In this experiment， the effects of single application of organic fertilizer and mixed application of organic fertilizer on the restoration of degraded natural mowing land were evaluated from the perspective of vegetation-soil-microorganism. The natural mowing land in Altay Mountains was used as the object of study. Three fertilization measures， single application of organic fertilizer （M）， mixed application of organic fertilizer and biological fertilizer （M+NY）， mixed application of organic fertilizer and compound fertilizer （M+NPK）， were used to explore the responses of grassland vegetation-soil-microorganism to fertilization. The results showed that fertilization significantly increased grassland community height， biomass， soil organic matter content， available nitrogen， available phosphorus， available potassium content and electrical conductivity （ P<0.05）， and significantly reduced soil pH value （ P<0.05）. There were significant differences in the richness of 5 phyla in soil bacteria （ P<0.05）， and there were significant differences in the richness of 2 phyla in soil fungi （ P<0.05）. The grey system correlation degree showed that compound fertilizer + organic fertilizer had the best effect on promoting vegetation growth， improving soil nutrients and increasing the number of microorganisms， and had a rapid recovery effect on the vegetation-soil-microbial system of reseeding natural mowing land. The results of the experiment provide theoretical basis， data support and technical support for the production and restoration of organic fertilizer single application and organic fertilizer mixed with other fertilizers in reseeding natural mowing land.

This study examines the relationship and dynamic changes between soil particle size, fractal dimension, and soil nutrients under different grazing treatments in a desert steppe region. The goal is to provide a theoretical basis for the formulation of grazing management strategies and the restoration of soil erosion in the region. The study analyzed the effects of grazing on soil particle size, fractal dimension, and nutrients using plots with four different grazing treatments and one control group, and further explored the relationship among these factors. The results showed:(1) Compared to the control group, as grazing intensity increased, the clay and silt content in the soil exhibited a declining trend, with clay content decreasing by 0.14% to 0.88% and silt content decreasing by 1.21% to 4.65%. In contrast, the sand content increased with grazing intensity, with an increase ranging from 1.07% to 5.53%. Enclosure and grazing exclusion effectively increased the fine particle content in the soil. (2) The soil fractal dimension gradually decreased with increasing grazing intensity, with the D value of the fractal dimension being highest in the control treatment and significantly lower under heavy grazing than in other grazing treatments. The fractal dimension was significantly positively correlated with soil clay and silt content ( P<0.01) and significantly negatively correlated with sand content ( P<0.01). Soil particle composition was identified as an important factor limiting the fractal dimension, which can serve as a critical indicator for assessing soil quality. In desert steppe regions, moderate grazing can effectively improve soil quality, but grazing intensity should be controlled to moderate levels or lower.

This study was conducted to evaluate the effects of different cover cropping strategies on the soil's physical and chemical properties,as well as the bacterial community structure in organic kiwifruit ( Actinidia chinensis) orchards in the Guanzhong Area. This experiment was conducted in 2021 at the Yangling Baiheng Organic Kiwi Orchard in Shaanxi Province. Three artificial cover cropping measures were tested: Lolium multiflorum+ Astragalus sinicus, Lolium multiflorum+ Glycine max, Lolium multiflorum+ Vicia villosa,with natural grass used as a control. The chemical properties and bacterial community structure of the soil in the topsoil(0~20 cm) were determined. The results showed that the organic matter of artificial grass increased by 8.8%~11.9% compared to the control,with the organic matter content of Lolium multiflorum+ Vicia villosa reaching 26.69 g·kg ^-1;The activities of soil urease,alkaline phosphatase,catalase were increased ( P<0.05),with Lolium multiflorum+ Vicia villosa having the most significant effect ( P<0.05). The bacterial beta diversity and the interaction relationship between bacterial communities in artificial cover cropping measures increased,while the abundance of metabolic functional genes in organismal systems significantly decreased( P<0.05). In summary,planting Lolium multiflorum+ Vicia villosa. and Lolium multiflorum+ Astragalus sinicus in organic kiwifruit orchards in the Guanzhong area can enhance the soil micro-ecological environment.

