Nutrient Budgeting Using NUTMON - Toolbox in an Irrigated Farm of Semi Arid Tropical Region in India - A Micro and Meso Level Modeling Study

Mining of nutrients from soil is a major problem causing soil degradation and threatening long-term food production in developing countries. In present research, an attempt was made for carrying out nutrient budgeting, which includes the calculation of nutrient balance at micro (plot / field) and meso (farm) level and evaluation of trends in nutrient mining / enrichment. A nutrient budget is an account of inputs and outputs of nutrients in an agricultural system. NUTrient MONitoring (NUTMON) is a multiscale approach that assess the stocks and flows of N, P and K in an well defined geographical unit based on the inputs viz., mineral fertilizers, manures, atmospheric deposition and sedimentation and outputs of harvested crop produces, residues, leaching, denitrification and erosion losses. The nutrient budgeting research in an irrigated farm at Coimbatore district revealed that the nutrient management practices are not appropriate and sustainable. Soil nutrient pool has to offset the negative balance of N and K, hence there is an expected mining of nutrient from the soil reserve in the research area. The management options / policy interventions to mitigate this mining by manipulating all inputs and outputs in a judicious way with an integrated system approach are suggested and one of the ways for redefining the fertilizer recommendation based on site specific using DSSIFER (Decision Support System for Integrated Fertilizer Recommendation) was worked out.