The System of Rice Intensification
- SRI -

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SRI has the disadvantage of sounding "too good to be true." This is the main reason why it was not taken seriously by agricultural scientists for many years, though this is now changing. Also, it is hard for farmers to believe, for example, that they can get twice as much yield by using only 5 to 10 kg of seed per hectare instead of the 50 to 100 kg per hectare they are used to using -- or that they can achieve this by using only about half as much irrigation water. Additional benefits of SRI are outlined in the 2005 Uphoff article: Features of the System of Rice Intensification apart from Increases in Yield (10p, pdf).

SRI methods increase the productivity of:

  • water -- since yields can double or more with only half as much water, the productivity of water is greatly increased -- this is especially important in countries or places where water is becoming scarcer;
  • land -- yields as indicated above can average about 8 t/ha once the methods are used correctly, and can be twice that or more when they are used with precision and skill;
  • labor -- SRI does require more labor - about 26% in one Madagascar evaluation, 11% in a Sri Lankan survey - but depending on the cost of labor, the value of increased production increases the returns to labor by at least 50% and often several hundred percent. Once the methods have been mastered, the labor requirements for SRI decline. Also, implements are being developed that save labor. In Cambodia, over half the farmers using SRI now report that is is labor-saving for them.

Environmental Benefits: SRI is environmentally-friendly. Reduced demand for water frees up water for other uses; soil that is not kept saturated has greater biodiversity. Unflooded paddies do not produce methane, one of the major "greenhouse gases" that are contributing to global warming. There can be more nitrous oxide from unflooded paddies, which offsets to some extent the gains from reducing methane emissions, but when nitrogen fertilizer is not used, this effect should be small. On balance, SRI should improve environmental conditions.

Equity Considerations: SRI also has the benefit of being particularly accessible for farmers who have small landholdings and need to get the highest yields possible from their available land. Since poorer households have relatively more labor compared to land, SRI is one of the few agricultural innovations that has a bias in favor of equity. It is true that very poor households may find it difficult to invest labor in SRI because they need to be earning daily incomes, even if their returns to labor would be higher from SRI. However, since returns to land, labor and water are all higher with SRI, any household that grows rice and is labor-constrained will do better by using SRI methods on just a part of its landholding, using its other land for production of other crops when labor is available.

Active Role for Farmers: SRI methods are most productive when used with skill and care, so there will probably continue to be long-term advantage for labor-intensive production with SRI. However, SRI should be seen as a set of principles that are applied through various techniques, rather than as a fixed technology to be adopted as a "package." There is synergy among practices that makes their use together more beneficial than just using certain of the practices; but any of the practices should give some improvement in yield. We anticipate that various kinds of mechanization will over time make SRI suitable for larger scale production.

Farmers are encouraged to experiment with the methods and to evaluate the results for themselves, not just to "adopt" SRI. The best spacing between plants, for example, needs to be determined in relation to particular soil, climatic, hydrological and other conditions. Exactly when and how to apply water depends on soil characteristics and field position. So recommendations for spacing, water management, age of seedling, etc. are not offered as universal. Instead, principles are presented -- to be understood, tested and adapted by users to suit their own conditions. It is hoped that what farmers learn from using SRI may help them to become more innovative producers in other respects.

Grain Quality: When SRi paddy is milled, the outturn if often proving to be higher, as there are fewer unfilled grains (less chaff) and fewer broken grains (because they resist shattering). In Andhra Pradesh, India, the rice millers association is promoting SRI and paying a higher rice per bushel, as outturn has gone from about 67% to about 75%. The sugar cooperative in Cuba that has pioneered the new production methods in that country reports that its outturn has gone up from 60% before to 68-71% now with SRI. This adds about 15% more productivity on top of the higher yields of paddy.

Faster Maturing: Farmers are finding that SRI methods often, though not always, reduce the time required for grain maturation. In Cambodia, on average, SRI crops are ripening about 7 days sooner than regular crops of the same variety. In Andhra Pradesh, India, ripening is 7-10 days sooner. (It has been alleged that SRI crops take longer to mature, but this is not the experience in the field.) In Nepal during monsoon season 2004, farmers got more than a doubling of yield (3.37 to 7.85 t/ha) with a 15-day reduction in time to maturity. Being able to harvest sooner reduces farmers' risks of damage from pests or from typhoons, cyclones or other extreme weather than can come the end of the season.

Health Benefits: By reducing the application of agrochemicals in rice production, the resulting grain has little or no chemical residues. No systematic nutritional analyses have been done yet on SRI grains, but the larger root systems could enhance their micronutrient content, suggested by the higher grain weight and greater resistance to shattering. Many things are still not known about SRI in technical terms. This page will be updated as more information becomes available.


The Sustainable Rice Systems Program
Cornell International Institute for Food, Agriculture and Development (CIIFAD)
For more information, contact: The SRI Group
last updated: August 11, 2005

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