To uncover the effects of arbuscular mycorrhizal fungi (AMF) on reseeding species at different growth period,a microcosm experiment was carried out using Bromus inermis, Agropyron cristatum, Leymus chinensis,and Poa pratensis as test material. This experiment was set up as a factorial design containing two AMF inoculation treatments (with AMF,without AMF) and three growth period (seedling,jointing,jointing after mowing). We measured above-ground and below-ground biomass,root colonization,soil hyphal density,mycorrhizal growth response,and plant-available phosphorus. Our results showed that AMF inoculation increased the above biomass and below biomass of B. inermis and L. chinensis,compared with none inoculation. However,AMF inoculation did not affect the above biomass and below biomass of A. cristatum and P. pratensis at jointing after mowing period,compared with none inoculation. Mycorrhizal growth response (MGR) of four species was positive at each period,and the lowest MGR of A. cristatum, L. chinensis,and P. pratensis was at jointing period after mowing. From seedling to jointing period,AMF root colonization of these four species significantly increased. Soil hyphal density in B. inermis, A. cristatum,and L. chinensis reached the maximum level at jointing period after mowing. Therefore,the symbiotic relationships between AMF and plants depend on growth periods of plants and were species specific. Overall,from seedlings to adults,the abundance of AMF in roots and outside roots increased,while the response of MGR showed a decreasing trend. This indicated that AMF had a strong growth-promoting effect on plant seedlings,and this growth-promoting effect was not related to AMF abundance.

Artificial grassland establishment is an effective method for managing grassland degradation in the Sanjiangyuan area. This study analyzed the availability of soil nutrients and the mechanism of carbon,nitrogen,and phosphorus cycling and balancing by examining the content of key nutrient elements and their proportional relationships in soils sown with different pasture grasses in the Sanjiangyuan area. The finds suggest that the contents of soil organic carbon,total nitrogen,and total phosphorus in the artificial grassland were significantly higher than those in the degraded grassland. Additionally,the soil nutrient improvement effect of mixed-seeded artificial grassland was better than that of single-seeded artificial grassland. Further correlation analyses revealed that soil C:N was limited by carbon and nitrogen,soil C:P was limited by carbon,and soil N:P was limited by carbon and nitrogen. In summary,the main limiting nutrient elements in the region are carbon and nitrogen. Therefore,supplementing these nutrients appropriately can improve the soil quality of artificial grassland. This study's results provide an valuable reference forsoil quality improvement in the Sanjiangyuan area through rational pasture mixing.

Arbuscular Mycorrhizal Fungi （AMF） play an important role in maintaining the function of grassland ecosystems. Grazing is one of the main utilization modes of grasslands， which has a profound effect on the symbiotic relationship between plants and AMF. However， the regulatory effects of grazing on the Stipa breviflora-AMF symbiosis and its driving mechanisms remain unknown. This study， conducted in the S. breviflora grassland of Inner Mongolia， examined the effects of different grazing intensities—no grazing， light grazing （LG）， moderate grazing （MG）， and heavy grazing （HG）—on the AMF colonization rate in S. breviflora roots. The results revealed a significant decline in the AMF colonization rate with increasing grazing intensity. The colonization rates were 65.89%， 59.89%， 52.89% and 41.33% under different grazing intensities， respectively. Spore density and hyphal length density decreased with increasing grazing intensity. In addition， increased grazing intensity led to longer total root length and smaller root diameter in S. breviflora， along with higher soil density and pH but lower soil organic carbon and available phosphorus. However， soil moisture and nitrate nitrogen content peaked under light grazing. Soil nitrate nitrogen and available phosphorus were identified as the primary factors influencing the reduction in AMF colonization. In conclusion， grazing negatively affects AMF colonization in desert steppes by decreasing nitrogen and phosphorus nutrient effectiveness in the soil. This study provides empirical data and theoretical insights that support the development of sustainable grazing management strategies to maintain the health and resilience of desert steppe ecosystems.

This paper reviewed the application and effects of deficit irrigation on alfalfa cultivation,focusing on the methods of optimizing crop yield and water use efficiency under limited water resources. By analyzing existing literature,the combined application of precision irrigation scheduling and advanced agricultural technologies were discussed,as well as the impacts of these strategies on soil health and ecosystems. The study found that deficit irrigation had significant effects on improving water use efficiency and maintaining high yields of alfalfa. Meanwhile,the directions for future research was emphasized,including the necessity of integrated management strategies. This paper provided a new perspective and policy recommendations for agricultural water resources management.

Grassland is the largest terrestrial ecosystem in China, serving as the cornerstone for safeguarding national ecological security, fostering ethnic unity, and propelling regional economic-social development. In the new era, the ecological conservation of grassland and the green and high-quality development of grass industry are confronting with both new opportunities and challenges. This article delves into several aspects, including grassland technological innovation, the utilization of “the third national land resource survey” data in grassland management, the establishment of germplasm resource breeding and multiplication base of native grass, and the cultivation of local advanced talents in the western region. The aim is to provide references for cultivating new quality productive forces in the grass industry and promoting its high-quality transformation and development under the new circumstances.

