Book excerpt: The System of Rice Intensification, known as SRI, is a management strategy for crop improvement. Its ideas, insights and practices are based on scientifically validated knowledge for increasing the production of not only irrigated rice but of other crops as well. SRI represents a paradigm shift in agricultural thinking and practice toward agroecological farming that can be used by even the poorest smallholding farmers in ecologically fragile regions of the world to achieve food security in the face of the climate-change challenges ahead. When the author Norman Uphoff first learned about SRI in Madagascar in 1993, this production system which offered higher yields with reduced inputs seemed implausible to him. But the professor put aside his skepticism after seeing farmers who had been getting rice yields of just two tons per hectare produce four times more rice-for three years in a row-on their very poor soils, not changing their varieties or relying on agrochemical inputs, and using less water. Now, he's helping to disseminate this dramatically effective methodology with this accessible, easy-to-use sourcebook. It offers explanations, research references, vivid pictures, and concrete examples of the award-winning SRI methodology to anyone interested in the development of practicable sustainable food systems. Now, he's helping to disseminate this revolutionary methodology with this accessible, easy-to-use primer. It offers explanations, resources, and concrete examples of the award-winning SRI to anyone interested in the development of practicable sustainable food systems.