Simulation of soil water leaching and nitrate-N loss with leachate in the field using HYDRUS-1D model.

Based on a stationary experiment,soil water leaching deep drainage and nitrate-N loss with leachate in a soil(yellow fluvo-aquic soil)representative of the Huang-Huai-Hai Plain were simulated with the HYDRUS-1D model.The results showed that under conventional water and nitrogen management,percolation of soil water and nitrate leaching were very serious in the soil,causing a loss of about 23.7% of the total amount of irrigation and precipitation,and about 15.9% of the total N applied during two successive rotations;the amount of nitrate leaching in the season of winter wheat was higher than in the season of summer maize;and the modified irrigation and fertilization management pattern reduces the nitrate-N loss by 74.7% as was compared with the conventional one,thus saving 211.5 mm of irrigation water and N 423.5 kg·hm~(-2).