Grassland sand degradation is serious at the eastern edge of the Tibetan Plateau. The comparative study of soil organic carbon mineralization and its temperature sensitivity between grassland sand degradation and natural restoration can provide theoretical support for the enhancement of grassland carbon pool and precise restoration management. In this experiment,typical sandy grassland and long-term natural restoration (10 years) sandy grassland were selected in Zoige County,and soil samples were collected from the topsoil (0-10 cm) and subsoil (20-30 cm) for mineralization incubation at constant temperatures (5℃,15℃ and 25℃). The results showed that compared with the sandy grassland,the mineralization rate of soil organic carbon under the natural restoration pathway decreased by 40%,the soil organic carbon stock increased by 2.23-2.57 times,the temperature sensitivity of SOC decomposition increased from 0.55-1.57 to 0.80-2.73,and the Q ₁₀ of the subsoil was the highest;The cumulative mineralization of soil organic carbon and the initial SOC content of both types of grassland soils showed a highly significant negative correlation,and the SOC mineralization rate of the subsoil was significantly higher than that of the topsoil. The potential risk of SOC mineralization and becoming a carbon source would be increased under the climate warming in the future,and the smart management strategy of the deepsoil should be strengthened.

In recent years, the Chinese government has continuously introduced policies to support oat cultivation. Encouraged by these policies and driven by market demand, the oat ( Avena sativa L.) industry has experienced new developments, characterized by:1) Increasingly refined support policies and a continually solidifying foundational status;2) Expanding planting scale and rising commercial rates of oat grass;3) Improving industry chains and the growing strength of outsourcing service organizations;4) Enhanced levels of intelligent production and significant advancements in digital management;5) Diversified planting models for the “three idle fields” (spring fallow fields, autumn fallow fields, winter fallow fields), with large-scale production becoming the norm. Despite the strong momentum of the oat industry, it faces several new challenges:insufficient innovation and utilization of oat germplasm resources;increasing constraints from arable land and water resources;a weak foundation for oat cultivation;and persistent contradictions between the supply and demand of high-quality oats. In response to the increasing national support and strong market demand for oat industry development, it is essential to first adopt a comprehensive food strategy by incorporating oats into livestock production elements and implementing integrated measures. Secondly, technology resources should be consolidated to enhance the utilization of oat germplasm resources and increase the innovation of new oat varieties. Finally, resource allocation should be optimized to address issues of limited arable land and water resources for oat cultivation, strengthen the utilization of oats in the “three idle fields”, and expand the planting area of oats.

Forage is an important material basis for the benign development of herbivorous animal husbandry,and forage industry is an important part of its development,which plays an important role in optimizing agricultural structure. At present,Hulunbuir forage industry resources (27.96 million tons annual output) include mainly three plates:natural forage,artificial forage and straw forage,accounting for 32.8% of the effective utilization of resources. However,focusing on the industrial level,there are still many problems:no quantitative standard for classification and grading,loss and waste of grass resources,information asymmetry between market supply and demand,scientific and technological low level of forage industry,difficult formation of industrial chain,etc. At the same time,it is also facing with problems in resources,technology,policy and so on. This paper combed the present situation of the production of natural forage,artificial forage and straw forage industry in Hulunbuir,and comprehensively analyzed the problems existing in the development of Hulunbuir forage industry. Measures and suggestions were proposed,including optimized forage industry,strengthened forage storage construction to reduce waste and loss,diversified grass product technology research and development,artificial grassland construction to reduce grassland bearing pressure,supporting forage industry leading enterprises,and others,to provide reference for the high-quality development of Hulunbuir forage industry.

In order to exert the complementary effect of whole plant maize and leguminous grass on livestock production and improve the utilization rate of forage grass in northwest Sichuan,whole plant maize,whole plant soybean and whole plant vicia sativa were used as experimental materials in this study,and a total of 5 treatments were set up:three forage grasses single silage,70% whole plant maize and 30% whole plant soybean,and 70% whole plant maize and 30% whole plant vicia sativa. Samples were taken for analysis after 30,60,90,and 120 days. The results showed that the whole plant maize mixed with legume grass significantly improved the crude protein content of corn and soluble carbohydrate and lactic acid content of leguminous grass,significantly decreased pH,AT/NT and butyrate in legume grasses ( P<0.05). In the two mixed forage treatments,the content of soluble carbohydrates and lactic acid in the whole plant maize and whole plant Vicia sativa mixed silage group increased more,and the mean content of pH,propionic acid and butyric acid was the lowest,4.03,2.6 and 0.38 g·kg ^-1DM,respectively. In conclusion,the mixed silage of whole plant maize,whole plant soybean and whole plant vicia sativa could better balance the nutritional quality of the two forages and obtain better silage,and the combination of whole plant maize and whole plant vicia sativa was better in the Northwest Plateau Area of Sichuan region.

