In 2003, the CGIAR Secretariat asked the Standing Panel on Impact Assessment (SPIA) to initiate a series of impact assessment studies on natural resources management (NRM) research. The main objectives of this SPIA initiative were to obtain better information on the demonstrable impacts of CGIAR investments in NRM research, to identify gaps in data and methodology, and to provide avenues for better NRM impact assessment in the future. The impact brief presented here describes the major results of one of seven center NRM impact assessments emerging from this SPIA initiative: Laxmi V., Erenstein O., and Gupta R.K. Forthcoming. The case of zero tillage technology in India. In: The Impact of Natural Resource Management Research: Studies from the CGIAR (Zilberman D. and Waibel H., Eds). CAB International:
Wallingford, UK.
Science Council Brief Standing Panel on Impact Assessment Number 13
When Zero Means Plenty: the Impact of Zero-tillage in India South Asia’s rice–wheat systems were a cradle of the Green Revolution. From the late 1960s to the mid-1980s, crop yields rose steadily, increasing food security, raising incomes, and creating jobs. But the revolution has since run out of steam: research has shown that yields are stagnating or even falling, while soil and water quality are also in decline.
FAO/19480/G. Bizzarri
It is against this background that the Rice–Wheat Consortium (RWC) of the Indo-Gangetic Plains (IGP)1 is developing and promoting environmentally friendly technologies that increase farm productivity and conserve natural resources. The most promising of these is zero-tillage (ZT), whereby wheat is sown immediately after the rice harvest, foregoing intensive tillage operations and saving diesel fuel, tractor hours, water, soils, and labor.
Nourishing the Future through Scientific Excellence
In a marked departure from its traditional role in strategic and applied research, the Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT), the center that convenes the RWC, took on the job of speeding up the diffusion of ZT technology. This was accomplished by working with national researchers, equipment manufacturers and farmers to design, test, adapt, and disseminate a tractor-drawn drill and to facilitate farmer uptake. As a result of this work, ZT wheat is now the most widely adopted resourceconserving technology in the IGP, especially in India.
How it works Traditional cultivation in South Asia’s rice–wheat systems is very intensive, degrading the region's soils. Excessive groundwater abstraction has lowered the water table in many areas, while irrigation is also associated with waterlogging and salinity. There is thus an urgent need for technologies that are both more productive and more friendly to the environment. As the term implies, ZT means planting crops without tilling. This is done by using a mechanical tractor-drawn drill to draw a narrow furrow into which seed is inserted. This allows the residues from the previous harvest to be retained as mulch to benefit subsequent crops.
C o n s u l tative Group on International Agricultural R esea rch
The technology has numerous advantages. It leads to higher yields at lower production costs, a critical factor in a more liberal and competitive market. It is also environmentally and socially friendly, saving water, soil, energy, and labor. By eliminating tillage it drastically reduces machinery costs. The ZT drill is highly efficient, placing seeds and fertilizer at the right depth and in the right quantities. And because irrigation water flows more rapidly on smooth untilled than on rugged tilled soil, ZT also reduces the amount of water needed. CIMMYT and RWC’s main contribution to the ZT project was expertise in designing and implementing on-farm experiments. These organizations were also instrumental in building a public–private partnership to manufacture and disseminate ZT drills.
Assessment methodology This impact assessment study had three components: a literature review, focus group discussions, and modeling. The literature review examined available trial data, which focused mainly on the technical aspects of ZT at plot level. These secondary data varied in scientific rigor and often lacked measures of variability or statistical analyses. Focus groups were convened in six villages to analyze at first hand the socioeconomic impact of ZT wheat and to validate the secondary data. The groups included both adopters and non-adopters, divided by gender and by wealth (farm size). Modeling covered the technology's economic impact. Environmental and social impacts were not modeled due to lack of reliable data.
