Abstract
NUTrient MONitoring (NUTMON) is interactive computer software that helps decision-makers use data and models to solve unstructured problems. An attempt was made to carry out nutrient audits, which include the calculation of nutrient balance at the field (farm) level and the evaluation of trends in nutrient mining/enrichment using the NUTMON-Toolbox. Nutrient Monitoring (NUTMON) is a multiscale approach that assesses the stocks and flows of N, P, and K in a well-defined geographical unit based on the inputs viz., mineral fertilizers, manures, meteorological data, atmospheric deposition, sedimentation, and outputs of harvested crop products, residues, leaching, denitrification, and erosion losses. The nutrient budgeting study was carried out using the NUTMON model for the Long-term fertilizer experiment trial, adopting the standard procedures and calculations (viz., Chemical fertilizers and Integrated nutrient management). The calculated nutrient balances at crop activity level indicated a Positive balance for nitrogen and phosphorus in 100 % NPK + FYM @10 t ha-1, and a negative balance was observed for potassium in all maize treatments. The results revealed that the nutrient management practices are not appropriate and sustainable. Management options to mitigate this mining by judiciously manipulating all inputs and outputs through an integrated system approach are suggested, and one way to redefining the nutrient recommendation based on site-specific requirements was worked out. A strategy was worked out to derive the nutrient prescription rate using site-specific soil test results for the individual crops of the selected farms. By assuming prescribed nutrients are applied to the individual PPUs, nutrient balances were simulated with NUTMON-Toolbox, and the results indicate positive balances for N and P and negative balances for K.