南方红壤区不同侵蚀程度下土壤有机质空间变异的影响因素研究

Spatial Variability of Organic Matter and Its Influencing Factors in Red Soil with Different Erosion Degrees in South China

研究不同侵蚀程度下土壤有机质空间变异的影响因素对指导耕地利用和水土保持工作的开展具有重要意义。论文以江西省兴国县耕地土壤有机质为研究对象,分析了不同侵蚀程度下土壤有机质的空间变异及其影响因素。结果表明:随着侵蚀程度的加深,兴国县土壤有机质含量呈下降趋势。不同侵蚀程度下土壤有机质含量差异显著(P<0.001),等级均为四级。变异系数由大到小依次为中度侵蚀(43.70%)>剧烈侵蚀(37.78%)>重度侵蚀(34.88%)>极强度侵蚀(34.44%)>无明显侵蚀(34.38%)>轻微侵蚀(28.91%)。在无明显侵蚀和轻微侵蚀时,高程和剖面构型是影响土壤有机质空间变异的主要因子。在中度侵蚀和重度侵蚀时,主要影响因素变为坡度。但在极强度侵蚀和剧烈侵蚀时,高程、坡度、坡向、成土母质和剖面构型对土壤有机质含量都影响显著(P<0.05)。因此,不同侵蚀程度下土壤有机质空间变异影响因素不尽相同。在不同侵蚀程度下合理开展耕地利用和水土保持工作有利于最大限度地节约资源。

SPSS and GIS were applied to analyze the spatial variability of soil organic matter（SOM） and its influencing factors in red soil with different erosion degrees in Xingguo County in Jiangxi Province.The results showed that the SOM content tends to decline with the increase of soil erosion degree.Significant differences of SOM content were found in soil with different erosion degrees（P0.001）,and the soil of each erosion degree can be divided into four grades of SOM content,with the coefficient of variation decreasing in the order of moderate erosion（43.70%）,fierce erosion（37.78%）,serious erosion（34.88%）,extremely intensive erosion（34.44%）,no significant erosion（34.38%） and slight erosion（28.91%）.In the cases of no significant erosion and slight erosion,the elevation and profile pattern are the main controlling factors affecting spatial variability of SOM.When the erosion is moderate or serious,slope becomes the main factor.The elevation,profile configuration,slope and parent material all have significant effects on the SOM content in soil with extremely intensive erosion or fierce erosion.The research indicated that there are various controlling factors in soil with different erosion degrees.It can maximize saving resources when reasonably using of cultivated land,soil and water according to the erosion level of soil.The study is of great significance for cultivated land use and soil and water conservation.