Soil pH in Liaoning Tobacco Planting Area and Its Impact Tobacco Quality

154 samples of soil and middle tobacco leaf collected in seven tobacco planting counties in Liaoning Province were examined in this experiment.Soil pH value,the contents of nicotine,reducing sugar,total sugar,potassium and total nitrogen in tobacco leaves were measured.The relationship between the soil pH value and the intrinsic quality of tobacco leaves were analysed through the method of mathematical statistics.The results showed that the soil pH value was mostly suitable for tobacco growing,about 12%of pH value high or low.Soil pH value had significant correlations with the contents of total nitrogen, nicotine,potassium in tobacco leaves.When the soil pH value changed from 4.0 to 6.5,the soil pH value and nicotine content had a negative relationship;on the contrary when the soil pH value changed from 6.5 to 9.0,they had a positive relationship. The relationships between soil pH value and total nitrogen,potassium and total sugar were negetive.