Analysis and Evaluation of the Medium Elements State of Tobacco-Growing Soil in Main Areas of Tongren

In order to investigate medium elements in tobacco growing soils of Tongren and supply micronutrients to tobacco fields to improve the production and quality of tobacco,the microelement nutrients in 90 soil samples collected from 4 tobacco growing counties in Tongren were analyzed,and their distribution was evaluated.The results showed that the average content of exchangeable calcium was 8.65 cmol/kg,and was the highest and lowest in Sinan and Dejiang,respectively.10.00% of the soils samples were deficient in calcium.The average content of exchangeable magnesium was 2.34 cmol/kg,and 18.89% of the soils samples were deficient in magnesium.The average ratio of soil exchangeable calcium content to soil exchangeable magnesium content was 8.85,41.11% and 26.67% of the soils were physiologic deficient in calcium and magnesium.The available sulfur conten t in soil was rich with the mean of 33.52 mg/kg.Among the soil samples collected,15.56% of them were considered as lack or potentially lack of sulfur.It is suggested to use calcium,magnesium and sulfur fertilizerrs according to the local soil medium element status based on the special fertilizer for flue-cured tobacco.