As a high-value cool-season grass species cultivated worldwide，perennial ryegrass （Lolium perenne L.） frequently faces various abiotic stresses. Fructans are the primary reserve carbohydrates in perennial ryegrass，which play a crucial role under abiotic stress conditions and significantly enhance stress tolerance. This article reviews research progress on fructan metabolism in perennial ryegrass in China and internationally，focusing on its biosynthesis and degradation pathways，as well as the regulatory mechanisms of certain biomolecules on fructan metabolism. In addition，metabolic changes and underlying mechanisms of fructans in perennial ryegrass were illustrated under various abiotic stresses including drought，low temperature，salinity，waterlogging，nitrogen deficiency，and mowing，with prospects on future research directions.

To investigate salt tolerance in alfalfa （Medicago sativa） germplasm， 30 alfalfa accessions of diverse origins were subjected to salt stress （200 mmol/L NaCl） for 15 days. Responses were evaluated through changes in seedling morphology， photosynthetic parameters， and physiological indices compared to control plants （CK， irrigated with Hoagland nutrient solution）. The results demonstrated that NaCl treatment decreased plant height， leaf area， leaf relative water content， root activity， shoot dry weight， chlorophyll a， chlorophyll b， transpiration rate， stomatal conductance， net photosynthetic rate， intercellular CO₂ concentration， water use efficiency， catalase （CAT） activity， and potassium （K⁺） content relative to CK. Conversely， root dry weight， root-to-shoot ratio， stomatal limitation value， proline content， malondialdehyde （MDA） content， peroxidase （POD） activity， superoxide dismutase （SOD）， sodium （Na⁺） content， and the Na⁺/K⁺ ratio exhibited increases. Regression analysis identified stomatal conductance， root activity， root-to-shoot ratio， and Na⁺ content as critical indicators for salt tolerance evaluation. The clustering analysis based on the comprehensive evaluation value of the membership function shows that the 30 alfalfa accessions were classified into four distinct tolerance categories： high salt-tolerant， moderately salt-tolerant， low salt-tolerant， and salt-sensitive. Accessions 7254 and 7657 exhibited high salt tolerance.

Salt stress leads to the accumulation of reactive oxygen species （ROS） in plants， causing damage to plant cells. However， the enzymatic antioxidant system is responsible for scavenging ROS in plant cells and protecting cells from ROS damage. At present， there are few functional analyses of genes related to ROS-scavenging enzymes in alfalfa （Medicago sativa） in response to salt stress. Based on the transcriptome data of roots and leaves of salt-tolerant alfalfa cultivar （GIB） and salt-sensitive cultivar （LS） under salt stress， this study identified 28 differentially expressed genes related to ROS-scavenging. Twenty-eight genes are distributed on 19 chromosomes， belonging to five gene families： MsGST， MsPOD， MsAOX， MsGRX and MsPrdx， among which MsGST （12） and MsPOD （11） families account for the largest proportion. The physicochemical properties of ROS scavenging enzyme proteins were different among the members of each gene family. There were highly similar conserved motifs in the members of the gene family. Phylogenetic analysis showed that MsGSTUs and MsPODs were located in the branches defined by Tau and AtPERs in Arabidopsis thaliana， respectively， suggesting that they had similar evolutionary processes and similar functions.Real-time fluorescence quantitative PCR analysis showed that the expression levels of MsGSTU26， MsPOD2 and MsPOD4 genes in GIB leaves under salt stress were significantly higher than those in LS， and the promoter regions of the three genes had elements （G-box and CGTCA-motif） related to adverse stress. It indicated that the MsGSTU26， MsPOD2 and MsPOD4 genes may be involved in the regulation of the adaptability of GIB and LS to salt stress.

The production performance and nutritional value of alfalfa remain pivotal concerns in the alfalfa industry development.This study evaluated 36 alfalfa accessions （31 cultivated varieties and 5 wild germplasms） using Grey Correlation Analysis.The results revealed significant differences （P<0.05） in both agronomic performance and forage quality parameters among the 36 alfalfa accessions. Hay yield of alfalfa ranged from 5380.74 to 12663.31 kg/hm²， with the high-yielding accession M10 demonstrating the highest fresh forage yield （54457.13 kg/hm²）. Notably， the medium-yielding accession M7 exhibited superior nutritional profiles with 19.03% of crude protein， while M11 had the highest relative feed value of 152.76. Accessions were selected by comprehensive analysis of grey correlation as three utilization categories：nine as superior， 25 as moderate， and 2 as inferior. Furthermore， wild alfalfa germplasm M31 and M32 exhibited superior comprehensive evaluation scores， demonstrating significant breeding potential for cultivar development. This research provides reference for alfalfa cultivar introduction in Urumqi County and supplies outstanding germplasm resources for development and utilization of native alfalfa in Xinjiang.

Plant rhizosheath is the sheath-like structure tightly adhering to the root surface. The unique physical， chemical， and microbiological characteristics of the rhizosheath contribute to vital environmental and biochemical functions including rhizosphere soil aggregation， formation of soil aggregates， enhanced water and nutrient uptake， promotion of microbial colonization， and drought stress resistance. This review provides comprehensive understanding for the research status about rhizosheath in formation and the function and objectively demonstrates current research hot spot. CiteSpace software and bibliometric methods were conducted to retrieve a total of 2812 publications related to rhizosheath from January 1， 2008， to April 30， 2023 in Web of Science （WOS） Core Collection and China National Knowledge Infrastructure （CNKI） database with key words “Rhizosheath”， “Root hair”，“Root exudate”，‘Root sheath’， ‘Root secretion’， and ‘Root hair’. This review illustrates biological， chemical， and physical interactions determining rhizosheath development and plant absorption of water and nutrient from perspectives of plant rhizosheath formation and function. The review aims to provide guidance for further research on molecular genetic mechanisms of rhizosheath development and the application on crop breeding.

Smart prataculture represents a vital component of modern agriculture and serves as a key strategy for promoting sustainable agricultural development and advancing the initiative “Big Food View” in China. As global challenges such as climate change and land degradation intensify， traditional grassland management models are increasing unable to meet the requirements of modernization. The integration of artificial intelligence （AI） technologies presents unprecedented opportunities for the advancement of prataculture， greatly enhancing the efficiency， precision， and intelligence of grassland management. AI-driven smart prataculture employs cutting-edge technologies such as machine learning， deep learning， big data analytics， and the Internet of Things （loT）. Through comprehensive data collection and analysis， these technologies enable real-time monitoring， precise prediction， and adaptive management of grassland growth， resource allocation， and livestock production. While the application of AI demonstrates substantial potential in optimizing grassland productivity， ecological restoration， and livestock health monitoring， significant challenges remain in data collection， technological dissemination， infrastructure development， talent cultivation， economic feasibility， and policy support. In the future， continued innovation in AI technologies and the integration of interdisciplinary approaches are expected to accelerate the intelligent transformation of prataculture in China. This evolution will promote comprehensive intelligence， precision， and transparency across the entire industry chain， from production and ecological protection to resource utilization and market systems， thereby providing new insights for the sustainable development of smart agriculture.

