The quantity of soil microbes and the structure of ammonium oxidizing bacterial （AOB） community were analyzed using the dilution plate counting and most probable number method （MPN）, and denaturing gradient gel el...The quantity of soil microbes and the structure of ammonium oxidizing bacterial （AOB） community were analyzed using the dilution plate counting and most probable number method （MPN）, and denaturing gradient gel electrophoresis （DGGE）, respectively. Fertilizer application tended to increase the number of soil microbes and alter the AOB community compared to the control with no fertilizer application （CK）. Among the eight fertilizer treatments, soil samples from the treatments of mineral fertilizers （e.g., N, P, K） in combination with farmyard manure （M） had greater number.s of soil microbes and more complex structure of AOB community than those receiving mineral fertilizers alone. The principal component analyses （PCA） for ammonium oxidizing bacterial community structure showed that the eight fertilizer treatments could be divided into two PCA groups （PCA1 and PCA2）. For the soil sampled after rice harvest, PCA1 included NP, NM, NPM and NPKM fertilizer treatments, while PCA2 was consisted of CK, N, M and NPK fertilizer treatments. For soil samples collected after wheat harvest, PCA1 was consisted of M, NM, NPM and NPKM fertilizer treatments, while PCA2 was composed of CK, N, NP and NPK fertilizer treatments. For a given rotation, the richness of AOB community in PCA1 was greater than that in PCA2. In addition, AOB community structure was more complex in the soil after rice harvest than that after wheat harvest. The results indicated that different fertilizer treatments resulted in substantial changes of soil microbe number and AOB community. Furthermore, mineral fertilizers （N, NP, NPK） combined with farmyard manure were effective for increasing the quantity of soil microbes, enriching AOB community, and improving the soil biofertility.展开更多
Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtain...Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtained from the soils close to the rhizosphere of ‘big＇ and ‘small＇ plants from small plots which exhibited large local heterogeneity in plant vigour. A metabarcoding approach was used to profile bacterial and fungal compositions, using two primer pairs for 16 S ribosomal RNA genes（16S r DNA） and one for the fungal internal transcribed spacer（ITS） region. Of the two 16 S r DNA primer sets, the 341F/805 R resulted in sequences of better quality. A total 28 operational taxonomic units（OTUs） had differential relative abundance between samples from ‘big＇ and ‘small＇ plants. However, plausible biological explanation was only possible for three fungal OTUs. Two were possible phytopathogens： Verticillium spp. and Alternaria alternata although the latter has never been considered as a main pathogen of strawberry in the UK. For samples from ‘small＇ plants, the abundance of these OTUs was much greater than from ‘big＇ plants. The opposite was true for a mycorrhizal OTU. These results suggest that soil microbes related to crop production can be identified using metabarcoding technique. Further research is needed to assess whether A. alternata and Verticillium spp. could affect strawberry growth in the field.展开更多
In semi-arid areas of China,gravel and sand mulch is a farming technique with a long history.In this study,a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plate...In semi-arid areas of China,gravel and sand mulch is a farming technique with a long history.In this study,a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plateau to determine the effects of long term mulch on soil microbial and soil enzyme activities.We found that after long term gravel-sand mulch,compared with bare ground,soil organic matter,alkali nitrogen,conductivity decreased,while pH and soil moisture increased.Urease,saccharase and catalase decreased with increased mulch thickness,while alkaline phosphatase was reversed.The results of Illumina MiSeq sequencing shows that after gravel-sand mulch,the bacterial and fungal community structure was different from bare land,and the diversity was reduced.Compared with bare land,the bacteria Proteobacteria and Acidobacteria abundance increased with increased thickness,and Actinobacteria was opposite.Also,at the fungal genus level,Fusarium abundance was significantly reduced,and Remersonia was significantly increased,compared with bare land.Redundancy analysis(RDA)revealed that soil environmental factors were important drivers of bacterial community changes.Overall,this study revealed some of the reasons for soil degradation after long term gravel-sand mulch.Therefore,it is recommended that the addition of exogenous soil nutrients after long term gravel-sand can help improve soil quality.展开更多
The diversity of vegetation configuration is the key to ecological restoration in open-pit coal mine dump.However,the recovery outcomes of different areas with the same vegetation assemblage pattern are completely dif...The diversity of vegetation configuration is the key to ecological restoration in open-pit coal mine dump.However,the recovery outcomes of different areas with the same vegetation assemblage pattern are completely different after long-term evolution.Therefore,understanding the causes of differential vegetation recovery and the mechanism of plant succession is of great significance to the ecological restoration of mines.Three Pinus tabulaeformis plantations with similar initial site conditions and restoration measures but with different secondary succession processes were selected from the open-pit coal mine dump that has been restored for 30 years.Soil physicochemical properties,enzyme activities,vegetation and microbial features were investigated,while the structural equation models were established to explore the interactions between plants,soil and microbes.The results showed that original vegetation configuration and soil nutrient conditions were altered due to secondary succession.With the advancement of the secondary succession process,the coverage of plants increased from 34.8%to 95.5%(P<0.05),soil organic matter increased from 9.30 g kg^(-1)to 21.13 g kg^(-1)(P<0.05),and total nitrogen increased from 0.38 g kg^(-1)to 1.01 g kg^(-1)(P<0.05).The activities of soil urease and p-glucosidase were increased by 1.7-fold and 53.26%,respectively.Besides,the secondary succession also changed the soil microbial community structure and function.The relative abundance of Nitrospira genus which dominates the nitrification increased 5.2-fold.The results showed that urease andβ-glucosidase promoted the increase of vegetation diversity and biomass by promoting the accumulation of soil organic matter and nitrate nitrogen,which promoted the ecological restoration of mine dumps.展开更多
In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soi...In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soil microbe.However,limited researches were conducted to study the impacts of land-use patterns on the diversity and community of soil microorganisms in this area.The study aimed to investigate soil microbial community diversity and composition using high-throughput deoxyribonucleic acid(DNA)sequencing under different land-use patterns(apricot tree land,apple tree land,peach tree land,corn land,and abandoned land).The results showed a substantial difference(P<0.050)in bacterial alpha-diversity and beta-diversity between abandoned land and other land-use patterns,with the exception of Shannon index.While fungal beta-diversity was not considerably impacted by land-use patterns,fungal alpha-diversity indices varied significantly.The relative abundance of Actinobacteriota(34.90%),Proteobacteria(20.65%),and Ascomycota(77.42%)varied in soils with different land-use patterns.Soil pH exerted a dominant impact on the soil bacterial communities'composition,whereas soil available phosphorus was the main factor shaping the soil fungal communities'composition.These findings suggest that variations in land-use pattern had resulted in changes to soil properties,subsequently impacting diversity and structure of microbial community in the Loess Plateau.Given the strong interdependence between soil and its microbiota,it is imperative to reclaim abandoned lands to maintain soil fertility and sustain its function,which will have significant ecological service implications,particularly with regards to soil conservation in ecologically vulnerable areas.展开更多
Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes....Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes. Here we tested the hypothesis that soil microbes which can degrade allelochemicals may accumulate in soils over time by adaptation and therefore increase the degradation of allelochemicals and alleviate the allelopathic effects in biological invasions. As expected, soil microbes signifi- cantly decreased the allelopathic effects of leaf leachates of eight in the nine invasive plant species studied. In addition, Ageratina adenophora showed lower allelopathic effects in soil with long or intermediately invasion history than those in soil with short invasion history. The two main allelo- chemicals of the invader were degraded more rapidly with increasing invasion history in the soil. Correspondingly,biomass and activity of the soil microbes were higher in the soils with long invasion history than in that with short invasion history. Our results indicate that soil microbes may graduaUy adapt to the allelochemicals of Ageratina and alleviate its allelopathic effects and thus support the above hypothesis. It is necessary to consider the effects of soil microbes when testing the roles of allelopathy or the novel weapons hypothesis in biological invasions.展开更多
Objective To study the effect of autotoxicity and the co-effect of autotoxicity and soil microbes from continuous cropping soil on Angelica sinensis growth, root yield and content of essential oils, and soilmicrobalpo...Objective To study the effect of autotoxicity and the co-effect of autotoxicity and soil microbes from continuous cropping soil on Angelica sinensis growth, root yield and content of essential oils, and soilmicrobalpopulation. Methods The pot experiments were conducted upon A. sinensis seedlings in continuous cropping soil. At the different growth stages, we determined the seedlings in growth parameters, root yield, content of essential oils, ethanol extract, and cultivable microbial populations in rhizosphere soil. Results A. sinensis seedlings were significantly inhibited in growth, root yield and quality. Compared with the control, the composition and structure of soil microbes were changed and the diversity indexes of bacteria functional groups were reduced in rhizosphere soil ofA. sinensis. A. sinensiscropping problems were more seriously after the treatment with combination of autotoxicity and soil microbes than with autotoxicity alone. Conclusion The autotoxicityand soil microbes from continuous cropping soil of A. sinensis could cause the continuous cropping obstacle together.展开更多
Aims Linkages formed through aquatic-terrestrial subsidies can play an important role in structuring communities and mediating ecosystem functions.Aquatic-terrestrial subsidies may be especially important in nutrient-...Aims Linkages formed through aquatic-terrestrial subsidies can play an important role in structuring communities and mediating ecosystem functions.Aquatic-terrestrial subsidies may be especially important in nutrient-poor ecosystems,such as the freshwater sand dunes surrounding Lake Michigan.Adult midges emerge from Lake Michigan in the spring,swarm to mate and die.Their carcasses form mounds at the base of plants,where they may in crease plant productivity through their nutrient inputs.However,the effect of aquatic-terrestrial subsidies on plant productivity could depend on other biotic interactions.In particular,soil microbes might play a key role in facilitating the conversion of nutrients to plant-available forms or competing for the nutrients with plants.Methods In a greenhouse experiment,we tested how carcasses from lake emerge nt midges(Chironomidae)and soil microbes indepe ndently and interactively influe need the performance of a common dune grass,Calamovilfa longifolia.To determine whether midges influenced abiotic soil properties,we measured how midge additions influe need soil nutrients and soil moisture.Important Findings Midges greatly increased plant biomass,while soil microbes in flue need the magnitude of this effect.In the absence of soil microbes plant biomass was seven times greater with midges than without midges.However,in the presence of soil microbes,plant biomass was only three times greater.The effect of midges might be driven by their nutrient inputs into the soil,as midges contained 100 times more N,10 times more P and 150 times more K than dune soils did.Our results suggest that soil microbes may be competing with plants for these nutrients.In sum,we found that midges can be an important aquatic-terrestrial subsidy that produces strong,positive effects on plant productivity along the shorelines of Lake Michigan,but that the impact of aquatic-terrestrial subsidies must be considered within the context of the complex interactions that take place within ecological communities.展开更多
The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current lite...The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current literature, reporting specifically on the impact of production intensification on habitats and yield constraints caused by weeds. Secondly, in alleviating these effects over the short term, ecological measures that enhance species diversity in conserved habitats and promote semi-natural habitats in the agricultural landscape, are discussed. In large-scale intensive agriculture, weed control is predominantly rooted in agrochemical applications in the form of herbicides. Long lasting intensive agricultural practices show discord both with the promotion of the biodiversity of microbes belowground and aboveground and with organisms involved in the breaking down of plant material. The presence of native species in the surroundings, in combination with hedgerows and field margins, with a comparatively intricate and balanced variety of plants in a sheltered environment, are essential for settlement of benign insects, particularly in the face of intensive agricultural production. The promising tactic of advantageous seed predators enables decreased herbicide applications. Crop mosaics arranged to advance compatibility at the landscape scale are important to bolster pollination services and insect management, while ecological variety in the surroundings acts as a safety net for habitat diversity. Weed control in combination with different tactics of vegetation use, comprising cover cropping, hedgerows and field margins, sets up safe havens in the landscape, and improves the diffusion of complementary life forms. Field margins perform a meaningful natural function as point of provision for forage, safe havens and distribution passageways for pollinators and insect predators. Production practices that promote more heterogeneity and combine high density semi-natural safe havens and habitat conservation in agro ecosystems are beneficial to species diversity across trophic levels and contribute to agricultural production stability and food safety.展开更多
Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial c...Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial communities, the soil microbial communities were assessed by plate counts, phospholipid fatty acid （PLFA） and Biolog microplate techniques in five plant communities, i.e., soybean field （SF）, artificial turf （AT）, artificial shrub （AS）, natural shrub （NS）, and maize field （MF） in Jinan, Shandong Province, North China. The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate. Legumes could significantly enhance the number of cultural microorganisms, microbial biomass, and community catabolic diversity. Except for SF dominated by legumes, the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types. These results confirmed that high number of plant species, legumes, and natural vegetation types tend to support soil microbial communities with higher function. The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community. Different research methods led to varied results in this study. The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.展开更多
