Leymus chinensis (Trin.) Tzvel is a high-quality perennial native grass species in China, boasting a host of desirable traits such as high biomass yield, superior forage quality and excellent palatability for livestock. The purpose of this study was to explore Lactiplantibacillus plantarum (LP), 5 x 10(6) CFU/g of fresh weight (FW); cellulase (CE, xylanase and cellulase activities of 100,000 and 10,000 mu/g, 1% FW), and their combinations (LPCE, 5 x 10(6) CFU/g FW). Silage fermentation quality and bacterial community of L. chinensis were analyzed after 60 days of fermentation. The chopped material (500 g) was mixed well and then packaged into individual polyethylene bags (dimensions 22 cm x 35 cm) with three replications. Following a 60-day ensiling period, all additives significantly decreased the pH compared with the control group (CK, p < .05). The lactic acid (LA) and water-soluble carbohydrate (WSC) contents accumulated (p < .05), whereas acidic detergent fiber (ADF) and neutral detergent fiber (NDF) contents decreased (p < .05) in LPCE group on Day 60, and LPCE group exhibited superior fermentation quality, as indicated by large amounts of LA (similar to 18.75 g/kg dry matter [DM]), relatively low pH (similar to 4.01), acceptable levels of ammonia nitrogen (similar to 5.38 g/kg total nitrogen) and trace amounts of butyric acid (<2 g/kg DM). Lactiplantibacillus was dominant in all treated groups, whereas Enterobacter was predominant in CK. The LP and LPCE groups inhibited the reproduction threats posed by harmful microorganisms and decreased the growth and reproduction of Enterobacter, Pseudomonas and Pantoea during ensiling. Overall, LPCE can be used as a strategy to improve the fermentation quality, chemical composition and microbial community composition of Leymus chinensis silage.
Herein, a long-term fertilizer application trial was conducted on a clover (CL)-grass mixed sown grassland established on the andosols in Hokkaido's Konsen district. The experiment combined the presence or absence of the three main nutrients-nitrogen (N), phosphorus (P) and potassium (K)-with or without calcium (Ca) and magnesium (Mg) fertilization. We assessed the influence of fertilization on forage yield and alterations in botanical composition up to the 54th year following establishment. The treatments that maintained high yield levels for >50 years were the no nitrogen (-N) and three-nutrients (3F) plots with Ca and Mg applications. These findings support the statement by Omura et al. (1985) that stable high-yield forage production requires maintaining sown species in the Konsen region, especially CL, restraining N fertilization, applying sufficient P and K, and maintaining an appropriate soil pH through Ca and Mg fertilization. Contrastingly, the continuation of the trial clearly showed its high adaptability to low soil pH, although the redtop (RT, Agrostis alba L.) had previously been regarded only as tolerant to low-P conditions.
This study evaluated the effects of different theoretical lengths of cut on nutrient preservation and fermentation kinetics of low-moisture Italian ryegrass (approximately 80% dry matter [DM]). After harvest, the forage was field-wilted for 2 days and then manually chopped to 10, 20, or 30 mm for ensiling, and silage samples were collected on Days 1, 2, 3, 5, 10, 20, 30, 45, and 60. During fermentation, DM content initially decreased and subsequently increased, resulting in a slight increase for the 10-mm group but a significant decrease for the 30-mm group (from 84.06% to 78.88%, p < .05). Structural carbohydrate concentrations increased after ensiling, with both neutral detergent fiber (NDF) and acid detergent fiber (ADF) showing significant elevations across treatments. The most pronounced increase occurred in the 30-mm group, particularly for NDF (from 69.45% to 75.71%, p < .01). CP content in the 20-mm group was significantly lower than that in the 10- and 30-mm groups (p < .01), whereas in vitro dry matter (DM) digestibility remained relatively stable and did not differ among treatments. Fermentation patterns were similar across groups, as pH and water-soluble carbohydrate (WSC) contents declined only slightly throughout ensiling. However, during the early fermentation stage (first 10 days), the 10-mm group exhibited a relatively rapid decline in pH, reaching 6.16. Accordingly, lactic acid accumulation was significantly higher in the 10- and 20-mm groups (0.84% and 1.40% DM, respectively) than in the 30-mm group (0.46% DM, p < .01). By the end of ensiling, the 10-mm treatment achieved the highest TDN level. Overall, shorter theoretical lengths of cut promoted early lactic acid fermentation and more effective acidification in heavily wilted forage. Therefore, reducing cutting length to approximately 10 mm is recommended to improve the fermentation quality of low-moisture Italian ryegrass silage.
