Optimized Nitrogen Application Rate Significantly Increases Total Economic Value and Quality of Flue-Cured Tobacco due to the Improvement of Superior Tobacco Yield

Abstract

With the improvement of irrigation and transportation infrastructures, single tobacco cultivation has been converted into tobacco–vegetable double cultivation in Yunnan Province. High residual nitrogen (N) levels in soil before tobacco transplanting induced by the excessive N input during the vegetable cultivation season resulted in a reduction of economic income and the quality of flue-cured tobacco. Therefore, the objective of this paper is to describe the optimization of N management and to provide a better understanding of the mechanism of optimal N application rate on the economic benefit and quality of tobacco. A field experiment with six N application rates (0, 45, 60, 75, 90, and 105 kg N ha−1) was carried out with a randomized block design in 2021 and 2022 in Yunnan Province. The economic value and yield, intrinsic chemical and processing quality, leaf growth rate and agronomic characters were determined.

Keywords

• nitrogen application rate
• leaf growth rate
• prosperous growth stage
• soil residual n