The five grassland using models,enclosed achnatherum splendens grassland,degraded achnatherum splendens grassland,excavating pit,artificial grassland and farmland,were selected to test the effects of different using model on soil carbon,nitrogen and phosphorus content in Tara beach,Gonghe County,Qinghai Province.The results showed that soil organic carbon content in 0-10 cm and 10-20 cm as follow tendency: enclosed achnatherum splendensdegraded schnatherum splendens grasslandexcavating pitfarmland and artificial grassland,which illustrated the degradation and reclamation caused to organic carbon content in topsoil decrease.In same soil layer,there was no significant difference of soil organic carbon content between farmland and artificial grassland.In 0-10 cm,10-20 cm and 20-40 cm,nitrogen content in farmland was the highest,then artificial grassland.it was mainly because of nitrogen fertilization and dead grass burying.Total nitrogen in excavating pit(now the artificial restoration) was the lowest.Total nitrogen in the 0-40 cm layer in enclosed achnatherum aplendens grassland was higher than degraded achnatherum splendens grassland,but it was reversed in the 40-80 cm layer,which illustrated the enclosure inreased soil total nitrogen,and degradation may lead to nitrogen transfer to the lower soil layor.The total phosphorus content changed similarly with total nitrogen.Soil total organic carbon,nitrogen and phosphorus were all decreased with soil depth.%以青海省共和县塔拉滩封育芨芨草（Achnatherum splendens）草原、过牧芨芨草草原、取土坑、人工草地和农田为研究对象,对不同利用方式及不同深度下土壤有机碳、全氮、全磷含量进行了分析研究。结果表明：0～10cm和10～20cm土层土壤有机碳含量顺序均为封育芨芨草草原〉退化过牧芨芨草草原〉取土坑〉农田〉人工草地,说明退化和开垦均导致表层土壤有机碳含量的下降。在同一土层内,农田和人工草地（退耕地）的有机碳含量差异不显著（P〉0.05）。在0～10,10～20和20～40cm的3个土层,农田的全氮含量最高,人工草地次之,主要是由于人为施加氮肥和翻压枯草等因素造成,取土坑的全氮含量最低;同时,0～40cm的土层,封育芨芨草草原的土壤全氮含量高于退化过牧芨芨草草原,40～80cm的土层,封育芨芨草草原的土壤全氮含量低于退化过牧芨芨草草原,说明封育使土壤上层的全氮含量增加,而草原退化导致氮向下层转移。全磷含量的变化规律与全氮相似。各草地的有机碳、全氮和全磷含量随土壤深度增加而下降。
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