In this study， strain TL-3 was isolated from naturally infected Cenchrus longispinus， and identified as Alternaria alternata by morphological and molecular biology. The herbicidal activity of TL-3 was determined by paper dish method and indoor biocontrol test. The results showed that the inhibition rate of TL-3 fermentation broth on the growth of roots and buds of C. longispinus was 67.65%， 59.65%， respectively. The incidence rate of stem and leaf diseases was as high as 63.89%. However， the inhibition rate of TL-3 on the germination of C. longispinus seeds was relatively weak， with an inhibition rate of only 10.02%. The herbicidal activity of TL-3 fermentation broth on six kinds of common farmland weeds showed that it had obvious pathogenic effect on Chenopodium album， Echinochloa crusgalli， Amaranthus retroflexus and Chloris virgata. The disease incidence was 85.65%， 84.94%， 50.91%， 41.51%， and the disease index was 85.93， 87.04， 44.35 and 45.15， respectively. The incidence and disease index of C. album and E. crusgalli were significantly higher than those of other weeds （P<0.05）. The disease incidence of Setaria viridis and Digitaria sanguinalis were 23.28% and 29.25%， respectively， and the disease index was 29.44， and 27.98， respectively. The results showed that the disease incidence of Medicago sativa and Melilotus officinalis was 45.07% and 40.88%， respectively， and the disease index was 40.26 and 44.39， respectively. The disease incidence of M. sativa was significantly higher than that of other forage and crops （P<0.05）， and the disease index of M. officinalis was significantly higher than that of other forage and crops （P<0.05）. The incidence rates of maize， wheat， oats， and Medicago ruthenica were 26.32%， 24.32%， 29.07%， and 28.90%， respectively， and the incidence rates of Glycine max， Solanum lycopersicum， Brassica oleracea， and Brassica pekinensis were 11.11%， 10.71%， 14.92%， and 9.21%， respectively， Solanum melongena， Capsicum annuum， Elymus dahuricus， Leymus chinensis， Cucumis sativus and Spinacia oleracea showed no obvious symptoms compared with the control group. The results indicated that strain TL-3 was safe. In summary， strain TL-3 had a significant pathogenic effect on C. longispinus and can be safely used in artificial grasslands/or wastelands mainly composed of L. chinensis. It is a new solution for the control of C. longispinus and has the potential to be developed as a bioherbicide.

Setaria viridis （L.） P. Beauv， a widely adaptable herbaceous plant distributed throughout China， possesses significant ecological and forage value. Due to its notable stress tolerance and its role as an important model plant， Setaria viridis has attracted wide interest in recent years. This article reviews research findings on the biological characteristics， genetic diversity， ecological value， and cultivar development of Setaria viridis， and offers perspectives for further research. It will provide theoretical references for the development， utilization， and breeding of new Setaria viridis varieties.

The response of grassland plants to grazing pressure and their subsequent growth dynamics are critical for maintaining ecosystem stability. As the primary interface for grazing interactions， leaf growth status is not only regulated by external environmental factors， but also significantly influenced by the metabolic activities of epiphytic microorganisms. This research investigated the responses of epiphytic microbial community characteristics of dominate species to grazing in temperate typical grasslands of northern China. High-throughput sequencing technology was applied to analyze the diversity and community composition of phyllosphere bacterial and fungal of Leymus chinensis， Stipa grandis， and Cleistogenes squarrosa. Results showed that：（1） Under both grazing and enclosure conditions， the epiphytic microbial communities of all three plant species were consistently dominated by bacterial phyla including Pseudomonadota， Bacillota， Bacteroidota， Actinobacteriota， and Acidobacteriota， along with fungal phyla Ascomycota and Basidiomycota. Notably， grazing disturbance significantly reduced the relative abundance of Proteobacteria in L. chinensis phyllosphere communities， creating ecological niches for colonization of other microbial taxa. Under grazing conditions， concurrently， a significant reduced in Filobasidium abundance within fungal communities of L. chinensis was observed， This change may reduce the risk of plant disease. （2） Under grazing conditions， the phyllosphere exhibited an enrichment of unique microbial taxa. Thermotogota was detected for the first time in bacterial communities of L. chinensis， while Kickxellomycota was identified as novel colonizer in fungal communities of C. squarrosa. These newly identified microbial taxa may significantly influence the adaptability and functional diversity of phyllosphere microenvironments. （3） The responses of functional classification in phyllosphere fungi to grazing and host specificity were significantly stronger. Under grazing conditions， relative abundance of pathogenic fungal decreased， whereas beneficial fungi increased， indicating that grazing may indirectly suppress pathogen proliferation by altering the phyllosphere microenvironment. In conclusion， effects of grazing directly alters phyllosphere microbial community structure by modifying host plant characteristics and their associated microenvironments， ultimately increasing microbial diversity and the proportion of beneficial microorganisms.

Overgrazing will destroy grassland， aggravate vegetation degradation， and induce soil wind erosion. In this study， wind erosion monitoring was conducted on Stipabreviflora desert steppe under different grazing intensity （CK: control， LG: light grazing， MG: moderate grazing， HG: heavy grazing）. Plant community coverage was also measured to explore the patterns of aeolian sediment flux at sand collection height of 0-120 cm aboveground and its relationship with vegetation under different grazing intensities. The results showed that during the growing season of Stipa breviflora desert steppe： (1) Under different grazing intensities， the plant community coverage from May to October demonstrated the pattern of CK>LG>MG>HG. Under the same grazing intensity， it initially increased then decreased. (2) With the increase of grazing intensity， the total aeolian sediment flux rose gradually， with the value under LG， MG and HG reaching 1.40， 1.82， and 1.95 times of that under CK， respectively. (3) There was a significant negative correlation between plant community coverage and total aeolian sediment flux across all grazing intensities （P<0.05）. (4) The functional relationship among grazing intensity （G）， plant community coverage （C）， and total aeolian sediment flux （Q） was constructed： Q=（0.003 5G²－0.020 2G－0.032 7） C+（-0.251 2G²+1.478G+2.463 6）. The goodness of fit （R²） of plant community coverage and total aeolian sediment flux in CK， LG and MG was greater than 0.9， indicating high goodness-of-fit， while R² of HG was only 0.54， which offers a more integrated solution by striking a viable balance between aeolian sediment flux reduction and herder livelihood needs.Despite ideal windbreak and sand fixation performance of the CK and LG treatments， the MG treatment integrated the requirement of grassland ecosystem multifunctional role on aeolian sediment flux bloking and livelihood needs of herdsmen. This finding provides a scientific basis for exploring ecological protection and resource utilization in desert steppe， and has important practical value for establishing a sustainable and coordinated human-land grassland management framework.

Silage is a critical component of livestock diets in China and worldwide due to its high nutritional value and palatability. However， silage is highly susceptible to contamination by harmful fungi， leading to reduced quality， resource loss， and potential risks to both animal and human health during feeding. This review summarizes current knowledge on the major harmful fungi associated with silage and outlines corresponding control strategies. The objective is to enhance silage quality， safeguard feed safety， and support the sustainable， green， and high-quality development of the livestock industry.

