A model for soil water and nitrogen transport in water storage pit irrigation

In order to improve the use efficiency of nitrogen fertilizer and decrease the loss of nitrogen fertilizer, a two-dimensional mathematical model on soil water movement and nitrogen transformation was set up by integrating the basic equation of soil water and nitrogen transport with characteristics of water and nitrogen transport in soil under water storage pit irrigation, and solved numerically by finite volume method. The model verification results showed that good agreement was obtained between simulated and measured values of soil water contents, ammonium concentrations and nitrate concentrations. It indicated that the mathematic model was correct and solving the model with finite volume method was feasible, the mathematical model can be satisfactorily used to describe the soil water and nitrogen transport properties under water storage pit irrigation.