Research On The Calcium,Magnesium And Sulphur Distribution Characteristics Of Tobacco-growing Soil And Its Influencing Factors In Yongshun

Yongshun is one of the main tobacco-growing area of Hunan Province. In order to further determine the secondary element nutrient supply situation in the soil of yongshun tobacco production, This study analyzed the content of secondary element and its influencing factors in the current level of the tobacco production, according to provide the reference to the fertilization and the secondary element diagnostic of the yongshun tobacco production, then we get the following conclusion:1.Exchangeable calcium content is generally on the high side. Average exchangeable calcium content is 1561.73 mg.kg^-1.Appropriate exchangeable calcium content accounted for only 22.45% of all soil samples, high commutativity calcium content accounted for 53.06%; Another 23.81% of the soil samples there are different levels of acalcerosis. Extreme acalcerosis sample is in MaoBa Town, exchangeable calcium content is 193.90 mg.kg^-1, this town needs to supplement calcium fertilizer.2.Available sulfur content of the tobacco production is very rich, average available sulfur content is 50.88 mg.kg^-1. Available sulfur content medium level soil sample accounted for 86.90% of all soil samples, the content of available sulfur soil samples which is acalcerosis accounted for only 10.34%,The town which the soil effective sulfur content is low, mainly focus on Gaoping township and Shidi township, It is recommended to use sulfur Fertilizer in these township.3.Exchangeable magnesium content of the tobacco production is appropriate. Average exchangeable magnesium content is 178.26 mg.kg^-1. Medium level of the exchangeable magnesium soil samples accounted for 70.75% of all soil samples, Another 29.25% of the soil samples are magnesium deficiency, and exchangeable magnesium content which is extreme lack of accounted for 4.76% of all soil samples. From the point of exchangeable magnesium space distribution, the overall level of the exchangeable magnesium content in the main tobacco-growing area of this county is rich, but uneven distribution, and spatial difference is large. Exchangeable magnesium content in the county of the southwest and central region is rich, and the north and south of the county extremely Magnesium deficiency.4.The change area scope of pH in the tobacco-growing area of Yongshun is pH4.21-pH6.81.The author used multiple comparison method to compare correlation of pH and the three secondary element nutrients found that exchangeable calcium and effective magnesium present a sharply rising trend with the increase of pH; The content of the Exchangeable Calcium is in the highest average of each soil type, and the content of Exchangeable Calcium of paddy soil is next only to limestone soil; We also found that exchangeable Calcium and Magnesium content increased with increase in organic matter content of the soil available sulfur content and trend,the Smoke is decreased with the trend of organic matter.