以大水位埋深的栾城试验站为例,开展玉米秸秆覆盖及对照条件下冬小麦田间试验,运用土壤水分通量法和包气带水均衡的原理,分析了秸秆覆盖农田的土壤水分效应。结果表明在大水位埋深条件下,覆盖秸秆麦田的入渗补给量(165.02 mm)小于不盖秸秆(192.91 mm),作物腾发量和土壤水消耗量大于不覆盖处理,说明秸秆覆盖不利于降水、灌溉水的入渗补给,但可以抑制土壤水分棵间无效蒸发,增加作物蒸腾量,充分利用土壤水,从而提高土壤水分的利用效率,揭示了秸秆覆盖对农田土壤水分调控的机理,为干旱区推广秸秆覆盖技术提供了理论依据。同时,对大水位埋深条件下土壤水分通量法的适用性进行了探讨。
In this paper,field experiments of winter wheat with or without corn straw mulching are carried out at Luancheng Station under deep-water table depth.The soil water flux method and water balance method for unsaturated zone are used to analyze straw mulch's effect on soil water in cropland.The result shows that when water table depth is deep,the recharge amount with straw mulch(165.02 mm)is smaller than that without straw mulch(192.91 mm),but crop evapotranspiration and the change of soil moisture during the growth of winter wheat were bigger.It indicates that straw mulch makes against the infiltration of precipitation and irrigation,restrains evaporation loss of soil water,adds crop transpiration,makes full use of soil water,and use soil water effectively,which reveals the mechanism of straw mulch for soil water control management.The study provides a theoretical foundation for applying straw mulch technique in arid regions.Meanwhile,the application of the soil water flux method is discussed under deep water table depth.