To identify suitable forage oat cultivars and determine the optimal cutting stage for saline alkali soils in the Hetao Irrigation District, 14 domestic and foreign forage oat cultivars were evaluated. Differences in yield, forage quality, and digestibility characteristics were analyzed across different growth stages, and comprehensive screening was conducted using grey relational analysis. The results showed that plant height differed significantly among cultivars and growth stages, and all cultivars exhibited an "S" shaped growth curve. In terms of cultivar main effects, fresh forage yield and hay yield ranged from 21 451.67 to 38 916.53 kg/hm² and from 5 620.76 to 8 359.18 kg/hm², respectively. The crude protein (CP) contents of the ‘Leader’ (Souris), ‘Baler’ and ‘Baler No.2’ exceeded 10.00% of dry matter (DM) and were significantly higher than those of other varieties except ‘Yellow oat’. The neutral detergent fiber (NDF) contents of ‘Baler’, ‘Baler No.2’, and ‘Yellow oat’ was significantly lower than those of most other varieties, except ‘Leader’ (Souris). The acid detergent fiber (ADF) contents of ‘Leader’ (Souris), ‘Baler’, and ‘Baler No. 2’ were significantly lower than those of other cultivars, except ‘Yellow oat’, while acid detergent lignin (ADL) content was lowest in ‘Haymaker’, ‘Baler’, and ‘Helios’. ‘Haymaker’ had the highest ether extract (EE) content. Regarding cutting stage, hay yield and dry to fresh ratio followed the order milk stage > flowering stage > heading stage. At the flowering stage, fresh forage yield and water-soluble carbohydrate (WSC) content were highest, while CP, dNDF₃₀, dNDF₄₈, NDFD₃₀, NDFD₄₈, IVTDMD₃₀, and IVTDMD₄₈ were second only to those at the heading stage. ADL content was also significantly lower at flowering than at the milk stage. The relative feed quality (RFQ) values of ‘Haymaker’ and ‘Baler’ were significantly higher than those of all other cultivars except ‘Leader’ (Souris). Gray relational analysis showed that NDF, IVTDMD₄₈, ash, dNDF₃₀, and IVTDMD₃₀ ranked as the top five weighted indicators. Both equal weight and weighted correlation degrees ranked ‘Baler’, ‘Haymaker’, and ‘Leader’ (Souris) among the top three cultivars. In conclusion, NDF was the primary indicator for evaluating the production performance of forage oats in saline alkali soils of the Hetao Irrigation District. ‘Baler’, ‘Haymaker’, and ‘Leader’ (Souris) showed the best overall performance and were suitable for cultivation in this region. The flowering stage provided the best comprehensive production performance and was recommended at the optimal cutting stage.

Tenaccessions of Thinopyrum intermedium were subjected to drought stress simulated by 15% polyethylene glycol (PEG) in hydroponic culture. Plant height, root length, shoot dry weight, root dry weight, and other indices were measured. Correlation analysis, principal component analysis, membership function analysis, and cluster analysis were integrated to comprehensively evaluate drought resistance, and the differences in physiological responses among accessions with contrasting drought resistance were analyzed under drought stress. The results showed that all the indices were positively correlated with each other in all accessions under drought stress (P＜0.01). Multivariate statistical analysis was used to calculate the comprehensive evaluation values of drought resistance (D value) of ten accessions of Thinopyrum intermedium, and based on D value, cluster analysis classified them into three drought-resistant categories: three highly drought-resistant accessions, five moderate drought-resistant accessions, and two weak drought-resistant accessions. The highly drought-resistant accessions of Thinopyrum intermedium enhanced their drought resistance through increasing antioxidant enzyme activities and osmotic content. In this study, the highly drought-resistant accessions of Thinopyrum intermedium were identified, and their physiological mechanisms of drought resistance was illustrated, thus providing a theoretical basis for the breeding of new drought-resistant varieties.

