Buffer study on the suitable pH value of tobacco soil in part areas of Yunnan Province

The range of suitable pH value of tobacco soil in part areas of Yunnan Province was studied.The results show that compared with 1982,the average of pH value diminishes 0.30 in 2002,accounting for 4.8% of the general average of pH value.The acidity is high in mountain soil,and the acidity changes fast in the soil of advanced areas.Ca(OH)₂ should be applied to regulate the soil pH value in some areas of Yunnan Province.