Soil properties, microbial communities and enzyme activities were studied in soil amended with replicase （RP）-transgenic or non-transgenic papaya under field conditions. Compared with non-transgenic papaya, signific...Soil properties, microbial communities and enzyme activities were studied in soil amended with replicase （RP）-transgenic or non-transgenic papaya under field conditions. Compared with non-transgenic papaya, significant differences （P〈0.05） were observed in total nitrogen in soils grown with transgenic papaya. There were also significant differences （P〈0.05） in the total number of colony forming units （CFUs） of bacteria, actinomycetes and fungi between soils amended with RP-transgenic plants and non-transgenic plants. Compared with non-transgenic papaya, the total CFUs of bacteria, actinomycetes and fungi in soil with transgenic papaya increased by 0.43-1.1, 0.21-0.80 and 0.46-0.73 times respectively. Significantly higher （P〈0.05） CFUs of bacteria, actinomycetes and fungi resistant to kanamycin （Km） were obtained in soils with RP-transgenic papaya than those with non-transgenic papaya in all concentrations of Km. Higher resistance quotients for Km＇ （kanamycin resistant） bacteria, actinomycetes and fungi were found in soil planted with RP-transgenic papaya, and the resistance quotients for Km＇ bacteria, actinomycetes and fungi in soils with transgenic papaya increased 1.6-4.46, 0.63-2.5 and 0.75-2.30 times. RP-transgenic papaya and non-transgenic papaya produced significantly different enzyme activities in arylsulfatase （5.4-5.9x）, polyphenol oxidase （0.7-1.4x）, invertase （0.5-0.79x）, cellulase （0.23-0.35x） and phosphodiesterase （0.16-0.2x）. The former three soil enzymes appeared to be more sensitive to the transgenic papaya than the others, and could be useful parameters in assessing the effects of transgenic papaya. Transgenic papaya could alter soil chemical properties, enzyme activities and microbial communities.展开更多
Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jins...Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jinsha River, China. Results showed that Hymenoptera, Araneae and Collembola were the dominant groups of soil animals in the plots studied. The numbers of groups and individuals and density of soil animals in the dry red soil series were higher than those in the Vertisol series, and the numbers of individuals and density of soil animals decreased with the degree of soil degradation. Bacteria dominated microbiocoenosis not only in the dry red soils but also in the Vertisols. Microbial numbers of the dry red soil series were higher than those of Vertisol series, and decreased with the degree of soil degradation. The activities of catalase, invertase, urease and alkaline phosphatase declined with the degradation degree and showed a significant decline with depth in the profiles of both the dry red soils and the Vertisols, but activities of polyphenol oxidase and acid and neutral phosphatase showed the same tendencies only in the Vertisols. It was concluded that the characteristics of soil animals, microorganisms and enzymatic activity could be used as the bio-indicators to show the degradation degree of the dry red soils and Vertisols. Correlation among these soil bio-indicators was highly significant.展开更多
Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in South...Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in Southeast China, and that two representative tree species （Castanopisi carlesii and Cunninghamia lanceolata） may have different soil microbial community composition. Phospholipids fatty acid analysis （PLFA） of seasonal shifts and was used to assess the effect vegetation types on soil microbial community structure. A total of 22 different PLFAs were identified from all the soil samples. The bacterial PLFAs accounted for 62.37% of the total PLFAs, followed by fungi （28.94%）, and the minimum was actinomycetes （6.41%）. Overall, the level of PLFAs in C. carlesii soil was greater than those in C. lanceolata soil, and significant differences were observed in some seasons. The amounts of total, bacteria, actinomycic and fungal PLFAs significantly changed with the seasons and followed a sequence order （summer 〉 autumn 〉 spring 〉 winter）. The bacteria/fungi PLFAs and G （＋）/G （-） PLFAs of two vegetation types also changed with the seasons and the ratios in summer and autumn were higher than those in spring and winter. The correlation analysis of microbial PLFAs and soil physicochemical properties showed that the total, bacteria, fungal, actinomycic, G （＋） and G （-） PLFAs were significantly positive correlation with TOC, TN, TP, TK and moisture content. We concluded that the seasonal shifts and vegetation types affect soil microbial community composition by changing the soil physicochemical properties.展开更多
Soil microbes may be critical players in determining the allelopathic potential of some plants. Low levels of plant community biodiversity in Eucalyptus plantations have been attributed to the allelopathic potential o...Soil microbes may be critical players in determining the allelopathic potential of some plants. Low levels of plant community biodiversity in Eucalyptus plantations have been attributed to the allelopathic potential of these tree species. The role of soil microbes in the allelopathic effect of leaf leachates of the hybrid tree Eucalyptus grandis x E. urophylla, was tested in Petri dish assays with Brassica chinensis as a receiver plant. Soils were collected from either a local garden (soil A) or a Eucalyptus plantation (soil B) and half of each soil was sterilized to remove microbes. These soils were then treated with E. grandis x E. urophylla leachates for 0-72 h. Seed germination of B. chinensis was significantly inhibited in soils treated with leaf leachates relative to untreated soils. The inhibitory effect of the leaf leachates was more pronounced in sterilized soils. Total phenolic content was obvious lower in nonsterile leachate-treated soils than in sterile soils. Biomass of B. chinensis was negatively correlated with the total phenolic content in soils. Our findings suggest that soil microbes can alleviate the allelopathic potential of Eucalyptus and thereby its negative impact on plant growth.展开更多
Soil microorganisms are sensitive indicator of soil health and quality. Understanding the effects of vegetation biomass and seasonal change on soil microorganisms is vital to evaluate the soil quality and implement ve...Soil microorganisms are sensitive indicator of soil health and quality. Understanding the effects of vegetation biomass and seasonal change on soil microorganisms is vital to evaluate the soil quality and implement vegetation restoration. This study analyzed the soil phospholipid fatty acids(PLFAs) in fresh and withered Kudzu(Pueraria montana var. lobata) vegetation conditions in different seasons. The results showed that vegetation biomass and seasonal change significantly affected microbial biomass and its community structure. Both fresh and withered Kudzu cover significantly increased soil microbial biomass, and the growth effect of microbes in the soil with fresh Kudzu cover was more obvious than that with withered Kudzu cover. Compared with the dry season, the rainy season significantly increased the microbial biomass and the B/F(the ratio of bacterial to fungal PLFAs) ratio but dramatically reduced the G+/G-(the ratio of gram-positive to gram-negative bacteria PLFAs). Kudzu cover and seasonal change had a significant effect on microbial structure in soil covered by higher vegetation biomass. Furthermore, soil temperature and moisture had different correlations with specific microbial biomass in the two seasons. Our findings highlight the effect of Kudzu vine cover on the soil microenvironment and soil microhabitat, enhancing the soil quality in the Dry-hot Valley of Jinsha River, Southwest China.展开更多
