干旱区生态环境知识资源中心

Mining of nutrients from soil is a major problem causing soil degradation and threatening long-term food production in developing countries. In this paper an attempt was made for carrying out nutrient audits, which includes the calculation of nutrient balance at micro- (plot/field) and meso-level (farm) 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 assesses the stocks and flows of N, P, and K in a well-defined geographical unit based on the inputs viz., mineral fertilizers, manures, atmospheric deposition and sedimentation and outputs of harvested crop products, residues, leaching, denitrification, and erosion losses. The calculated nutrient balances at crop activity level indicated a negative balance for cereals and pulses, whereas positive for most of the horticultural crops. Similarly the results showed a negative balance for N and K and positive for P at farm level. Soil nutrient pool has to offset the negative balance of N and K, hence there will be an expected mining of nutrients from the soil reserve in the study 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 also discussed.