2016. 57

Katherine is a modern thriving regional centre that offers a wide range of services to many far-flung communities.

plants],” Ms Challita said.

“The advantage of this is that it lasts way longer than soil, so we don’t have to keep adding fertiliser, manure, and it doesn’t clog up the hydroponics system.

“The pellets contain a certain amount of nutrients and the rest has to be added through the water.”

The plants are irrigated and fertilised through drip irrigation, which is recirculated through the system.

Ms Challita said the controlled environment of the greenhouse allowed for even growing conditions.

“It is quite hot here, so we need fans to control the temperature,” she said.

“Then we have a cooling pump to cool the water down, because that is the most important bit. It is not the air temperature, but the water temperature that affects the plants.

“We also have wet walls [which] are used to remove the humidity within the greenhouse,” Ms Challita said.

Ms Challita said a new crop could be planted in the hydroton immediately after harvest.

“We don’t need to work the soil, we don’t need to ad fertiliser, mulch, leave it rest. We can keep growing in cycles, one after the other using the clay pellets.”

Produce from the greenhouse is being sold to the Katherine community and local cafes.

Katherine Indigenous Women’s Association chairperson Taryn Kruger aims to engage the community with the garden.

“The other way is showing them how to grow it in the beds,” she said.

“Bringing back that ‘80s thing where everyone used to grow everything in their backyard and now it’s like run to

nearby Katherine is nitmiluk national Park, which embraces the dramatic Katherine Gorge and its many ancient rock paintings.

58 . Practical Hydroponics & Greenhouses . September . 2016

the markets.” have also started requesting fresh Ms Kruger said tomato and produce from the garden, with more rosella were two of the more expected to come. popular plants, and there were Ms McJannett said that if the initiative plans to run a competition to see in Katherine proves successful, Food who could make the best rosella Ladder would look at starting similar jam. Ms Kruger said they greenhouses in communities across the had already approached the Northern Territory. schools, which had already “We really want to be working with started their gardens, to help communities all around the Top End, I them maintain their own plants don’t know why all communities shouldn’t Garlic seeds have begun to as well as setting up a training have access to great quality produce,” sprout in the Food ladder garden at the community she said. hydroponics community greenhouse site.

“In that process we really look forward Katherine Indigenous Women’s greenhouse. to working with government to make this Association has also been a real strategic rollout to address working with Charles Darwin University for its members nutrition in the Top End. We look forward to making a big to become qualified trainers and assessors to further dent in nutrition and making meaningful jobs for people develop the skills with the community. Local businesses in communities.” b

Angie siputro, Hamish Dowell, Taryn Kruger and lina Challita have been working to build a greenhouse in the centre of Katherine. (ABC rural: Daniel Fitzgerald)

Practical Hydroponics & Greenhouses . September . 2016. 59

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