中文摘要：

农田土壤水分模拟是农业用水管理的重要依据。以根系层土体水量平衡方程为依据，考虑根系层下界面水分通量，构建了农田土壤水分变化模拟模型，该模型由作物蒸发蒸腾量模型、根区下界面水分通量模型以及水量平衡方程等组成。依据山西水利职业技术学院试验基地2006—2008年3年棉花试验资料，确定了模型参数。结果表明，土壤储水量模拟计算值与实测值有较好的一致性，其相关系数达到0．9287，F检验结果（F=96.44〉R0.001-3．27）达到高度显著水平，所建立的土壤水分变化模拟模型可用于棉花田间土壤水分的模拟计算，计算精度平均达到5．3％～15．8％；模型较好地反映了农田土壤水分转化过程以及降水、蒸发和深层土壤水分对作物蒸发蒸腾及产量的影响。

英文摘要：

Simulation of soil moisture in farmland is the important basis of agricultural water management. Based on the water balanee equation of root zone, taking the lower boundary water flux of root zone into account, a farmland soil moisture simulation model was set up in this paper. It contains crop evapotranspiration model, lower boundary water flux model and water balance equation. The parameters of the model were fixed based on the observation data of soil moisture during the growing season of cotton in irrigation experimental base of Shanxi Technical College of Water Conservancy in 2006-2008 year. The soil moisture value simulated by the model agreed well with the measured ones, the multiple correlation coefficient reached 0. 928 7, the F test result（F42. 06~〉F0.001 2. 83） reached high significance level. The established farmland soil moisture simulation model can be used to calculate the field soil moisture, the mean calculation accuracy can reach 5. 3~ ~ 15. 8~. The model well reflected the field soil moisture conversion process, as well as the effect of precipitation, evaporation and deep soil moisture on crop evapotranspiration and output.