Soil Available Nutrient Contents and Their Influencing Factors in Tobacco Growing Region in Chongqing

In order to identify the main influencing factors on soil available nutrient contents in Chongqing, canonical correlation analysis was conducted by using variable altitude, topsoil thickness, pH, organic matter, and soil available nutrient contents. Descriptive statistic results showed that the soil acidification was severe in some regions of Chongqing. Soil available nitrogen, phosphorus, and potassium were sufficient to tobacco growth. The trace elements, except for available boron, molybdenum and chlorine, were high or very high. The canonical correlation analysis results suggested that the content of available nitrogen, copper, zinc, iron, and B increased with increasing soil organic matte. The contents of available potassium and Zn decreased with the altitude decreasing. With the decreasing of soil pH, the content of available phosphorus and iron decreased, but soil exchangeable calcium content increased. Soil exchangeable magnesium content increased with increasing soil topsoil thickness. Therefore, the problem of soil acidification, low in organic matter, shallow topsoil layer need to be solve in order to provide suitable environment for higher yield and quality of flue-cured tobacco.