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

围绕本区旱作农田生产现实,运用“肥力梯度”田区研究,和联合国FAO推荐的概算等方法,所展现出各气候类型区主要作物耗水系数,和降水应能实现的生产潜力,虽低于灌溉农田的热量生产潜力,却也令人鼓舞。研究揭示,现阶段高原旱作农田降水生产潜力受制于地力水平,即在一定范围内,地力水平与耗水系数、作物产量密切相关。研究指出:“干旱固然是高原农业生产经常威胁,然而地力不足,乃是导致水分无谓耗损的更为直接原因”。多种途径,有所侧重地培肥地力,是使降水的潜在生产力充分化为现实生产力的重要方面。

THE PRODUCTIVE POTENTIAL OF PRECIPITATION OF DRY FARMING AND ITS EXPLOIRATION IN THE SEMIARID AND SUBHUMID AREAS OF NORTHWESTERN LOESS PLATEAU

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.