This study investigated the effects of papaya peel incorporation (0%, 15% and 30%) into a 50:50 mixture of corn and rice straw on fermentation quality, chemical composition and in vitro ruminal digestion. The silage was prepared 1 kg in a fermentation bag (16 cm & times; 25 cm) and ensiled for 45 days at room temperature (15-25 degrees C), with six replicates per treatment. The results showed that papaya peel addition significantly (P < 0.05) decreased the dry matter and neutral detergent fiber contents of mixed silage, while significantly (P < 0.05) increasing the crude protein and water-soluble carbohydrate contents of mixed silage. Compared to the control group, both treatments (15% or 30% papaya peel) exhibited higher acetic acid and ammonia-N concentrations (P < 0.05). The 30% papaya peel treatment additionally showed higher lactic acid bacteria counts and lower yeast populations (P < 0.05). In vitro fermentation results showed that 30% papaya peel treatment achieved the highest in vitro dry matter digestibility (P < 0.05). This study demonstrates that incorporating 30% papaya peel effectively improves the quality of mixed corn straw and rice straw silage, enhancing its nutritional value for ruminants.
We evaluated the effects of forage diversity on nutritional value, secondary metabolites and ruminal fermentation parameters. Five treatments with increasing forage diversity-Grass (G), Grass + Legume (GL), Grass + Legume + Forb (GLF; three species), GLF-6 (six species; two species per group) and GLF-9 (nine species; three species per group)-were cultivated and analyzed for nutritional composition, secondary metabolites, in vitro digestibility, gas production and ruminal fermentation characteristics. Dry matter (DM), crude protein (CP) and neutral detergent fiber (aNDFom) varied among treatments, with numerically higher CP in GLF and GLF-9 and lower DM in GLF and GLF-9. Total phenolic and flavonoid contents also varied, with quercetin, luteolin, and kaempferol numerically increasing in GLF-6 and GLF-9, and rutin decreasing from 294.82 mu g/g DM in G to 89.89 mu g/g DM in GLF-9. In vitro digestibility, total gas and methane production, short-chain fatty acids and ruminal pH were not significantly affected by forage diversity based on quadratic regression analysis. Rutin in forage was almost undetectable in ruminal fluid. Overall, increasing forage species diversity did not substantially impact forage nutritional composition, digestibility or ruminal fermentation characteristics.
Accurate estimation of aboveground biomass (AGB) in alpine ecosystems is challenging because of strong phenological variability, heterogeneous canopy structure and complex spectral-biomass relationships. Using 2 years (2023-2024) of monthly ground-based hyperspectral observations collected during the growing season (May-September), this study examined alpine meadow, degraded alpine meadow and alpine shrub communities on the northeastern Qinghai-Tibetan Plateau. Four regression approaches-elastic net, random forest (RF), support vector regression with a radial basis function kernel and extreme gradient boosting (XGBoost)-were compared with an emphasis on temporal transferability. A two-stage feature selection framework combining correlation screening and LASSO regression was applied to smoothed, first-derivative and continuum-removed spectra, reducing more than 1000 spectral predictors to approximately 20 physiologically meaningful features. Tree-based ensemble models, particularly RF and XGBoost, consistently achieved the highest predictive performance and showed strong robustness across vegetation types. Model accuracy exhibited clear seasonal dependence, with lower performance early in the growing season and marked improvement during mid and late season periods. The most informative predictors were concentrated in the red-edge, near-infrared and shortwave-infrared regions, and models based on these optimized features matched or exceeded full-spectrum performance. The results demonstrate that combining targeted spectral features with ensemble learning provides a robust framework for seasonal AGB estimation in heterogeneous alpine grasslands.
