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Is ecological agriculture productive? A key question that is often asked about ecological agriculture, including organic agriculture, is whether it can be productive enough to meet the world’s food needs. While many agree that ecological agriculture is desirable from an environmental and social point of view, there remain fears that ecological and organic agriculture produce low yields. Please find below a paper that summarizes some of the available evidence to demystify the productivity debate and demonstrate that ecological agriculture is indeed productive, especially so in developing countries. With best wishes, Third World Network Is Ecological
Agriculture Productive? Introduction A key question that is often asked about ecological agriculture, including organic agriculture, is whether it can be productive enough to meet the world’s food needs. While many agree that ecological agriculture is desirable from an environmental and social point of view, there remain fears that ecological and organic agriculture produce low yields. This short paper will summarise some of the available evidence to demystify the productivity debate and demonstrate that ecological agriculture is indeed productive. In general, yields from ecological agriculture can be broadly comparable to conventional yields in developed countries. In developing countries, ecological agriculture practices can greatly increase productivity, particularly if the existing system is low-input, which is the largely the case for Africa. This paper will focus mainly on evidence from developing countries. Evidence from global modelling A recent study examined a global dataset of 293 examples and estimated the average yield ratio (organic : non-organic) of different food categories for the developed and developing world (Badgley et al., 2007). For most of the food categories examined, they found that the average yield ratio was slightly less than 1.0 for studies in the developed world, but more than 1.0 for studies in developing countries. On average, in developed countries, organic systems produce 92% of the yield produced by conventional agriculture. In developing countries, however, organic systems produce 80% more than conventional farms. With the average yield ratios, the researchers then modeled the global food supply that could be grown organically on the current agricultural land base. They found that organic methods could hypothetically produce enough food on a global per capita basis to sustain the current human population, and potentially an even larger population, without putting more farmland into production. Moreover, contrary to fears that there are insufficient quantities of organically acceptable fertilizers, the data suggest that leguminous cover crops could fix enough nitrogen to replace the amount of synthetic fertilizer currently in use. This model suggests that organic agriculture could potentially provide enough food globally, but without the negative environmental impacts of conventional agriculture. Evidence from reviews of ecological agriculture projects In a review of 286 projects in 57 countries, farmers were found to have increased agricultural productivity by an average of 79%, by adopting “resource-conserving” or ecological agriculture (Pretty et al., 2006). A variety of resource conserving technologies and practices were used, including integrated pest management, integrated nutrient management, conservation tillage, agroforestry, water harvesting in dryland areas, and livestock and aquaculture integration into farming systems. These practices not only increased yields, but also reduced adverse effects on the environment and contributed to important environmental goods and services (e.g., climate change mitigation), as evidenced by increased water use efficiency and carbon sequestration, and reduced pesticide use. The work built on earlier research, which assessed 208 sustainable agriculture projects. The earlier research found that for 89 projects for which there was reliable yield data, farmers had, by adopting sustainable agriculture practices, achieved substantial increases in per hectare food production - the yield increases were 50-100% for rain-fed crops, though considerably greater in a number of cases, and 5-10% for irrigated crops (Pretty and Hine, 2001). Disaggregated data show:
