赣南不同母质及植被覆盖对红壤水稳性的影响

目的]探讨赣江流域地区植被恢复对土壤抗侵蚀能力提高的作用机理以及土壤水稳定性的测定方法。方法]选取3种不同成土母质(花岗岩、红砂岩、第四纪红土),每一种母质又设置了3种植被覆盖条件下的红壤,应用静水天平法测定土壤的水稳性指数,并研究其随时间的变化规律。结果]赣南红壤的水稳性随浸水时间延长而减弱,这种减弱变化不受母质类型和植被覆盖的变化而改变。林草地和灌草地土壤水稳性在浸水过程中土壤的水稳性指数较为稳定,下降幅度小,(林下)裸地土壤浸水后水稳性指数下降幅度较大。以(林下)裸地作为对照,3种母质的林草地、灌草地的水稳性指数均有显著提高。结论]静水天平法特别适合研究土壤水稳性的动态变化规律。赣江流域红壤地区的植被恢复有助于提高土壤的水稳定性。

Effects of Different Parent Material and Vegetation Coverage on Water Stability Index of Red Soils in Gannan Area

Objective] This paper aimed to investigate the mechanism of soil erosion resistance by vegetation restoration and the water stability index of red soil in Ganjiang river basin area.Methods] Soil samples developed from three parent materials(the granite, red sandstone and quaternary red earth) under different vegetation coverage were selected, to explore the dynamic change of water stability by using hydrostatic balance method.Results] The dynamic change of water stability of red soils decreased with soil immersion time in all samples. This decreasing trend was less in woodland and shrub land compared to bare land. Soil water stability in both woodland and shrub land improved significantly, compared to bare land developed from all the three parent materials.Conclusion] The hydrostatic balance method is more suitable to study the dynamic change of water stability. Vegetation restoration is beneficial to the improvement of soil water stability in Gannan area.