To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agric...To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agricultural Experimental Station of Chinese Academy Sciences in the Low Plain of the North China Plain,comprising four irrigation treatments:irrigation once at the jointing stage for winter wheat with irrigation water containing salt at fresh water,3,4 and 5 g·L^(–1),and maize irrigation at sowing using fresh water.Manure application was conducted under all irrigation treatments,with treatments without manure application used as controls.The results showed that under long-term irrigation with saline water,the application of manure increased the soil organic matter content,exchangeable potassium,available phosphorus,and total nitrogen content in the 0–20 cm soil layer by 46.8%,117.0%,75.7%,and 45.5%,respectively,compared to treatments without manure application.The application of manure reduced soil bulk density.It also increased the proportion of water-stable aggregates and the abundance of bacteria,fungi,and actinomycetes in the tillage soil layer compared to the controls.Because of the salt contained in the manure,the application of manure had dual effects on soil salt content.During the winter wheat season,manure application increased soil salt content.The salt content was significantly reduced during the summer maize season,owing to the strong salt-leaching effects under manure application,resulting in a smaller difference in salt content between the manure and non-manure treatments.During the summer rainfall season,improvements in soil structure under manure application increased the soil desalination rate for the 1 m top soil layer.The desalination rate for 0–40 cm and 40–100 cm was averagely by 39.1%and 18.9%higher,respectively,under manure application as compared with that under the nomanure treatments.The yield of winter wheat under manure application was 0.12%lower than that of the control,owing to the higher salt content during the winter wheat season.In contrast,the yield of summer maize improved by 3.9%under manure application,owing to the increased soil nutrient content and effective salt leaching.The results of this study indicated that manure application helped maintain the soil physical structure,which is important for the long-term use of saline water.In practice,using manure with a low salt content is suggested to reduce the adverse effects of saline water irrigation on soil properties and achieve sustainable saline water use.展开更多
Green manuring is essential for improving soil quality and nutrient uptake.With the gradual depletion of phosphorus(P)resources,more attention is being paid to the role of green manures in cultivation systems,such as ...Green manuring is essential for improving soil quality and nutrient uptake.With the gradual depletion of phosphorus(P)resources,more attention is being paid to the role of green manures in cultivation systems,such as maize-green manure intercropping,to find possible pathways for enhancing soil P utilization.A maize-green manure intercropping experiment was started in 2009 to investigate the effects and mechanisms for enhancing P uptake and yield in maize.Three species of green manures(hairy vetch(HV),needle leaf pea(NP),sweet pea(SP))and a sole maize treatment(CK)were used,resulting in four treatments(CK,HVT,NPT,and SPT)in the experiment.During 2020-2023,the intercropping treatments enhanced maize yields in 2020 and 2021,particularly in HVT with increases of 13.7%(1.96 t ha^(-1))and 13.0%(2.13 t ha^(-1))compared with CK,respectively.Grain P accumulation of maize was significantly higher in the intercropping treatments than CK in 2020,2021,and 2023,and with an average increase of 10.6%over the four years(5.2% for NPT,10.8% for SPT and 15.9% for HVT)compared with CK.Intercropping promoted maize growth with a greater root length density and a higher organic acid release rate.HVT changed the soil properties more dramatically than the other treatments,with increases in the acid phosphatase and alkaline phosphatase activities of 29.8 and 38.5%,respectively,in the topsoil(0-15 cm),while the soil p H was reduced by 0.37 units compared to CK(p H=8.44).Intercropping treatments facilitated the conversion of non-labile P to mod-labile P and stimulated the growth of soil bacteria in the topsoil.Compared with CK,the relative abundance of Gemmatimonadota,known for accumulating polyphosphate,and Actinobacteriota,a prominent source of bioactive compounds,increased significantly in the intercropping treatments,especially in HVT and SPT.A PLS-PM analysis showed that intercropping promoted soil P mobilization and the enrichment of beneficial bacteria by regulating maize root morphology and physiology.Our results highlight that maize-green manure intercropping optimizes root traits,soil properties and bacterial composition,which contribute to greater maize P uptake and yield,providing an effective strategy for sustainable crop production.展开更多