To address the summer survival challenges of cool-season turfgrass in the Yangtze River Delta region, this study systematically evaluated the heat tolerance of eight tall fescue (Festuca arundinacea Schreb.) cultivars under extreme high-temperature conditions in Shanghai. Principal component analysis (PCA) and other methods were used to condense the 12 indicators to three principal components. Root expansion capacity (root length, root surface area, root volume) and branching complexity (number of root tips, number of root forks) were identified as the primary indicators for assessing heat adaptation, followed by growth vigor (greenness, coverage, aboveground biomass, root-to-shoot ratio, etc.) and vertical structural traits (turf height and root biomass, etc.). Based on comprehensive evaluation, the cultivars 'Vertex', 'Police Chief', and 'Tahuo No.2' demonstrated the best heat tolerance performance. During high-temperature stress, these three cultivars showed increases of 10.72%-16.00% in coverage, 3.64%-8.53% in greenness, 31.75%-133.47% in aboveground biomass, and 42.41%-104.01% in root biomass compared with the poorest-performing cultivars. Moreover, their root architecture parameters showed small fluctuations, and turf height remained below 100 mm, exhibiting stable root development with dwarf characteristics. These cultivars therefore represent promising candidates for evergreen turfgrass use in Shanghai.

The combined use of Chinese milk vetch (Astragalus sinicus L.) and rice straw is an important practice for improving soil fertility in paddy fields in southern China. With the increasing adoption of mechanical rice harvesting, variation in rice stubble height may affect yield and nutrient uptake of Chinese milk vetch. A field experiment was conducted to evaluate the effects of different rice stubble heights on yield, nutrient concentration, and nutrient uptake of Chinese milk vetch. The experiment followed a completely randomized design with six treatments: no rice straw returned to the field (CK), rice stubble height of 40 cm (S40), 30 cm (S30), 20 cm (S20), 10 cm (S10), and 0 cm (S0), with the straw evenly distributed on the soil surface. The results showed that rice stubble height significantly affected the yield and nutrient uptake of Chinese milk vetch, with the S40 treatment achieved the highest fresh forage yield. Compared with S40, the CK treatment reduced fresh forage yield by 50.1%, and the ranking of fresh forage yield was S40>S30>S20>S10>S0>CK. Nutrient uptake, including nitrogen, phosphorus, and potassium, showed a pattern similar to that of fresh forage yield. As rice stubble height decreased, nutrient uptake by Chinese milk vetch also declined, with the highest values consistently observed under S40. Principal component analysis provided a comprehensive ranking of treatment performance as S40 (3.46)>S20 (0.38)>S30 (0.26)>S10 (-0.97)>S0 (-1.00)>CK (-2.14). Cluster analysis further grouped the treatments into three categories: (Ⅰ) S40, (Ⅱ) S30 and S20, (Ⅲ) CK, S10 and S0. Overall, maintaining a relative high rice stubble height after mechanical harvesting was beneficial for achieving high yield and efficient nutrient uptake in Chinese milk vetch. This practice provides a strong material basis for green manure incorporation and offers theoretical support for improving soil fertility and promoting sustainable agricultural development in red soil regions.

