辽西玉米秸秆深还田对土壤团聚体特征的影响研究

Study on the Effect of Maize Stalk Returning on Soil Aggregates in the Western Liaoning Province

摘要: 秸秆还田可以影响土壤结构和养分储备，这对可持续农业至关重要。为了探讨秸秆还田对土壤团聚体稳定性的影响，本研究通过大田试验，采用秸秆深埋还田开沟扶垄犁深施玉米秸秆的方法，比较了整秸秆还田和碎秸秆还田两种模式下，不同秸秆还田量对土壤团聚体分布特征及团聚体稳定性的影响。研究结果表明：秸秆还田对辽西地区土壤团聚体的形成具有一定的促进作用，整秸秆还田和碎秸秆还田均促进土壤中大团聚体(>0.25 mm)的形成，土壤的平均重量直径增加，分形维数下降，碎秸秆还田更利于土壤大团聚体的形成，亚表层土壤团聚度略高于表层土壤。秸秆还田量以400 kg/667 m2~1200 kg/667 m2为宜。研究结果为辽西地区秸秆还田改良土壤结构提供一定的理论依据。

Abstract: Maize stalk return can affect soil structure and soil nutrient stocks, which are important for sus-tainable agriculture. To study the effect of the maize stalk returned on stability of soil aggregate, this study adopted the plough for deep furrowing and ridge of maize stalk through the field trials, compared the effect of different quantity of maize stalk returned on soil aggregate distribution and stability under two modes of whole maize stalk returned and crushed maize stalk returned. The results show that, in the western Liaoning province, the corn stalk return had significantly (p < 0.05) higher soil aggregate stability than CK, both the whole maize stalk returned and crushed maize stalk returned can promote the format of macro-aggregates (>0.25 mm) in soil, the mean weight diameter of the soil aggregates increased and the fractal dimension decreased at all depths, yet the crushed maize stalk returned was more efficiency. Subsurface soil agglomeration was slightly higher than surface soil. The amount of maize stalk returned was better from 400 to 1200 kilogram per 667 square meter. The results will provide a theoretical basis for improving the soil structure by returning maize stalk to the field in the western Liaoning province.