Soil microbial flora and influencing factors of soil microbes in soil and gravel-sand mixed layer（ SGSML）,roots denseness layer（ RDL）,eluviate layer（ EL） and calcium accumulation layer（ CAL） in gravel-sand mul...Soil microbial flora and influencing factors of soil microbes in soil and gravel-sand mixed layer（ SGSML）,roots denseness layer（ RDL）,eluviate layer（ EL） and calcium accumulation layer（ CAL） in gravel-sand mulched fields（ GSMFs） with different gravel mulched years（ 1,6,12,19 and 25 years） were studied. The results showed that in the composition of soil microbes in the GSMFs,the quantity of bacteria was the largest,followed by actinomycetes,while the number of fungi was the smallest. The total quantity of soil microorganisms in the GSMFs dropped rapidly with the increase of soil depth,which was related to the sudden decrease in the quantity of bacteria. The number of microbes in the RDL was larger than that in the SGSML with few roots due to the effects of root distribution. The number of bacteria and actinomycete in the growing season was larger than that in the non-growing season,while the quantity of fungi in the growing season was smaller than that in the non-growing season. The quantity of bacteria and fungi was the largest in the GSMFs which had been mulched with gravel for 6-12 years. With the increase of mulching time,the GSMFs aged gradually,so their quantity reduced gradually. The quantity of actinomycetes was the smallest in the GSMFs which had been mulched with gravel for 6-12 years and increased with the increase of mulching time. The number of soil microbes in the GSMFs had a good correlation with soil moisture content,p H and mulching time. Soil total carbon content was an important factor restricting the quantity of soil microbes in the GSMFs.展开更多
This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass ni...This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.展开更多
The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen（N）levels are important indicators of the effect...The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen（N）levels are important indicators of the effect of reclaimed water irrigation on environment.This study evaluated soil physicochemical properties and microbial community structure in soils irrigated with reclaimed water and receiving varied amounts of N fertilizer.The results indicated that the reclaimed water irrigation increased soil electrical conductivity（EC）and soil water content（SWC）.The N treatment has highly significant effect on the ACE,Chao,Shannon（H）and Coverage indices.Based on a 16S ribosomal RNA（16S rRNA）sequence analysis,the Proteobacteria,Gemmatimonadetes and Bacteroidetes were more abundant in soil irrigated with reclaimed water than in soil irrigated with clean water.Stronger clustering of microbial communities using either clean or reclaimed water for irrigation indicated that the type of irrigation water may have a greater influence on the structure of soil microbial community than N fertilizer treatment.Based on a canonical correspondence analysis（CCA）between the species of soil microbes and the chemical properties of the soil,which indicated that nitrate N（NO3-–-N）and total phosphorus（TP）had significant impact on abundance of Verrucomicrobia and Gemmatimonadetes,meanwhile the p H and organic matter（OM）had impact on abundance of Firmicutes and Actinobacteria significantly.It was beneficial to the improvement of soil bacterial activity and fertility under 120 mg kg^-1 N with reclaimed water irrigation.展开更多
Semi-sealed preservation of soil samples at different moisture of 4% and 23 %, respectively, was simulated to observe the variations of soil microbial communities and determine the contents and isotopic compositions o...Semi-sealed preservation of soil samples at different moisture of 4% and 23 %, respectively, was simulated to observe the variations of soil microbial communities and determine the contents and isotopic compositions of the total organic carbon and total nitrogen on the 7th and 30th day, respectively. The results show that during preservation, the quantity of microbial communities tended to increase first and then decrease, with a wider variation range at higher moisture （23%）. At the moisture content of 23 %, the microbial communities became more active on the 7th day, but less after 30 days, and their activity was stable with little fluctuation at the moisture content of 4%. However, there were no significant changes in the contents and isotopic compositions of the total organic carbon and total nitrogen. During preservation, the responses of soil microbes to the environment are more sensitive to changes in the total nitrogen and organic carbon contents. It is thus suggested that the variations of microbial communities have not exerted remarkable impacts on the isotope compositions of the total nitrogen and total organic carbon.展开更多
[Objective] This study aimed to investigation the effects of tranagenic Bt ＋ CpTI cotton cultivation on functional diversity of microbial communities in rhizospbere soils. E Method] By using the Biolog method, a comp...[Objective] This study aimed to investigation the effects of tranagenic Bt ＋ CpTI cotton cultivation on functional diversity of microbial communities in rhizospbere soils. E Method] By using the Biolog method, a comparative study was conducted on the utilization level of single carbon source by microbes in the rhi- zosphere soils of transgenic Bt ＋ CpTI cotton sGK321 and its parental conventional cotton ＇ Shiyuan 321＇ at different growth stages. [ Result ] The results showed that, compared with the parental conventional cotton, the average well-color development （AWCD） value of micmhial communities in rhizospbere soils of transgenie Bt ＋ CpTI cotton were significantly higher （P 〈 O. 05） at seedling stage and budding stage while significantly lower at flower and boll stage and bell opening stage. Shannon-Wiener diversity index （H） and Simpson dominance index （D） of microbial communities in rhlzesphere soils of transgenic cotton and conventional cotton varied with the different growth stages, whereas the Shannon-Wiener evenness index （E） showed no significant difference between transgenie cotton and convention- al cotton at four growth stages. Principal component analysis indicated that the patterns of carbon source utilization by microbial communities in rhizospbere soils were similar among transgenic cotton at seeding stage and flower and boll stage and parental conventional cotton at seeding stage and budding stage, which were also similar between tranagenic cotton at budding stage and parental conventional cotton at flower and boll stage. [ Conclusion] Analysis of different carbon sources indi- cated that the main carbon sources utilized by soil microbes were carbohydrates, amino acids, carboxylie acids and polymers.展开更多
基金the National Key Technology R&D Program of China (2006BAD05B06 and 2006BAD 02A14-13)
文摘The quantity of soil microbes and the structure of ammonium oxidizing bacterial （AOB） community were analyzed using the dilution plate counting and most probable number method （MPN）, and denaturing gradient gel electrophoresis （DGGE）, respectively. Fertilizer application tended to increase the number of soil microbes and alter the AOB community compared to the control with no fertilizer application （CK）. Among the eight fertilizer treatments, soil samples from the treatments of mineral fertilizers （e.g., N, P, K） in combination with farmyard manure （M） had greater number.s of soil microbes and more complex structure of AOB community than those receiving mineral fertilizers alone. The principal component analyses （PCA） for ammonium oxidizing bacterial community structure showed that the eight fertilizer treatments could be divided into two PCA groups （PCA1 and PCA2）. For the soil sampled after rice harvest, PCA1 included NP, NM, NPM and NPKM fertilizer treatments, while PCA2 was consisted of CK, N, M and NPK fertilizer treatments. For soil samples collected after wheat harvest, PCA1 was consisted of M, NM, NPM and NPKM fertilizer treatments, while PCA2 was composed of CK, N, NP and NPK fertilizer treatments. For a given rotation, the richness of AOB community in PCA1 was greater than that in PCA2. In addition, AOB community structure was more complex in the soil after rice harvest than that after wheat harvest. The results indicated that different fertilizer treatments resulted in substantial changes of soil microbe number and AOB community. Furthermore, mineral fertilizers （N, NP, NPK） combined with farmyard manure were effective for increasing the quantity of soil microbes, enriching AOB community, and improving the soil biofertility.
