通过野外考查和室内分析研究表明 :黄土高原地区刺槐和侧柏林都可明显提高土壤有机质和营养元素的含量 ,降低 p H和容重 ,增加土体中团聚体的数量 ,提高土地的生产能力 ;能有效地减少水土流失 ,促进土壤粘粒形成 ,防止土地退化和保护生态环境。其中刺槐林地速效养分丰富 ,粘粒和 >0 .2 5mm水稳性团聚体的数量大 ,有明显的粘化层 ,侧柏林地则酸性强 ,容重低 ,>0 .0 5 mm的微团粒含量较高 ,刺槐林防止土地退化的效益强于侧柏林。 Through the field test and indoor analysis, the results showed that both Robinia pseudoacacia and Platycladus orientalis forest can significantly increase soil organic matter and nutrient content, reduce p H and bulk density, increase the amount of soil aggregates and improve the productivity of the land; Effectively reduce soil erosion, promote the formation of soil clay, prevent land degradation and protect the ecological environment. Among them, Robinia pseudoacacia forest land is rich in available nutrients, clay particles and> 0.2 mm water-stable aggregates are large in number, with obvious sticky layer, while Platycladus orientalis is acidic, low bulk density,> 0. Higher content, Robinia pseudoacacia forest land degradation benefit is stronger than the side berberis.