Early and rapid identification of F1 hybrid progeny and acquisition of true hybrids are of great significance to the breeding and genetic research of Trifolium repens superior strains. Six phenotypic traits of 2 Trifolium repens parent materials and 55 F1 hybrids were mapped by clustering heat map,and 3 pairs of specific SSR primers were selected to identify the authenticity of F1 hybrids. The results showed that the 57 materials in the cluster heat map could be divided into 2 classes according to the phenotypic characters of their parents. A total of 281 distinct bands and 137 polymorphic bands were obtained by amplification with 19 pairs of selected primers. The polymorphic sites accounted for 48.41%. The PIC of each SSR site ranged from 18.49% to 43.58%,with an average value of 34.73%. A total of 53 true-hybrids were identified by three pairs of specific primers,and the true-hybrid ratio was 96.36%,which was basically consistent with the results of UPGMA cluster analysis. The 19 pairs of SSR molecular marker primers have high polymorphism,which can be directly used for genetic diversity analysis of Trifolium repens and hybrid identification and other related studies. The identified F1 generation true hybrids of Trifolium repens can lay a foundation for subsequent breeding work.

In order to qualitatively and quantitatively elucidate the research progress,research hot spots and development trends of ecology-livelihood research both domestically and internationally, 2 062 articles about the studies on relationship between ecology and livelihoods from 2011 to 2022 retrieved in the Web of Science (WOS) and CNKI databases were used to analyze the co-occurrence,hot spots,clustering and emergence of the literature data with the bibliometric analysis software CiteSpace. The results indicated that the number of publications on ecology-livelihood studies both domestically and internationally had increased slowly,and then rapidly,but had shown a downward trend in the past two years. International studies mainly focus on the fields of geography,sustainability and ecology,presenting a trend of interdisciplinary,diversified and refined research directions. Research hot spots mainly focus on biodiversity conservation,political ecology,ecological protection,livelihoods,impacts and influences. Domestic studies mainly focus on the fields of ecology and geographic sciences,with research hot spots mainly focused on livelihood and policy performance evaluation. The researches are oriented towards national policies and lacks innovation. Compared with studies of foreign countries,there is insufficient attention paid to biodiversity conservation,the relationship between ecosystem services and livelihood. Here we put forward proposals for future researches in this field in China to promote coordinated and sustainable development of ecology,society and economy.

In order to improve Agrobacterium tumefaciens-mediated genetic transformation efficiency of alfalfa ( Medicago sativa L.),we used alfalfa variety 'Zhongmu No.1' as plant material. The genetic transformation system of alfalfa mediated by agrobacterium was optimized by selecting the highly regeneration plant,using young leaves as explants,adjusting the hormone ratio in the medium,adding glutamine,and giving a cold treatment during agrobacterium infection. The results showed that the transient transformation efficiency of 'Zhongmu No.1' increased from 32% to 92% and the stable transformation efficiency increased to 31% by adding 150 μmol·L ^-1 acetosyringone to the bacterial suspensions solution,and using 300 μmol·L ^-1 glutamine during infection. The genetic transformation system of alfalfa reported in this paper provides technical support for efficient genetic improvement and gene functional study of alfalfa.

In recent years,research on grassland carbon sinks has attracted much attention,and related research results have emerged. This paper assessed global research trends and priorities on grassland carbon sinks using bibliometrics based on the Web of Science Core Collection. The study found that the research focus on grassland carbon sinks had changed over the past three decades,from assessing the carbon sequestration potential of grasslands and the effects of high CO ₂ concentrations on plant and soil organic carbon,to the effects of land use and management practices on carbon and nitrogen storage of grasslands and the effects of plant communities on the carbon cycle. Finally,the study focused on the effects of organic carbon and climate change on grassland carbon sinks. Terms such as nitrogen,sequestration,dynamics,carbon,grassland and management were high-frequency keywords in the study of grassland carbon sinks,and hot research terms in recent years were organic carbon,climate change and the Loess Plateau. Based on the results of the current study,it was recommended fully considering the interaction of climate change,land use and management systems when assessing the potential of grassland carbon sinks;strengthening large-scale spatial and temporal monitoring to comprehensively assess the characteristics of grassland carbon sinks;and conducting in-depth research on the regulation of grassland carbon sinks by climate change and abiotic processes to provide theoretical support for grassland restoration and mitigation measures.