基金funded by Innovate UK(100867)with matching funding from several commercial companiesthe financial assistance of the China Scholarship Council(201306300133 and 201506300012)
文摘Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtained from the soils close to the rhizosphere of ‘big＇ and ‘small＇ plants from small plots which exhibited large local heterogeneity in plant vigour. A metabarcoding approach was used to profile bacterial and fungal compositions, using two primer pairs for 16 S ribosomal RNA genes（16S r DNA） and one for the fungal internal transcribed spacer（ITS） region. Of the two 16 S r DNA primer sets, the 341F/805 R resulted in sequences of better quality. A total 28 operational taxonomic units（OTUs） had differential relative abundance between samples from ‘big＇ and ‘small＇ plants. However, plausible biological explanation was only possible for three fungal OTUs. Two were possible phytopathogens： Verticillium spp. and Alternaria alternata although the latter has never been considered as a main pathogen of strawberry in the UK. For samples from ‘small＇ plants, the abundance of these OTUs was much greater than from ‘big＇ plants. The opposite was true for a mycorrhizal OTU. These results suggest that soil microbes related to crop production can be identified using metabarcoding technique. Further research is needed to assess whether A. alternata and Verticillium spp. could affect strawberry growth in the field.
基金This study was funded by the National Key R&D Program(Grant No.2016YFC0501403-3).
文摘In semi-arid areas of China,gravel and sand mulch is a farming technique with a long history.In this study,a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plateau to determine the effects of long term mulch on soil microbial and soil enzyme activities.We found that after long term gravel-sand mulch,compared with bare ground,soil organic matter,alkali nitrogen,conductivity decreased,while pH and soil moisture increased.Urease,saccharase and catalase decreased with increased mulch thickness,while alkaline phosphatase was reversed.The results of Illumina MiSeq sequencing shows that after gravel-sand mulch,the bacterial and fungal community structure was different from bare land,and the diversity was reduced.Compared with bare land,the bacteria Proteobacteria and Acidobacteria abundance increased with increased thickness,and Actinobacteria was opposite.Also,at the fungal genus level,Fusarium abundance was significantly reduced,and Remersonia was significantly increased,compared with bare land.Redundancy analysis(RDA)revealed that soil environmental factors were important drivers of bacterial community changes.Overall,this study revealed some of the reasons for soil degradation after long term gravel-sand mulch.Therefore,it is recommended that the addition of exogenous soil nutrients after long term gravel-sand can help improve soil quality.
基金supported by the National Natural Science Foundation of China(Grant Nos.41807515,41907405,and 51974313)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX21-2118).
文摘The diversity of vegetation configuration is the key to ecological restoration in open-pit coal mine dump.However,the recovery outcomes of different areas with the same vegetation assemblage pattern are completely different after long-term evolution.Therefore,understanding the causes of differential vegetation recovery and the mechanism of plant succession is of great significance to the ecological restoration of mines.Three Pinus tabulaeformis plantations with similar initial site conditions and restoration measures but with different secondary succession processes were selected from the open-pit coal mine dump that has been restored for 30 years.Soil physicochemical properties,enzyme activities,vegetation and microbial features were investigated,while the structural equation models were established to explore the interactions between plants,soil and microbes.The results showed that original vegetation configuration and soil nutrient conditions were altered due to secondary succession.With the advancement of the secondary succession process,the coverage of plants increased from 34.8%to 95.5%(P<0.05),soil organic matter increased from 9.30 g kg^(-1)to 21.13 g kg^(-1)(P<0.05),and total nitrogen increased from 0.38 g kg^(-1)to 1.01 g kg^(-1)(P<0.05).The activities of soil urease and p-glucosidase were increased by 1.7-fold and 53.26%,respectively.Besides,the secondary succession also changed the soil microbial community structure and function.The relative abundance of Nitrospira genus which dominates the nitrification increased 5.2-fold.The results showed that urease andβ-glucosidase promoted the increase of vegetation diversity and biomass by promoting the accumulation of soil organic matter and nitrate nitrogen,which promoted the ecological restoration of mine dumps.
基金supported by the Science and Technology Planning Project of Gansu Province,China(23ZDKA017).
文摘In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soil microbe.However,limited researches were conducted to study the impacts of land-use patterns on the diversity and community of soil microorganisms in this area.The study aimed to investigate soil microbial community diversity and composition using high-throughput deoxyribonucleic acid(DNA)sequencing under different land-use patterns(apricot tree land,apple tree land,peach tree land,corn land,and abandoned land).The results showed a substantial difference(P<0.050)in bacterial alpha-diversity and beta-diversity between abandoned land and other land-use patterns,with the exception of Shannon index.While fungal beta-diversity was not considerably impacted by land-use patterns,fungal alpha-diversity indices varied significantly.The relative abundance of Actinobacteriota(34.90%),Proteobacteria(20.65%),and Ascomycota(77.42%)varied in soils with different land-use patterns.Soil pH exerted a dominant impact on the soil bacterial communities'composition,whereas soil available phosphorus was the main factor shaping the soil fungal communities'composition.These findings suggest that variations in land-use pattern had resulted in changes to soil properties,subsequently impacting diversity and structure of microbial community in the Loess Plateau.Given the strong interdependence between soil and its microbiota,it is imperative to reclaim abandoned lands to maintain soil fertility and sustain its function,which will have significant ecological service implications,particularly with regards to soil conservation in ecologically vulnerable areas.
