毛乌素沙地南缘不同植被恢复类型的土壤养分效应

为了探讨植被恢复对土壤养分的影响,研究了毛乌素沙地南缘天然草地、人工封育草地、撂荒地、退耕还林地、固定沙地5种不同植被恢复类型区的土壤养分特征。结果表明:不同植被恢复类型对土壤有机质、全氮、有效氮、速效磷的影响存在明显差异;灌草结合的人工封育草地、退耕还林地、固定沙地土壤有机质、全氮、有效氮的含量高于以草本为主的天然草地和撂荒地,但土壤速效磷的含量刚好相反;植被对表层0~20 cm土壤养分的影响大于下层20~60 cm土壤,植被作用下土壤养分向表层富集;采用柠条进行退耕还林,能够充分发挥其根系特性,有利于改良深层土壤养分。

Effects of Different Vegetation Restoration Types on Soil Nutrients in Southern Edge of Mu Us Sandy Land

In order to discuss the effects of vegetation restoration on soil nutrient status,the variation characteristics of soil nutrients among 5 different vegetation restoration types（natural grassland,enclosed grassland,abandoned land,land as returning farmland to woodland,fixed sandy land） on soil nutrient status were studied in southern edge of Mu Us sandy land.The results showed that：the influence of different vegetation restoration types on soil organic matter,total nitrogen,available nitrogen and available phosphorus were conspicuously different.The contents of soil organic matter,total nitrogen and available nitrogen in these lands（enclosed grassland,land as returning farmland to woodland and fixed sandy land） which were the combination of shrub and herb,were higher than in those lands（natural grassland and abandoned land） with mainly herb.But just the opposite,the contents of soil available phosphorus in these were lower than in those. The influence of vegetation on the surface 0-20 cm soil nutrient was greater than that on the deep 20-60 cm soil,also the soil nutrient was to surface enrichment under the action of vegetation.Planting the species （Caragana korshinskii） for converting cropland to forest could give full play to its root system characteristics, which could be helpful for improving deeper soil nutrient.