To identify the optimal combination of sowing rate and row spacing for oat (Avena sativa) production in the alpine arid and semi-arid regions of Xinjiang, a field experiment was conducted using a two-factor randomized complete block design. The cultivar Longyan 5 was used as the experimental material, with four: 150 kg/hm²(S1), 180 kg/hm² (S2), 225 kg/hm² (S3), and 270 kg/hm² (S4), and two row spacings treatments: 15 cm (L1) and 30 cm (L2). The effects of different sowing rate and row spacing combinations on the growth, forage yield, and nutritional quality were evaluated using correlation analysis and principal component analysis. The results showed that the interaction between sowing rate and row spacing had highly significant effects on plant height, stem diameter, number of effective tillers, and leaf-stem ratio among the eight treatment combinations (P<0.01). When maximizing fresh forage yield was the primary object, the S2L1 treatment produced the highest fresh yield, reaching 82 340 kg/hm². For the coordinated improvement of yield and quality, the S2L2 treatment exhibited the best overall performance, with fresh forage yield, crude protein content, and relative forage quality reaching 81 986.67 kg/hm², 11.26%, and 104.11, respectively. Correlation analysis revealed that stem diameter and fresh forage yield were extremely significant positive correlation with crude protein content and relative forage quality (P<0.01). Principal component analysis further showed that S2L2, corresponding to a sowing rate of 180 kg/hm² and a row spacing of 30 cm, achieved the highest comprehensive score and was therefore identified as the optimal combination for high yield and high-quality oat production in the study area. These findings provide a theoretical basis and technical support for optimizing oat cultivation practices and ensuring forage supply for animal husbandry in the alpine arid and semi-arid regions of Xinjiang.

The desert steppe of Inner Mongolia constitutes an important ecological barrier in northern China. Understanding the photosynthetic efficiency of dominant species and their response to long-term different grazing intensities is of great significance for elucidating how this ecosystem adapts to human activities and climate change. This study was conducted in the Stipa breviflora desert steppe with a 20-year grazing history. Net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and intercellular CO₂ concentration (Ci) were measured for six dominant plant species under four different grazing intensities. The results showed that: (1) among the six dominant species in the desert steppe, Convolvulus ammannii exhibited the highest Pn, Gs, and Tr. Regarding the overall effect of grazing intensity, the values of Pn, Gs, Tr, and Ci under light grazing treatment were significantly higher than those under heavy grazing (P<0.05), showing a pattern of stimulation under low grazing intensity and impairment under high grazing intensity; (2) From the perspective of plant photosynthetic pathway, C₄ species generally showed higher Pn, Gs, and Tr than C₃ species, indicating that C₄ plants have stronger photosynthetic capacity and greater environmental adaptability in the desert steppe ecosystem; (3) In terms of different life forms, forbs had the highest Pn, Gs, and Tr, while subshrubs had the lowest. Moreover, as grazing intensity increased, forbs remained relatively stable, showing stronger grazing tolerance, whereas subshrubs exhibited greater fluctuations and were more sensitive to changes in grazing intensity. In summary, among the six dominant species in the desert steppe, C. ammannii has exhibited the strongest photosynthetic capacity. Grazing intensity, photosynthetic pathway, and life forms jointly shaped the adaptive strategies of dominant species in response to grazing disturbance in the desert steppe.

Shrub branch mulching and sheep manure addition have shown potential in degraded grassland restoration practices for improving soil moisture and nutrient availability, respectively. However, the mechanisms and effects of these two measures, whether individually or combined, on soil water and nutrient regulation and dominant forage growth in desert steppe remain unclear. Therefore, a two-factor split-plot experiment was conducted in the desert steppe of Yanchi, Ningxia. The main plots consisted of three levels of Caragana korshinskii branch mulch treatments: no mulch, short-branch mulch (5-10 cm), and long-branch mulch (70-130 cm). The subplots included four sheep manure addition levels of 0 kg/hm², 4 000 kg/hm², 8 000 kg/hm², and 16 000 kg/hm². Their effects on soil moisture, temperature, nutrients, and dominant forage growth were investigated. The results showed that: (1) Compared with no branch mulch, both short-branch mulch and long-branch mulch reduced soil temperature and increased soil water content, whereas sheep manure addition had no significant effect on soil moisture or temperature; (2) Both branch mulch and sheep manure addition significantly decreased soil pH and increased the contents of soil organic carbon, nitrogen, and phosphorus; (3) Branch mulch and sheep manure addition significantly promoted the growth of dominant forages. All growth indices of Agropyron mongolicum were highest under the short-branch mulch and 8 000 kg/hm² sheep manure addition treatment, while Lespedeza potaninii performed best under the long-branch mulch and 8 000 kg/hm² sheep manure addition treatment; (4) Redundancy analysis indicated that soil water content, temperature, and nutrients were key environmental factors influencing forage growth, with particularly pronounced effects on Agropyron mongolicum. In summary, branch mulch mainly improved soil hydrothermal conditions, whereas sheep manure addition primarily enhanced soil nutrient supply. Their combination effectively promoted the growth of dominant forages in desert steppe, providing a scientific basis for grassland ecological restoration and sustainable management.