Atrazine,a persistent triazine herbicide,poses environmental and health risks.This study examines the synergis-tic remediation of atrazine-contaminated soil using green manure plant(GMP)hairy vetch(Vicia villosa Roth,...Atrazine,a persistent triazine herbicide,poses environmental and health risks.This study examines the synergis-tic remediation of atrazine-contaminated soil using green manure plant(GMP)hairy vetch(Vicia villosa Roth,VV)and the exogenous atrazine-degrading bacterium Arthrobacter sp.ATR1.Soil samples contaminated with atrazine at 5 and 20 mg/kg were treated with control(CK),ATR1(CKatr),hairy vetch(VV),and combined hairy vetch and ATR1 remediation(VVatr).The results indicated that the VVatr treatment exhibited the most effective atrazine removal,achieving enhancements of 56.12%at 5 mg/kg and 54.51%at 20 mg/kg compared to CK after 28 days.Soil enzyme activities,including urease,sucrase,and alkaline phosphatase,were significantly elevated in the VV and VVatr treatments,contributing to improved soil quality.Additionally,the CKatr,VV,and VVatr treat-ments enhanced bacterial diversity and richness while altering the microbial community structure.The VV and VVatr treatments notably enriched indigenous atrazine-degrading bacteria and nitrogen-fixing bacteria in the rhizosphere.This microbial enrichment upregulated the Atrazine degradation and Nitrogen metabolism pathways,facilitating both atrazine removal and nitrogen cycling in the soil.And VVatr treatment promoted the stability of the microbial network and enhanced the cooperative relationship between key indigenous atrazine-degrading and nitrogen-fixing bacteria.These findings explain the mechanism of plantmicrobe combined remediation of atrazine-contaminated soil from the perspective of rhizosphere microorganisms and offer a theoretical basis for the practical application of this method.展开更多
The lateral transport of labile organic carbon represents a critical pathway for soil organic carbon(SOC) loss,reducing organic carbon sequestration and increasing the risk of waterbody pollution.Livestock manure appl...The lateral transport of labile organic carbon represents a critical pathway for soil organic carbon(SOC) loss,reducing organic carbon sequestration and increasing the risk of waterbody pollution.Livestock manure application on croplands serves as a common fertilizer reduction practice to sustain crop yields,enhance SOC sequestration,and reduce water erosion.However,limited quantitative assessments have examined the effects of livestock manure substitution on labile organic carbon lateral loss and fluxes in long-term experiments.This study conducted a three-year field investigation on subtropical sloping croplands to assess the impact of livestock manure substitution on dissolved organic carbon(DOC) and particulate organic carbon(POC) loss via surface runoff,interflow and eroded sediments.There are four treatments:no fertilization(CK);chemical nitrogen fertilizer(SF),40% nitrogen substitution with pig manure(PMF),and 100% nitrogen substitution from pig manure(PM).Compared to SF treatment,long-term livestock manure substitution in PMF and PM treatments significantly(P<0.05) reduced annual cumulative surface runoff fluxes by 13.5 and 21.6%,respectively.Manure applications decreased annual sediment fluxes by 12.9 and 19.1%,respectively.Soil water stable aggregates for mean weight diameter(MWD) increased significantly by 37.7 and 73.6%.Annual cumulative POC loss flux via eroded sediment under PMF and PM treatments increased significantly(P<0.05) by 61.1 and 47.9%,respectively.The labile organic carbon loss fluxes,including DOC and POC losses,under PMF and PM treatments increased significantly(P<0.05) by 11.9 and 31.4%,respectively.These results demonstrate that while water erosion intensity decreases due to enhanced soil aggregate stability,the risk of labile organic carbon loss increases after long-term livestock manure substitution in subtropical sloping croplands.Future research should examine labile organic carbon lateral migration under various soil types and slope gradients for livestock manure application in subtropical agricultural ecosystem croplands to better understand extreme rainfall effects.展开更多
