The purpose of this study was to investigate the effects of different additives on the fermentation quality， nutrient composition and in vitro fermentation of stylo silage. Fresh stylo was ensiled with addition of 1.00% tea polyphenols （TPP）， coconut shell activated carbon （CSAC） or calcium lignosulfonate （CL）， along with additive-free control group （CK）. After 42 days fermentation at room temperature， fermentation quality， nutritional components and in vitro rumen fermentation were determined. The results showed that compared with the CK group， the addition of TPP and CSAC significantly reduced （P<0.05） the silage pH value and in vitro rumen gas production， significantly increased （P<0.05） soluble carbohydrate， true protein， lactic acid content and Flieg’s score comprehensive score， and the addition of TPP significantly reduced （P<0.05） ammonia nitrogen content and proportion， but CSAC led to a higher number of yeasts and molds in Stylosanthes silage. The addition of CL increased （P<0.01） lactic acid bacteria population， in vitro rumen fermentation gas production and 30 h dry matter digestibility of the silage， and decreased （P=0.01） its neutral detergent fiber content. In conclusion， the results indicated that all the three additives had certain effects on the quality of stylo silage， with the comprehensive effects of tea polyphenols was superior. Adding 1.00% tea polyphenols could reduce protein degradation of stylo grass during ensiling fermentation， increase the lactic acid concentration， improve the silage fermentation quality and nutritional value.

In order to fully utilize the by-products of safflower （Carthamus tinctorius） and explore the best ratio of mixing silage in different proportions with forage oats （ Avena sativa ） and safflower stems and leaves， six treatments were designed in this study. Oats and safflower stems and leaves were mixed with fresh weight， and the mixing ratios were 10∶0 （CK）， 9∶1 （H₁₀）， 8∶2 （H₂₀）， 7∶3 （H₃₀）， 6∶4 （H₄₀） and 5∶5 （H₅₀）. Each treatment was repeated in three groups. After sealing and fermentation for 60 days， the samples were taken and analyzed. The fermentation quality， nutritional value and bacterial community structure were determined. The results showed that the sensory evaluation results of the experimental group were still good or above. The pH values of CK group and H₁₀ group were significantly higher than those of other experimental groups （P<0.05 ）. There was no significant difference in ammonia nitrogen content among the experimental groups. The contents of lactic acid and acetic acid in H₃₀ group were significantly higher than those in other experimental groups （P<0.05）， and the contents of acid detergent fiber and neutral detergent fiber were the lowest. There was no significant difference in acid detergent fiber content among the experimental groups. The contents of propionic acid and butyric acid in CK group were significantly higher than those in other experimental groups （P<0.05）. The dry matter content and soluble sugar content increased with the increase of the proportion of mixed silage， while the crude protein content was decreased in the opposite direction. Combined with the comprehensive evaluation of the membership function method， it was concluded that the silage fermentation quality of the H₃₀ group was the best， in terms of microorganisms， at the phylum level， the dominant bacteria in each test group were Firmicutes. At the genus level， except for the unidentified-Chloroplast in the H₄₀ group， the dominant bacteria in the other test groups were Weissella. The results of comprehensive analysis showed that the optimal mixing ratio of oats and safflower stems and leaves was 7∶3， and the fermentation quality and nutritional quality were significantly improved.

Grasslands disturbed by mining activities in alpine regions exhibit slow recovery under natural conditions. Although organic amendments have been demonstrated to improve soil structure and water retention， their medium- to long-term effects on soil nutrient dynamics and microbial community composition remain unclear. This study investigated the regulatory effects of an organic amendment on the physicochemical properties and microbial community structure of grassland soils in high-altitude mining areas. The results showed that the organic amendment significantly enhanced soil moisture retention and nutrient accumulation. After three years of restoration， soil water content， particulate organic carbon （POC）， and total nitrogen （TN） at a depth of 25 cm increased by 17.07%， 22.86%， and 24.72%， respectively. Despite the gradual decomposition of the organic amendment in surface soil over time， its beneficial effects persisted in deeper layers. Additionally， the organic amendment improved bacterial community composition by increasing the relative abundances of Proteobacteria， Actinobacteria， and Acidobacteria. Mantel tests and redundancy analysis （RDA） further revealed that the organic amendment enhanced the positive correlations between soil nutrient parameters and microbial community structure， thereby facilitating microbial succession and ecological functional recovery.