In recent years, the intensification of global nitrogen deposition has induced a shift from traditional N limitation to phosphorus limitation in alpine meadows. However, whether phosphorus supplementation alleviates or exacerbates the negative effects of nitrogen deposition remains to be systematically elucidated. To clarify the regulatory mechanisms of combined nitrogen and phosphorus addition on plant community and soil properties in alpine meadows, a five-year field control experiment was conducted in the alpine meadow of the Sejila Mountains in southeastern Xizang starting in 2019. A total of nine combined nitrogen and phosphorus addition treatments with varying gradients [nitrogen: 50, 75 and 100 kg/(hm²·a); phosphorus: 10, 15 and 20 kg/(hm²·a)] were established, along with a control treatment (Natural condition). The results indicated that: Long-term combined nitrogen and phosphorus addition significantly led to plant diversity decline and community structure differentiation (P<0.05), with the Shannon-Wiener index showing a maximum reduction of 21.32% under the high nitrogen and phosphorus treatment; The regulatory effect of phosphorus input on plant community characteristics exhibited a distinct nitrogen-level dependency. Under the low nitrogen treatment [50 kg/(hm²·a)], phosphorus addition effectively alleviated diversity loss with increasing phosphorus application; however, this mitigating effect was no longer significant under the high nitrogen background [100 kg/(hm²·a)];Nutrient inputs altered interspecific competition patterns, with the dominance of Cyperaceae species increasing with nutrient addition, while that of Asteraceae species significantly decreased (P<0.05); Long-term nitrogen and phosphorus addition significantly reduced soil pH (P<0.05), with greatest reduction of 8.28% observed under high nitrogen and high phosphorus treatment. Simultaneously, soil available potassium content decreased significantly across all fertilization treatments (P<0.05), with a maximum reduction of 52.79% observed under the high nitrogen and low phosphorus treatment. Correlation analysis further revealed a significant positive correlation between soil pH, available potassium content, and plant diversity (P<0.05). In conclusion, high-intensity joint nutrient inputs represent a critical driving force for plant diversity decline and soil acidification in alpine meadows, while phosphorus availability plays a buffering role under low nitrogen conditions, albeit with limited regulatory capacity under high nitrogen backgrounds. Long-term nitrogen and phosphorus inputs further affect plant community stability by acidifying the soil and altering nutrient balance.

Based on a long-term grazing experiment platform with a gradient of stocking rates [0、0.81、1.92、2.73 sheep/(hm²·a)], this study employed a single-factor randomized block design to investigate the response mechanisms of plant community species diversity to stocking rate and life form functional groups in the Stipa breviflora desert steppe of Inner Mongolia, and to elucidate the coupling relationship between multi-scale diversity dynamics and functional groups interaction. The results showed that: With increasing of stocking rate, α and γ diversity of plant communities decreased, whereas β diversity increased under light grazing. The shrub and semi-shrub functional group contributed the largest proportion of variance in community diversity at the α and γ scales (>60%), while the annual and biennial plants functional groups and the shrub and semi-shrub functional group played key roles in explaining variance the β scale (43.61% and 43.42%, respectively); The species diversity of the perennial grass functional group showed no significant response to stocking rate. Complementary diversity trends between perennial forbs and shrubs and semi-shrubs were observed, which may partially buffer the negative effects of grazing on community diversity. Meanwhile, the species diversity of annual and biennial plants was significantly negatively correlated with that of perennial forbs and shrubs and semi-shrubs (P<0.05). In conclusion, grazing regulates multi-scale diversity by altering species composition and interactions among functional groups. The tolerance of the shrub and semi-shrub functional group, coupled with the dynamic compensation of annual and biennial plant functional group, represents an important mechanism sustaining diversity in the desert steppe. The findings provide a theoretical basis for ecological restoration and sustainable management of degraded grasslands.

