Nutrient Budgeting in Tropical Agro Ecosystem-Modeling District Scale Soil Nutrient Balance in Western Zone of Tamil Nadu Using Nutmon-Toolbox

摘要

This study attempts to apply nutrient monitoring (NUTMON) methodology for carrying out nutrient audits, which includes calculation of nutrient balance at a regional 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. 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. In the present investigation an attempt was made for nutrient budgeting at district scale in a semi-arid region of South India, using NUTMON methodology. Nutrient balance was worked out for Coimbatore district, which is the potential agricultural area in Western Zone of Tamil Nadu, India. The calculated nutrient balances were negative for N (?10.1 kg ha^-1) and K (?9.8 kg ha^-1) and positive for P (21.9 kg ha^-1). Soil nutrient pool has to offset the negative balance of N and K, there will be an expected mining of nutrient from the soil reserve in the study area. The management options to mitigate this mining by manipulating all inputs and outputs in a judicious way with an integrated system approach are also discussed.