This study was designed to systematically investigate the effects of different hybrid Pennisetum varieties and microbial additive treatments on the silage quality of hybrid Pennisetum. A total of six hybrid Pennisetum genotypes were employed， with each genotype assigned to a control group （CK）， Lactobacillus paracasei （LP） group， Bacillus subtilis （BS） group， and Lactobacillus paracasei + Bacillus subtilis （LP+BS） group. The inoculation dosages for both L. paracasei and B. subtilis were standardized at 1×10⁶ CFU·g^-1 fresh weight （FW）. Following a 30-day fermentation period， nutritional parameters and fermentation indices were quantified， with comprehensive evaluation conducted via Flieg scoring system and principal component analysis （PCA）.Results demonstrated that probiotic amendments significantly enhanced crude protein （CP） content in‘PI_587000’and‘536321’genotypes， while markedly reducing neutral detergent fiber （NDF） content in ‘536321’and‘103’genotypes. Supplementation with LP and LP+BS notably decreased the ammonia nitrogen ∶ total nitrogen （NH₃-N∶TN） ratio in‘Sunongke No.2’‘ 536321’‘102’and‘103’ （P<0.05）， whereas all BS-treated groups exhibited significantly higher NH₃-N∶TN ratios than LP+BS treatments （P<0.05）. Genotypes‘102’and‘103’showed elevated lactic acid （LA） accumulation. Integrative analysis of Flieg scores and NH₃-N∶TN ratios indicated that ‘late-maturing Pennisetum’displayed optimal fermentation performance， with LP+BS demonstrating the most pronounced improvement in forage silage quality. PCA yielded five principal components with a cumulative contribution rate of 86.558%， confirming‘late-maturing Pennisetum’as the top-performing genotypes and LP+BS as the most effective additive treatment. Conclusively，‘late-maturing Pennisetum’is preferable as silage substrate for hybrid Pennisetum， and the LP+BS consortium represents the optimal probiotic additive for enhancing silage quality.

In this study， alfalfa（Medicago sativa L.）was used as the experimental material. Through field control experiments and randomized block design， the effects of irrigation water temperature （surface water and groundwater） and irrigation amount （65%-75% field capacity， 55%-65% field capacity， 45%-55% field capacity） on yield， quality and irrigation water use efficiency of alfalfa were studied. Hay yield， irrigation water use efficiency， crude protein， ash， acid detergent fiber content and relative feeding value of alfalfa were analyzed， and the irrigation methods with high yield， high quality and high water efficiency of alfalfa were determined， in order to provide theoretical basis and practical guidance for optimizing irrigation management and efficient production of alfalfa. The main results are as follows， compared with groundwater irrigation， surface water irrigation significantly increased hay yield （17.36%-21.72%）， crude protein content （4.98%-7.07%）， crude ash content （0.47%-1.25%） and relative feeding value （3.61%-5.53%）， and decreased acid detergent fiber content （1.06%-2.98%） and neutral detergent fiber content （1.97%-4.42%）. Under mild drought stress， crude protein （20.33%）， crude ash （8.22%）， acid detergent fiber （22.48%）， neutral detergent fiber （39.96%） and relative feeding value （168.75） reached the optimal value. The irrigation water use efficiency of surface water treatment was the highest （2.73 kg·m^-3） under severe drought stress. Groundwater and severe drought stress synergistically inhibited root physiological activity， aggravated the decrease of yield and quality， and reduced water use efficiency.

Alfalfa （Medicago sativa L.） is a globally important leguminous forage crop， widely cultivated and utilized due to its high biomass yield， nutritional value， strong adaptability， and excellent palatability. Flowering time is a critical stage in alfalfa growth cycle， directly affecting forage yield and quality. However， variations in environmental factors and genetic characteristics often lead to significant differences in flowering time， which in turn affecting its production， cultivation， management， and harvesting efficiency. In recent years， significant progresses have been made in the field of molecular biology， revealing the regulatory mechanisms of flowering gene expression was influenced by photoperiod， temperature and hormones. However， in China， the research on alfalfa flowering time regulation remains insufficient， with challenges including weak basic research， outdated breeding techniques， and inconsistent flowering periods among cultivars. This review summarizes the recent advances in the regulation of alfalfa flowering time， explores the ecological factors and genetic mechanisms influencing flowering， and proposes future optimization strategies for breeding and cultivation management. The aim is to provide theoretical support and practical guidance for high-yield， high-quality alfalfa breeding and sustainable utilization.