In order to investigate the effects of different mowing stubble heights and fertilization on the dominant species and soil trace element contents in meadow grassland， this research focused on Hulunbeier meadow steppe. Trace element contents of the dominant species Leymus chinensis and the surface soil （0～10 cm） were determined under the following treatment combinations：six mowing stubble heights （3， 6， 9， 12， 15 cm， and no mowing） and two fertilization levels （no fertilization and fertilization）. The results showed that mowing significantly increased （P<0.05） the total soil manganese （Mn） content. Fertilization significantly reduced （P<0.05） iron （Fe）， copper （Cu）， zinc （Zn）， molybdenum （Mo） contents of L. chinensis， whereas total Mn and Zn contents， available Zn and Mo contents， and effective coefficients of Mn， Zn， and Mo in soil were increased （P<0.05）. The interaction of mowing and fertilization did not affect the contents of Fe， Mn， Cu， Zn， Mo and boron （B） significantly. The highest total soil Mn content of 435.4 mg/kg was observed with the 12 cm stubble height under no fertilization treatment. When fertilization was applied， the highest Fe （191.6 mg/kg）， Mn （35.5 mg/kg）， Zn （10.8 mg/kg）， and B （4228.3 mg/kg） contents in L. chinensis were recorded， at the 6 cm stubble height， while available contents of Fe （126.7 mg/kg）， Mn （94.5 mg/kg）， Cu （1.4 mg/kg） and Mo （1.3 mg/kg） in soil reached maximum values with the 12 cm stubble height. Fertilizer application with 12 cm stubble height increased the effective coefficients of soil Mn， Zn， Mo and B by 0.1， 0.2， 0.4 and 1.9×10^-4， respectively. Compared with the treatment without fertilization， fertilization at a stubble height of 12 cm increased the contents of Fe， Mn， Cu and B of L. chinensis. This research can provide a practical reference for the establishing sustainable mowing system in meadow steppe.

Nitrogenase is the key enzyme driving the natural nitrogen cycle， as it catalyzes the conversion of inert dinitrogen （N₂） into bioavailable ammonia （NH₃）. The most extensively studied nitrogenases， molybdenum nitrogenase （Mo-nitrogenase） and vanadium nitrogenase （V-nitrogenase）， differ significantly in their structure， catalytic properties， and environmental responses. Structurally， V-nitrogenase contains a unique δ subunit and has distinct encoding genes compared to Mo-nitrogenase. For catalytic mechanisms， Mo-nitrogenase exhibits higher specificity for N₂ reduction， whereas V-nitrogenase demonstrates broader substrate range and reduces alternative substrates such as acetylene. Furthermore， the two enzymes exhibit different sensitivity to carbon monoxide （CO）： Mo-nitrogenase is easily inhibited by CO， while V-nitrogenase can reduce CO even under high concentrations. These differences shape their functional performance in diverse environments. By systematically illustrating the structural， catalytic， and environmental differences between these nitrogenases， this study deepens the understanding of dynamic biological nitrogen fixation. The findings provide a critical theoretical basis for optimizing nitrogen management in grassland agriculture and offer guidance for the restoration of degraded ecosystems， such as grasslands， forests， and deserts.

Following the implementation of two cycles of the Grassland Subsidy and Reward Policy （GSRP）， optimizing its design and execution to simultaneously enhance herder livelihoods and restore steppe ecosystem services remains a critical challenge. This study investigated stocking rate responses among herders in China's desert steppe region， employing stratified random sampling across six pastoral townships combined with satellite remote sensing data. Structural equation modeling and statistical analysis were used to assess stocking rates under the GSRP framework. The results showed that the GSRP exerted the strongest influence on stocking rates relative to other factors. Stocking rates exhibited an exponential decline in response to increases in both the total subsidy amount and its proportion within household income； however， the rate of decline moderated beyond specific thresholds. Based on the fitting equation， the amount of grassland compensation （¥29296.93） and its income proportion （23.79%） were calculated with the stocking rate of 1 sheep unit/hm² as the reference value， and the herder groups were divided accordingly， the response characteristics of different herder groups to the grassland subsidy policy were analyzed. Results identified herder groups receiving subsidies below ¥29296.93 with a subsidy proportion below 23.79% as optimal responders， demonstrating rapid stocking rate reduction with increasing subsidies. Herder groups falling into either of the two intermediate categories （subsidy<¥29296.93 and proportion>23.79%； or subsidy>¥29296.93 and proportion<23.79%） were moderate responders， representing key targets for enhanced policy effectiveness. Herder groups falling into either of the two intermediate categories （subsidy<¥29296.93 and proportion>23.79%； or subsidy>¥29296.93 and proportion<23.79%） had limited response to the policy， it is the target groups to improve the effectiveness of the subsidy measures in the next step. However， the herder groups receiving subsidies exceeding ¥29296. 93 with a proportion above 23.79% had no obvious response to the policy. The next step should be to focus funding on groups that are more responsive to policy. Moving forward， GSRP optimization in desert steppe regions should elevate subsidy benchmarks， integrate household economic characteristics into policy design， and implement tailored strategies for distinct herder groups.

Nutrient enrichment is a key driver of plant diversity loss in grassland ecosystems. However， the specific pathways and mechanisms underlying species diversity reduction under different nutrient additions influence remain insufficiently understood. This study investigated the effects of nitrogen （N）， phosphorus （P）， and combined nitrogen and phosphorus （N+P） additions on alpine meadows located on the eastern edge of the Tibetan Plateau， using the natural community as a control. The main objective was to examine changes in species richness， biomass， and light transmission， and to elucidate the direct and indirect mechanisms contributing to species richness decline under these experimental treatments. The results showed as follows：（1） N was identified as the primary limiting nutrient for aboveground biomass. Both N and N+P additions significantly increased aboveground biomass （P<0.05）， primarily due to an increase in the biomass of grasses； （2） N and N+P additions significantly reduced species richness （P<0.05）， whereas P addition alone had no significant effect； （3） The mechanisms underlying the reduction in species richness under N and N+P treatments were consistent and involved both direct effects of nitrogen and indirect effects via increased aboveground biomass， which in turn reduced light availability.

To investigate the mitigation effect of externally applied γ-aminobutyric acid （GABA） on the growth of alfalfa seedlings under drought stress， this study explored five new drought-resistant alfalfa lines （P1， P2， P3， P4， and P5） and five drought-sensitive materials （15354， 7657， 7470， 7740， and 15578）. With normal water supply as the control （CK）， drought stress was simulated using the previously screened stress intensity （-1.6 MPa PEG-6000）. Under this drought stress treatment， exogenous GABA was applied at concentrations of 0， 5， 10， and 15 mmol/L （designated as T1， T2， T3， and T4， respectively） to analyze their effects on the physiological characteristics of alfalfa seedlings. Results showed that external GABA application significantly increased superoxide dismutase， peroxidase， catalase， leaf relative water content， and root activity in alfalfa under drought stress， while the content of proline， soluble sugar， soluble protein， malondialdehyde， hydrogen peroxide， and the production rate of superoxide anion were decreased. Membership function analysis revealed the optimal alleviation of GABA on drought-stressed alfalfa under the T3 treatment， with significantly stronger mitigation effect on sensitive genotypes compared with drought-resistant lines. The results provide a theoretical basis for the rational application of GABA in drought-tolerant cultivation of alfalfa.

