应用EPIC模型计算黄土塬区作物生产潜力的初步尝试

The application of EPIC model to calculate crop productive potentialities in loessic yuan region

黄土高原地区土壤侵蚀强烈,土地现实生产力水平低,研究该地区作物生产潜力可以为有效提高作物产量及合理进行农业生产规划提供依据。论文介绍了EPIC(侵蚀—生产力影响计算模型)的特点、组成部分及应用步骤,对部分作物参数进行了修订。以黄土塬区冬小麦和春玉米为例,对EPIC模型的适用性进行了分析和验证,表明EPIC在黄土高原地区作物生产潜力模拟研究中具有较好的适用性。结果显示,冬小麦产量模拟值与实测值之间多年平均误差为7.78%;春玉米多年平均误差为9.60%。冬小麦水分胁迫天数多年平均为9.9天,最少为1.7天(1993年),最多为23.1天(1995年);春玉米水分胁迫天数多年平均为13.4天,最少为1.1天(1993年),最多为44.2天(1995年),与各年作物生育期降水情况基本一致。此模型经修正后在正常年份模拟值较为精确,在干旱年份对作物、土壤等参数的修正方法需要进一步探讨。

In Loess Plateau,soil erosion is very intensive,and the actual productivity is low.To study the region's crop yield potential can offer grounds for increasing crop yield and conducting agricultural production programming.This paper introduces the characteristics,component,and application procedure of EPIC,and revises some crop parameters.Taking the maize and wheat as example,we proved that there is a good adaptability for EPIC model to be used in Loess Plateau for crop productivity simulation research.The results indicated that the average deviation between simulated and measured values for wheat was7.78%,that for maize9.60%;the number of annual average water stress days of wheat was9.9,the minimum was1.7,the maximum was23.1,that of maize was13.4,1.1,22.1.These values are in accordance with actual rainfall condi tions of the growing period of the above mentioned crops.The revised model is very accurate in normal years,but it is necessary to improve the revision method of the crop and soil parameters in arid years.