Content and Change of Available Manganese in Tobacco-Growing Soil from Xiangxi

In order to understand the distribution of available manganese contents in tobacco growing soils of Xiangxi,distribution frequency of available manganese contents,differences among different counties,soil types,altitude and spatial distribution of available manganese contents were analyzed by collected 488 soil samples.The results were as follows : ①Available manganese contents in the tobacco soil was little higher with a mean of 81.478 mg / kg,amplitude of 10.04~280.48 mg / kg and variation coefficient of 81.06%.About 17.98% of the soil samples of available manganese contents were suitable for tobacco cultivation.②There were no significant differences among the different counties on the contents of available manganese,and the order of available manganese content in soil for different counties were Yongshun Guzhang Huayuan Longshan FenghuangBaojingLuxi.③There was extremely significant differences among different soil types for the contents of available manganese,and the order of available manganese content in soil for different soil types were red ash soillime soilyellow soilred soilpaddy fieldyellow brown soil.④There were significant differences among the different altitudes for the contents of available manganese,especially between the group [800 m,1 000 m)and [1 000 m,+∞).⑤Kriging interpolation map indicated that the spatial distributions of available manganese were plaque shape distribution and its main area was in flower arrangement style,the content of which was 45.3~89.1 mg / kg.