The transition from the solitarious to the gregarious phase in the grasshopper Oedaleus decorus asiaticus is a key process underlying population outbreaks, yet the metabolic regulatory mechanisms involved remain poorly understood. In this study, liquid chromatography mass spectrometry (LC‑MS) based untargeted metabolomics was used to compare whole body metabolic profiles of third instar nymphs under three conditions: solitarious controls (CK) and individuals subjected to high density crowding for 1 day (O1d) or 5 days (O5d) to induce gregarization. Principal component analysis (PCA) showed good biological reproducibility within groups and clear separation among treatments. A total of 3393metabolites were putatively identified in both positive and negative ion modes. Differential metabolites were screened using the criteria VIP≥1 and P<0.05. Compared with CK, 1 682 and 1 032 differential metabolites were detected in the positive and negative ion modes on the 1st day, and increased to 2 072 and 1 455 respectively on the 5th day. KEGG enrichment analysis revealed that linoleic acid metabolism, alanine, aspartate, and glutamate metabolism and amino acid biosynthesis pathways were significantly enriched at O1d (P<0.05), while ascorbate and aldarate metabolism, purine metabolism, and α‑linolenic acid metabolism were the major enriched pathways at O5d. Fourteen metabolites closely associated with phase transition were identified, including juvenile hormone Ⅲ, ecdysone, D‑glucose, trehalose, and dopamine. Overall, phase transition in O. decorus asiaticus involves temporal reprogramming, shifting from the activation of amino acid and carbohydrate metabolism to remodeling of lipid and keto acid metabolism, with hormone signaling and energy metabolic acting in a coordinated manner during gregarization.

Weeds can significantly reduce the yield and quality of Medicago sativa and have become one of the most important pest groups in M. sativa fields. The Yellow River Basin is the core production area of M. sativa in China, where it is of great significance to carry out weed prevention and control in M. sativa fields. To systematically clarify the weed communities characteristics in M. sativa fields in the Yellow River Basin, field weed surveys were conducted in M. sativa planting areas of Shandong, Henan, Shanxi, Shaanxi, Inner Mongolia, Ningxia and Gansu. The results showed that the weeds in M. sativa fields of the Yellow River Basin belonged to 27 species, 25 genera and 12 families. Poaceae, Chenopodiaceae and Asteraceae were the dominant families. Gramineous weed species such as Setaria viridis were overwhelmingly dominant, while Chenopodium glaucum was the predominant broadleaf weed. Weed communities in M. sativa fields across the Yellow River Basin exhibited distinct geographical differences. Overall, the number of weed species in the middle and lower reaches was higher than that in the upper reaches. Specifically, Digitaria sanguinalis and Eleusine indica were the dominant species in the middle and lower reaches, including Shandong, Shanxi, and Henan provinces. S. viridis and other weed species were dominant in the middle reaches (Shaanxi and Inner Mongolia), while Echinochloa crusgalli and Cirsium japonicum were dominant in the upper reaches (Ningxia and Gansu). The priorities of weed control in M. sativa fields vary among regions. Broadleaf weeds should be the main target in Gansu. Gramineous weeds should be primarily controlled in Henan, Shanxi, Inner Mongolia, Shaanxi and Ningxia, while both gramineous and broadleaf weeds need to be managed in Shandong. This study clarified the weed community characteristics and occurrence dynamics in M. sativa fields of the Yellow River Basin, thereby providing a scientific basis for environmentally-friendly weed management in this region.