With the increasing demand for healthy pet diets， pet forage as an important material for the healthy growth of herbivorous pets has attracted much attention. The vigorous development of the pet economy has promoted the rapid growth of the pet forage industry， but it still faces challenges such as insufficient varieties， singular production methods， unstable quality， small enterprise scale， and a non-standard market. Collectively， these factors limit the supply of pet forage and impact the industry’s intrinsic growth potential. Therefore， within the grassland agriculture system based on an all-encompassing approach to food， we should cultivate a new type of agricultural management entity that follows the ‘planting forage-making forage products-raising pets’ model to meet market demand， enrich the economic content of the grass industry， and enhance the added economic value of the traditional forage industry. By combing domestic forage industry policies， pet feed policies， and pet forage production demands， this paper discussed the market value， development characteristics， and trends of pet forage in China. It also proposed three types of contradictions and countermeasures that hinder the development of pet forage grass， providing practical guidance and a theoretical basis for the sustainable and healthy development of the pet forage industry. The growth of the pet forage industry plays a pivotal role in fostering rural revitalization， bolstering the development of rural collective economies， and enhancing the economic prosperity of farmers.

Reseeding Medicago falcata in Hulunbuir meadow grassland can effectively improve grassland productivity and forage quality,and promote the restoration of degraded grassland. In order to solve the problems of weak growth of yellow alfalfa seedlings and low success rate of establishment,this experiment adopted indoor pot experiment. The no-sterilized soil of degraded grassland in Hulunbuir was used as the matrix soil,and the commonly used species of degraded grassland,yellow alfalfa,was used as the research object to explore the effects of arbuscular mycorrhizal fungi (AMF) on the growth of Medicago falcata seedlings. The results showed that the growth of alfalfa seedlings was regulated by the type and combination of AMF inoculation. After the single inoculation of Funneliformis mosseae,the aboveground and underground biomass of alfalfa decreased,while the simultaneous inoculation of F. mosseae and C. etunicatum significantly increased the underground biomass and total biomass of alfalfa,counteracting the negative effect of the single inoculation of F. mosseae. The joint inoculation of F. mosseae and C. etunicatum activated soil available phosphorus,increased soil nitrogen content,and promoted the absorption of Fe,K,Mg,Mn and P by the roots of alfalfa,thus promoting the growth of alfalfa. Therefore,simultaneous inoculation of F. mosseae and C. etunicatum might promote the growth of alfalfa seedlings and improve the success rate of alfalfa reseeding in Hulunbuir degraded meadow grassland.

In this study,two alfalfa ( Medicago sativa L.) materials 'Baoding’ and 'ZN-1’ were treated with the mixed saline-alkali solution (NaCl∶Na ₂SO ₄∶NaHCO ₃∶Na ₂CO ₃ in 1∶1∶1∶1 ratio at pH 9.3) at the concentrations of 0 mmol·L ^-1,40 mmol·L ^-1 and 80 mmol·L ^-1,and compared for the tolerance. The morphology,physiology,and expression of the selected genes that are involved in ROS-scavenging,ion transport,and photosynthetic regulation were investigated at the alfalfa seedling stage,to look into the response to mixed saline-alkali stress. The results showed that with the increase of mixed saline-alkali concentration,significant ( P＜0.05) damage was observed in the plant height,dry weight,chlorophyll content,photosynthetic rate,and Fv/Fm,in both the alfalfa materials. Compared with 'Baoding’,'ZN-1’ demonstrated significantly higher saline-alkali tolerance,as evidenced by higher plant height,more biomass,more contents of chlorophyll content,proline,and soluble sugar,stronger antioxidant activity,promoted robust photosynthesis,and less accumulation of ROS in leaves and Na ⁺in root. In 'ZN-1’,the significantly up-regulated genes were associated with the pathways of ROS scavenging,proline biosynthesis,Na ⁺ vacuolar compartmentalization,and chlorophyll maintenance. In summary,proline biosynthesis,Na ⁺ vacuolar compartmentalization,chlorophyll maintenance,and antioxidants may play an important role in the 'ZN-1’ tolerance of mixed saline-alkali stress.