Against the backdrop of China’s “dual-carbon” strategy and the advancement of ecological civilization， scientific assessment of the ecosystem service values and the realization of ecological product value have becomeacritical approach to harmonize ecological protection and economic development. As the dominant type of grassland ecosystem in China， temperate grasslands play crucial roles in carbon sequestration， water conservation， wind erosion control， and biodiversity maintenance. This article systematically reviews the research progress and methodological framework in economic valuation of temperate grassland ecosystem services， both in China and internationally. The applicability and limitations of major models were compared， and deficiencies in current Chinese research regarding data precision， parameter localization， service coverage， and policy integration were analyzed. This review proposes that future research should focus on constructing multi-scale integrated assessment frameworks， improving model localization and data sharing mechanisms， and strengthening the integration between assessment results and policies such as ecological compensation， GEP accounting， carbon trading， etc.， thereby forming the closed-loop mechanism of “Assessment-Accounting-Compensation-Feedback”. This study aims to provide theoretical foundation and decision support for valuing temperate grassland ecosystem services and realizing the value of ecological products.

In order to investigate the root-specific genes regulating root growth of alfalfa （Medicago sativa），transcriptome sequencing was performed to analyze differentially expressed genes （DEGs） and their functions between the aerial parts （stems and leaves） and root system of alfalfa cultivar Zhongmu No. 1. The results showed that compared to aerial parts，a total of 15258 DEGs were identified in root system，including 5095 up-regulated and 10163 down-regulated. The GO functional annotation demonstrated significant enrichment of these DEGs in cellular process，metabolic regulation，and biocatalytic activities. KEGG pathway enrichment analysis showed significant enrichment of these DEGs in pathways related to porphyrins and chlorophyll metabolism，photosynthesis-antenna protein synthesis，and carbon fixation in photosynthetic organisms. Six candidate up-regulated genes exhibiting significant differential expression were selected for real-time quantitative PCR validation. The results indicated high concordance between their expression patterns and transcriptome sequencing data.

This study investigated the effects of various fertilization treatments on natural mowing grassland in the Altay Mountains， combining field investigations with indoor laboratory analyses. The experiment included four fertilization measures：no fertilization （control）， compound fertilizer， organic fertilizer and bio-bacterial fertilizer. The primary objective was to assess these treatments on grassland plant community characteristics， soil nutrients， and soil microorganisms. The results showed as follows：（1） Compound fertilizer application significantly increased aboveground biomass （P<0.05）， but decreased underground biomass in the 0~10 cm soil layer. Bio-bacterial and organic fertilizers increased species diversity， while compound fertilizer reduced it. Notably， the Shannon-Wiener index was significantly higher under bio-bacterial fertilizer than under compound fertilizer （P<0.05）； （2） Fertilization significantly lowered soil pH and increased soil organic matter content. Organic fertilizer significantly increased available nitrogen content （P<0.05）， while compound fertilizer significantly raised available phosphorus and available potassium concentrations （P<0.05）； （3） Fertilization significantly increased the number of bacterial operational taxonomic units （OTUs） and decreased fungal OTUs （P<0.05）， indicating shifts in microbial community structure and enhanced microbial diversity. A comprehensive evaluation using a membership function approach indicated that compound fertilizer had the most substantial effect in improving degraded natural meadows. These findings provide a scientific basis for enhancing the productivity and soil fertility of natural meadows through appropriate fertilization strategies.

Fertilization is a key strategy for restoring degraded grasslands. To identify suitable nitrogen （N） and phosphorus （P） fertilization gradients for enhancing the productivity and soil characteristics of degraded alpine meadows， a lightly degraded alpine meadow in Dangxiong County， Xizang Autonomous Region， was selected for study. A two-factor randomized block design was employed， with four nitrogen levels （N0：0 kg N/hm²， N1：60 kg N/hm²， N2：90 kg N/hm²， N3：120 kg N/hm²） and four phosphorus levels （P0：0 kg P₂O₅/hm²， P1：30 kg P₂O₅/hm²， P2：60 kg P₂O₅/hm²， P3：90 kg P₂O₅/hm²）， resulting in 16 N-P treatments combinations， with N0P0 treatment serving as the control （CK）. Grassland productivity and soil characteristics were evaluated to determine the optimal N-P combinations. The results showed that the combined application of nitrogen and phosphorus fertilizers significantly enhanced aboveground biomass compared with the control， with the N2P2 and N2P3 treatments increasing biomass by 136.9% and 111.9%， respectively （P<0.05）. The combined application also improved soil organic carbon content， particularly in the 0-10 cm soil layer， where the N2P1 and N2P3 treatments reached 15.67 g/kg and 15.26 g/kg， respectively. Available phosphorus content was highest under N2P3 treatment in both 0-10 cm and 10-20 cm soil layers， while total nitrogen content was greatest under N3P1 treatment. Grey correlation analysis of aboveground biomass and soil characteristics （0-10 cm） indicated that N2P3 treatment provided the most favorable comprehensive improvement in productivity and soil nutrient status， followed by N3P3 treatment. Therefore， the combination of 90-120 kg/hm² nitrogen fertilizer with 90 kg/hm² phosphorus fertilizer is recommended as the optimal strategy for the restoration of degraded alpine meadows in Dangxiong County， Xizang Autonomous Region.

Moisture content is a key indicator of seed quality，and its accurate and rapid determination is essential for seed grading. With the increasing use of seed coating technology in seed production and trade，traditional high （low） constant-temperature method often severely underestimated the actual moisture content of coated seeds due to the influence of coating materials. To address this issue，four coated forage species： Medicago sativa，Elymus dahuricus，Lolium perenne and Dactylis glomerata，were selected as experimental materials. By analyzing the relationship between water activity of coated seeds and the moisture content of naked seeds，a predicted model for coated seeds moisture content based on water activity was developed. The goodness-of-fit values of the prediction models for the four species were 0.9003，0.9124，0.9076，and 0.9323，respectively，with relative errors of 2.87%，4.08%，3.07% and 4.14%. These results indicated that seed water activity can serve as a reliable，non-destructive，and rapid indicator for determining the moisture content of coated seeds.