Efficiency gains drive rapid adoption The focus group interviews confirmed that ZT not only eliminated tillage costs but also increased wheat yields. The discussions reported a yield gain of 6 per cent in Haryana and of about 10 per cent (325 kg/ha) in eastern Uttar Pradesh. Unlike conventional wheat tillage, which is very timeand tractor-intensive, ZT pared down the turnaround time between crops: wheat could be sown in a single pass almost immediately after the rice harvest. This advanced wheat sowing by 7–10 days in Haryana and by 8–25 days in Bihar. Specifically, ZT: n Reduced the number of field operations from an average of seven to one, translating into 8–12 hours per hectare saved in tractor time (a 60–90 per cent saving) n Reduced water usage by about 1 million liters per hectare (a saving of 20–35 per cent) n Improved soil structure, fertility, and biological properties n Typically reduced the incidence of weeds, primarily due to the earlier emergence of wheat and to reduced soil disturbance n Improved the population dynamics of certain wheat pests and diseases n Increased wheat yield by 6–10 per cent and reduced production costs by 5–10 per cent. These efficiency gains have led to rapid and widespread adoption of ZT (see Table 1). Adoption started in
Table 1. Geographic distribution of rice–wheat system and estimated zero tillage/reduced tillage (ZT/RT) spread in the Indo-Gangetic Plains of India
State
Area under rice–wheat rotation (1998–2001) (‘000 ha)
Punjab Haryana Uttar Pradesh, Uttaranchal
Area with ZT/RT wheat (‘000 ha) by year 2001–2002
2002–2003
2003–2004
2190
20
50
215
910
97
275
350
5130
12.6
45
235
1830
0.4
1
18
330
0
0
0
10,390
130
371
818
and Himalachal Pradesh Bihar West Bengal Total area
Source: Pal et al. (2003); RWC (2004)2
ZT has succeeded in India because: n It responded to strong farmer demand and provided substantial market opportunities for the private sector (see Figure 1). n RWC catalyzed the public–private partnership needed to develop and disseminate the technology. It also facilitated technology transfer by establishing on-farm trials and forging strong links with other interested organizations. n Scientists worked closely with farmers and manufacturers. Farmers tested the machines in their fields, providing feedback for refining the technology. n Several manufacturers were involved, ensuring competitive prices, high quality, good after-sales service, and plentiful supplies. n The technology was strongly supported by State and local governments. CIMMYT's role and commitment were instrumental in this success. Its status as an international public-sector organization enabled it to act as an honest broker, lowering transaction costs and reducing uncertainty about the technology. Without CIMMYT and RWC's investment in R&D, widespread adoption of ZT would probably have been delayed by 5 to 10 years. Although these were not measured, ZT also has wider environmental benefits: n Reducing greenhouse gas emissions and fossil fuel consumption: researchers estimated annual savings of 91 kg of carbon dioxide emissions per ZT hectare. Based on adoption of ZT on 3.43 million hectares of wheat land, this amounts to a total reduction of 0.31 million tonnes of emissions per year. In addition, 120 million liters of diesel fuel were estimated to have been saved, adding US$50 million to annual benefits. n Mulching: the retention of crop residues as mulch avoids burning, thereby reducing air pollution, with benefits to human health as well as the environ-
Figure 1. ZT drills sold and ZT manufacturers in Haryana and Punjab, 1994–2003
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:FBS Source: Derived from Parwez et al. (2004).3
n
ment. Mulching also improves nutrient use and water use efficiency. Water use efficiency: in 2002–2003 alone, ZT farming on 250,000 hectares saved an estimated 75 million cubic meters of water. Water scarcity is an increasingly critical issue across the IGP, pitting farmers against domestic and industrial water users. It is especially critical in northwestern India, where scarcity has ignited inter-State conflicts.
Cost–benefit analysis Two factors contributed to the overall profitability of ZT: yield increases and cost savings. The latter accrued mainly in land preparation, but also in irrigation and other inputs. Using conservative estimates based on the secondary data verified in focus group interviews, the ZT R&D program yielded a net present value of US$94 million, equivalent to a benefit–cost ratio of 39 and an internal rate of return (IRR) of 57 per cent. Assuming a more optimistic scenario, the IRR rises to 66 per cent. Neither of the two scenarios takes into account the long-term environmental benefits of ZT. Were these to be included in the analysis, the IRR would be even greater. It is thus fair to conclude that the CIMMYT–RWC investment in ZT R&D in India has been highly beneficial.
Reflections and lessons This case study shows that CGIAR centers and the consortia they support can achieve tremendous impact in
Manufacturers
Drills sold
Haryana, where the technology, besides meeting farmers’ needs, found a favorable institutional context. The State's decision to subsidize the manfacture and sale of ZT drills encouraged rapid uptake, while RWC’s participatory and collaborative approach was a further factor promoting adoption. The pace of adoption in neighboring Punjab has also been rapid. Other adopting states include Uttar Pradesh, Uttaranchal and Himalachal Pradesh and, to a lesser extent, Bihar. Thus far, the technology has spread faster in the better endowed, intensively farmed areas than in areas where farm size is smaller and farmers are poorer.
