Abstract:

To investigate the regulatory effects of different livestock manures on aerobic fermentation of tobacco stalks, composting experiments were conducted with tobacco stalks mixing separately with swine manure (T1), sheep manure (T2), cattle manure (T3), and chicken manure (T4) at an initial C/N ratio of 25:1. Key parameters including pile temperature, pH, electrical conductivity (EC), total organic carbon (TOC), total nitrogen (TN), carbon-to-nitrogen ratio (C/N), total phosphorus (TP), total potassium (TK), and germination index (GI) were dynamically monitored to evaluate manure-type effects on the maturation process. The results demonstrated that all treatments met thermophilic-phase sanitation standards, with post-fermentation (63 d) pH stabilizing between 8.00-8.50. Treatments T1 and T2 exhibited significantly lower EC but higher TOC than T3 and T4. Nutrient analysis showed that at the end of composting, the TN content in treatment T2 was significantly higher than that in T1, T3, and T4. The C/N ratios of all treatments eventually fell below 15. TP content peaked in T4 and reached minimum in T2, with TK accumulation following T4>T3>T1>T2. Maturity assessment showed significantly higher GI values in T1 and T2 versus T4, indicating superior compost maturity and reduced phytotoxicity. In summary, swine manure (T1) and sheep manure (T2) effectively enhanced organic matter conversion efficiency, optimized nutrient balance, and accelerated maturation, establishing them as optimal amendments for tobacco stalk valorization. This study provides critical theoretical and technical parameters for composting optimization.

Key words: tobacco stalk, composting, livestock manure, aerobic fermentation, compost maturity, resource utilization