灌溉地区由于地下水位升高而引起的土壤次生盐溃化,常常成为提高农作物产量的主要障碍。在这种情况下,各种降低地下水位的措施都应重视。沿渠道的农田防护林带的排水作用,在国内外都有过研究,并日益引起更多的注意。 灌溉地区的农田防护林,除了防风和改善农田小气候外,还有显著的排水作用。沿渠道的林带象抽水机一样,将土壤深层的水份散发到空气中,减少渠道渗漏水对地下水的补给,降低地下水位,减轻渠道两侧农田土壤的次生盐渍化。 Soil secondary salinization in irrigated areas due to an increase in groundwater level is often a major obstacle to increasing crop yields. Under such circumstances, various measures to reduce the water table should be taken seriously. Drainages from farmland shelterbelts along the canal have been studied both at home and abroad and have drawn increasing attention. Irrigated areas of farmland shelterbelts, in addition to windbreak and improve the microclimate of farmland, there are significant drainage. The forest along the channel resembles a water pump, distributing the deep water of the soil to the air, reducing the supply of seepage water to the groundwater, lowering the water table and alleviating the secondary salinization of farmland soil on both sides of the canal.