Effects of Nitrogen Application Rate and Method on Yield and Quality of Flue-cured Tobacco and Nitrogen Use Efficiency in Nanxiong Tobacco Area

In order to explore appropriate nitrogen application rate and method for southern rainy tobacco areas, taking Yueyan 97 as the experimental material, the study investigated the effects of different nitrogen application rates and ratios between base fertilizer and dressing on the yield and quality of flue-cured tobacco as well as nitrogen use efficiency through split-plot design. The nitrogen application rate was set with three levels, 75, 135, 195 kg/hm2; the ratio between chemical nitrogen base fertilizer and dressing was also set with three levels, 10 ∶ 0(basal application), 7 ∶ 3, 3 ∶ 7; no fertilizer was set as the control to calculate nitrogen use efficiency. The results showed that increasing the nitrogen application rate could reduce the content of total sugar and reducing sugar of flue-cured tobacco, but it could also increase the nicotine content. Increasing the nitrogen application rate and using different nitrogen application methods had no significant effects on nitrogen use efficiency. Nitrogen application rate and the ratio between chemical nitrogen base fertilizer and dressing mainly impact the chemical composition of upper leaves. In Nanxiong tobacco area, applying nitrogen at the rate of 135 kg/hm2 and combining with the ratio between base fertilizer and dressing of 7 ∶ 3 had the best effect.