Effects Of Different Nitrogen Fertilizer Levels And NPK Ratio On The Growth,Yield And Quality Of Flue-cured Tobacco

Adopting K326 and Xiangyan No.3 as the experimental material, this paper studied the effects on the growth, disease-resistance, economic trait, leaf weight and the main chemical components of flue-cured tobacco under different nitrogen fertilizer levels and NPK ratio, in order to provide theoretical basis for the improvement of tobacco production. The main results are summarized as follows:1. Respectively increasing the amount of N, P and K fertilizer is beneficial to the growth and development of tobacco. When the amount of N fertilizer exceeds 11.5 kg/667m2, the maturity of flue-cured tobacco is poor and not obvious stratification. At mature stage, it's best for promoting the agronomic traits of tobacco by increasing P fertilizer, followed by increasing K fertilizer, and increasing N fertilizer application shows the worst.2. In terms of the incidence rate of each treatment, when the amount of N fertilizer is in the range of 8.5 kg/667m?10.5 kg/667m2, and appropriately increasing the amount of P and K fertilizer at the same time, it can make the tobacco plant get good nutrition for disease resistance and reducing the loss of disease.3. Comprehensive analysis of economic characters, when the amount of N fertilizer is in the range of 9.5 kg/667m2?10.5 kg/667m2 (calculation with the pure nitrogen), and appropriately increasing the amount of P and K fertilizer at the same time, it can make the tobacco plant get good economic trait.4. It's beneficial to increase leaf weight of flue-cured tobacco by adding different proportions of nitrogen, phosphorus and potassium fertilizer. The influence on leaf weight of different varieties is different by adding a unit of fertilizer amount, and the result shows K326> Xiangyan No.3.5. The content of total sugar and reducing sugar of flue-cured tobacco is opposite trend with the increase of N fertilizer application, and positively correlated with the amount of K fertilizer application. The content of total nitrogen and the nicotine significantly increased with increasing N fertilizer application, and significantly decreased with increasing K, and it's beneficial to increase the nicotine content with increasing P fertilizer. With increasing the amount of K fertilizer application, it can increase the K content, the ratio of sugar to nicotine and potassium to chlorine of tobacco leaves. When the amount of N fertilizer application is 9.5 kg/667 m2, the ratio of sugar to nicotine is the highest, meanwhile, it can increase the smoking strength and meet the requirements of high quality tobacco.