To clarify the impact of wind turbines on biodiversity and soil properties of grasslands， this study took a wind power area with wind turbines installed and operated for 15 years in the temperate meadow steppe of Inner Mongolia as the research area， and selected a grassland without wind turbines as the control area. The plant community， insect community， soil microorganisms， and soil physical and chemical properties in the area were investigated， and the relationships among these factors were analyzed. The results showed that compared with the grassland in the control area， the vegetation coverage， aboveground biomass， and community diversity of the grassland in the wind power area decreased significantly （P<0.05）. The number of insects in the wind power area increased significantly （P<0.05）， but the diversity of the insect community decreased significantly （P<0.05）. The number of soil fungi and community diversity in the wind power area were all significantly reduced （P<0.05）.Soil moisture content， bulk density， total nitrogen， ammonium nitrogen， alkali-hydrolyzable nitrogen， total phosphorus， and total potassium in the wind power area were all significantly reduced （P<0.05）. Correlation analysis found that there was a significant relationship between soil physicochemical properties and soil microbial communities. Overall， during the operation period of wind power stations， it will cause the degradation of grassland plant communities， the loss of soil nutrients and reduce plant diversity， and lead to a homogenization of the insect community structure.

Dof （DNA-binding with one finger） transcription factors are plant-specific regulators playing critical roles in plant response to environmental stresses. This study comprehensively identified MrDof gene family based on the genome-wide of Medicago ruthenica. We performed analyses including collinearity assessment， phylogenetic analysis， and chromosomal localization on the Dof family members. Furthermore， by integrating transcriptome data of M. ruthenica under drought stress and qRT-PCR validation， we explored the potential functions of these genes in drought stress responses. The results showed that a total of 33 MrDof genes were identified in M. ruthenica， and the number of amino acids encoded by these genes ranged from 157 to 492 aa. According to the evolutionary relationships among M. ruthenica， Medicago truncatula and Arabidopsis thaliana， these genes were classified into eight distinct groups （Group A， B1， B2， C1， C2.1， C2.2， C3， D1 and D2）. The 33 genes were unevenly distributed across nine chromosomes. Expression pattern analysis demonstrated that five genes （MrDof11， MrDof13， MrDof22， MrDof27， and MrDof30） were significantly induced by drought stress.

To explore the effects of different grazing intensities on soil microbial biomass in alpine meadow，this study investigated the variation characteristics in soil microbial biomass and interactions between soil physicochemical properties and microbial parameters including biomass，microbial quotient，and stoichiometric ratios under no grazing （CK），light grazing （LG），moderate grazing （MG），heavy grazing （HG），and extreme grazing （EG） conditions in the alpine meadow of Tianzhu Zangzu Autonomous County on the northeastern edge of the Qinghai-Tibet Plateau. The results showed that both microbial biomass carbon （MBC） and phosphorus （MBP） reached the maximum levels under LG，which were significantly higher compared with EG condition （P<0.05）. Soil microbial biomass nitrogen （MBN） was highest under HG，followed by MG，while MBN was significantly lower under EG compared with HG （P<0.05）. Soil microbial quotient carbon （qMBC），microbial quotient phosphorus （qMBP） and the MBC∶MBN ratio were all highest under LG，whereas microbial quotient nitrogen （qMBN），MBC∶MBP ratio，and MBN∶MBP ratio were highest under MG. Soil bulk density emerged as the predominant factor influencing microbial biomass，microbial quotients，and their stoichiometric ratios. These findings indicate that both light and moderate grazing intensities benefit the accumulation of microbial biomass and promote efficient utilization and transformation of soil nutrient in alpine meadows. In contrast，extreme grazing leads to soil fertility decreasing and a reduction of microbial biomass. A win-win scenario of ecology sustainability and economic benefits will be achieved when apporiate grazing intensities adopted.

In this research， effects of varying apple pomace to citrus pulp ratios on the volatile compounds were analyzed by headspace-gas chromatography-mass spectrometry to evaluate the odor composition of wheat straw mixed silage. Silage was fermented for 45 days using mixtures of citrus pulp and apple pomace at mass ratios （m/m） of 0∶4 （T0）， 1∶3 （T1）， 2∶2 （T2）， 3∶1 （T3）， and 4∶0 （T4）. The water content was adjusted to approximately 65% by adding wheat straw. The results showed that the ammonia nitrogen content of T2， T3 and T4 groups was less than 5%， and there was no significant difference in silage pH and lactic acid content. Compared with T0， the relative abundance of Lactobacillus （P<0.05） in T4 was significantly higher， while relative abundances of Enterobacter and Weissella （P<0.05） were lower. The contents of esters such as ethyl acetate and 2-methylbutyl acetate gradually increased with the increase in apple pomace mixing ratio， while the contents of terpenes such as D-limonene and α-acacia gradually decreased. The relative abundance of Enterobacter positively correlated with acetic acid， ammonia-nitrogen， and D-limonene contents （P<0.01）， and had negative correlation with lactic acid， ethyl acetate， and 2-methylbutyl acetate contents （P<0.01）. In summary， the 2∶2 mixture of apple pomace-citrus pulp improved fermentation quality and volatile compound profiles， and maximized citrus pulp utilization efficiency.

Alfalfa （Medicago sativa） was introduced into China following Zhang Qian's diplomatic missions to the Western Region during the Han Dynasty. However， scholarly consensus regarding its precise provenance remains elusive. This study critically examines the origin of alfalfa in Han China by analyzing 43 historical texts from various periods that document its source， integrated with modern research findings. Our analysis reveals significant discrepancies in the proposed origins of Han-era alfalfa across ancient records and contemporary studies， coalescing into six primary hypotheses： （1） the Western Regions broadly； （2） Dayuan （Ferghana）； （3） Jibin （Kashmir region）； （4） Wusun； （5） Anxi （Parthia）； and （6） unspecified foreign lands. While Wang Yi of the Eastern Han Dynasty was the first scholar documented to explicitly associate alfalfa with the Western Regions， his era postdates those of Zhang Qian， Sima Qian， and Ban Gu. Consequently， the attribution solely to the broader Western Regions lacks substantive historiographical support. Alfalfa was firstly recorded in Shiji·Dayuan Liezhuan， and there were abundant similar records in the later historical books， that is， it is certain that the alfalfa in the Han Dynasty came from Dayuan and was brought from Dayuan by the Han envoys to the Western Regions. Although no extant texts explicitly record the introduction of alfalfa from Jibin to the Central Plains， the possibility cannot be entirely excluded following the initial introduction from Dayuan， as suggested by relevant accounts in the Hanshu （Book of Han）， Xiyu Zhuan （Account of the Western Regions）. The proposed origins from Wusun， Anxi， or other unspecified foreign lands lack convincing support from primary historical sources and warrant further validation.

