Study on Characteristics and Influencing Factors of Chlorine of Soils and Tobacco Leaves in Wenshan Tobacco Growing Areas

For a better understanding of water-dissolving chlorine contents of soil and tobacco leaf and influencing factors in Wenshan tobacco growing areas, 276 soil samples and 381 tobacco leaf samples were collected by the technology of Global Position System (GPS). Chloride contents, spatial distribution and influencing factors were analyzed by geostatistics with GIS and statistical methods. The results were as follows:The average content of water-dissolving chlorine in various tobacco-planting soils was 13.81mg/kg in Wenshan. Chlorine content of 61.95% of the soil samples was in the appropriate level (10.00-30.00 mg/kg), which was very fit for tobacco planting. The content of chlorine in tobacco leaves was low, and the average value of it was 0.15% with coefficient of variation as high as113.33%. Only 8.66% of the leaf samples had a chlorine content in the appropriate level (0.30%-0.80%), 37.27% of the leaf samples had a chlorine content of 0.10%-0.30%, and 51.71% of the leaf samples had a chlorine content less than 0.10%. The lack of chlorine in tobacco leaves was mainly due to the amount and intensity of rainfall which caused leaching. The results revealed that in Wenshan tobacco growing areas chlorine content of the soil samples was in the appropriate level, but chlorine content of the tobacco leaf was relatively low, which is not suitable for the production of high-quality flue-cured tobacco. In order to improve the tobacco quality, appropriate application of chlorine-containing fertilizers must be recommended and be dynamic monitored.