Opportunities for water saving with higher yield from the system of rice intensification

The system of rice intensification (SRI) developed in Madagascar, is showing that by changing the management of rice plants, soil, water and nutrients it can increase the yields of irrigated rice by 25-50% or more while reducing water requirements by an equivalent percent. This gives farmers incentive to reduce their irrigation water use when growing rice, especially since SRI methods can also reduce farmers' costs of production which increases their net income ha(-1) by even more than yield. Even though these results sound fantastic, the validity of SRI concepts and practices has been demonstrated in more than 20 countries to date. This article considers, first, the methods that make these improvements possible and how these are achieved. It then briefly surveys SRI experience in five Asian countries, incentives in addition to yield, water-saving and profitability for adopting SRI, and possible limitations or disadvantages with the methodology. Next, it comments on the debate over SRI in the agronomic literature and then adds to the empirical record by reporting in some detail on SRI evaluations in two of India's main rice-growing states, Andhra Pradesh and Tamil Nadu, where water availability is becoming more problematic and where SRI use is spreading. Finally, the article briefly discusses some implications of saving irrigation water by changing resource management rather than by using on more or different inputs.