Sainfoin is a perennial forage legume with many desirable characteristics such as easy to establish, bloat-free trait for grazing ruminants and providing pollinator habitat and biological nitrogen fixation to soil. However, adoption of this species is often hindered by high seed cost associated with its larger seed size compared to other forage legumes. One possible solution is to improve desirable sainfoin seed traits with an increased number of seeds per unit weight. This study was conducted using an RNA-Seq technique to identify differentially expressed genes (DEGs) associated with sainfoin seed development at 7, 14 and 21 days after pollen fertilization from genotypes differing in seed size. More than 92.8% clean sequence reads were mapped to the sainfoin reference genome, and 771 DEGs were identified at the three time points. Certain DEGs were consistently expressed across all three seed developmental stages, and these genes were specific to each seed small group. Gene ontology analysis showed that the identified DEGs were significantly associated with 51 Gene Ontology (GO) terms across "biological process," "cellular component" and "molecular function" domains. Two DEGs, LeOno04cG0222300 and LeOno01dG0039200, were highly expressed in small seed genotypes. These identified DEGs and related genomic resources may be useful for marker-assisted breeding in sainfoin for a reduced seed size.
Cultivation as a summer annual grass in temperate regions of new extremely late-maturing guineagrass cultivar "Umaku" without heading with fertilizer application entails risks of toxic nitrate nitrogen (nitrate-N) concentration in the grass. No report has described a study of nitrate-N in guineagrass without heading cultivated as an annual grass in temperate regions. Therefore, for two years, we clarified nitrogen fertilizer effects on dry matter yield (DMY), nutritional values and nitrate-N concentration in Umaku without heading cultivated as a summer annual grass. Subsequently, we evaluated management strategies aimed at optimizing nitrogen application to enhance DMY and crude protein (CP) content without increasing nitrate-N. Treatments were factorial combinations of two basal fertilizer applications (10 or 20 g N/m2, respectively, as S or D treatment) and two grasses ("Umaku" and "OKI-1" of Urochloa hybrid as a control) in a randomized complete block design with three replicates. Although differences between years in all measurements were significant, CP and nitrate-N for the D treatment were significantly higher than for the S treatment. Nitrate-N values of both grasses exceeded the toxic thresholds (0.2% DM) in all except for the S treatment of 2020. Delaying harvest until after a sufficient yield has been attained is suggested as an effective strategy for suppressing nitrate-N concentrations. For Umaku, approximately 620 g/m2 of DMY with 10 g N/m2 fertilizer application and at least 800 g/m2 of DMY with 20 g N/m2 fertilizer application are recommended. The derived relation between total nitrogen and nitrate-N well demonstrated that cultivation as annual summer grass without heading carries a risk of toxic nitrate-N concentration (0.2% DM) when the supplied nitrogen fertilizer is intended to achieve a CP content exceeding 9%. However, because of our limited dataset, further data accumulation is necessary. Furthermore, measuring nitrate-N concentrations at the time of harvesting on farm is required for preventing nitrate-N poisoning.
High Andean grasslands are vulnerable to changes in their nutritional quality and carbon sequestration capacity, especially in grazing systems. This study evaluated soil quality and native grasses by measuring carbon, physicochemical parameters, and the nutritional quality of predominant species in the wet Puna of Jun & iacute;n, Peru. Significant differences were found in carbon storage and nutritional quality across different grazing grassland sites. Soil carbon levels were consistently high across all sites, with significant concentrations at San Pedro de Cajas (14.26% +/- 11.7%; p < 0.05), and its carbon stock (210.7 +/- 111.3 Mg/ha) exceeded that of Jun & iacute;n (+68%) and Ulcumayo (+107%). Also, the flat topography at this site is presumed to have influenced its soil fertility. No adverse relationship was observed between carbon content and animal units, regardless of continuous or rotational grazing system, and a strong negative Pearson correlation (r = -0.84) between total carbon and bulk density indicated the prevalence of organic materials and no soil compaction. It emphasizes how landscape features affect soil quality and ecosystem processes. The protein content of key species exhibited a strong Pearson correlation with plant phosphorus (r = 0.93), digestible organic matter (DOM), and metabolizable energy (ME; r = 0.75). The Redundandy Analysis (RDA) showed that plant functional traits are driven by chemical and physical gradients, underscoring the combined effects of nutrient availability and site constraints on pasture productivity and forage quality. Among native grasses, Cebadilla (Calamagrostis vicunarum [Wedd.] Pilg.) emerged as the most favorable option for animal nutrition and exhibited a significantly higher crude protein content (8.23% +/- 0.89%), Metabolizable energy value (8.16 MJ/kg), and C/N ratio (similar to 40). Future research should focus on linking soil and forage quality with animal physiological responses to improve understanding of grazing impacts and guide sustainable management in high-altitude grasslands.
