Relationship between the Phosphorus Contents in Soil and in Flue-cured Tobacco in Enshi Tobacco-growing Areas

Distributions of the phosphorus content in soil and flue-cured tobacco and their relationships were analyzed in Enshi tobacco-growing areas of Hubei Province.The results indicated that the phosphorus content in soil in Enshi tobacco-growing areas was low,and the total and available phosphorus contents were respectively 0.63±0.23 g kg-1 and 16.88±12.73 mg kg-1.There existed high significant positive correlation between the total phosphorus content and the available phosphorus content,and correlation coefficient was 0.6353.Significant differences were found between different altitudes or soil depths.As for the total and the available phosphorus contents,the order was high altitude middle altitude lower altitude;while for different soil depths,0-20 cm 20-40 cm 40-60 cm.The phosphorus content of flue-cured tobacco was low with the mean of 1.68±0.32 g kg-1.Significant differences were also found between different cultivars or altitudes.As for the phosphorus content of different cultivars of flue-cured tobacco,the order was Yunyan 87 K326 Yunyan85;while for different altitude,high altitude middle altitude lower altitude.Though differences of the phosphorus content among different grades were not significant,the phosphorus content increased as the stalk positions were higher.Linear regression equation of y=0.1224+0.0026x was established between the phosphorus content of flue-cured tobacco(y) and the available phosphorus content(x) in soil,with high significant correlation coefficient of 0.8582.After the available phosphorus content in soil was grouped,the phosphorus content of flue-cured tobacco increased with the increment of soil available phosphorus content.