郑家沟土地作物生产力的估算及其应用

以地貌及其所主导的水热条件、肥力状况和土地利用现状为依据，将郑家沟流域的农耕地分为１０个类型，并在此基础上建立了作物生产力估算模型。对估算结果的分析表明：土壤因素和农业经营管理水平是制约作物生产力提高的主要因素，发展农业的主要措施是坚决退耕２５°以上陡坡地，治理水土流失，改善生产条件，合理调整农作物布局。马铃薯生产力最高，对水分、土壤反应不敏感，应在旱地相对稳定其面积；玉米表现出最大的水分增产潜力，应布局在水地和水分条件较好的川台地和坝地上；大豆的肥力增产潜力最大，应解决土壤含磷不高的问题。

Estimation and Application of Land Crop Productivity in Zhengjiagou

The farmland in Zhengjiagou watershed can be divided into 10 types according to landforms,water and heat condition, fertilizer condition, present situation of land use, and based on these conditions, the estimation model for calculating crop productivity were set up. The analysis of the estimation result indicated that soil type and farm management level are main factors restricting crop productivity, the main measures,for developing agriculture are to retreat from steep farmland with slope gradient over 25°, control soil loss, improve farm condition, reasonally adjust crop distribution etc. Potato has the highest productivity, insensitive to soil fertilizer and water condition, so it should be arranged in dryland with stable area; maize has the greatest water potential to increase output, so it should be arranged in irrigated land, plain and damland with better water condition; beau has the greatest fertilizer potential to increase output, while problem of low phosphorous content should be solved.