Leaf serration in forage corn (Zea mays L.) is often observed under field conditions. In this study, field cultivation experiments were conducted over 3 years to determine the factors affecting the appearance and development of this trait and to assess its potential impact on corn productivity. We also evaluated soil mineral conditions using leaf serration as an indicator. The number of symptomatic leaves per plant decreased after spraying with calcium chloride solution (3 g/L), and the development of leaf serration was also suppressed. Therefore, leaf serration in corn grown under field conditions may be a symptom of calcium deficiency. Occurrence of leaf serration did not significantly affect the dry matter yield of corn shoots at the yellow-ripe stage, which is considered optimal for ensiling. This was because the yield, which included the leaves, stems, and ears, was not affected by calcium spraying. The number of leaves with symptoms increased logarithmically with an increase in soil exchangeable potassium content, owing to the decrease in calcium concentration in the corn plant caused by excessive amounts of soil potassium. The appearance of symptoms differed significantly among corn varieties, and the highest number of symptomatic leaves occurred in the variety with the highest calcium concentration. Different regression equations were obtained from the relationships between soil exchangeable potassium content and the number of symptomatic leaves in varieties with low and high calcium concentrations. The soil exchangeable potassium content was estimated using these equations, with the number of symptomatic corn leaves after silking as an indicator. With two or more symptomatic leaves per plant, the soil exchangeable potassium content was adequate for forage corn production. We suggest that a reduction in potassium input should be implemented in fertilization management if corn plants develop leaf serration.
Predicting the dry matter yield (DMY) of the first harvest of perennial ryegrass (Lolium perenne L.) following overwintering helps assess the risk of winter damage. This study compared machine learning (ML) models for the prediction of DMYs based on well-organized examined data for cultivar registration trials across 13 locations in Hokkaido, Japan, over the period from 1983 to 2022, including the DMYs of first harvests, daily weather data, seedling and examined years, number of harvests in the previous year, date of last harvest in the autumn of the previous year, date of first harvest and experimental designs (drilled-row plots or sward plots, and whether mixed with other species). The yield estimation models were developed using 17 ML methods with default hyperparameter settings. Among the ML models, successful methods included tree-based algorithms. The accuracy scores (R 2 ) were 0.80-0.91 for training data (5-fold cross-validation), and 0.79-0.92 for test data. The permutation feature importance in the best model (light gradient boosting machine) indicated that the daily minimum temperature and snow depth in winter could have a significant impact on the DMYs of the first harvests following overwintering. Additionally, the partial dependence plots revealed that frequent cutting increased the risk of overwintering damage and that it identified a specific autumn harvest period that negatively affected yield and persistence after overwintering. In conclusion, the ML model, incorporating weather and pasture management data, demonstrated high predictive performance (R 2 = 0.92) for forecasting overwintered yield loss of perennial ryegrass in frozen soil areas of Hokkaido.
We quantified the interspecific variation in root growth responses to soil compaction across 15 wild Mongolian grassland species and classified their root growth patterns to inform the biological restoration of grassland soils compacted by vehicle traffic. Plants were grown in compacted and uncompacted soil, and we determined root dry mass, diameter, length, specific root length, root depth index and root-to-shoot ratio. Compaction affected root traits in all species differentially, leading to a wide range of trait magnitude in compacted soil. Two primary features effectively explained this interspecific variation: the thick, short root morphology under compaction and the extent to which roots thickened and shortened as an adaptive response. Perennials and monocots generally exhibited thicker and shorter roots in compacted soil compared to annuals and dicots. These findings demonstrate that certain species possess root characteristics making them highly advantageous for the reclamation of compacted soils in Mongolia, and our classification can contribute to selecting those species.
