青海湖南岸不同覆被类型土壤碳氮含量比较

Comparisions of soil carbon and nitrogen content under different landcover in the southern region of the Qinghai Lake

以青海湖南岸的鬼箭锦鸡儿灌丛、矮嵩草草地和油菜＋燕麦混播农田为研究对象,对3个样地土壤基本理化性质和0-30cm不同层次土体的有机碳、全氮含量分别进行了测定,结果显示：所测样地土壤均呈偏碱性,土壤容重介于0.80-1.19 g/cm^3,农田土壤容重居高。不同覆被类型下,上层30cm土体单位面积有机碳、全氮储量由高到低均为：灌丛〉农田〉草地,分别为15.71 kg/m^2、10.16 kg/m^2、7.54 kg/m^2和1.76 kg/m^2、1.20 kg/m^2、1.11 kg/m^2,灌丛与草地、农田间差异显著（P〈0.05）,农田与草地间差异不显著（P〉0.05）。覆被类型和土地利用方式对研究区域土壤的基本理化性质和土壤碳、氮含量有显著的影响。

Three land cover types,Caragana jubata shrub,Kobresia huinilis grassland and mixture cropland of Brassica juncea and Avena sativa in the southern region of the Qinghai Lake, were seleted to investigate their soil physical - chemical properties and soil organic carbon and total nitrogen content. The results showed that soil of the three sites was weak alkaline. The bulk density ranged from 0. 80 g/cm^3 to 1.19g/cm^3 and the bulk density of the cropland was larger than the other sites. The storage of soil organic carbon and total nitrogen per unit area varied in the order of shrub 〉 cropland 〉 grassland,their values were 15.71 kg/m^2,10. 16 kg/m^2,7.54 kg/m^2 and 1.76 kg/m^2, 1.20 kg/m^2, 1.11 kg/m^2 respectively. The soil organic carbon and total nitrogen in Caragana jubata shrub soil were significantly higher than that both in Kobresia humilis grassland and mixture cropland （P 〈 0. 05）,and no difference was found between Kobresia humilis grassland and mixture cropland （P 〉 0. 05）. Land cover and land use had significant impact on the soil physical - chemical properties and soil organic carbon and nitrogen content.