高寒沙化草地不同灌木根际与非根际土壤氮素、有机碳含量特征

Characteristics of Nitrogen and Organic Carbon Content in Rhizosphere and Bulk Soil under Different Shrubs in the Alpine Sandy Grassland

选取玛曲县高寒沙化草地人工种植的三种灌木,研究其根际与非根际土壤各种形态氮素、有机碳的含量特征及土壤pH的差异。结果表明,相对于非根际土壤,根际土壤有机碳的含量高出71.5%,而根际全氮含量平均低11.0%。三种灌木铵态氮含量均高于硝态氮含量;根际土壤对有机碳表现出更加明显的富集效应。土壤有机碳和土壤全氮、铵态氮之间均呈现显著相关(P<0.05),表现为线性关系;而根际与非根际土壤有机碳与硝态氮则均无相关性。

In the Maqu alpine sandy grassland,three cultivated shrubs were selected to study the various forms of nitrogen,the contents of organic carbon and pH changes in both rhizosphere and bulk soil.The results showed that organic carbon in the rhizosphere was higher by 71.5% than that of bulk soil.Total nitrogen in the rhizosphere was lower by 11.0%.The content of ammonium were higher than that of nitrogen in three shrubs soil.The rhizosphere soil showed more obvious enrichment effect on organic carbon.The differences of organic carbon,total nitrogen and ammonium between the rhizosphere and bulk soil showed significant linear relationships（P0.05）.There was no correlation in soil organic carbon and nitrogen between the rhizosphere and bulk soil.