The walk-over-weighing (WoW) system and a body weighing system utilizing a dead-end chute have been developed to reduce the labor involved in weighing grazing cows. However, challenges persist, such as abnormal body weight readings in the WoW and agonistic behavior in the dead-end chute system. In this study, the dead-end chute was redesigned with separate entrance and exit routes. The exit was positioned at a 45 degrees outward angle at the other end from the entrance to facilitate movement away from the chute. Six cows with prior dead-end chute experience were used to evaluate the effectiveness of the improved chute design by comparing incidences of agonistic behavior, daily visit frequency, time spent per visit and time spent drinking per day between the improved chute and the dead-end chute. Six cows with no chute experience were used to investigate the learning process in the improved chute. Additionally, using the same 12 cows, we tested whether cows were more likely to use the exit or move backward toward the entrance when using the improved chute. The mean occurrence rate of agonistic behavior was significantly lower in the improved chute than in the dead-end chute. Cows with no experience entered the improved chute independently within 5 days after grazing began. Subsequently, as the number of usage days increased, the time spent per visit decreased, while drinking time was extended. In the improved chute, when no cows were present near the chute, three out of 12 cows used the forward exit; however, when other cows were present near the entrance, 10 cows exited through the exit chute. These findings suggest that the improved chute is effective for the management of grazing cattle.
Black oat (Avena strigosa Schreb.) is an important grass species that is commonly used as fodder and green manure in Japan. Consequently, it is agriculturally important to understand the changes in productivity and agronomic traits caused by differences in the sowing time for oat cultivars used throughout several growing seasons. In this study, the productivities and agronomic traits were evaluated for two black oats cultivars, namely "Ricky" and "Terara," which were recently developed as early cultivars in Japan. These characteristics were examined under both late-summer and spring sowing conditions in a warm region of Japan to evaluate their response patterns to different sowing seasons. The 3-year mean dry matter yield of "Ricky" was 75.3 kg/a under late-summer sowing conditions and 86.7 kg/a under spring sowing conditions, representing an 18% higher yield under spring sowing conditions. For "Terara," three-year mean dry matter yield was 69.4 kg/a under late-summer sowing conditions and 76.3 kg/a under spring sowing conditions, representing a 10% higher yield under spring sowing conditions. These results indicate that both cultivars were more productive when sown in spring. The number of days from germination to heading did not differ between the two conditions for "Ricky" but was significantly earlier (5.2 days) under late-summer sowing conditions in "Terara." In addition, the plant height was higher (17 cm) under spring sowing conditions for "Ricky," whereas no difference was observed for "Terara." These results demonstrated that the response patterns of agronomic traits caused by different sowing times differed between cultivars classified as the same early cultivar. "Ricky" and "Terara" showed stable productivity under both late-summer and spring sowing conditions in the warm regions of Japan. "Ricky" consistently showed higher yields, while "Terara" performed comparably to commercial cultivars. Their nematode-suppressing traits could further support their potential as dual-purpose grasses for fodder and green manure.
The paper compared the nutritional content and some physicochemical parameters of silages obtained with three forage crops, namely corn, corn-soybean mix and sorghum, and three frequent vegetable wastes, namely carrot, beet and potato. Dry matter (DM), pH, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and in vitro dry matter digestibility (IVDMD), lactic acid (LA) and butyric acid (BA) concentrations were examined in six silage types. DM, CP, NDF, ADF, IVDMD and LA contents differed significantly (P < 0.05) among the treatments. Corn silage had a greater DM percentage (32.66%) than ensiled vegetable residues. The highest concentration of CP was observed in fermented forage crops (8.70-9.50%). Silages made of vegetable residues showed significantly reduced ADF values (22.50-23.16%) as compared to ensiled forage crops (32.00-39.16%). The lowest NDF was observed in carrot silage (31.66%). Ensiled potato recorded the highest rate of in vitro digestion (86.33%). In the correlation analysis, it was observed that a highly positive correlation (P < 0.01) existed between DM and CP (r = 0.945), NDF (r = 0.943), and ADF (r = 0.851). Likewise, high positive correlations were evident between CP and NDF (r = 0.954) as well as ADF (r = 0.807). As compared to IVDMD, this was negatively and weakly correlated with ADF (r = 0.653, P < 0.01), DM (r = 0.617, P < 0.01) and NDF (r = 0.545, P < 0.05). Results show that vegetable-residue silages could be used as an alternative to ensiled forage crops.