基金We are grateful to Da-Wen Li and Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences for field assistance. This work was supported by the National Natural Science Foundation of China （31100410, 31470575 and 30830027）, the National Key Technology R＆D Program of China （2011BAD30B00）, and Chinese Academy Science 135 Program （XTBG-T01, F01）.
文摘Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes. Here we tested the hypothesis that soil microbes which can degrade allelochemicals may accumulate in soils over time by adaptation and therefore increase the degradation of allelochemicals and alleviate the allelopathic effects in biological invasions. As expected, soil microbes signifi- cantly decreased the allelopathic effects of leaf leachates of eight in the nine invasive plant species studied. In addition, Ageratina adenophora showed lower allelopathic effects in soil with long or intermediately invasion history than those in soil with short invasion history. The two main allelo- chemicals of the invader were degraded more rapidly with increasing invasion history in the soil. Correspondingly,biomass and activity of the soil microbes were higher in the soils with long invasion history than in that with short invasion history. Our results indicate that soil microbes may graduaUy adapt to the allelochemicals of Ageratina and alleviate its allelopathic effects and thus support the above hypothesis. It is necessary to consider the effects of soil microbes when testing the roles of allelopathy or the novel weapons hypothesis in biological invasions.
基金Natural Science Foundation of China(31060182)Agricultural Biotechnology Research and Application Development of Gansu province(GNSW-2010-18)
文摘Objective To study the effect of autotoxicity and the co-effect of autotoxicity and soil microbes from continuous cropping soil on Angelica sinensis growth, root yield and content of essential oils, and soilmicrobalpopulation. Methods The pot experiments were conducted upon A. sinensis seedlings in continuous cropping soil. At the different growth stages, we determined the seedlings in growth parameters, root yield, content of essential oils, ethanol extract, and cultivable microbial populations in rhizosphere soil. Results A. sinensis seedlings were significantly inhibited in growth, root yield and quality. Compared with the control, the composition and structure of soil microbes were changed and the diversity indexes of bacteria functional groups were reduced in rhizosphere soil ofA. sinensis. A. sinensiscropping problems were more seriously after the treatment with combination of autotoxicity and soil microbes than with autotoxicity alone. Conclusion The autotoxicityand soil microbes from continuous cropping soil of A. sinensis could cause the continuous cropping obstacle together.
基金supported by the Cougar Initiative to Engage(CITE)program(to A.B.G.)the Texas Ecological Laboratory(Ecolab)program(to H.L.)the National Science Foundation(DEB-1754287 to K.M.C.).
文摘Aims Linkages formed through aquatic-terrestrial subsidies can play an important role in structuring communities and mediating ecosystem functions.Aquatic-terrestrial subsidies may be especially important in nutrient-poor ecosystems,such as the freshwater sand dunes surrounding Lake Michigan.Adult midges emerge from Lake Michigan in the spring,swarm to mate and die.Their carcasses form mounds at the base of plants,where they may in crease plant productivity through their nutrient inputs.However,the effect of aquatic-terrestrial subsidies on plant productivity could depend on other biotic interactions.In particular,soil microbes might play a key role in facilitating the conversion of nutrients to plant-available forms or competing for the nutrients with plants.Methods In a greenhouse experiment,we tested how carcasses from lake emerge nt midges(Chironomidae)and soil microbes indepe ndently and interactively influe need the performance of a common dune grass,Calamovilfa longifolia.To determine whether midges influenced abiotic soil properties,we measured how midge additions influe need soil nutrients and soil moisture.Important Findings Midges greatly increased plant biomass,while soil microbes in flue need the magnitude of this effect.In the absence of soil microbes plant biomass was seven times greater with midges than without midges.However,in the presence of soil microbes,plant biomass was only three times greater.The effect of midges might be driven by their nutrient inputs into the soil,as midges contained 100 times more N,10 times more P and 150 times more K than dune soils did.Our results suggest that soil microbes may be competing with plants for these nutrients.In sum,we found that midges can be an important aquatic-terrestrial subsidy that produces strong,positive effects on plant productivity along the shorelines of Lake Michigan,but that the impact of aquatic-terrestrial subsidies must be considered within the context of the complex interactions that take place within ecological communities.
文摘The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current literature, reporting specifically on the impact of production intensification on habitats and yield constraints caused by weeds. Secondly, in alleviating these effects over the short term, ecological measures that enhance species diversity in conserved habitats and promote semi-natural habitats in the agricultural landscape, are discussed. In large-scale intensive agriculture, weed control is predominantly rooted in agrochemical applications in the form of herbicides. Long lasting intensive agricultural practices show discord both with the promotion of the biodiversity of microbes belowground and aboveground and with organisms involved in the breaking down of plant material. The presence of native species in the surroundings, in combination with hedgerows and field margins, with a comparatively intricate and balanced variety of plants in a sheltered environment, are essential for settlement of benign insects, particularly in the face of intensive agricultural production. The promising tactic of advantageous seed predators enables decreased herbicide applications. Crop mosaics arranged to advance compatibility at the landscape scale are important to bolster pollination services and insect management, while ecological variety in the surroundings acts as a safety net for habitat diversity. Weed control in combination with different tactics of vegetation use, comprising cover cropping, hedgerows and field margins, sets up safe havens in the landscape, and improves the diffusion of complementary life forms. Field margins perform a meaningful natural function as point of provision for forage, safe havens and distribution passageways for pollinators and insect predators. Production practices that promote more heterogeneity and combine high density semi-natural safe havens and habitat conservation in agro ecosystems are beneficial to species diversity across trophic levels and contribute to agricultural production stability and food safety.
基金Project supported by the Outstanding Young Scientists Foundation Grant of Shandong Province (No.2005BS08010)China Geological Survey Project (No.1212010310306)Key Project of Natural Science Foundation of Shandong Province (No.Z2006D04).
文摘Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial communities, the soil microbial communities were assessed by plate counts, phospholipid fatty acid （PLFA） and Biolog microplate techniques in five plant communities, i.e., soybean field （SF）, artificial turf （AT）, artificial shrub （AS）, natural shrub （NS）, and maize field （MF） in Jinan, Shandong Province, North China. The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate. Legumes could significantly enhance the number of cultural microorganisms, microbial biomass, and community catabolic diversity. Except for SF dominated by legumes, the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types. These results confirmed that high number of plant species, legumes, and natural vegetation types tend to support soil microbial communities with higher function. The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community. Different research methods led to varied results in this study. The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.
