A two-year field experiment was conducted to address the effects of mixture composition and legume-grass seeding ratio on the biomass yield and nutritional quality of legume–grass mixtures. Alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), red clover (Trifolium pratense L.), orchardgrass (Dactylis glomerata L.), perennial ryegrass (Lolium perenne L.), and tall fescue (Festuca arundinacea Schreb.) were selected as plant materials. A total of seven legume–grass mixtures (A1: white clover, orchardgrass, and tall fescue; A2: alfalfa, orchardgrass, and tall fescue; B1: alfalfa, white clover, orchardgrass, and tall fescue; B2: red clover, white clover, orchardgrass, and tall fescue; C1: alfalfa, white clover, orchardgrass, tall fescue, and perennial ryegrass; C2: red clover, white clover, orchardgrass, tall fescue, and perennial ryegrass; and D: alfalfa, red clover, white clover, orchardgrass, tall fescue, and perennial ryegrass) were sown in two legume-grass seeding ratios (L:G) of 4:6 and 5:5. The results showed that A2 produced a higher two-year average biomass yield (14.20 t/ha) in L:G of 4:6 than that of other mixtures. The grasses biomass yield proportion decreased while legume biomass yield proportion increased with prolonged establishment time. A2 showed a higher crude protein yield (2.5 t/ha) in L:G of 4:6. C2 and A1 showed lower neutral detergent fiber (4.6 t/ha) and acid detergent fiber (2.8 t/ha) yields in L:G 5:5, while diverse mixtures showed higher water-soluble carbohydrate yields. Overall, A2 showed a relative feed value of 146.50 in L:G of 4:6, indicating that it has not only produced the higher biomass yield but also had a better nutritional quality.

Oat (Avena sativa L.) is one of the important forage crops in the world. However, oat grown in Southwest China has higher moisture content and their preservation face significant challenges. In addition, existing commercial lactic acid bacteria (LAB) have poor fermentation effects in hot and humid regions. Consequently, the current study investigated the response of oat fermentation quality and microbial community to self-selected LAB inoculation. The treatments were: CK, sterilized water; LP694, Lactobacillus plantarum 694; LR753, Lactobacillus rhamnosus 753; and LPLR, LP694 combined with LR753, followed by 1, 3, 7, 14, and 60 days (d) of fermentation. The results showed that LAB inoculation significantly raised the lactic acid content, and decreased the level of pH value, acetic acid, and ammonia-N in oat silage. The LR753 group had a significantly higher (p < 0.05) lactic acid content (60.95 g kg^–1 DM), and lower pH value (3.95) and ammonia-N content (10.1 g kg^–1 DM) followed by the LPLR group. The LR753 showed lower NDF (54.60% DM) and ADF (39.73% DM) contents than other groups. The Lactobacillus was a prevalent genus in LAB-treated groups, and its relative abundance reached maximum in LP694 (69%) on day 3, while in the LR753 group (72%) on 60 days. The Lactobacillus rhamnosus, Lactobacillus plantarum, and Lactobacillus fermentum became the dominant species in LAB-treated groups with fermentation time. The Lactobacillus genus was positively correlated with WSC (R = 0.6, p < 0.05), while negatively correlated with pH (R = −0.5, p < 0.05), and BA (R = −0.5, p < 0.01). Overall, the LR753 group had better fermentation quality and preservation of nutritional components providing theoretical support and guidance for future oat silage production in Southwest China.

Information regarding relationships between forage yield and soil enzymes of legume–grass mixtures under nitrogen (N) fertilization can guide the decision-making during sustainable forage production. The objective was to evaluate the responses of forage yield, nutritional quality, soil nutrients, and soil enzyme activities of different cropping systems under various N inputs. Alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), orchardgrass (Dactylis glomerata L.), and tall fescue (Festuca arundinacea Schreb.) were grown in monocultures and mixtures (A1: alfalfa, orchardgrass, and tall fescue; A2: alfalfa, white clover, orchardgrass, and tall fescue) under three N inputs (N1: 150 kg ha⁻¹; N2, 300 kg ha⁻¹; and N3: 450 kg ha⁻¹) in a split plot arrangement. The results highlight that A1 mixture under N2 input had a greater forage yield of 13.88 t ha⁻¹ year⁻¹ than the other N inputs, whereas A2 mixture under N3 input had a greater forage of 14.39 t ha⁻¹ year⁻¹ than N1 input, but it was not substantially greater than N2 input (13.80 t ha⁻¹ year⁻¹). The crude protein (CP) content of grass monocultures and mixtures significantly (P < 0.05) increased with an increase in the rate of N input, and A1 and A2 mixtures under N3 input had a greater CP content of 18.91% and 18.94% dry matter, respectively, than those of grass monocultures under various N inputs. The A1 mixture under N2 and N3 inputs had a substantially greater (P < 0.05) ammonium N content of 16.01 and 16.75 mg kg⁻¹, respectively, whereas A2 mixture under N3 had a greater nitrate N content of 4.20 mg kg⁻¹ than the other cropping systems under various N inputs. The A1 and A2 mixtures under N2 input had a substantial higher (P < 0.05) urease enzyme activity of 0.39 and 0.39 mg g⁻¹ 24 h⁻¹ and hydroxylamine oxidoreductase enzyme activity of 0.45 and 0.46 mg g⁻¹ 5 h⁻¹, respectively, than the other cropping systems under various N inputs. Taken together, growing legume–grass mixtures under N2 input is cost-effective, sustainable, and eco-friendly, which provide greater forage yield and improved nutritional quality by the better utilization of resources.