China is rich in Urtica resources, which have important medicinal, edible, and forage values and show considerable potential for further development. To identify potential bioactive compounds in native medicinal Urtica plants, Urtica cannabina at the vegetative stage was analyzed using ultra performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). The results showed that U. cannabina contained 57 compounds belonging to seven major classes. These included 26 organic acids, 13 flavonoids, seven alcohols, phenols, and esters, six phenylpropanoids, three terpenoids, one anthraquinone, and one sterol. Among these compounds, chlorogenic acid has been proven to possess multiple biological activities, including antibacterial and antioxidant effects, while quercetin was known for anti-inflammatory activity and potential role in immune regulation. These findings indicate that Urtica plants represented by U. cannabina contain diverse bioactive components with clear pharmacological potential and broad prospects for development. They may be used in functional foods, such as antioxidant health products and immune regulating beverages, or as natural feed additives to improve livestock immunity and promote growth.

As keystone animal species in grassland ecosystems, rodents adopt feeding strategies that profoundly influence population dynamics, plant community structure, and ecosystem nutrient cycling. This review systematically summarized the methodological frameworks used to study the diets and feeding strategies of grassland rodents in China. It described the principles, advantages, and limitations of major diet analysis methods, including direct observation, stomach content analysis, fecal analysis, cheek pouch analysis, stable isotope analysis, and DNA metabarcoding. The applicability of each method was also discussed, along with the increasing trend toward integrating multiple methods. With respect to feeding strategies, this review synthesized the regulatory roles of internal physiological factor, such as sex, age, and reproductive stages, and external environmental factors, including seasonal variations, human disturbances, interspecific competition, and predation risk. By dynamically adjusting their diets in response to internal and external factors, rodents not only maintained their own survival but also promoted trophic niche differentiation and facilitated sympatric coexistence. The analysis showed that research in this field had shifted from qualitative description to quantitative analysis, from short-term observation to long-term monitoring, and from macroscopic morphological examination to molecular level techniques. With increasing interdisciplinary integration, future studies are expected to combine traditional approaches with modern molecular techniques and promote standardized research frameworks, thereby providing more systematic theoretical support and technical tools for adaptive grassland management and biodiversity conservation.

Paspalum urvillei is a perennial grass in the family Poaceae. As an invasive species with rapid growth and high biomass production, it has considerable potential for forage utilization. However, its low water-soluble carbohydrate and crude protein contents, together with high fiber levels, limit its nutritional value. In addition, its vigorous growth during the hot season makes postharvest preservation difficult, and the harvested material is prone to contamination by spoilage microorganisms, resulting in decay, mold growth, and reduce feeding value. Ensiling offers an effective approach to address these limitations. In this study, P. urvillei harvested at the vegetative stage was used as silage material to evaluate the effects of combined inoculation with Lactobacillus plantarum (LP) and different concentrations of Bacillus subtilis (BS) on silage quality. A two-factor completely randomized design was employed, with LP applied at 0 or 1.0×10⁶ cfu/g fresh weight (FW) and BS applied at 0, 1.0×10⁴, 1.0×10⁵, and 1.0×10⁶ cfu/g FW, resulting in eight treatments. After 45 days of ensiling, nutritional quality, fermentation characteristics, and aerobic stability were measured. The results showed that combined LP and BS inoculation significantly reduced silage pH (P<0.01), increased lactic acid content to a maximum of 4.82% of dry matter (DM), and decreased the ammonia nitrogen to total nitrogen ratio to a minimum of 3.03%. Crude protein (CP) content increased to a maximum of 6.72% of DM, while neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents decreased. All inoculated silages exhibited good aerobic stability, with no visible spoilage within 96 h. Among the treatments, LP₆BS₄, consisting of LP at 1.0×10⁶ cfu/g FW and BS at 1.0×10⁴ cfu/g FW, demonstrated the best overall performance.