Effects of nitrogen levels on growth of flue-cured tobacco in different types of tobacco-planting soil

The field experiment was conducted to probe into the effects of nitrogen levels on growth of flue-cured tobacco in different types of tobacco-planting soil. The results indicated that nitrogen application was conducive to the increasing of weight per leaf of flue-cured tobacco. The nicotine content of tobacco had a close correlation with nitrogen application rate,total nitrogen,total sugar, reducing sugar,ratio of nitrogen to alkali,ratio of sugar to alkali,ratio of sugar to nitrogen,and so on. Based on the comprehensive consideration of the yield,output value,average price,proportion of superior leaf and intrinsic chemical composition of flue-cured tobacco in different nitrogen treatments of the field experiment,the following was preliminarily obtained: under the condition of no organic fertilizer,it was beneficial to the formation of high-quality tobacco when the nitrogen application rates were respectively 165.0-192.0 kg·hm- 2,142.5-165.0 kg·hm- 2,120.0-142.5 kg·hm- 2in yellow clayey soil,yellow podzolic sandy land,blue standard lime marl field,whose soil alkali-hydrolyzable nitrogen contents were 105.61 mg·kg- 1,142.29 mg·kg- 1,168.37 mg·kg- 1.