THE PRODUCTIVE POTENTIAL OF PRECIPITATION OF DRY FARMING AND ITS EXPLOIRATION IN THE SEMIARID AND SUBHUMID AREAS OF NORTHWESTERN LOESS PLATEAU
西北黄土高原半干旱—半湿润地区旱作农田降水生产潜力及开发途径

The efficiency of Soil Moisture Consumption (ESMC) and the Productive Potential of Precipitation (PPP) of several mainly planted crops in different agrometeorological areas of Northwestern Loess Plateau are obtained from both the field trial of fertilizer and calculat-nig with the formula recommended by FAO. Results show that PPP of dry farming in the Loess Plateau, though lower than the Productive Potential of Hearer irrigation farming, is rather, great and varies as soil fertility changes, i.e., ESMC and crop yield are closely interrela-ted with soil fertility. Studies indicate that, although drought often threats agriculture in Loess PJateau, lowness soil fertility is a more direct limiting factor. Thus to better soil fertility is a important way to bring the potential productivity into real productivity.