拉萨地区不同类型土壤有机质含量的测定及分析

目的]研究拉萨地区不同类型土壤有机质含量。方法]以拉萨地区林地、耕地、草地、沼泽、荒地为研究对象,采用重铬酸钾氧化-硫酸消化法对样品进行测定,并对所得数据进行分析。结果]不同土层有机质含量存在一定差异,较深土壤中一般有机质含量相对较低,不同类型土壤有机质的含量亦不同。土壤有机质含量高于临界值(20 g/kg)土样占90.86%,处于较高含量水平(≥30 g/kg)仅为2.67%。拉萨地区不同类型土壤,有机质含量由高到低依次为耕地、沼泽、草地、林地、荒地。结论]拉萨地区不同类型土壤,有机质含量分布以中低等水平为主,为中低等肥力土壤。

Determination and Analysis of Soil Organic Matter Content in Different Types of Soil in Lhasa Area

Objective]Soil organic matter content in different types of soil in Lhasa area was studied.Method]The samples were determined by potassium dichromate oxidation-sulfuric acid digestion,and the data were analyzed by using determination results of forest land,cultivated land,grassland,swamp and wasteland in Lhasa area.Result] There were some differences in organic matter content in different soil layers.The content of organic matter in the deep soil was relatively low,and the content of organic matter in different soils were also different.Soil organic matter content above the critical value (20 g/kg) soil samples accounted for 90.86%,soil organic matter content at a higher level (≥ 30 g/kg)soil samples was only 2.67% of all samples.The order of different types of soil organic matter content in Lhasa area from high to low was cultivated land,swamp,grassland,woodland,wasteland.Conclusion]The soil organic matter in different types of soil in Lhasa area is dominated by middle and low level,which is medium and low fertile soil.