To investigate the genetic variation characteristics and agronomic potential of the polycotyledon trait in alfalfa （Medicago sativa L.），this study evaluated the phenotypic diversity of alfalfa cotyledonous mutations under field cultivation. Eleven agronomic quantitative traits were assessed using the Kruskal-Wallis non-parametric test，mean analysis method，and the entropy-weight TOPSIS method. The results showed that： （1） The polycotyledonous mutation rate in the test population was 1.44%，with 29 phenotypic variation patterns were identified；（2） the B8 type （tricotyledon-one unifoliolate true leaf-normal main stem-erect branches） exhibited the highest mutation rate （41.28%），followed by the B2 type （dicotyledon-two unifoliolate true leaves-normal main stem-erect branches） at 8.74%；（3） Mean analysis indicated that differences among variant types were mainly associated with branch number and plant height；（4） The entropy-weight TOPSIS evaluation ranked the B2 type highest （score： 0.8389），followed by the B8 type （0.6297），whereas the B12 type （tricotyledon-one unifoliolate true leaf-clustered branch） scored lowest. This study provides the first systematically characterization of phenotypic diversity and agronomic polycotyledonous alfalfa variants and offers novel mutant germplasm resources for breeding innovation.

Grazing is a primary utilization of grassland ecosystems， where livestock behaviors， specifically feeding， trampling， and excrement deposition， directly or indirectly alter soil physicochemical and biological properties. These alternations， in turn， differentially affect biogeochemical processes within the grassland ecosystem. However， the mechanisms by which these behaviors influence soil greenhouse gas （GHG） emissions remain poorly understood. To address this knowledge gap， this study systematically explored the emission mechanism and key influencing factors of carbon dioxide （CO₂）， methane （CH₄）， and nitrous oxide （N₂O） in grassland soil by analyzing the interactions between major grazing behaviors and soil environmental conditions. The results showed that feeding behavior can alter vegetation biomass and regulate vegetation community structure， thereby modifying exogenous carbon inputs to influencing soil CO₂ emissions. Trampling behavior impacts soil physical structure and microenvironmental conditions， which in turn affect soil aeration and microbial activity， leading to variable effects on soil respiration and associated CH₄ and CO₂ emissions. These effects are closely dependent on grassland type and trampling intensity. In contrast， dung and urine deposition increase nitrogen input to the soil and enhance N₂O emissions， primarily by altering soil chemical properties and microbial dynamics. The characteristics of the excreta， grassland type， and environmental conditions all play important roles in regulating nutrient availability and GHG emission in pastoral systems. These findings elucidate the distinct processes and potential mechanisms through which livestock behaviors affect soil GHG emissions in grassland and provide a theoretical basis for optimizing grazing management to mitigate emissions in pastoral ecosystems.

In order to explore the effects of drought stress on agronomic traits of different alfalfa varieties （strains）， 12 alfalfa varieties （strains） were used as materials in this study， pot experiments were carried out in greenhouse and two treatments of drought stress and rewatering were conducted at seedling stage， the agronomic traits （plant height， aboveground fresh and dry weight， root length， root fresh and dry weight， root shoot ratio， stem diameter， root diameter， branch number） of alfalfa materials after treatment were determined， and through the comprehensive drought resistance coefficient， principal component comprehensive evaluation， grey correlation degree and drought resistance index for comprehensive evaluation of drought resistance ability. The results showed that the new strain 1 had the highest drought resistance coefficient in aboveground fresh weight， aboveground dry weight， plant height， root length and branch number， the drought resistance coefficient of stem diameter of new strain 2， the drought resistance coefficient of root diameter of Gannong No.7 and drought resistance coefficient of root fresh weight and root shoot ratio of Zhongtian No.3 were the highest， the drought resistance coefficient of aboveground fresh weight，aboveground dry weight， root fresh weight， root dry weight， plant height， root length and branch number of Zhongmu No.3 was the lowest， the drought resistance coefficient of stem diameter in Gannong No.3 and drought resistance coefficient of root shoot ratio in Zhongtian No.2 were the smallest. The comprehensive drought resistance coefficient， principal component comprehensive evaluation， grey correlation degree and cluster analysis showed that the new strain 1， Zhongtian No.3 and Zhongmu No.1 had strong drought resistance. The drought-resistant germplasms identified by the Drought Resistance Index （DRI） method were new strain 1， Zhongtian No.3， new strain 3， Zhongmu No.1， and Gannong No.7， all of which displayed DRIs greater than 1. Comprehensive evaluation across multiple methods revealed that new strain 1， Zhongtian No.3， and Zhongmu No.1 possessed the strongest drought resistance.

In order to explore potassium-solubilizing microbial resources and investigate their effects on alfalfa （Medicago sativa） growth， this study isolated and screened potassium-solubilizing bacteria （KSB） with strong potassium-solubilizing ability from the rhizosphere soil of alfalfa using selective media. The potassium-solubilizing， phosphate-solubilizing， and indole-3-acetic acid （IAA）-producing capabilities of these strains were measured， and their identities were confirmed via 16S rRNA gene sequencing. Subsequently， pot experiments were conducted using the selected superior strains to validate their impact on alfalfa growth. The results demonstrated that 21 KSB strains were isolated and screened from the alfalfa rhizosphere， among which 10 exhibited potassium-solubilizing activity， with solubilized potassium levels ranging from 1.57 to 7.96 μg/mL and solubilization rates ranging from 12.07% to 57.50%. Five strains （jk6-5、jk20-1、jk20-2、jk20-3 and jk20-8） with high potassium-solubilizing activity also demonstrated IAA production and phosphate-solubilizing abilities. Their IAA secretion levels ranged from 9.60 to 11.77 μg/mL， while inorganic phosphate solubilization ranged from 2.84 to 173.96 μg/mL， and organic phosphate solubilization from 35.34 to 62.55 μg/mL. Based on 16S rRNA gene sequencing， strains jk20-8， jk20-1， and jk20-2 were identified as Pantoea ananatis， strain jk20-3 belonged to the Paenibacillus hordei group， and strain jk6-5 was identified as Priestia megaterium. Inoculation of the superior strains jk20-8， jk20-3， and jk6-5 into alfalfa significantly increased plant height， root length， aboveground biomass， underground biomass， and nitrogen （N）， potassium（K）， and phosphorus （P） contents in plants. Additionally， soil available N， available P， available K， and organic matter contents were enhanced， with strain jk20-8 exhibiting the most pronounced growth-promoting effects. In conclusion， the potassium-solubilizing strain jk20-8 serves as a promising candidate for developing potassium-solubilizing microbial fertilizers.

Ecosystem services （ES） and ecological risk （ER） respectively represent the capacity of ecosystems to support human well-being and the potential for degradation under external disturbances. In recent years， the cumulative impacts of glacier retreat， permafrost degradation， and grassland deterioration have led to a decline in ES and an increase in ER on the Qinghai-Xizang Plateau. Therefore， exploring the coupling relationship between ES and ER on the Plateau is of great importance for accurately identifying ecological degradation processes， improving regional ecological resilience， and supporting effective environmental management. Based on remote sensing and statistical data from 2000 to 2020， this study evaluated important ES indicators and constructed an ER assessment framework using the InVEST model and landscape ecological risk assessment methods. The results showed that： （1） From 2000 to 2020， mean annual grassland productivity increased from 91.63 g/m² to 107.52 g/m²， while carbon storage declined from 6 571.73 Mg to 5 897.60 Mg. Water yield decreased from 122.10 mm to 86.55 mm in 2015 and rebounded to 110.71 mm in 2020. Habitat quality declined from 0.51 to 0.45， and soil conservation showed periodic fluctuations， ranging between 33 391.59 g/m² and 25 772.08 g/m². （2） The overall ER level showed a slight decline， but high-risk areas still accounted for over 19%， primarily concentrated in ecologically fragile zones such as Kekexili， the Qiangtang Plateau， and the Qaidam Basin. （3） Correlation analysis revealed significant negative correlations between ER and both grassland productivity （R² = -0.66， P < 0.05） and habitat quality （R² = -0.73， P < 0.05）. Carbon storage， water yield， and soil conservation also exhibited moderate negative correlations， suggesting that ER exerts an overall inhibitory effect on ES.

