Late-Season Nitrogen Application to Tobacco Produced in Fine-Textured Soils

摘要

Late-season nitrogen (N) assimilation can greatly impact the yield and quality of flue-cured tobacco, particularly in the fine-textured Piedmont soils of North Carolina. Research was conducted in 2015 to 2016 to evaluate the effects of N application rate and number of N applications to the yield, quality, value, and leaf chemistry of flue-cured tobacco. Liquid N (28% urea ammonium nitrate) was applied at 50, 70, and 90 lb N/acre. Each rate was either applied in two splits (0.5 rate 7-10 days after transplanting and 0.5 rate at layby) or three (0.5 rate 7-10 days after transplanting, a 0.25 rate at layby, and a 0.25 rate 2 weeks after layby) after transplanting. Cured leaf N concentration was similar at 50 and 70 lb N/acre (2.58 and 2.61%, respectively) but was increased in treatments receiving 90 lb N/ acre (2.77%). Additionally, three N applications (2.73%) increased cured leaf N relative to two N applications (2.58%). The same treatment parameters did not impact yield or value but reduced cured leaf quality in one growing environment due to prolonged N assimilation. Results indicate that current recommendations for N application rates (50 lb/acre) and timings (split-applied twice in equal portions) are adequate to obtain maximum yield, quality,and value on fine-textured soils similar to those evaluated in this study.