The database on agricultural sustainability (comprising the 286 projects) was reanalyzed to produce a summary of the impacts of organic and near-organic projects on agricultural productivity in Africa (Hine and Pretty, 2008). The average crop yield increase was even higher for these projects than the global average (79%): 116% increase for all African projects and 128% increase for the projects in East Africa. For Kenyan projects, the increase in yield was 179%, for Tanzanian projects 67% and for Ugandan projects 54%. Moreover, all case studies that focused on food production in this research where data have been reported, showed increases in per hectare productivity of food crops, which challenges the popular myth that organic agriculture cannot increase agricultural productivity. Evidence from specific ecological agriculture interventions Data from the Tigray Project in the Tigray Region in Ethiopia, where a project on ecological agriculture has been carried out since 1996, concretely demonstrate the benefits of compost on productivity. Preliminary data collected in 1998 had already shown that using compost gave similar yield increases as chemical fertilizers. Data collected in 2002, 2003 and 2004 showed that, on average, composted fields gave higher yields, sometimes double, than those treated with chemical fertilizers (Araya and Edwards, 2006). In a new paper written for the UN Food and Agriculture Organization (FAO), statistical analysis on a larger data set over the years 2000 to 2006 inclusive confirms that compost use in Tigray has increased yields in all the crops analysed (Edwards et al., 2008). In total, data was collected from 974 fields from 19 communities. Grain and straw yield data were obtained for barley, durum wheat, finger millet, hanfets (a mixture of barley and durum wheat), maize, sorghum, teff, faba bean and field pea. Except for field pea, the compost generally doubled the grain yield when compared to each respective check (crops grown without any inputs). (For field pea, the increase in yield was approximately 28%.) The difference was significant (95% confidence limit). The application of compost also increased straw yield compared to the check, but not to the same extent as it increased grain yield. The use of compost also gave higher yields than the use of chemical fertilizer, though differences in the yields from compost and from chemical fertilizer were not as great as the differences between the use of compost and the check. For sorghum and faba bean the yields from the use of compost and chemical fertilizer were similar. But the yield difference for all the other crops was greater with that from the compost treatment being always higher than that from the use of chemical fertilizer. The results also showed that compost not only increases the overall biomass yield, but also increases the proportion of the grain to straw in the yield. Since 1998, the Bureau of Agriculture and Rural Development of Tigray Region has adopted the making of compost as part of its extension package and by 2007 at least 25% of the farmers are making and using compost. A reflection of the success of this approach is that between 2003 and 2006, grain yield for the Region almost doubled from 714 to 1,354 thousand tonnes. Since 1998, there has also been a steady decrease in the use of chemical fertilizer from 13.7 to 8.2 thousand tonnes. There are many other specific examples of increased yields following the application of ecological agriculture practices, some of which are summarized below (Hine and Pretty, 2008; Parrott and Marsden, 2002; Pretty and Hine, 2001; Scialabba and Hattam, 2002). In Africa:
In Latin America:
In Asia:
Conclusion It is clear that ecological agriculture is productive and has the potential to meet food security needs, particularly in the African context. The International Assessment of Agricultural Knowledge, Science and Technology for Development concurs that an increase and strengthening of agricultural knowledge, science and technology toward agroecological sciences will contribute to addressing environmental issues while maintaining and increasing productivity (IAASTD, 2008). Moreover, ecological agricultural approaches allow farmers to improve local food production with low-cost, readily available technologies and inputs, without causing environmental damage. References Araya, H. and Edwards, S. 2006. The Tigray experience: A success story in sustainable agriculture. Third World Network Environment and Development Series 4. TWN: Penang. Badgley, C., Moghtader, J., Quintero, E., Zakem, E., Chappell, M.J., Avilés-Vázquez, K., Samulon, A. & Perfecto, I. 2007. Renewable Agriculture and Food Systems, 22: 86-108. Edwards, S., Asmelash A., Araya, H. and Egziabher, T.B.G. 2008. The impact of compost use on crop yields in Tigray, Ethiopia, 2000-2006 inclusive. Hine, R. and Pretty, J. 2008. Organic agriculture and food security in Africa. United Nations Conference on Trade and Development (UNCTAD) and United Nations Environment Programme (UNEP): Geneva and New York. IAASTD. 2008. International Assessment of Agricultural Knowledge, Science and Technology for Development. www.agassessment.org Parrott, N. and Marsden, T. 2002. The real Green Revolution: Organic and agroecological farming in the South. Greenpeace Environment Trust: London. Pretty, J. & Hine, R. 2001. Reducing food poverty with sustainable agriculture: a summary of new evidence. UK: University of Essex Centre for Environment and Society. Pretty, J.N., Noble, A.D., Bossio, D., Dixon, J., Hine, R.E., Penning de Vries, F.W.T. & Morison, J.I.L. 2006. Resource-conserving agriculture increases yields in developing countries. Environmental Science and Technology (Policy Analysis) 40(4): 1114-1119. Scialabba, N.E-H. and Hattam, C. (eds). 2002. Organic Agriculture, Environment and Food Security. Rome: FAO.
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