Spatio and Temporal Variability of Soil Organic Matter in Wenshan Tobacco Growing Regions of Yunnan

In order to understand the spatio-temporal variability of soil organic matter in Wenshan tobacco growing regions of Yunnan province, the variation trend and spatial distribution characteristics of soil organic matter from 2005 to 2011 were analyzed by multivariate statistical approaches. The results indicated that the organic matter content was sufficient, with an average of 2.70%, but varied in a circle of increase-reduce-increase-reduce-increase-reduce across years. The content was positively correlated with annual precipitations with a correlation coefficient of 0.64, and positively correlated with elevation with a correlation coefficient of 0.42. Soil organic matter for most of counties was high, with the highest in Xichou and lowest in Guangnan. It was higher in northwest Wenshan, lower in middle Wenshang, but higher in the southeast Wenshan.