不同土层土壤有机质含量对速效氮分配的影响

为广西东兰县退耕还林地的肥料管理提供理论依据。采用典型抽样的方法设置土壤剖面，分A、B层采集土壤样品，利用重铬酸钾法测定土壤有机质的含量，碱解扩散法测定土壤中的速效氮，采用等级法和方差分析方法，比较每一种立地类型A、B层之间的有机质和速效氮含量的显著性差异。A层或B层的土壤有机质和速效氮含量在7种立地类型间存在着显著性差异，A层的土壤有机质含量对速效氮的分配影响呈明显的正相关，B层的土壤有机质含量对速效氮的分配关系影响不明显。B层土壤有机质和速效氮的含量相对较少，对于种植深根性的植物，应在深耕的同时多施用农家肥或无机氮。

Effect on the Distribution of Organic Matter Content on the Available Nitrogen in Different Layer of Soil

The research studied the theoretical basis of management of fertilizer in the forests of farmland returned in Donglan country in Guangxi. The soil profiles were established by the typical sampling method, and soil samples were collected from layer A and B in soil respectively. Soil organic matter content was determined by potassium dichromate, the soil available nitrogen was determined by alkali diffusion method, the author compared the difference of soil organic matter and available nitrogen between Layer A and B in each sites by rating methods and analysis of variance. The results showed that the magnificent difference for soil organic matter and available nitrogen exist between layer A and B in 7 sites. The influence of soil organic matter content on the distribution of available nitrogen was a significant positive correlation in layer A. The soil organic matter content had no magnificent influence on the distribution of available nitrogen in layer B. There was less soil organic matter and available nitrogen in layer B. Deep-root plants could be fertilized with more manure or inorganic nitrogen.