峡江县土壤养分空间特征及与地形因子的相关性

The Spatial Characteristics of Soil Nutrients and the Correlation with Topographic Factors in Xiajiang County

研究区域耕地土壤养分的空间特征及其与地形因子的相关性,可为土壤养分的有效保持和耕地资源的高效利用提供依据。以江西省峡江县为例,运用地统计学方法与GIS技术,对土壤养分的空间特征与空间自相关性进行了分析,并探讨土壤各养分与地形因子之间的相关性。结果表明:(1)峡江县土壤养分分布均符合正态分布,变异系数由大到小依次为有效磷(56.64%)>速效钾(37.69%)>碱解氮(26.67%)>有机质(22.60%)。(2)峡江县土壤养分总体呈现中部低,四周高,东部含量大于西部的特点,桐林乡土壤养分含量较高,巴邱镇含量较低,空间分布不均匀。经空间自相关分析可知,土壤养分H—H型聚集主要集中于研究区东部,L—L则位于研究区西部。(3)高程与土壤养分之间均为显著正相关关系;坡度与有机质、有效磷、碱解氮均呈现显著负相关;坡向与有机质、速效钾显现出显著正相关关系,碱解氮则显现出极显著正相关关系;曲率和地形起伏度与土壤养分均未表现出显著的相关关系,坡度变率与土壤养分均显现出显著的负相关关系。

The spatial characteristics of soil nutrients and their correlation with topographic factors can be used to provide evidence for effective conservation of soil nutrients and efficient utilization of cultivated land resources.Taking Xiajiang County of Jiangxi Province as an example,we analyzed the spatial characteristics and spatial autocorrelation of soil nutrients by using geostatistics and GIS technology,and also discussed the correlation between soil nutrients and terrain factors.The results showed that：（1）the distribution of soil nutrients in Xiajiang County accorded with the normal distribution;the coefficient of variation decreased in the order：available phosphorus（56.64%）〉available potassium（37.69%）〉alkaline hydrolysis nitrogen（26.67%）〉organic matter（22.60%）;（2）soil nutrients in Xiajiang County showed the low level in the middle part,high level in four sides,and larger in the east than in the west;the soil nutrient contents in Tonglin town was relatively high,and the contents in Baqiu town was low,and the spatial distribution was uneven;the spatial autocorrelation analysis showed that the H—H type aggregation of soil nutrients mainly concentrated in the eastern part of the study area,while L—L was located in the western part of the study area;（3）elevation was significantly positively correlated with soil nutrients;slope gradient was significantly negatively correlated with organic matter,available phosphorus and alkaline hydrolysis nitrogen;slope aspect was significantly positively correlated with organic matter,available potassium,and was a very significantly positively correlated with alkaline hydrolysis nitrogen,soil nutrients had no significant correlations with the curvature and the terrain;slope variability was significantly negatively correlated with soil nutrients.