基于EPIC模型的黄土高原旱地草粮轮作田土壤湿度模拟

Soil moisture simulation of cereal-alfalfa rotation system in the arid-land Loess Plateau based on EPIC model

土壤水分是黄土高原地区粮食生产的关键因子,EPIC模型自建立以来在世界范围内得到了广泛的应用,是研究土壤水分动态的有效工具,因此,在黄土高原地区验证EPIC模型的土壤湿度模拟精度对该地区土壤水分的模拟研究具有重要的现实意义。本研究应用长期定位试验观测值和EPIC模型对草粮轮作田[苜蓿(Medicagosativa)-苜蓿-苜蓿-苜蓿-马铃薯(Solanumtuberosum)-冬小麦(Triticumaestivum)-冬小麦-冬小麦]土壤湿度进行了模拟研究。结果表明,在苜蓿草地、冬小麦田和马铃薯田中0~2.0 m土层土壤湿度的观测值和模拟值相关系数分别为0.756、0.973和0.790,RMSE值分别为0.028、0.011和0.023 m/m;模拟值与观测值的土壤湿度剖面分布总体上一致。EPIC模型能够较好模拟草粮轮作田土壤水分的动态变化规律,可以用来模拟研究黄土高原草粮轮作田土壤水分动态变化及其土壤湿度的剖面分布。建立合理的土壤数据库和作物根系分布方程将会进一步提高模型对土壤湿度的模拟精度;增加模型中的土层数有利于提高模型对深根系作物土壤湿度的模拟精度。

Soil moisture is a key factor affecting the crop production in the Loess Plateau.Erosion Productivity Impact Calculator(EPIC) model has been widely applied to effectively simulate soil water throughout the world since it has been established.The long-term experimental data from forage-cereal rotation land(alfalfa-alfalfa-alfalfa-alfalfa-potato-winter wheat-winter wheat-winter wheat) was used to evaluate the accuracy of simulated soil water by EPIC model.This study showed that mean correlation coefficients b...