Soil-nutrient-water management for maximising crop yields

Water management practices for maximization of crop yields both under irrigated agriculture as in wheat and under inundated conditions as in rice are discussed. Rate limiting steps for the migration of nutrient-ions under different moisture conditions are discussed and the relative importance of mass flow, diffusion and dispersion is indicated. Soil-water-nutrient interactions studied using phosphorus 32P, sulphur 35S and zinc in different soil types under different moisture conditions are discussed. The need for an intensive study of these interactions on field crops for evolving cultural practices required for miximising crop yield is indicated. (author)