Review of SRI modifications in rice crop and water management and research issues for making further improvements in agricultural and water productivity

Abstract

Much of the focus of agricultural improvement efforts in recent decades has been on modifying crops' genetic potential more than on improving cropping practices and production systems. Certainly, this genocentric approach has made significant contributions to food production in certain parts of the world under the banner of ''the Green Revolution.'' Yields have been raised substantially through varietal improvements and the increased use of inputs, including energy, agrochemicals, and delivering more water to crops through irrigation technology. In the past two decades, however, gains from this strategy have decelerated, with increasing economic and environmental costs of this input-dependent approach. Accordingly, there is reason to consider what can be accomplished by making optimizing changes in crops' growing environments both above ground and, especially, below ground. The System of Rice Intensification (SRI) developed in Madagascar has been showing that, by modifying crop, soil, water and nutrient management, it can under most of the circumstances evaluated thus far raise of the productivity of land, water, seeds, capital, and labor used for irrigated rice production. This article summarizes and reflects on the evidence provided in the preceding articles in this special issue. It draws on the scientific evaluations and field experience from Asia, Africa, and Latin America to offer some conclusions about the methodology known as SRI. Since this methodology is still evolving, no final assessment is possible. Much more research and evaluation remain to be done, and there will be further modifications and refinements since making adaptations to local conditions is regarded as intrinsic to the methodology. Further improvements in SRI will come from both researchers and farmers, with the latter considered as partners rather than simply adopters. This is consistent with SRI's representing a paradigm shift more than a fixed technology. The article identifies a number of areas for additional research that can probably improve factor productivity still further.

【Short Report】Influence of the Improved System of Rice Intensification (SRI) on Rice Yield, Yield Components and Tillering Characteristics under Different Rice Establishment Methods

“…Chen et al (2006) attributed the rice yield improvement in SRI to the increased panicles per area. However, Tao and Ma (2003) found that heavy panicles might be the key to the high yield performance in SRI, which was in agreement with the hypothesis that SRI rice plants had an advantage in individual tillers (Kassam et al, 2011;Zhu et al, 2011). Our results indicate that SRI might play an important role in single panicle development in MT and TP, which provided evidence for the importance of a strong individual tiller.…”

“…The positive effect of SRI on TP rice has been well documented (Stoop et al, 2002;Lin et al, 2005;Kassam et al, 2011;Zhu et al, 2011). In the current study, similar results were found in the TP and MT systems.…”

“…The system of rice intensification (SRI), a widely used but controversial rice cultivation method developed in Madagascar during the early 1980s (Dobermann, 2004;Sheehy et al, 2004;Stoop et al, 2009;Uphoff et al, 2009;Kassam et al, 2011), has generated considerable global debate. According to Stoop et al (2002), SRI is not a fixed technological package, but rather a set of principles for raising the productivity of all of the factors involved in rice production, including land, labor, capital, seed and water.…”

Innovating at the margins: the System of Rice Intensification in India and transformative social innovation

“…The rapid growth of the Internet, through e-mail and websites, and more recently social media, helped the spread of SRI across the world with continuous adaptation. An estimated 10 million farmers across 50 countries have experimented with many or all SRI principles on more than 4 million hectares (Kassam et al 2011. Most of the spread of SRI has been from five Asian countries-China, India, Vietnam, Indonesia, and Cambodia.…”

Agricultural intensification in Nepal, with particular reference to systems of rice intensification

“…These papers invited responses from the SRI community (Stoop and Kassam 2005;Uphoff et al 2008;Stoop et al 2009;Kassam et al 2011). Especially claims of very high yields, yields that went beyond what is considered the yield potential for rice, raised much commentary.…”