The CIMMYT–RWC ZT project achieved a high rate of return because it addressed the issue of how to scale up, a problem plaguing many NRM technology projects. This project developed the necessary institutional mechanisms for upscaling, including incentives for private-sector involvement. The fact that the technology could be embodied in a private good was a major factor contributing to widespread adoption. Given this scenario, a key future challenge for NRM research is to design technologies that are attractive to the private sector but that also have environmental benefits. This case study also illustrates the importance of planning for impact assessment at the outset of a project. Few farm surveys were available to document the yield effects of ZT adoption. Relying almost solely on secondary data verified by a few focus group interviews inhibits econometric impact assessment. There is still some uncertainty with regard to the benefits calculated. These reservations aside, the case study highlights the comparative advantage of CGIAR centers and programs in helping countries speed up technology adaptation and diffusion. The study gauged impact on the basis of private gains alone, without setting a value on environmental and social benefits. This approach was dictated by data limitations, but it also has its merits: private gains correspond more closely to the immediate interests of farmers and other individual stakeholders and are thus a better indicator of potential adoption.
What next? ZT cannot be extended to the entire IGP region due to agroclimatic and socioeconomic limitations. Technology adoption has so far proceeded fastest in the highpotential areas, but in fact it is the areas with less intensive agriculture that stand to gain most in terms of yield gains and cost savings. ZT therefore has immense potential to reduce regional inequality and poverty. The success of ZT drills depends on three critical factors – affordability, availability, and correct usage. Of the three, it is availability that may pose the biggest
Science Council Secretariat A Unit of the CGIAR System Office c/o FAO Viale delle Terme di Caracalla, 00153 Rome, Italy www.sciencecouncil.cgiar.org t: 39 06 57056696 f: 39 06 57053298 e: sc-secretariat@fao.org
bstacle to adoption in lower potential areas, where o there tend to be fewer entrepreneurs who are prepared to risk manufacturing the drills. ZT opens the door to the development of other technologies, including ZT-specific wheat varieties. It also carries the promise of greater crop intensification and diversification. In addition, the technology could be adapted to other food crops. Its current use for wheat alone is limiting: more significant environmental gains could be realized if the entire rice–wheat system were to convert to year-round conservation agriculture. These themes should be the focus of future NRM research on rice–wheat systems. Landless laborers reported they had lost some of their seasonal employment on rice–wheat farms, but ZT has also created new opportunities for manufacturers and machine hire. The potential multipliers associated with ZT-induced changes – particularly in intensification, diversification, and service industries – doubtless compensate for the unemployment attributed to ZT. However, this assertion needs to be substantiated by further studies. More research is also needed to quantify the environmental benefits of ZT. Progress in this area is needed urgently, not merely to improve the accuracy of future cost–benefit analyses but also to retain stakeholder confidence in the existence of these benefits and their long-term impact on farmers' incomes. Finally, it is important to acknowledge that ZT is not a panacea. Technological interventions must be complemented by enabling policy reform on such thorny issues as the subsidy and taxation regimes that currently undermine the sustainability of rice–wheat systems in the IGP.
Notes 1 The Rice Wheat Consortium of the Indo-Gangetic Plains (RWC; www.rwc.cgiar. org) brings together international and national agricultural researchers from Bangladesh, India, Nepal, and Pakistan. 2 Pal S., Jha A.K., Goel R., and Gulia P.K. 2003. Ploughing Against Traditional Wisdom: Impact of resource conservation technologies for the rice-wheat system. National Centre for Agricultural Economics and Policy Research: New Delhi, India.; RWC. 2004. Highlights 2003–2004. Rice–Wheat Consortium for the Indo–Gangetic Plains: New Delhi, India. 3 Parwez M.S., Malik R.K., Rai K.N., and Morris M.L. 2004. Diffusion of Zero-Till Seed Drills in Haryana. Internal report. Rice-Wheat Consortium for the IndoGangetic Plains: New Delhi, India.
October 2006
Prepared by Green Ink Ltd (www.greenink.co.uk)
promoting NRM technologies by playing the role of a technically competent, honest broker.