Abstract:

In order to understand the distribution of pH in tobacco growing soils of Xiangxi, distribution frequency of pH value, difference of different county, difference of different soil types, difference of different altitude and Spatial distribution of tobacco-growing soil pH value were analyzed by collected 488 soil samples. The results were as follows: (1) The soil pH in the tobacco soil was generally suitable for tobacco cultivation, with a spatial mean of 5.87 and variation coefficient of 11.13%. About 72.75% of the soil samples has pH between 5.5-7.0 most suitable for high quality tobacco cultivation. (2) The soil pH for different counties of Xiangxi tobacco lands was in the following order: Baojing＞Longshan＞Luxi＞Fenguang＞Huayuan＞Yongshun＞Guzhang. (3)The soil pH for different soil types was in the following order too: yellow-brown ash soil＞rendzina soil＞yellow ash mud＞yellow ash soil＞yellow soil＞red soil＞light yellow ash mud＞paddy soil. (4) The soil pH value was increasing with the rise of altitude in tobacco growing soils of Xiangxi. (5) The unobserved points of tobacco growing soils of Xiangxi were estimated and the contour map was obtained using the Kriging method. The results indicated that the spatial distributions of the soil pH value were plaque. The high value area of the soil pH value was in some areas of Baojing, Longshan, Yongshun, respectively. The low value area of the soil pH value was in some areas of Guzhang.