Utilizing the Genetic Potentials of Traditional Rice Varieties and Conserving Rice Biodiversity with System of Rice Intensification Management

The genetic potentials of rice cultivars will need to be expressed to their fullest if global rice production is to be expanded enough by 2050 to meet the increased demand of the expanding population while the availability of land and water per capita dwindles. New and 'improved' rice varieties have contributed greatly to increased production over the past 50 years, but the rate of rice yield increase based on genetic changes has declined in recent decades compared with the early years of the Green Revolution. In fact, many rice consumers continue to prefer to consume 'traditional' rice varieties (referred to also as local, native, unimproved, or indigenous varieties) because of their taste, aroma, texture, and other qualities. Furthermore, many farmers prefer to cultivate these varieties because of their better adaptation to local climatic and soil conditions and their evolved resistance to endemic stresses. The practices that comprise the System of Rice Intensification (SRI), including transplanting rice seedlings at a young age, wide spacing between plants, keeping the soil well aerated rather than inundated, and enhancing soil organic matter, provide traditional rice varieties with micro-environments that are more favorable for the expression of their genetic and agronomic potentials. Interactions among rice plants, soil characteristics, water, energy, and other inputs improve the phenotypic and physiological performance of rice plants. This paper considers how the cultivation of traditional rice varieties with SRI methods can raise yields, reduce farmers' costs of production, and generate higher incomes while contributing to the conservation of rice biodiversity.