自然降雨条件下结皮层团聚体稳定性变化特征研究

发布时间：2018-09-11 21:19

【摘要】：通过野外定位监测和室内分析相结合的方法,以三峡库区典型黄壤为研究对象,结合Le Bissonnais(LB)法中快速湿润(FW)、慢速湿润(SW)和预湿润振荡(WS)3种处理方法定量分析结皮层与表土层团聚体稳定性的差异。研究结果表明:在降雨作用下土壤团聚体稳定性存在较大的动态变化,结皮层团聚体稳定性在自然降雨作用下呈现波动式上升的趋势。FW、SW、WS处理下,结皮层土壤团聚体平均质量直径变化范围分别为0.73~2.13 mm、1.70~2.90 mm和2.27~3.16 mm,下层土壤在FW处理下团聚体稳定性呈波动式上升趋势,平均质量直径变化范围为0.70~1.27 mm,在SW和WS处理下呈略微下降趋势,其变化范围分别为1.69~2.83 mm和2.53~2.95 mm。在降雨影响下,土壤结皮与下层土壤团聚体稳定性存在较大的差异,随着降雨场次的增加,结皮层团聚体稳定性逐渐高于下层土壤,且两者差值逐渐增大。在土壤有机质、阳离子交换量、pH值等理化性质基本不变的情况下,土壤团聚体稳定性在自然降雨影响下也存在较大的动态变化。
[Abstract]:Through the combination of field monitoring and indoor analysis, the typical yellow soil in the three Gorges Reservoir area is taken as the research object. The difference of aggregate stability between crust and topsoil was quantitatively analyzed by using three methods of rapid wetting (FW), slow wetting (SW) and pre-wetting oscillating (WS) in Le Bissonnais (LB) method. The results show that the stability of soil aggregates has a large dynamic change under the effect of rainfall, and the stability of the aggregates in the stratification cortex shows a fluctuating upward trend under the action of natural rainfall. The mean mass diameters of aggregates in cortical soils ranged from 0.73 to 2.13 mm,1.70~2.90 mm and from 2.27 to 3.16 mm, respectively, and the stability of aggregates increased in a fluctuating trend under FW treatment. The mean mass diameter ranged from 0.70 to 1.27 mm, with a slightly decreasing trend under SW and WS treatments, with a range of 1.69 mm and 2.532.95 mm., respectively. Under the influence of rainfall, the stability of aggregates in soil crust and soil layer was significantly different. With the increase of rainfall frequency, the stability of aggregates in the crust was gradually higher than that in the lower soil, and the difference between them gradually increased. Under the condition that the physical and chemical properties of soil organic matter, cation exchange capacity and pH value are basically unchanged, the stability of soil aggregates also has great dynamic changes under the influence of natural rainfall.
【作者单位】：北京林业大学水土保持学院;北京市水土保持工程技术研究中心;
【基金】：国家自然科学基金项目(41401299)
【分类号】：S152.4

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