As pastoral social-ecological system faces the problem of increasing fragmentation,the self-governance of public pasture has garnered scholarly attention. However,under the current grassland contracting system of China,the feasibility and implementation mechanisms of self-governance system remains under explored. This study tracked a public pasture area in Inner Mongolia for three consecutive years,utilizing the SES framework to analyze the complex system. A related game model was developed to examine the interaction mechanisms among herders under the self-governance system. The results indicated that the sustainable utilization of grassland resources was crucial for reducing herders' long-term production costs. The pastoral community has established a self-governance system for public pasture to conserve long-term production costs. During the implementation of the system,dynamic rules for grass-livestock balance were formulated based on the condition of grass growth and livestock body condition. Operable penalty mechanisms and flexible intervention by local governments have promoted the effective operation of the self-governance system. Moreover,the interplay between grazing strategies among herders and social interaction games has led to the self-imposition of the governance system at a lower cost. The effective implementation of this system contributes to the fairness of grassland resource utilization,fosters trust among herders and local governments,and enhances mutual benefit and production efficiency. Therefore,exploring a diversified grassland resource management system that integrates self-governance and contracting is warranted.

The genes codon usage of species has a bias,which can avoid the wrong incorporation of amino acids. The bias of Medicago codon has not been reported. In order to reveal the codon bias characteristics of Medicago genome,we used software to analyze the codon composition of the coding region,the relative synonymous codon use frequency (RSCU),and other parameters of four Medicago species to explore the codon bias characteristics. At the same time,we used various methods to analyze the influencing factors causing the codon bias of Medicago,and calculated the optimal codon of Medicago. Finally,the evolutionary relationship of codon usage bias among species was studied by cluster analysis. The results showed that the codon bias of four Medicago species was relatively weak,of which ‘Zhongmu No.1’ was the weakest,and the third position of Medicago codon prefered A/T;The codon bias of four Medicago species was greatly affected by natural selection pressure,and most of the optimal codons ended in A/T. The bias of four Medicago species was similar and close to Nicatiana tabacum L.and Solanum lycopersicum L.. This study provides a theoretical basis for the application of Medicago codon optimization,especially through the optimization to improve the expression of Cas9 protein to promote gene editing.

The objective of this experiment was to explore the effect of Neolamarkia cadamba leaf essential oil (NCEO) on the fermentation quality and bacterial community of stylo ( Stylosanthes guianensis L.) and rice( Oryza sativa L.) straw silage. Based on the weight of fresh stylo and rice straw,adding the 0.5% and 1% NCEO into materials for 30 days ensiling. Vacuumed and sealed after three replicates of each treatment were packed into plastic bags (20 cm×30 cm). After 30 days of ensiling,the chemical composition and silage indexes of the samples were evaluated statistically. The results of fermentation parameter,protein fraction and bacterial community indicated that NCEO addition decreased ( P<0.05) pH value,ammonia-N content,and numbers of lactic acid bacteria and coliform bacteria both in stylo and rice straw silage. And lactic acid content and true protein proportion of rice straw silage increased ( P<0.05) with NCEO addition. Lactobacillus was the most dominant genus and increased with NCEO addition in rice straw silage. The NCEO addition also increased the relative abundance of Allorhizobium,Methylobacterium and Xanthomonas. In conclusion,the 1% NCEO addition was an effective way to improve the fermentation of stylo and rice straw silage.

In order to understand the changes of soil physicochemical properties and soil ions under different saline degradation states,this study took the grassland of Songnen temperate meadow as the research object,compared the soil ions and soil physicochemical properties under the non-saline-alkali,light,moderate and heavy saline degradation grassland,and analyzed the changing rules of soil physicochemical properties and ions and their interrelationships in the process of saline degradation.The results shows that soil K ⁺,Na ⁺,Mg ²⁺,Ca ²⁺,Cl ^-,HCO ^- ₃,SO ^2- ₄,CO ^2- ₃ increased significantly with the increase of salinity ( P＜0.05),and cation exchange capacity decreased significantly ( P＜0.05). With the change of salinity, soil conductivity, pH and total potassium increased significantly, while soil total nitrogen and alkali-hydrolyzable nitrogen decreased significantly( P＜0.05). Compared with non-degraded grassland soil,the soil water content of light and moderate saline-alkali grassland increased significantly ( P＜0.05),and the available phosphorus content decreased significantly. The content of available phosphorus in heavily degraded saline-alkali grassland increased significantly ( P＜0.05),Soil TN,AN,AP,K ⁺ showed a significant correlation with the degree of salinization. Soil AN and TN contents were higher in non-degraded grassland,while AP and K ⁺ contents were higher in heavily degraded grassland. This study provides a basis for the rational selection of restoration measures for saline degraded grassland in Songnen Plain.

