皇甫川流域植被恢复对改善土壤肥力的作用研究

在野外调查基础上,对皇甫川流域五分地沟试验区油松林、锦鸡儿灌丛、本氏针茅草原、百里香草原和撂荒地的土壤有机质和养分进行测定及分析,结果表明:(1)植被恢复能显著提高土壤中有机质含量水平,增加速效养分的数量,改善土壤肥力状况;(2)土壤肥力的提高效益大多随深度增加而明显减小,其中油松林的土壤有机质的表聚性最为明显;(3)人工植被相对于天然植被对总氮的固定作用更为明显,而对总磷的固定作用劣于天然植被。最后,对植被恢复提高土壤肥力的机理和不同植被对土壤肥力的恢复效应进行了探讨。

Effects of Vegetative Restoration on Improving Soil Fertility inHuangfuchuan Basin

The soil organic matter and nutrient contents of Pinus tabulaeformis woods, Caragana intermedia shrubs, Stipa bungeana steppe, Thymus serphyllum steppe and non-cultivated land of Wufendigou experimental area in Huangfuchuan basin are measured and analyzed. The results showed that: (1) Vegetative restoration could increase the contents of the soil organic matter and rapidly available nutrient remarkedly, and improve the soil fertility; (2) With the increase of the soil depth, the benefit that vegetative restoration heightened the degree of soil fertility was decreased obviously, and the feature of soil organic matter gathering on the surface was most significant in Pinus tabulaeformis woods; (3) The fixation effect of total N in artificial vegetation was more obvious than that in natural vegetation, but it was converse on the fixation effect of total P. The mechanism of vegetative restoration heightening soil fertility and the restoration effect of soil fertility in different vegetation were discussed.