Correlation analysis of soil pH value and major elements in tobacco leaves in southeast Chongqing

To assess the influence of soil pH on tobacco quality in southeast Chongqing, the soil samples and composition of tobacco leaves were analyzed. Taking 149 soil samples and the corresponding 149 flue-cured middle tobacco leaf samples from typicality smoke generation countries in southeast Chongqing, Pengshui and Wulong counties as materials, the distributive characteristics and relationship soil pH value and the contents of 9 elements(total K, total Cl,total P, B, Mn, Ni, Cu, As, Fe) in middle tobacco leaves were analyzed. The results indicated that:(1) the tobacco planting soil of Pengshui and Wulong counties was mainly acid soil(4.5pH≤5.0), and the pH of the soil samples was within the most appropriate range for the growth of flue-cured tobacco respectively accounted for 26.2% and 36.8%. In addition, there was only a little difference on soil pH value between different villages.(2) There was difference on the contents of elements of flue-cured middle tobacco leaves between Pengshui and Wulong counties, as the same between different villages. The maximum coefficients of variation were found in Cu,As,total Cl,Mn, and the minimum was total P.(3) The soil pH value had correlation with the contents of elements of flue-cured middle tobacco leaves. And the content of total P had significant positive correlation with soil pH value, the contents of Mn and Cu had significant negative correlation with soil pH value, and the content of Ni had highly significant negative correlation with soil pH value. The results indicated that the soil acidification phenomenon in southeast Chongqing was serious. Furthermore, the tobacco quality in this area could be improved to a certain degree by changing the adidification soil.