To investigate the effects of exogenous H ₂O ₂ on alfalfa（ Medicago sativa）seeds germination and AsA-GSH cycle in embryonic root mitochondria， this study took alfalfa seeds as materials to study the seed germination characteristics and seedling growth status under different concentration gradients （0%， 0.25%， 0.5%， 1% and 2%） of H ₂O ₂ treatments， and then extracted embryonic root mitochondria to determine the changes in AsA-GSH cycle antioxidant enzyme activities and antioxidant contents. The results showed that germination characteristics and seedling growth of alfalfa seeds were significantly （ P<0.05） inhibited under 2% H ₂O ₂ treatment. With the increase of treatment concentration， the malondialdehyde （MDA） content exhibited an increase trend， while the activity of glutathione reductase （GR） in the AsA-GSH cycle initially was increased， then decreased， and subsequently increased again. The activities of superoxide dismutase （SOD）， monodehydroascorbate reductase （MDHAR）， and dehydroascorbate reductase （DHAR） followed a pattern of increaed first and then decreasing， whereas the ascorbic acid （AsA） content increased and then decreased gradually. The levels of dehydroascorbic acid （DHA） and oxidized glutathione （GSSH） showed an increasing trend. It was indicated that exogenous H ₂O ₂ treatment affected the germination and growth process of alfalfa seeds， and the high concentration of H ₂O ₂ inhibited the germination and seedling growth of alfalfa seeds， and strengthened the operation of the antioxidant system to resist the stress caused by exogenous H ₂O ₂.

Trifolium pratense cv. Minshan,an excellent legume forage,is suitable for growing in Min County,Gansu Province. Previous investigations have found that red clover suffered serious yield losses due to field diseases. However,systematic studies on the effects of diseases on performance of the plant remained unclear. This study aimed to investigate the major diseases and their occurrence patterns in the fields. Additionally,the study examined the impact of Stemphylium leaf spot disease on the growth and quality of red clover. The main field diseases were Stemphylium leaf spot,Leptosphaerulina leaf spot,and Longiseptatispora leaf spot,caused by Stemphylium sarcniforme, Leptosphaerulina trifolii,and Longiseptatispora meliloti,respectively. Among them,Stemphylium leaf spot had the highest severity,with a peak incidence rate of 26.67% and a disease severity index of 8.20 and caused a 20.14% reduction in fresh weight,a 20.93% decrease in chlorophyll content,and various changes in nutritional indicators. Stemphylium leaf spot had a significant impact on the growth and quality of red clover. This study provided a clear understanding of major diseases occurring in red clover fields in Min County,particularly the impact of Stemphylium leaf spot on the growth and quality. The findings provided valuable insights for disease prevention and control of red clover cultivation in this region.

This study investigated the effects of nitrogen application rate and row spacing on seed yield and quality of Leymus secalinus using a split-plot experimental design. The main factor was the nitrogen supplementing level (N0 0 kg·hm ^-2,N1 60 kg·hm ^-2,N2 120 kg·hm ^-2,N3 180 kg·hm ^-2),and the secondary factor was row spacing (R1 30 cm,R2 40 cm,R3 50 cm,R4 60 cm). Through grey correlation degree and stepwise regression analysis,we comprehensively analyzed the seed yield and quality,identified key factors affecting seed yield,and screened for the optimal planting combination of Leymus secalinus breeding. The results showed that:the main factors affecting the seed yield of Leymus secalinus were the number of reproductive branches,thousand-grain weight,seed number per spikelet,spikelet number per reproductive branches,with the seed number/spikelet being the most significant contributor to the yield. Grey correlation analysis revealed that the optimal seed yield and seed quality were obtained at a nitrogen supplementing level of 120~180 kg·hm ^-2 and a planting row spacing of 60 cm. However,there were no significant differences in actual and potential seed yield between 120 kg·hm ^-2 nitrogen treatment and 180 kg·hm ^-2 nitrogen treatment. Therefore,considering the economic and ecological benefits,a nitrogen supplementing level of 120 kg·hm ^-2 and a planting row spacing of 60 cm can be used to achieve the best seed yield and quality.

The aim of this experiment was to investigate the effect of different moisture contents (67.69%，59.43%，47.26% and 38.07%) on the quality of alfalfa ( Medicago sativa L.) silage after adding compound Lactobacillus and 2% molasses,respectively. The composite lactic acid bacteria were composed of Lactobacillus plantarum and Lactobacillus brucelli,with an equal addition of 1×10 ⁷ cfu·g ^-1 FW. After anaerobic fermentation at room temperature,the nutritional quality,fermentation quality and microbial quantity of silage alfalfa were determined. The results showed that wilting significantly affected the contents of crude protein (CP),acid detergent fiber (ADF),ammonia nitrogen,and organic acid in alfalfa silage( P<0.05);The use of composite lactic acid bacteria under different water conditions can significantly increase the lactic acid content after silage ( P<0.05),and reduce the content of acidic washing fiber,pH value,and ammonia nitrogen content ( P<0.05);Adding composite lactic acid bacteria can improve the bacterial community structure of alfalfa silage. According to principal component analysis,under the condition of 59.43% moisture content in alfalfa,adding composite lactic acid bacteria for silage has the best effect and can effectively improve the quality of alfalfa silage. Adding molasses has the best effect when the moisture content of the raw material is 47.26%.

