云南干热河谷区3种不同类型植被土壤的有效氮研究

Study on Soil Available Nitrogen(N) in 3 Different Types of Vegetation in Yunnan Dry-hot Valleys

为了揭示云南干热河谷区退化生态系统土壤有效氮的现状及与有机质含量的相关性,对会泽、县娜、姑镇典型的3种不同类型植被下土壤有效氮及有机质进行了测定分析。结果表明:3种类型植被土壤有效氮含量为车桑子灌丛林>银合欢林>扭黄茅草丛,平均分别为76.59 mg/kg、55.40 mg/kg和45.18 mg/kg;土壤有效氮随坡面变化表现为坡中>坡上>坡下;土壤有效氮与有机质呈现极显著的线性关系。

Soil available nitrogen （N） and organic matter （OM） in 3 different vegetation types of dryhot valley for Nagu Township, Huize County and Yunnan were analyzed to reveal the correlation of soil available N and OM in degraded ecosystem in Yunnan dry-hot valley. Result indicated that soil available N content was bushes of Dodonaea viseosa〉woods of Leucaena leucocephala〉grasses of Heteropogon contortus,which was 76.59 mg/kg, 55.40 mg/kg and 45.18 mg/kg respectively. Soil available N changed along with the slope, which was mesoslope〉top of slope〉base of slope. There was significant linear relationship between soil available N and OM.