Simulation model for agricultural non-point-source pollution [Water pollution]

A mathematical model has been developed for the estimation of nitrogen and phosphorus losses from croplands. The model predicts dissolved and solid-phase nitrogen and phosphorus in runoff and dissolved nitrogen percolation. The model does not require calibration and its parameters are determined from secondary data sources. Meteorological inputs are daily precipitation, temperature, and storm durations. Testing of the simulation model on field sites indicates that predicted nutrient losses are reasonably accurate and capture significant variations between fields and climatic regions. The model is well suited for evaluating non-point-source controls such as crop management, timing of field operations, soil and water conservation practices, and the timing and amounts of fertilizer applications. The model does not provide reliable estimates of nutrient losses associated with disposal of organic wastes.