Effect of mixed sowing of Dolichos lablab and Sorghum dochna on mixed forage silage quality

To evaluate the effect of different sowing rates of Dolichos lablab and Sorghum dochna on the quality of mixed forage silage, the silage (S₀) sown with S. dochna alone (sowing rate of 22.5 kg·ha⁻¹) and that with S. dochna and D. lablab (different sowing rates of 22.5, 45.0, 67.5, and 90.0 kg·ha⁻¹ for S₁, S₂, S₃, and S₄, respectively) were analyzed.” Nutritional components and fermentation quality were determined after 60 days of fermentation at room temperature (about 25 ℃). The results showed that the fresh and dry grass yields of S. dochna monoculture were the highest at 75.61 and 23.04 t·ha⁻¹, respectively. In the mixed-seeding treatment group, the neutral and acid detergent fiber contents in the mixed forage decreased significantly, while the crude protein content increased significantly (P < 0.05). The crude protein content of the mixed sowing silages was significantly higher than that of the S. dochna silage, and the contents of water-soluble carbohydrates, neutral detergent fiber, and acid detergent fiber were significantly lower than that of S. dochna silage (P < 0.05). Compared with S₀ treatment, S₂ treatment significantly increased lactic acid content and decreased acetic acid and butyric acid contents (P < 0.05). Based on the fresh hay yield, nutritional components, and fermentation quality of silage, the mixed silage of 45.0 kg·ha⁻¹ D. lablab and 22.5 kg·ha⁻¹ S. dochna was the most suitable for silage modulation. This study may provide theoretical guidance and technical support for the silage of soybean-grass mixtures in Ningxia.