Elymus excelsus Turcz. is a perennial herbaceous plant of the genus Elymus of the Poaceae family. It exhibits traits of vigorous growth,broad foliage,high nutritional value,and favorable palatability,rendering it a superior quality pasture species. In order to explore the drought tolerance of Elymus excelsus,this study used drought resist and drought sensitive Elymus excelsus previously screened from 8 wild resources in Northeast China as test materials,and used 20% PEG-6000 to simulate drought stress. Seedlings (5 weeks old) were treated for 0 (control),3,7 and 14 days. Phenotypes changes were observed,changes in physiological indicators were measured,such as osmotic regulatory substances,reactive oxygen metabolism and antioxidant enzyme activity. And transcriptome sequencing was performed to explore the physiological response and internal regulatory mechanism of Elymus excelsus under drought stress. The results showed that,under drought stress,the drought-tolerant Elymus excelsus exhibited significantly increased contents of proline (Pro),superoxide dismutase (SOD),catalase (CAT),and soluble sugar (SS) compared to the drought-sensitive type ( P <0.05). Increased,among which the proline content and soluble sugar content reached the highest on the 14th day of stress,increasing by 20.39% and 19.11% respectively compared with the drought sensitive type. Transcriptome analysis showed that there were 3 463 and 2 651 differentially expressed genes of drought resist and drought sensitive response genes respectively,of which 795 were co-regulated genes,633 were up-regulated and 159 were down-regulated. Drought-tolerant differentially expressed genes are mainly concentrated in pathways such as antioxidant activity,transferase activity,and arginine and proline metabolism. Among them, proB, rocF,and ALDH genes may be involved in the process of Elymus excelsus resisting drought stress. The research results provide a theoretical basis for further exploration of candidate genes and drought resist breeding of Elymus excelsus.

This study used Bromus inermis as the experimental material and applied manganese fertilizer combined with different concentrations of γ-polyglutamic acid (γ-PGA) at the early flowering stage. A systematic analysis was conducted on the chlorophyll content (SPAD value), soluble sugar and starch contents, as well as the yield components and seed yield of Bromus inermis. The results showed that the seed yield components, including the number of florets per spike, the number of seeds per spike, the number of spikelets per plant, the number of seeds per plant, thousand-seed weight, and seed yield, increased by 2.94% to 16.47%, 6.86% to 16.67%, 8.26% to 31.39%, 44.98% to 67.37%, 8.40% to 12.47%, and 19.61% to 27.98%, respectively, with the highest seed yield reaching 623.97 kg·hm-2. After the application of manganese fertilizer combined with γ-PGA, the SPAD value in the leaves of Bromus inermis increased, ensuring more effective photosynthesis and the accumulation of more organic matter. Soluble sugars and starch accumulated and transferred in the source and sink organs, prioritizing the growth and development of reproductive organs. Based on comprehensive evaluation, it was found that spraying 0.05% Mn + 1.5% γ-PGA at the early flowering stage of Bromus inermis could effectively increase the seed yield.

To investigate the impacts of grassland degradation on root traits of dominant species， we selected dominant species of temperate grasslands， Leymus chinensis， as object to evaluate its dynamics of root traits in four degradation level of grasslands： undegraded grassland （UD）， lightly degraded grassland （L）， moderately degraded grassland （M）， and highly degraded grassland （H）. The root traits included total root length （TRL）， root depth （RD）， root volume （RV）， root surface area （RSA）， specific root area （SRA）， root tissue density （RTD）， specific root length （SRL）， and root length density （RLD）. The results showed that TRL was significantly higher in highly degraded grassland （19.91 m） than in undegraded grassland （9.32 m）， while RSA （19.12 cm ²） and SRL （5.51 m·g ^-1） were significantly lower compared to undegraded grassland （RSA 56.12 cm ²， SRL 14.34 m·g ^-1）. SRAwas higher in lightly degraded grassland （42.82 cm ² ） than in other degraded grasslands. RTD increased with increasing degradation intensity， reaching its maximum in highly degraded grassland （1.14 g·cm ^-3）. These findings suggest that Leymus chinensis adapts to grassland degradation stress by altering root morphology.