Distribution Of Medium Trace Element Of Tobacco-growing Soil And Its Influencing Factors In Xiangxi

In order to understand the distribution of trace element in tobacco--planting soils and its influencing factors in Xiangxi, trace element of tobacco-growing soils and its influencing factors (Including soil types, altitude,soil pH and soil organic matter) were analyzed by the ways of descriptive statistics and variance analysis, collected 488 soil samples that exchangeable calcium, exchangeable magnesium, available sulfur, available zinc and available boron were detected. The results as follows:(1) Exchangeable calcium of tobacco-growing soil: ?Exchangeable calcium contents in the tobacco soil is high for tobacco cultivation with a mean of 1688.01mg/kg, amplitude of 193.90?6506.58mg/kg. About 20.29% of the soil samples of exchangeable calcium contents is suitable for tobacco cultivation.?The average content of exchangeable calcium from Baojing and Luxi were significantly greater than Guzhang and Fenghuang.?The average content of exchangeable calcium from red soils, yellow soils and yellow ash soil were significantly greater than light yellow ash mud. ? There existed no significant differences among different altitude soil for the contents of exchangeable calcium. ?Exchangeable calcium contents was increasing with the rise of pH in tobacco growing soils of Xiangxi. ?Exchangeable calcium contents was increasing with the rise of soil organic matter in tobacco growing soils of Xiangxi.(2) Exchangeable magnesium of tobacco-growing soil:?Exchangeable magnesium contents in the tobacco soil is generally suitable for tobacco cultivation with a mean of 177.76mg/kg, amplitude of 30.03?348.83mg/kg. About 32.38% of the soil samples of exchangeable magnesium contents is suitable for tobacco cultivation. ?There existed extremely significant differences among different counties for the contents of exchangeable magnesium. The average content of exchangeable magnesium was abundant level in Baojing Longshan and Fenghuang. The average content of exchangeable magnesium was lacking level in Guzhang. ?The average content of exchangeable magnesium from yellow-brown ash was significantly greater than paddy field.? The exchangeable magnesium contents was increasing with the rise of altitude in tobacco growing soils of Xiangxi.?Exchangeable magnesium contents was increasing with the rise of pH in tobacco growing soils of Xiangxi. ?Exchangeable magnesium contents was increasing with the rise of soil organic matter in tobacco growing soils of Xiangxi.(3) Available sulfur of tobacco-growing soil: ?Available sulfur contents in the tobacco soil is generally suitable for tobacco cultivation with a mean of 30.73mg/kg, amplitude of 0.28?98.33mg/kg. About15.64% of the soil samples of available sulfur contents is suitable for tobacco cultivation. ?There existed extremely significant differences among different counties for the contents of available sulfur. The average content of available sulfur from Longshan was significantly greater than the other counties.(3)The average content of available sulfur from rendzina soils and yellow soils were significantly greater than yellow ash mud,yellow ash soils,light yellow ash mud and yellow-brown ash soils. The average content of available sulfur from paddy field was significantly greater than yellow ash mud.?There existed extremely significant differences among different altitude soil for the contents of available sulfur.?Available sulfur contents was decreasing with the rise of pH in Xiangxi tobacco growing soils.?Available sulfur contents was increasing with the rise of soil organic matter in tobacco growing soils of Xiangxi.(4) Available zinc of tobacco-growing soil:?Available zinc contents in the tobacco-planting soil is little higher with a mean of 2.08mg/kg, amplitude of 0.23-6.09mg/kg. About 28.69% of the soil samples of available zinc contents is suitable for tobacco cultivation. ? The average content of available zinc from Longshan was significantly greater than Luxi. ?The average content of available ziner from yellow-brown ash soils was significantly greater than paddy field, rendzina soils, yellow ash soils and yellow soils. ?The available zinc contents was increasing with the rise of altitude in tobacco growing soils of Xiangxi.?There existed no significant differences among different pH soil for the contents of available zinc. ?Available zinc contents was increasing with the rise of soil organic matter in tobacco growing soils of Xiangxi.(5) Available boron of tobacco-growing soil: ?Available boron contents in the tobacco-planting soil is slight higher for tobacco cultivation with a mean of 0.73mg/kg, amplitude of 0.05-2.21mg/kg. About 30.00% of the soil samples of available boron contents is suitable for tobacco cultivation. ?There is extremely significant differences among the different counties for the contents of available boron, and the available boron contents of Guzhang county, Fenghuang county and Longshan county were higher than the other. ?There is extremely significant differences among different soil types for the contents of available boron, and the average content of available boron in yellow-brown soil was higher than red lime soil and red soil. ?The available boron contents was increasing with the rise of altitude in tobacco growing soils of Xiangxi. ?Available boron contents was increasing with the rise of pH in tobacco growing soils of Xiangxi.?Available boron contents was increasing with the rise of soil organic matter in tobacco growing soils from Xiangxi.