Sustainability in Rice Production in Southern Brazil.

            Flooded rice is grown over 1.2 million hectares in southern Brazil, with 7.3 ton/ha of average yield.  Crop sustainability is centered in five main objectives: preserving landscape, avoiding water and soil contamination, maximizing use efficiency of natural resources, pesticides and fertilizers, improving biodiversity and storing carbon in the soil and reducing methane emissions. The landscape management program selects suitable areas for rice production, for irrigation and drainage systems and for protection of surrounding areas by using riparian vegetation along rivers, lakes and small dams. These and other practices, such as soil management, avoid water contamination and nutrient and pesticides dispersion to water bodies and surrounding soils. Also, no drainage is allowed for at least 30 days after any pesticide is applied in order not to contaminate water and nearby soil. Natural resources use is optimized by controlled water management practices, shallow water level and no drainage, all in order to produce 1 kg rice per cubic meter water. Solar radiation efficiency is maximized by using high yield capacity varieties along with optimal date of seeding, in order to capture most of the radiation when it is at its maximum. Efficient use of pesticides is improved by using integrated pest management practices. The same system holds for weeds. Fertilizers are efficiently used by detecting crop needs trough soil analysis and applying the correct amount based on models of crop nutrient response. Rice fields are a source of very rich biodiversity. The species abundance indicates a healthy environment where a series of organism can survive and develop. Rice fields are of crucial importance to wildlife surviving during stress periods, especially during rainfall shortage, when surrounding food sources are scarce. By using no-till system more carbon can be stored in the soil organic fraction and methane emission can be reduced.