【摘要】 <正> 渭北塬区系指陕西黄土高原南部高原区和部分台原区,历来实行旱作农业。七十年代以来,发展了深机井灌溉,灌溉面积达百万亩以上。黄土塬区地下水的赋存特点是埋藏深,储量少。由此产生两个弱点,即单井流量小和提水费用高。因此,确定省水、增产、增收适合本区的灌溉制度和方式,就成为急需研究的新问题。更多还原

【Abstract】 The low irrigation quota system is proposed on the basis of the study on the water conditions of field in the loess plateau of Weibei. This system means to decrease by a big margin the routine irrigation quota accepted now and to increase the utilization efficency of irrigated water Consequently, the irrigation acreage can be extended at a same water supply.The main results obtained from the field experiments show that the irrigation quota may be decreased from 150m~3/mu originally to 70m~3/mu for winter wheat and from 140m~3/mu to no irrigation for corn in the years with normal rainfall. The wheat yield obtained from the low irrigation quota system has attained 96% of the yield from routine irrigation quota system and the utilization efficency of irrigated water is raised from 0.31kg/m~3 to 0.50kg/m~3The low irrigation quota system is based on the combination of using precipitation. soil water and irrigation water. Irrigation water supply can be decreased by making full use of water stored in the soil reservoir, from which wheat can get 150—200 mm water supply every year.更多还原