Integrating chemical, organic, water-soluble and microbial fertilizers achieve mutually benefits of high nutrient utilization, improved yield and quality in tobacco cultivation

Optimizing nutrient management measures is fundamental to balancing tobacco yield and quality. While individual effects of fertilizers are well-documented, the integrated synergy of organic amendments with water-soluble fertilizers or microbial agents remains relatively scarce. Hence, a two-year field experiment was conducted to evaluate the comprehensive effects of five distinct nutrient management measures, no fertilization (CK), conventional chemical fertilizer (CF), organic fertilizer combined with conventional chemical fertilizer (CM), organic fertilizer combined with water-soluble fertilizer (WS), organic fertilizer combined with a compound microbial agent (OM), on tobacco growth, nutrient uptake and its use efficiency, leaf chemical composition, yield, quality, and revenue. The results revealed that WS and OM treatments increased tobacco yield and quality (proportion of premium and medium-grade tobacco leaves) by 14.9%-24.6% and 1.6%-6.3%, respectively, compared to the CF treatment. These improvements were primarily driven by enhanced plant height, stem girth, number of leaves, leaf area index, biomass, nutrient use efficiency and total sugar, potassium contents. Specifically, WS and OM increased N use efficiency by 106.0%-130.9% and 97.4%-126.1%, P use efficiency by 62.7%-149.6% and 79.2%-112.4%, K use efficiency by 473.1%-551.4% and 474.6%-480.5%, tobacco yield by 20.9%-24.6% and 14.9%-19.1%, the proportion of premium-grade leaf by 6.5%-17.2% and 8.9%-11.1%, and tobacco revenue by 26.8%-29.0% and 22.8%-31.5%, respectively. In summary, both the WS and OM treatments significantly improved the nutrient use efficiency, tobacco yield, leaf quality and revenue; among these, the WS treatment demonstrated the best comprehensive performance. Thus, organic fertilizer combined with water-soluble fertilizer is crucial for promoting the sustainable development of the tobacco industry.