不同栽培年限日光温室土壤团聚体的组成及稳定性

目的]揭示不同栽培年限日光温室土壤团聚体分布及稳定性的变化趋势,为探明设施蔬菜栽培土壤结构变化规律提供理论依据。方法]以辽宁省新民市设施蔬菜栽培基地温室土壤为研究对象,并以温室外露地土壤为对照,研究了栽培年限为2,5,8,16a的日光温室土壤团聚体不同粒级的组成分布、机械稳定性、水稳性和团聚体破坏率的变化趋势。结果]不同栽培年限的土壤0.25mm团聚体数量、机械稳定性和水稳性均呈降低趋势,且低于露地土壤;栽培时间长于5a后,0.25mm团聚体数量、机械稳定性和水稳定性有所升高。供试土壤在栽培初期,土壤中有机质对团聚体的形成和稳定性维持没有起到促进作用,随着栽培时间的增长,有机质促进了团聚体的形成和稳定。结论]研究区域温室土壤团聚体稳定性随栽培年限的增长呈先降低后升高的趋势。

Size Hierarchy and Stability of Soil Aggregates in Solar Greenhouse Soils with Different Planted Years

Objective] Changing trends of size hierarchy and stability of soil aggregates in solar greenhouse soils were illustrated along years of plantation to provide some theoretical bases for the change of soil structure in vegetable cultivation.Methods] Soils with different plantation years in four vegetable greenhouses(with 2, 5, 8 and 16 years of plantation)in Xinmin City of Liaoning Province were selected as the research objects, and nearby soils in open fields outside of the greenhouses were selected for comparison. Indices of composition, mechanical stability, water stability and damage rate of soil aggregate were measured.Results] Within 5 years of plantation, quantity of >0.25 mm, mechanical stability and water stability of soil aggregates showed a decreasing trend along plantation, and they were lower than that of the comparative soil in open fields; After 5 years of plantation, they all were elevated significantly. At the beginning of the cultivation of the tested soil, organic matter didn't play its role in the aggregate formation and stability maintenance; While, with the increase of planting time, organic matter began to promote the formation and maintain the stability of soil aggregates.Conclusion] The stability of soil aggregate in the regional greenhouse decreased firstly and then increased with the increase of the planting years.