地膜和秸秆覆盖土壤肥力效应分析与比较

Analysis and Comparison of the Effects of Plastic Film Mulching and Straw Mulching on Soil Fertility

目的通过研究地膜(PM)和秸秆(SM)覆盖土壤肥力效应的特点,为二者的选择利用提供依据。方法利用盆栽和大田试验研究了地膜和秸秆覆盖对玉米农田土壤水分、温度、养分和微生物影响的差异。结果地膜和秸秆覆盖都有明显保水作用,但前者主要表现为增加了表层土壤水分含量,深层土壤含水量反而明显降低,而后者各层土壤水分都有明显提高;地膜覆盖兼有显著的增温效应,而秸秆覆盖土壤温度却明显低于对照,但在冬季低温短日照条件下,地膜覆盖土壤温度反而低于秸秆覆盖;秸秆覆盖不同程度地增加了土壤有机质和速效氮、磷、钾等养分含量,而地膜覆盖无此作用,甚至降低了表层土壤有机质含量;秸秆和地膜覆盖都不同程度地增加了土壤三大种群微生物数量,但秸秆覆盖增加幅度大于地膜覆盖。结论覆盖的主要目的是增温时,应选择地膜,主要目的是保水时,秸秆的效果更好,同时秸秆覆盖还具有增加土壤养分和生物活性的作用。

[ Objective ] The characteristics of effects of plastic film mulching （PM） and straw mulching （SM） on soil fertility were compared for their selective utilization. [ Method] The effects of PM and SM on soil moisture, temperature, nutrients, and microorganisms were studied in pot and field experiments. [ Result] Both of SM and PM had significant moisture-keeping capacity. SM increased soil moisture from the surface to the deep layers, but PM only increased soil moisture in the surface layer and the soil moisture decreased significantly in the deeper layers. PM also increased soil temperature significantly, and the soil temperature in SM treatment was lower than that in CK in the corn growing period, but the soil temperature in PM treatment was lower than that in SM treatment in winter season. SM increased soil organic matter and available N, P, and K to varying degrees and PM didn＇t, while soil organic matter in the surface layer decreased in PM treatment. SM and PM increased the quantities of bacteria, fungus, and actinomyces in soil, and the increases of soil microorganisms were bigger in SM treatment than in PM treatment. [Conclusion] Plastic film should be selected when the aim of mulching is to increase temperature. The effect of SM is better than that of PM when the aim of mulching is to keep soil moisture. SM also has the roles of increasing soil nutrients and bio-activity.