Predicting Water Movement in the Soil Profile of Corn Fields with a Computer-Based STELLA Program to Simulate Soil Water Balance

A simplified one-dimensional model STELLA was used to predict soil water movement in Illinois corn fields using soil water balance sheets. It offered the potential to increase understanding of soil nitrate and agrochemical leaching process. The model accounted for all possible annual inputs and outputs of water from a closed ecosystem as represented by corn fields. Water inputs included precipitation, while outputs included runoff, transpiration, evaporation and drainage. To run the model required daily inputs of two climatic data measurements such as daily precipitation and pan evaporation.