Effects of Soil Chemical Properties and Altitude on K Content in Flue-cured Tobacco Leaves in Qujing Area

The relationship between potassium content in middle leaves of flue-cured tobacco and soil nutrients with attitude was investigated to identify the relationship of chemical properties between tobacco planting soils and flue-cured tobacco leaves in Qujing,Yunnan Province.The results showed that the mean content of potassium in tobacco leaves in Qujing was 1.51%,ranging from 0.29% to 3.01%.Tobacco potassium content in Qujing was mainly affected by soil available potassium,and increased with the increment of soil available potassium.Furthermore,when the soil available potassium was less than 175.22 mg/kg,tobacco potassium content was greatly affected by soil available magnesium.When ranging from 175.220 to 276.010 mg/kg,water soluble chlorine in soil was the main factor affecting tobacco potassium content.When exceeding 276.010 mg/kg,tobacco potassium content was mainly affected by soil available magnesium.Otherwise,soil organic matter and sampling site altitude also had certain effect,where the altitude cut-points were 1700,1822 and 2023 m,respectively.Tobacco potassium content decreased with altitude increasing.