文摘Soil properties, microbial communities and enzyme activities were studied in soil amended with replicase （RP）-transgenic or non-transgenic papaya under field conditions. Compared with non-transgenic papaya, significant differences （P〈0.05） were observed in total nitrogen in soils grown with transgenic papaya. There were also significant differences （P〈0.05） in the total number of colony forming units （CFUs） of bacteria, actinomycetes and fungi between soils amended with RP-transgenic plants and non-transgenic plants. Compared with non-transgenic papaya, the total CFUs of bacteria, actinomycetes and fungi in soil with transgenic papaya increased by 0.43-1.1, 0.21-0.80 and 0.46-0.73 times respectively. Significantly higher （P〈0.05） CFUs of bacteria, actinomycetes and fungi resistant to kanamycin （Km） were obtained in soils with RP-transgenic papaya than those with non-transgenic papaya in all concentrations of Km. Higher resistance quotients for Km＇ （kanamycin resistant） bacteria, actinomycetes and fungi were found in soil planted with RP-transgenic papaya, and the resistance quotients for Km＇ bacteria, actinomycetes and fungi in soils with transgenic papaya increased 1.6-4.46, 0.63-2.5 and 0.75-2.30 times. RP-transgenic papaya and non-transgenic papaya produced significantly different enzyme activities in arylsulfatase （5.4-5.9x）, polyphenol oxidase （0.7-1.4x）, invertase （0.5-0.79x）, cellulase （0.23-0.35x） and phosphodiesterase （0.16-0.2x）. The former three soil enzymes appeared to be more sensitive to the transgenic papaya than the others, and could be useful parameters in assessing the effects of transgenic papaya. Transgenic papaya could alter soil chemical properties, enzyme activities and microbial communities.
基金Project supported by the Foundation for 100 Distinguished Young Scientists, the Chinese Academy of Sciences (No. B010108) the Foundation for the Cooperation Between the Chinese Academy of Sciences Yunnan Province.
文摘Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jinsha River, China. Results showed that Hymenoptera, Araneae and Collembola were the dominant groups of soil animals in the plots studied. The numbers of groups and individuals and density of soil animals in the dry red soil series were higher than those in the Vertisol series, and the numbers of individuals and density of soil animals decreased with the degree of soil degradation. Bacteria dominated microbiocoenosis not only in the dry red soils but also in the Vertisols. Microbial numbers of the dry red soil series were higher than those of Vertisol series, and decreased with the degree of soil degradation. The activities of catalase, invertase, urease and alkaline phosphatase declined with the degradation degree and showed a significant decline with depth in the profiles of both the dry red soils and the Vertisols, but activities of polyphenol oxidase and acid and neutral phosphatase showed the same tendencies only in the Vertisols. It was concluded that the characteristics of soil animals, microorganisms and enzymatic activity could be used as the bio-indicators to show the degradation degree of the dry red soils and Vertisols. Correlation among these soil bio-indicators was highly significant.
基金supported by the National Natural Science Foundation of China (Grant No.31500443)Fujian Province Department of Education Foundation (Grant No.JA15178)
文摘Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in Southeast China, and that two representative tree species （Castanopisi carlesii and Cunninghamia lanceolata） may have different soil microbial community composition. Phospholipids fatty acid analysis （PLFA） of seasonal shifts and was used to assess the effect vegetation types on soil microbial community structure. A total of 22 different PLFAs were identified from all the soil samples. The bacterial PLFAs accounted for 62.37% of the total PLFAs, followed by fungi （28.94%）, and the minimum was actinomycetes （6.41%）. Overall, the level of PLFAs in C. carlesii soil was greater than those in C. lanceolata soil, and significant differences were observed in some seasons. The amounts of total, bacteria, actinomycic and fungal PLFAs significantly changed with the seasons and followed a sequence order （summer 〉 autumn 〉 spring 〉 winter）. The bacteria/fungi PLFAs and G （＋）/G （-） PLFAs of two vegetation types also changed with the seasons and the ratios in summer and autumn were higher than those in spring and winter. The correlation analysis of microbial PLFAs and soil physicochemical properties showed that the total, bacteria, fungal, actinomycic, G （＋） and G （-） PLFAs were significantly positive correlation with TOC, TN, TP, TK and moisture content. We concluded that the seasonal shifts and vegetation types affect soil microbial community composition by changing the soil physicochemical properties.
基金supported by the Sci-technology program of Guangxi Province(No.Guikezhong 1347001)
文摘Soil microbes may be critical players in determining the allelopathic potential of some plants. Low levels of plant community biodiversity in Eucalyptus plantations have been attributed to the allelopathic potential of these tree species. The role of soil microbes in the allelopathic effect of leaf leachates of the hybrid tree Eucalyptus grandis x E. urophylla, was tested in Petri dish assays with Brassica chinensis as a receiver plant. Soils were collected from either a local garden (soil A) or a Eucalyptus plantation (soil B) and half of each soil was sterilized to remove microbes. These soils were then treated with E. grandis x E. urophylla leachates for 0-72 h. Seed germination of B. chinensis was significantly inhibited in soils treated with leaf leachates relative to untreated soils. The inhibitory effect of the leaf leachates was more pronounced in sterilized soils. Total phenolic content was obvious lower in nonsterile leachate-treated soils than in sterile soils. Biomass of B. chinensis was negatively correlated with the total phenolic content in soils. Our findings suggest that soil microbes can alleviate the allelopathic potential of Eucalyptus and thereby its negative impact on plant growth.
基金supported by the National Key Research and Development Program of China (2017YFC0505102)the National Basic Research Programme (973 Programme) of China (2015CB452704)+1 种基金the National Natural Science Foundation of China (No.41571277)the Key Programme of the “Western Light” Talents Cultivation programme of the Chinese Academy of Sciences (2014)
文摘Soil microorganisms are sensitive indicator of soil health and quality. Understanding the effects of vegetation biomass and seasonal change on soil microorganisms is vital to evaluate the soil quality and implement vegetation restoration. This study analyzed the soil phospholipid fatty acids(PLFAs) in fresh and withered Kudzu(Pueraria montana var. lobata) vegetation conditions in different seasons. The results showed that vegetation biomass and seasonal change significantly affected microbial biomass and its community structure. Both fresh and withered Kudzu cover significantly increased soil microbial biomass, and the growth effect of microbes in the soil with fresh Kudzu cover was more obvious than that with withered Kudzu cover. Compared with the dry season, the rainy season significantly increased the microbial biomass and the B/F(the ratio of bacterial to fungal PLFAs) ratio but dramatically reduced the G+/G-(the ratio of gram-positive to gram-negative bacteria PLFAs). Kudzu cover and seasonal change had a significant effect on microbial structure in soil covered by higher vegetation biomass. Furthermore, soil temperature and moisture had different correlations with specific microbial biomass in the two seasons. Our findings highlight the effect of Kudzu vine cover on the soil microenvironment and soil microhabitat, enhancing the soil quality in the Dry-hot Valley of Jinsha River, Southwest China.