The use of unmanned aerial vehicles for remote sensing is an effective method for monitoring crop growth, particularly for tall crops such as maize. High‐resolution imagery obtained from unmanned aerial vehicles enables the measurement of plant height, which is a critical indicator of crop growth. However, a reference plant height is required to assess growth. This study aimed to develop a model to predict the reference height for growth assessment using temperature data. Furthermore, a methodology was proposed to estimate model parameters from the relative maturity, thus enabling adaptation to a range of maize varieties. In 2022 and 2023, maize plant height was measured using an unmanned aerial vehicle at two flying altitudes (40 and 100 m) several times for 12 varieties with varying relative maturity. Moreover, a regression model was developed to predict the silking stage and identify the optimal sensing time 1 week before the silking stage. The results showed that the growth rate was not statistically different among the varieties, indicating that maximum plant height was determined by the duration of the growth period. A growth model was developed based on these results. The root mean square error (RMSE) for the model was 0.16 and 0.15 m for data sets from 40‐ and 100‐m altitudes, respectively. In estimating plant height, this growth model performed marginally better than the logistic curves used in existing studies. Additionally, a linear relationship was observed between relative maturity and the parameters of the developed growth model. Consequently, the newly developed growth model can predict the plant height for new varieties because the parameters of the model can be inferred from the relative maturity.
This study aimed to develop prediction models for organic acid concentrations in Capiaçu grass ( Pennisetum purpureum Schum) silage, based on fermentation parameters and chemical composition. Data were obtained from an experiment that evaluated BRS (Brazil Seeds) Capiaçu grass silage with the inclusion of dehydrated cashew pseudofruit ( Anacardium occidentale ) at levels of 0%, 10%, 20% and 30% (on a fresh matter basis). The most accurate models for predicting lactic acid used dry matter as the only predictor variable, reaching an R 2 of 0.98 and root mean square prediction error (RMSPE) of 1.52. In the case of acetic acid, the best prediction model combined pH and the quadratic terms of pH and buffering capacity (BC), with R 2 of 0.73 and RMSPE of 0.98. The most accurate prediction model for butyric acid included crude protein and BC, with R 2 of 0.51. The prediction model with the greatest predictive capacity for propionic acid combined organic matter, BC and the quadratic term of soluble carbohydrates, reaching R 2 of 0.75. Thus, prediction models for lactic acid ( R 2 = 0.98) are suitable for field applications, whereas those for butyric acid ( R 2 = 0.51) require caution. In the validation of the selected prediction models, all showed accuracy and precision with correlation and agreement coefficients ≥ 0.70 for most models. Prediction errors were low, and the null hypothesis ( β ₀ = 0 and β ₁ = 1) was accepted for all prediction models. The organic acids in Capiaçu‐grass silage can be estimated based on its pH and chemical composition, particularly dry matter, buffering capacity, crude protein, organic matter and soluble carbohydrates.
