关键词: 大气降水-土壤-作物系统, 旱作农业, 节水灌溉农业, 水分利用率

Abstract: According to the analysis of the precipitation-soil-crop system in Huang-Huai-Hai plain, this paper suggests that due to the midsummer rainfall plays an very important role in supplying water to crops, so in this plain dryland farming have greater potentialities.In case of irrigation area which can not be largely improved recently, we should develop at the same time the dryland farming and irrigated farming in this area, and possibly use the natural resources (Climate, underground water and so on) to develop the dryland farming. In other case, we should also study the rule of water consumptioni n irrigation areaed for limit irrigation water. Some technique can be used for raising the efficiency of water utilization, such as the use of chemical fertilizer, antt-infil-tration irrigation system etc.

Key words: precipitation-soil-crop system, reinfed agricul ure, limit irrigation water use efficieucy