渝西北土壤有机质空间变异及影响因素分析

Spatial Variability of Soil Organic Matter and Its Influence Factors of Hilly Area in Northwest Chongqing

【目的】深入认识重庆西北部丘陵区土壤有机质空间变异特征及影响因素,为农业生产、土地利用等提供科学依据。【方法】采用地统计学和GIS相结合的方法,进行有机质空间变异和基于土地利用类型修正的空间插值研究。【结果】研究区土壤有机质平均含量为16.26 g/kg,属中等偏下水平;变异系数为33.8%,存在中等程度的空间变异性;土壤有机质空间分布呈现中间高,两端低的趋势,合川区整体偏低。【结论】土壤有机质具有中等空间自相关性,空间变异性受结构因素(地形坡度、土壤类型)和随机因素(土地利用类型、耕作措施等)影响,土地利用类型是主控因素。

【 Objective】 The spatial variability of soil organic matter and its influence factors of hilly area in Northwest Chongqing ws discussed for providing scientific basis on agricultural production and land uses. [Method]The geostatistics and GIS methods were used to study, spa-tial variability of soil organic matter and spatial interpolation based on land uses amendment.【 Result】 The soil organic matter average content was 16. 26 g/kg, in the lower middle level and the variation coefficient was 33. 8 % , in the middle level. The spatial distribution of soil or-ganic matter was higher in middle, lower on both ends, and the whole Hechuan district was lower.【 Conclusion】 Geostatistical analysis sug-gested that soil organic matter had medium spatial correlation; The spatial variability were resulted from structure factors （topography slope and soil types） and random factors （land uses, farming measures, ect. ） , and land uses was the dominated factor.