Ammonia‐oxidizing bacteria (AOB) are key drivers of nitrogen cycling and plant growth, yet their roles in cytokinin biosynthesis and regrowth stimulation remain underexplored. This study investigated the multifunctional potential of a novel AOB strain, C5_3, in promoting compensatory regrowth of Lolium multiflorum following clipping. A pot experiment was conducted with six treatments: blank control (BT), nitrification inhibitor (DN), C5_3 inoculation (JI), C5_3 combined with the inhibitor (DJ), cytokinin‐producing strain S2 (JS) and S2 combined with the inhibitor (DS). Measurements were taken on Days 0, 7 and 14 of regrowth, including soil nitrate (NO₃ − –N) content, nitrification rate, zeatin riboside (ZR) content and transport rate, clipped leaf biomass and total plant biomass. The results indicated that inoculation with C5_3 significantly increased nitrification rates, reaching 2.5 times the level observed in the BT treatment, and enhanced C5_3 gene abundance, resulting in higher soil nitrate availability. C5_3 also elevated leaf ZR content and promoted its transport from root to shoot under both light and dark conditions. While S2 primarily enhanced cytokinin levels, C5_3 demonstrated dual functionality by improving both hormonal and nutritional pathways, leading to greater biomass accumulation ( p < .05). The nitrification inhibitor reduced microbial activity and plant regrowth, and its combination with C5_3 only partially mitigated these effects. Overall, these findings demonstrate that C5_3 stimulates compensatory regrowth in L. multiflorum through integrated microbial and hormonal pathways. Its dual functionality highlights its potential as a bioinoculant for sustainable forage production systems requiring rapid recovery after grazing or mowing.
This study aimed to evaluate the fermentation characteristics, nutritive value and in vitro ruminal digestibility of a mixed silage of sweet sorghum (SS) with peanut vine hay (PVH) or distiller grains (DG). Silage was produced without any additives (CON) or with 10% (P1) or 20% (P2) PVH or 10% (D1) or 20% (D2) DG on fresh matter. All silage was ensiled in capped bottles and preserved for 60 days. The lowest pH value was found in D2 silage, followed by D1, CON, P1 and P2 silage (P < .05). The D2 silage exhibited the highest lactic acid content, which was significantly greater than that observed in P2 silage (P < .05). The ammonia-N content of the CON silage was higher than that of the P2- and DG-treated silage (P < .05). The inclusion of PVH or DG in SS ensilage resulted in a linear increase in dry matter, crude protein, total digestible nutrients, and relative feed value and a decrease in organic matter, neutral detergent fiber, acid detergent fiber and water-soluble carbohydrates. Most in vitro rumen fermentation parameters tended to increase in silage treated with PVH or DG compared with CON silage, although no significant effect (P > .05) was found for the treatments. Furthermore, PVH- or DG-treated silage had a lower ruminal fermentation pH (P < .05). Our study demonstrates that the addition of PVH or DG can improve the fermentation quality, nutritional value and in vitro ruminal digestibility of SS silage. Notably, the fermentation efficacy of DG was higher than that of PVH. Therefore, inclusion of 20% PVH or DG in the silage formulation is recommended.
This study aims to determine how plant communities and soil characteristics respond to topography in three habitats in the basin unit of the Yellow River source zone. Based on the data of field plant community species and soil factors investigated in a typical alpine meadow, we established the relationship between plant community, soil characteristics and typical topographic habitats via correlation analysis, redundancy analysis (RDA), and structural equation modelling. The results showed that: (1) Shannon-Wiener diversity index and Pielou evenness index of the alpine meadow plant community are the highest in marshland habitat, which significantly increased by 44.97% and 48.34% over those of sunny habitat (P < 0.05); (2) Soil water content (SWC) and organic carbon (SOC) content in different habitats were the highest in marshland habitat, which were 87.05% and 155.31 g/kg, respectively, significantly higher than in sunny habitat (P < 0.05); (3) A large number of significant correlations (P < 0.05) exist between community characteristics and their stoichiometric ratios, soil physical and chemical properties and soil enzyme activity. RDA analysis revealed that the hydrogen (H) content of aboveground parts of plants, carbon-nitrogen ratio (C/N) of underground parts of plants, nitrogen-phosphorus ratio (N/P) of soil, the nitrate nitrogen (NH4+-N) content of soil and N-acetyl-glucosaminidase (NAG) enzyme activity exhibit the greatest influences on community characteristics, with a contribution rate of 70.0%, 51.4%, 79.4%, 72.2% and 91.3%, respectively, all reaching the significant level (P < 0.05). Soil nutrients affect plant diversity and productivity by affecting the nutrients and stoichiometry of aboveground and underground plants. This study shows that the change in topographic position can lead to differences in plant community characteristics and soil physical and chemical properties and has an important impact on the changes in extracellular enzyme activity and the eco-stoichiometric ratio.
