新疆南疆土壤有机质垂向分布特征及影响因素研究——以塔里木河下游不同土地利用类型为例

Study on vertical distribution characteristics and influencing factors of soil organic matter in Southern Xinjiang——Taking different land use types in the lower reaches of Tarim River as an example

以南疆塔里木河下游土壤有机质(SOM)为研究对象,运用显著性差异的方法分析不同土地利用类型SOM含量的垂向分布(0~200 cm)特征,并用Pearson相关分析揭示了SOM与含盐量、pH、全氮含量之间的影响关系。结果表明:1)由土地利用类型导致的SOM含量的差异主要表现在0~80 cm土层。2)研究区不同土地利用类型SOM含量随深度增加整体呈下降趋势,其中耕地SOM具有明显的表聚现象;林地SOM垂向变化呈“S”形,在120 cm处有明显低值;草地SOM垂向变化幅度小且在80~200 cm深度变化趋于平稳;盐碱地SOM含量随深度变化无明显规律。3)SOM含量在垂向上与土壤含盐量呈显著正相关(p<0.01),与pH呈显著负相关(p<0.01),与土壤全氮含量呈显著正相关(p<0.01)。

Taking soil organic matter(SOM)in the lower reaches of the Tarim River in Southern Xinjiang as the research object,the vertical distribution(0~200 cm)characteristics of SOM content in different land use types were analyzed using the method of significant differences.Pearson correlation analysis was used to reveal the relationship between SOM and salt content,pH,and total nitrogen content.The results indicate that:1)The difference in SOM content caused by land use types is mainly manifested in the 0~80 cm soil layer.2)The SOM content of different land use types in the study area shows an overall downward trend with increasing depth,and the SOM content of cultivated land exhibits obvious surface aggregation phenomenon;The vertical variation of forest SOM shows an“S”shape,with a significant low value at 120 cm;The vertical variation amplitude of grassland SOM is small and tends to stabilize at a depth of 80~200 cm;There is no significant pattern in the variation of SOM content with depth in saline alkali land.3)The content of SOM is significantly positively correlated with soil salinity in the vertical direction(p<0.01),significantly negatively correlated with pH(p<0.01),and significantly positively correlated with soil total nitrogen content(p<0.01).