In order to provide scientific basis for precise fertilization of sorghum，Sorghum sudanense and Sorghum bicolor × S. sudanense hybrid in China，this study was carried out by using a new method of crop soil testing and recommended fertilization system research. The results showed that the regression equations of relative yield of sorghum，S. sudanense and S. bicolor × S. sudanense hybrid under nitrogen deficiency treatment in China with the contents of soil total nitrogen （TN），soil alkaline hydrolysis nitrogen （AHN） and soil organic matter （OM） were as follows： y＝14.533ln（x _TN） + 79.118，y＝16.607ln（x _AHN）-0.035，y＝-0.056x _OM ² + 3.126x _OM + 45.625. The 1st to 7th grade indicators of AHN for sorghum，S. sudanense and Sorghum bicolor × S. sudanense hybrid in China were ≥414，227-414，124-227，68-124，38-68，21-38 and <21 mg/kg，respectively. The 1st to 7th grade indicators of TN were ≥4.3，2.2-4.3，1.1-2.2，0.6-1.1，0.3-0.6，0.15-0.3 and <0.15 g/kg in sequence. The 3st to 7th grade indicators of OM were 16-41，（10-16，41-47），（6-10，47-51），（2-6，51-55） and （<2，≥55） g/kg，respectively. When the nitrogen fertilizer use efficiency was 30%-50%，and the target yield of sorghum and S. sudanense seeds was determined to be 4.5-15 t/hm²，the suitable nitrogen application rate for soil grades 1 to 7 were 0，21-115，41-230，62-345，83-460，104-575 and 124-690 kg/hm²，respectively. When the target yield of fresh grass for sorghum，S. sudanense and Sorghum bicolor × S. sudanense hybrid was determined to be 45-240 t/hm²，the suitable nitrogen application rates for soil grades 1 to 7 were 0，27-240，54-480，81-720，108-960，135-1200 and 162-1440 kg/hm²，respectively. When the target yield of silage for sorghum，S. sudanense and Sorghum bicolor × S. sudanense hybrid was determined to be 30-120 t/hm²，the suitable nitrogen application rates for soil grades 1 to 7 were 0，33-220，66-440，99-660，132-880，165-1100 and 198-1320 kg/hm²，respectively.

This study focused on the moderately degraded alpine meadow in the eastern part of Qilian Mountains. A gradient of microbial fertilizer application rate was applied， namely CK （no microbial fertilizer）， BIM （7.5 g/m²）， BIIM （15 g/m²）， and BIIIM （22.5 g/m²）. The effects of different microbial fertilizer application rates on soil nutrient content， microbial community structure， and diversity of degraded alpine meadow were investigated. The results show that： In 0-10 cm soil layer， the soil nutrient content with microbial fertilizer application was significantly increased （P<0.05） compared with CK， with BIIM treatment showing the greatest effect. The contents of organic matter， available phosphorus， alkali hydrolyzable nitrogen， and available potassium were increased by 6.6%， 30.52%， 18.79% and 12.02%， respectively compared with CK； With the increase of soil depth， the effect of microbial fertilizer on soil nutrient content gradually declined； At the 20-30 cm depth， except for available potassium， no significant differences were observed among the treatments for any nutrients. The analysis of soil microbial community composition and diversity indicated that the effect of any bacterial fertilizer treatment on the diversity of fungal community was not significant， whereas the species richness of the bacterial community was significantly reduced by the BIIM treatment （P<0.05）. From the compositional perspective， the functional composition of microbial community was positively influenced by increasing the relative abundance of beneficial bacteria such as Penicillium， Mortierella， Bacillus， and Ferribacterium. Correlation analysis showed that the relative abundance of most beneficial bacteria was positively correlated with soil nutrient content. The results demonstrated that the application rate of 15 g/m² for the microbial fertilizer enriched with Bacillus subtilis， Bacillus mojavensis and Pseudomonas synxantha was effective. It significantly increased the content of key nutrients in soil and improved the soil microbial community structure， which could be applied in the restoration of regional degraded alpine meadow.

To investigate the growth adaptability of ten forage oat （Avena sativa L.） varieties in continuous alfalfa replanting fields in the northeastern Ordos and to identify high-quality varieties suitable for multiple cropping， ten representative forage oat varieties were selected based on preliminary screening. A randomized block design was employed to analyze and compare their growth period， agronomic performance， and nutritional quality. Partial least squares path model （PLS-PM） was further applied to examine the effects of varieties and harvest date on agronomic traits and forage quality， while the grey relational analysis method was used for comprehensive evaluation. The results showed that varieties reached the milk stage in approximately 70-80 days in the northeastern region of Ordos. Among varieties， ‘Sun God’ and ‘Yellow Oat’ exhibited significantly greater plant height （121.44 cm and 114.31 cm， respectively； P<0.05）. ‘White Oat No.7’ produced the highest hay yield （9414.79 kg/hm²）， followed by ‘Yellow Oat’ （9130.31 kg/hm²）， both significantly exceeding other varieties （P<0.05）. ‘Aiwo 256’ had the highest crude protein （CP） content （12.14% DM）， significantly higher than ‘Qingyin No.1’ and ‘Leader （Surui）’ （P<0.05）. ‘White Oat No.7’ showed significant lower acid detergent fiber （ADF） and neutral detergent fiber （NDF） contents than most varieties， except ‘Qinghai 444’ and ‘Qingyin No. 2’ （P<0.05）. Except for ‘Qingyin 2’，the potassium （K） content of ‘White Oat No.7’ was significantly lower than that of all other varieties， while its relative forage quality （RFQ） was significantly higher than those of other varieties （P<0.05）. Across harvest dates， oats harvested on September 9th exhibited significantly greater plant height， hay yield， dry-to-fresh ratio， and RFQ， while CP， ADF， and K content were significantly lower compared to earlier harvests （P<0.05）. In contrast， oats harvested on August 21st had higher CP， ADF and K contents but lower plant height， hay yield， dry-to-fresh ratio， and RFQ. Grey relational analysis identified CP， NDF， and hay yield as key indicators for evaluating forage oat productivity. Overall， ‘White Oat No.7’ and ‘Yellow Oat’ demonstrated superior performance and were recommended for re-cultivation after alfalfa cutting in the northeastern Ordos.