To investigate the responses of alfalfa root morphological traits to phosphorus supply， a total of 31 plant materials were selected comprising 30 varieties of Medicago sativa L. and one variety of Medicago falcata L.， and three levels of phosphorus addition treatments were set up at P₅ （5 mg·kg^-1 KH₂PO₄）， P₂₀ （20 mg·kg^-1 KH₂PO₄）， and P₅₀ （50 mg·kg^-1 KH₂PO₄）. To screen low phosphorus tolerant alfalfa varieties with high phosphorus use efficiency， we measured the aboveground and belowground biomass and root morphological indices for the 31 alfalfa varieties. The results indicated that the aboveground and belowground biomass of alfalfa were lowest under P₅ treatment. With increasing phosphorus supply， the aboveground biomass of alfalfa significantly increased， reaching its highest level under the P₅₀ treatment. Under the P₂₀ and P₅₀ treatments， the root biomass of alfalfa was significantly higher than that under P₅， but there was no significant difference between P₂₀ and P₅₀. However， the root morphology showed significant variation among different varieties. Among them， ‘HD’‘Algonguin’‘Magna Graze II’ and ‘Longmu 801’ had higher biomass than other varieties， and exhibited greater root morphological plasticity with higher root length， root volume， root surface area， and root diameter， which demonstrated tolerance to low phosphorus condition. The results provide a scientific basis for optimizing alfalfa cultivation and improving phosphorus fertilizer utilization efficiency.

This study aimed to explore the changes and linkages of plant community species diversity and niche under different grazing intensities in （Leymus chinensis） meadow steppe， providing a basis for rational utilization of grassland resources. Taking plant communities in Leymus chinensis meadow steppe under six grazing intensities， including no grazing （G₀=0 cow.AU·hm^-2）， light grazing （G₁=0.23 cow.AU·hm^-2）， light-moderate grazing （G₂=0.34 cow.AU·hm^-2）， moderate grazing （G₃=0.46 cow.AU·hm^-2）， moderate-heavy grazing （G₄=0.69 cow.AU·hm^-2）， and heavy grazing （G₅=0.92 cow.AU·hm^-2）， as research materials， we conducted plant community surveys and calculated diversity indices and niche indices. The results showed that diversity indices first increased and then decreased with increasing grazing intensity， peaking at moderate grazing. The species importance values changed significantly， where the dominant position of Leymus chinensis was replaced by Carex duriuscula as the important values gradually decreased. The importance value was positively correlated with niche breadth， and the correlation was the strongest under light-moderate grazing and moderate grazing. The niche overlap value first increased and then decreased， while the interspecific competition pressure remained stable under light-moderate grazing and moderate grazing. Therefore， controlling the number of grazing livestock based on the niche breadth and overlap value of species could help stabilize the grassland ecosystem and facilitate the sustainable utilization of grasslands.

In order to explore the photosynthetic physiological differences of oat ear organs and flag leaves under drought stress， a pot experiment was conducted using Avena sativa L.‘Kona’ as the experimental material. Drought stress was initiated after the first flower bloomed. Chlorophyll contents， photosynthetic enzyme activities， soluble sugar and starch contents in flag leaves and ear organs were measured at 0， 7 and 14 days after drought stress treatment. The results showed that the chlorophyll content in the glumes was higher than that of the flag leaves， while the chlorophyll content of the lemmas was lower. Drought stress significantly reduced the enzyme activities of Rubisco， PEPC， and PEPCK in the flag leaves， while it had no significant influence on the activities of Rubisco in glumes and PEPCK， NADP-ME， NAD-ME activities in both ear organs. In addition， the activities of Rubisco， PEPC and PEPCK in the glumes were significantly higher than those in the flag leaves. Drought stress significantly increased the soluble sugar and starch contents in the flag leaves， while had no significant influence on sugar contents in both ear organs. To sum up， the flag leaves of ‘Kona’ oats responded more sensitively to drought stress， while the ear organs， especially the glumes， maintained better stability.

To investigate the impact of compound drought and hot events （CH） on the productivity and phenology of forage oats （Avena sativa L.） in Shuozhou， and to explore how the accumulated temperature requirements during the growth period of forage oats should be adjusted for coping with such events， this study utilized validated APSIM （Agricultural Production System sIMulator）to conduct simulation analysis at six sites in Shuozhou within baseline and future scenarios in combination with climate model. Based on APSIM model validation （2023 aboveground biomass Normalized Root Mean Square Erro： 9.19%， 2022—2023 soil moisture NRMSE： 25.69%） and scenario simulations， the results indicate that future climatic hazards in Northern Shanxi will be intensified. By the 2070s， the frequency， duration， and intensity of CH would generally increase with a decreasing trend from east to west. This led to a reduction in forage oat yield of 2046.2 kg·hm^-2 during CH-occurring years compared to the multi-year average. Furthermore， the durations from emergence to initial flowering and from initial flowering to full flowering were prolonged by 0.97 days and 0.26 days， respectively. However， optimizing cultivar selection based on site-specific climate conditions could increase forage yield by 1.95% to 23.65%.The results of this study could provide a theoretical basis for forage oats production to cope with CH， and offer some guidance for breeding strategy and field management of forage oats in the future.