The strategic delay of aerobic deterioration in Sesbania cannabina and corn (SC) mixed silage, coupled with effective fermentation, could increase the protein-rich silage utilization by ruminants. Thus, we sought to investigate the role of a compound lactic acid bacteria (LAB) inoculant (Lactobacillus plantarum + Lactobacillus farciminis + Lactobacillus buchneri + Lactobacillus hilgardii; at a level of 106 CFU/g fresh weight) in enhancing the aerobic stability of SC mixed silage. Specifically, we focused on the potential for corn supplementation to improve fermentation quality while concurrently increasing the susceptibility of SC mixed silage to aerobic spoilage. Results revealed that compound LAB additive diversified the microbial community of SC mixed silage, making Lactobacillus hilgardii and Lactobacillus buchneri dominant bacterial species, while decreasing the abundance of Kazachstania humilis fungal specie. As a result, the LAB-treated mixed silages had higher acetic acid contents and lower yeast populations. Aerobic stability analysis revealed that the SC mixed silages with a high corn proportion deteriorated rapidly when the silages were exposed to air. The high aerobic stability of the LAB-treated mixed silages especially S7C3 contrasted with the low acetic acid concentrations in the CK mixed silages (processed with sterilized water), concomitant with increased Kazachstania humilis abundance. Our study revealed that inoculation with a compound LAB additive altered the consequences of aerobic exposure by increasing acetic acid production after ensiling, promoting diverse bacterial populations, and mitigating the negative effects of fungi on the aerobic stability of SC mixed silage.

Intercropping improves land-use efficiency under conditions of limited land and resources, but no information is currently available pertaining to land-use efficiency and silage quality based on whole-plant utilization. Therefore, a two-year field experiment was conducted with the following conditions: three maize–soybean strip intercropping patterns (SIPs), comprising two maize rows along with two, three, or four soybean rows (2M2S, 2M3S, and 2M4S, respectively); and two sole cropping patterns of maize (SM) and soybean (SS). The aim was to evaluate the biomass yield and silage quality under each condition. Our results showed that all SIPs had a land equivalent ratio (LER) of over 1.6 based on both fresh and dry matter yield, and a higher whole plant yield, compared to sole cropping. Specifically, 2M3S exhibited the highest whole crop dry matter LER (1.8–1.9) and yield (24.6–27.2 t ha⁻¹) compared to SM and SS (20.88–21.49 and 3.48–4.79 t ha⁻¹, respectively). Maize–soybean mixed silages also showed better fermentation quality with higher lactic acid content (1–3%) and lower ammonia-N content (2–8%) compared to SS silages, and higher crude protein content (1–1.5%) with lower ammonia-N content (1–2%) compared to SM silage. Among the intercropping patterns, 2M3S had the highest fermentation quality index V-score (92–95). Consequently, maize–soybean strip intercropping improved silage quality and biomass yield, with 2M3S being recommended, due to its highest LER and biomass yield, and most optimal silage quality.

Background: Elucidating the mechanism of fiber transformation underlying microbial metabolism is critical for improving fiber-rich silage digestibility and preserving silage energy for ruminant nutrient absorption. However, few studies have combined quantitative microbial function and transformation products in silage to explain this mechanism. Here, we constructed a workflow to detect the substrates and products of fiber transformation in mixed silage of Sesbania cannabina and sweet sorghum (SS) and combined the absolute quantification 16S rRNA sequencing to reveal this mechanism. Results: The synergistic effect of Lactobacillus cocktail and cellulase (LC) simplified the microbial diversity and minimized the microbial quantity, making Lentilactobacillus buchneri the dominant species in SS silage. As a result, the LC-treated silage had greater lactic acid content, lower pH value, and less NH₃-N content. The indigestible fibers were significantly decreased due to the synergistic effect of the Lactobacillus cocktail and cellulase. Changes in microbial structure during ensiling also resulted in metabolic alterations. The increased levels of microbial enzymes, including β-glucosidase and sucrose phosphorylase, involved in starch and sucrose metabolism led to the enrichment of monosaccharides (including glucose, xylose, mannose, galactose, ribose, rhamnose, and arabinose) in the LC-treated silage. We found that L. buchneri was positively associated with β-glucosidase and sucrose phosphorylase, reflecting the crucial contribution of L. buchneri to fiber decomposition in SS silage. Conclusion: Using an absolute quantitative microbiome, we found that LC treatment decreased the microbial biomass in SS silage, which in turn promoted the energy preservation in the SS silage. The cooperative interaction of the Lactobacillus cocktail and cellulase improved the fiber decomposition and in vitro dry matter digestibility rate by changing the microbiome structure and function in the SS silage, providing guidance and support for future fiber-rich silage production in the saline-alkaline region. Graphical