基金Supported by Sheng Tongsheng Science and Technology Innovation Foundation of Gansu Agricultural University(GSAU-STS-1427)Open Foundation for Breeding Base of National Key Laboratory Co-founded by Gansu Province+1 种基金the Ministry of Science and Technology-Gansu Provincial Key Lab of Aridland Crop Science(GSCS-2012-14)National Natural Science Foundation of China(31560356)
文摘Soil microbial flora and influencing factors of soil microbes in soil and gravel-sand mixed layer（ SGSML）,roots denseness layer（ RDL）,eluviate layer（ EL） and calcium accumulation layer（ CAL） in gravel-sand mulched fields（ GSMFs） with different gravel mulched years（ 1,6,12,19 and 25 years） were studied. The results showed that in the composition of soil microbes in the GSMFs,the quantity of bacteria was the largest,followed by actinomycetes,while the number of fungi was the smallest. The total quantity of soil microorganisms in the GSMFs dropped rapidly with the increase of soil depth,which was related to the sudden decrease in the quantity of bacteria. The number of microbes in the RDL was larger than that in the SGSML with few roots due to the effects of root distribution. The number of bacteria and actinomycete in the growing season was larger than that in the non-growing season,while the quantity of fungi in the growing season was smaller than that in the non-growing season. The quantity of bacteria and fungi was the largest in the GSMFs which had been mulched with gravel for 6-12 years. With the increase of mulching time,the GSMFs aged gradually,so their quantity reduced gradually. The quantity of actinomycetes was the smallest in the GSMFs which had been mulched with gravel for 6-12 years and increased with the increase of mulching time. The number of soil microbes in the GSMFs had a good correlation with soil moisture content,p H and mulching time. Soil total carbon content was an important factor restricting the quantity of soil microbes in the GSMFs.
基金Supported by Scientific and Technological Innovation Project of Gansu Agriculture and Animal Husbandry Bureaus(GNXC-2012-45)National Natural Science Foundation of China(41161049)
文摘This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.
基金the financial support for this research from the National High-Tech R&D Program of China (2012AA101404)the National Natural Science Foundation of China (51209208, 51479201)
文摘The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen（N）levels are important indicators of the effect of reclaimed water irrigation on environment.This study evaluated soil physicochemical properties and microbial community structure in soils irrigated with reclaimed water and receiving varied amounts of N fertilizer.The results indicated that the reclaimed water irrigation increased soil electrical conductivity（EC）and soil water content（SWC）.The N treatment has highly significant effect on the ACE,Chao,Shannon（H）and Coverage indices.Based on a 16S ribosomal RNA（16S rRNA）sequence analysis,the Proteobacteria,Gemmatimonadetes and Bacteroidetes were more abundant in soil irrigated with reclaimed water than in soil irrigated with clean water.Stronger clustering of microbial communities using either clean or reclaimed water for irrigation indicated that the type of irrigation water may have a greater influence on the structure of soil microbial community than N fertilizer treatment.Based on a canonical correspondence analysis（CCA）between the species of soil microbes and the chemical properties of the soil,which indicated that nitrate N（NO3-–-N）and total phosphorus（TP）had significant impact on abundance of Verrucomicrobia and Gemmatimonadetes,meanwhile the p H and organic matter（OM）had impact on abundance of Firmicutes and Actinobacteria significantly.It was beneficial to the improvement of soil bacterial activity and fertility under 120 mg kg^-1 N with reclaimed water irrigation.
基金supported by the National Natural Science Foundation of China (Grant no.40772112 and 40302024)the President Foundation of Graduate University of the Chinese Academy of Sciences.
文摘Semi-sealed preservation of soil samples at different moisture of 4% and 23 %, respectively, was simulated to observe the variations of soil microbial communities and determine the contents and isotopic compositions of the total organic carbon and total nitrogen on the 7th and 30th day, respectively. The results show that during preservation, the quantity of microbial communities tended to increase first and then decrease, with a wider variation range at higher moisture （23%）. At the moisture content of 23 %, the microbial communities became more active on the 7th day, but less after 30 days, and their activity was stable with little fluctuation at the moisture content of 4%. However, there were no significant changes in the contents and isotopic compositions of the total organic carbon and total nitrogen. During preservation, the responses of soil microbes to the environment are more sensitive to changes in the total nitrogen and organic carbon contents. It is thus suggested that the variations of microbial communities have not exerted remarkable impacts on the isotope compositions of the total nitrogen and total organic carbon.
基金Supported by Major Project for Breeding and Cultivation of Novel GM Varieties(2011ZX08012-005,2011ZX08011-002)Dean Fund of Chinese Academy of Agricultural Sciences(201020)
文摘[Objective] This study aimed to investigation the effects of tranagenic Bt ＋ CpTI cotton cultivation on functional diversity of microbial communities in rhizospbere soils. E Method] By using the Biolog method, a comparative study was conducted on the utilization level of single carbon source by microbes in the rhi- zosphere soils of transgenic Bt ＋ CpTI cotton sGK321 and its parental conventional cotton ＇ Shiyuan 321＇ at different growth stages. [ Result ] The results showed that, compared with the parental conventional cotton, the average well-color development （AWCD） value of micmhial communities in rhizospbere soils of transgenie Bt ＋ CpTI cotton were significantly higher （P 〈 O. 05） at seedling stage and budding stage while significantly lower at flower and boll stage and bell opening stage. Shannon-Wiener diversity index （H） and Simpson dominance index （D） of microbial communities in rhlzesphere soils of transgenic cotton and conventional cotton varied with the different growth stages, whereas the Shannon-Wiener evenness index （E） showed no significant difference between transgenie cotton and convention- al cotton at four growth stages. Principal component analysis indicated that the patterns of carbon source utilization by microbial communities in rhizospbere soils were similar among transgenic cotton at seeding stage and flower and boll stage and parental conventional cotton at seeding stage and budding stage, which were also similar between tranagenic cotton at budding stage and parental conventional cotton at flower and boll stage. [ Conclusion] Analysis of different carbon sources indi- cated that the main carbon sources utilized by soil microbes were carbohydrates, amino acids, carboxylie acids and polymers.