The spotted alfalfa aphid （Therioaphis trifolii） is recognized as one of the most damaging pests of alfalfa （Medicago sativa）. The application of exogenous elicitors represents a viable and environmentally friendly strategy that bolsters plant defenses while diminishing the risks that chemical pesticides pose to plants and the environment. This study focused on aphid-susceptible alfalfa cultivar， WL343 at the full-bloom stage. Salicylic acid （SA） and methyl jasmonate （MeJA） were sprayed with three concentrations （0.01， 0.1 and 1 mmol/L） to measure the effects on honeydew excretion and population growth of Therioaphis trifolii. The effects of exogenous elicitors at optimal concentrations on physiological characteristics of alfalfa under spotted alfalfa aphid stress were also analyzed. Results indicated that both SA and MeJA significantly reduced honeydew excretion and aphid population density， and optimal concentrations of SA and MeJA were 0.1 mmol/L and 0.01 mmol/L， respectively. The application of exogenous SA and MeJA significantly boosted the contents of soluble sugars， tannins and flavonoids， and enhanced the activities of polyphenol oxidase， superoxide dismutase and phenylalanine ammonia-lyase. Consequently， this regulated the physiological and metabolic responses of alfalfa， which suppressed aphid honeydew excretion and population growth thereby enhancing the plant defense against Therioaphis trifolii.

The overexploitation of agro-pastoral systems has driven widespread grassland reclamation in northern China，accelerating soil carbon and nutrient depletion. However，the mechanisms underlying the responses of soil organic carbon （SOC） and its fractions to grassland cultivation remain unclear. In this study，we investigated the effects of grassland reclamation on soil physicochemical properties and SOC fractions across three representative sites in the agro-pastoral ecotone： Jianping （Liaoning），Youyu （Shanxi），and Yuzhong （Gansu）. Cultivation significantly increased soil nitrate nitrogen but reduced SOC content by 24.17%. Among SOC fractions，labile free particulate organic carbon （fPOC） decreased significantly，whereas occluded particulate organic carbon （oPOC） and mineral-associated organic carbon （MAOC） remained unchanged. Random forest analysis identified soil electrical conductivity，moisture，and the carbon-to-nitrogen （C/N） ratio as the primary regulators of SOC and its fractions. Specifically，SOC and MAOC were mainly influenced by soil electrical conductivity and moisture，while the C/N ratio was the dominant driver of SOC and fPOC dynamics. Overall，grassland cultivation selectively depleted labile carbon pools while maintaining oPOC and MAOC，a process largely mediated by shifts in soil electrical conductivity，moisture，and the C/N ratio，ultimately reshaping SOC distribution and stability.

This study investigated the spatiotemporal dynamics of harvesting activities in Dongting Lake （South China） and their effects on Miscanthus lutarioriparius using multi-source satellite remote sensing data from 2015 to 2023. An object-oriented classification approach was applied to extract spatial distribution patterns based on vegetation spectral characteristics. Harvesting area （hectares） and landscape metrics were quantified through spatial and landscape pattern analyses in ArcGIS 10.7 and Fragstats 4.2. The results showed that the harvested area and harvest rate of Miscanthus lutarioriparius peaked in 2015 （57686.06 hm²； 55.69%） and declined to their lowest levels in 2019 （3743.21 hm²； 4.59%）. Following policy adjustments after 2018， harvesting intensity decreased， with spatial shifts toward the southern and eastern Lake regions， reflecting a northeastward migration trend. While early harvesting exhibited no preference for patch size， later mechanization promoted harvesting in large， contiguous Miscanthus lutarioriparius， reducing costs and improving efficiency. Correlation analyses indicate that harvesting maintained community aggregation and total area but altered shape complexity and spatial cohesion. These findings suggest that strategic planning of harvesting activities is essential to stabilize Miscanthus lutarioriparius populations， prevent further decline， and support wetland ecosystem. Expanding harvesting ranges may provide a pathway to achieving ecological and economic synergy for this species.

This study investigated the effects of companion crops on forage growth and soil physicochemical properties during the first year of establishing a perennial alpine mixed grassland （Elymus breviaristatus ‘Tongde’ and Puccinellia tenuiflora ‘Tongde’） on the Qinghai-Xizang Plateau. The impacts of Brassica napus， Vicia faba， and Avena sativa at sowing rates of 10%， 30%， and 50% of their respective monoculture amounts were assessed. Aboveground biomass， belowground biomass， forage nutritional quality， and soil physicochemical properties were measured. The results showed that companion crops significantly improved forage productivity， nutritive value， soil moisture， and nutrients availability compared with the control. The 50% Vicia faba treatment yield the greatest benefits， significantly enhancing aboveground biomass （321.83%）， belowground biomass （56.29%）， crude protein （132.22%）， ether extract （52.75%）， and relative feeding value （126.80%）， as well as soil moisture （14.35%）， total nitrogen （57.58%）， ammonium nitrogen （301.49%）， and nitrate nitrogen （185.00%）. Structural equation modeling indicated that soil nitrogen and phosphorus contents were the primary drivers of forage biomass， nutritional quality， and soil physicochemical properties. A comprehensive Technique for Order Preference by Similarity to an Ideal Solution （TOPSIS） evaluation further identified the 50% Vicia faba treatment as the optimal companion crop strategy for establishing perennial alpine mixed grasslands on the Qinghai-Xizang Plateau.

This study aimed to explore the impacts of salt stress on the photosynthetic characteristics and sugar metabolism of Astragalus cicer seedlings. A. cicer cultivar ‘Gan Green No. 2’ was treated by 120 mmol/L NaCl solution as salt stress simulation. Sampling was conducted at 0， 1， 3， 5， 7， 14， and 21 days after stress applied for relevant indices measurement. The results indicated that salt stress induced stomatal closure in the leaves of A. cicer seedlings resulting in reduced stomatal conductance reduction and impairment of the photosynthetic system. Simultaneously， the chlorophyll content， net photosynthesis rate， transpiration rate， actual photochemical efficiency， apparent photosynthetic electron transport rate （ETR）， and photochemical quenching coefficient were significantly decreased. However， the contents of sucrose， fructose， and glucose exhibited trends of increasing initially followed by declining. Moreover， the intercellular CO₂ concentration， non-photochemical quenching coefficient （NPQ）， starch content， sucrose synthase （SS） activity， and activities of soluble acid invertase （SAI） and neutral invertase （NI） increased and eventually stabilized with treatment time prolonged. In contrast， the sucrose phosphate synthase activity （SPS） gradually exhibited a decreasing trend. Correlation analysis demonstrated that soluble sugars content were closely related to photosynthetic parameters， suggesting that sugars may play a crucial role in regulating of photosynthesis and plant light use efficiency. Starch content was positively correlated with NPQ， indicating that starch may be involved in regulating photoprotection and energy dissipation. In conclusion， salt stress tolerance of A. cicer seedlings can be enhanced by regulating sugar metabolism-related enzyme activities and photosynthetic system， leading to increased soluble sugar and NPQ levels. The findings of this study provide valuable insights into the growth and physiological mechanisms of A. cicer in saline-alkaline soils.