SURPLUS AND DEFICIENCY OF WATER FOR MAIN CROPS AND THE RAINFED FARMING IN THE LOESS PLATEAU
黄土高原主要农作物水分盈亏与雨养农业问题

Climatically, the Loess Plateau is located in a transitional zone between the subhumid and semiarid regions. Water shortage for crops is the key limiting factor in agricultural production. The precipitation and evaporation, the relation between the water demand of main crops and precipitation, and the moisture situation in farmland and the surplus and deficiency of water are discussed in this paper. Based on these, the conclusions are: (1) developing rain-fed farming should be a fundamental policy in agricultural production in the Loess Plateau; (2) apart from millet, other crops are greatly limited by local conditions; (3) the basic way for increasing the production of crops should be to raise the moisture content of the soil and to increase the utilization coefficient of available moisture. So, levelling land, increasing the application of fertilizers and so on should be adopted in order to realize the above purposes.