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土壤覆盖地膜后增加了温度梯度,综述土壤物理学的研究成果,土壤水分是从热区向冷区运动。通过含水均匀的封闭覆膜系统中水分运动的观测和田间测定,以及覆膜防止返盐的效果分析,认为覆膜有抑制深层水分上行的作用。膜内土壤疏松,当含水不太多时,气相比例大,有利于温度梯度引起的水分运动。近地表温度梯度大,水分的下行显著。地膜覆盖作物播种时应考虑到这种水分运动,要求足墒播种,在水分稍差时可适当加深播种深度,或采用深播浅盖的方法。
After the soil mulching, the temperature gradient is increased. The research results of soil physics are reviewed. The soil moisture moves from the hot zone to the cold zone. Through the observation and field measurement of water movement in the closed water-covered film-covered system and the analysis of the effect of preventing the return of salt to the film, it is considered that the film has the effect of inhibiting the upward water upwards. Loose soil in the membrane, when the water is not too much, a large proportion of gas phase, is conducive to temperature gradient caused by water movement. Near the surface temperature gradient, water significantly downstream. Film mulching crops should be considered when sowing this kind of water movement, the requirements of soil moisture sowing, when the water is slightly worse may deepen the depth of planting, or the use of deep shallow cover method.