不同可降解膜覆盖对一维土柱土壤水分入渗和蒸发的影响

Effects of Different Degradable Membranes on Soil Water Infiltration and Evaporation in One-dimensional Soil Column

为了探索可降解膜覆盖对农田灌溉的影响机理,通过室内土柱试验,对普通地膜和三种不同可降解膜以及无膜覆盖条件下蒸发前后水分分布、不同时段蒸发量、不同土层温度进行了对比研究。结果表明:入渗结束后覆膜,经48 h的重分布,各处理组均可以对水分起保水作用,有效提高地下15~25 cm土壤水分含量,BD2处理(B型完全生物降解地膜,厚0.010 mm,主要成分PBAT设计降解诱导期60 d)的效果优于其他两种可降解膜,覆膜对5~15 cm土壤温度的保温作用明显。覆膜能抑制土壤水分蒸发,经过192 h各处理的累积蒸发量呈规律性增长,三种可降解膜对比可知:BD2处理对水分蒸发作用抑制明显,其保水保温作用与普通地膜差异不大,但可降解膜BD2处理最优。该研究可探明可降解膜覆盖对一维土柱土壤水分运动规律,并为建立相关模型提供参考。

In order to explore the mechanism of the effect of biodegradable film covering on farmland irrigation,the indoor soil column test is carried out to compare the water distribution before and after evaporation,the evaporation amount in different periods,and the temperature of different soil layers under common film and three different degradable films and without film covering conditions.The results show that after the infiltration,the film is re-distributed for 48 h,and each treatment group can maintain water retention effect,effectively improve the soil moisture content of 15~25 cm underground,and BD2 treatment(type B complete biodegradable mulch film,thickness 0.010 mm,the main component PBAT design degradation induction period 60 d)is better than the other two degradable membranes,the film has a significant heat preservation effect on 5~15 cm soil temperature.The film can inhibit the evaporation of soil water.The cumulative evaporation of each treatment after 192h increases regularly.The comparison of the three degradable membranes shows that BD2 treatment has obvious inhibition on water evaporation,and its water retention and heat preservation effect is not much different from ordinary film.The degradable film BD2 is optimally processed.This study can determine the law of soil moisture movement of one-dimensional soil column by degradable membrane covering,and serve as a reference for establishing related models.