Content and Change of Available Zinc of Tobacco-growing Soil in Xiangxi

In order to understand the distribution of available zinc contents of tobacco growing soils in Xiangxi,distribution frequency of available zinc contents,difference of different county,difference of different soil types,difference of different altitude and Spatial distribution of available zinc contents were analyzed by collected 488 soil samples.The results were as follows:(1) available zinc contents in the tobacco soil is little higher with a mean of 2.08 mg/kg,amplitude of 0.23~6.09 mg/kg and variation coefficient of 51.45%.About 28.69% of the soil samples of available zinc contents is suitable for tobacco cultivation.(2) there is extremely significant differences among the contents of available zinc in the different counties,and the order of available zinc content in soil for different counties were FenghuangLongshanYongshunHuayuanBaojingGuzhangLuxi.(3) there is extremely significant differences among the contents of available zinc in the different soil types and the order of available zinc content in soil for different soil types were yellow-brown ash soillight yellow ash mudyellow ash mudred soilpaddy fieldlime soilyellow ash soilyellow soil.(4)there existed extremely significant differences among the contents of available zinc in the different altitude.The contents of available zinc was increasing with the rise of altitude in tobacco growing soils of Xiangxi.(5) Kriging interpolation map indicated that the spatial distributions of available zinc were regularly distribution and reduced from the northern and south-western to the middle.