Enhancing soil organic carbon(SOC)stocks is a key aspect of modern agriculture,but whether this can be achieved by incorporating legume green manure crops in cereal production to substitute synthetic N fertilizers is ...Enhancing soil organic carbon(SOC)stocks is a key aspect of modern agriculture,but whether this can be achieved by incorporating legume green manure crops in cereal production to substitute synthetic N fertilizers is unknown.This study used a six-year(2017-2022)field study to explore the impacts of intercropping green manure with maize and reducing nitrogen fertilization on SOC stocks,while specifically focusing on the relationship between aggregate composition and carbon sequestration.Maize intercropped with common vetch(M/V),maize intercropped with rapeseed(M/R),and sole maize(M),were each tested at conventional(N2,360 kg ha^(-1))and reduced(N1,270 kg ha^(-1),25% reduced)N application rates.Soil was sampled in 2020,2021,and 2022.Compared with sole maize,intercropping with green manure(M/V and M/R)significantly increased SOC stocks which compensated for any negative effect due to the 25% reduction in N application.Based on 3-year averages,intercropping with M/V and M/R increased the SOC content compared to sole maize(M)by 12.1 and 9.1%,respectively,with intercropping further mitigating the negative impact of reduced nitrogen application.There was no significant difference between M/V and M/R.The SOC content at N1 was reduced by 9.3-10.5%compared to that at N2 in sole maize,but the differences in SOC stocks between N1 and N2 were not significant in the intercropping patterns(M/V and M/R).The intercropped M/V and M/R showed 20.9 and 16.3% higher SOC contents compared to sole maize at N1,with no differences at N2.Intercropping green manure led to a 5.3% greater SOC in the 0-20 cm depth soil in 2022 compared to that in 2020,due to the cumulative effect of two years of green manure intercropping.Intercropping green manure(M/V and M/R)increased the proportion of macroaggregates(>0.25 mm)and aggregate stability while reducing the proportion of microaggregates compared to sole maize under the N1 application.Structural equation modeling indicated that cropping patterns and nitrogen application levels mainly affect SOC indirectly by regulating the composition of macroaggregates and aggregate organic carbon(AOC).Correlation analysis further revealed that the composition of macroaggregates is significantly and positively correlated with the SOC content(R^(2)=0.64).In addition,intercropping green manure can maintain high crop yields by increasing SOC under reduced chemical nitrogen application.The results of this study show that intercropping green manure with grain crops can be a viable measure for increasing SOC sinks and maize productivity by optimizing the aggregate composition with reduced N application in the Hexi Oasis Irrigation Area.展开更多
Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse...Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils.展开更多
Biochar and animal manure application can improve crop yields in salt-affected soil.Previous studies have primarily applied biochar and animal manure either alone or at fixed ratios,while their combined effects with v...Biochar and animal manure application can improve crop yields in salt-affected soil.Previous studies have primarily applied biochar and animal manure either alone or at fixed ratios,while their combined effects with varying combination proportions are still unclear.To address this knowledge gap,we performed a 2-a experiment(2023-2024)in a salinized cotton field in Wensu County of Xinjiang Uygur Autonomous Region of China with the following 6 treatments:control;application of biochar(10t/hm^(2))alone(BC100%);application of cow manure(10 t/hm^(2))alone(CM100%);application of 70%biochar(7 t/hm^(2))combined with 30%cow manure(3 t/hm^(2))(BC70%+CM30%);application of 50%biochar(5 t/hm^(2))combined with 50%cow manure(5 t/hm^(2))(BC50%+CM50%);and application of 30%biochar(3 t/hm^(2))combined with 70%cow manure(7 t/hm^(2))(BC30%+CM70%).By measuring soil pH,electrical conductivity,soil organic matter,available phosphorus,available potassium,and available nitrogen at 0-20 and 20-40 cm depths,as well as yield components and cotton yield in 2023 and 2024,this study revealed that soil nutrients in the 0-20 cm depth were more sensitive to the treatment.Among all the treatments,BC50%+CM50%treatment had the highest value of soil pH(9.63±0.07)but the lowest values of electrical conductivity(161.9±31.8μS/cm),soil organic matter(1.88±0.27 g/kg),and available potassium(42.72±8.25 mg/kg)in 2024.Moreover,the highest cotton yield(5336.63±467.72 kg/hm^(2))was also observed under BC50%+CM50%treatment in 2024,which was 1.9 times greater than that under the control treatment.In addition,cotton yield in 2023 was jointly determined by yield components(density and number of cotton bolls)and soil nutrients(available phosphorus and available potassium),but in 2024,cotton yield was only positively related to yield components(density,number of cotton bolls,and single boll weight).Overall,this study highlighted that in salt-affected soil,the combination of biochar and cow manure at a 1:1 ratio is recommended for increasing cotton yield and reducing soil salinity stress.展开更多
Background The rapid development of intensive layer breeding has intensified odor pollution that must be paid attention to for the green transformation of the industry. This study used Jingfen No.6 laying hens as the ...Background The rapid development of intensive layer breeding has intensified odor pollution that must be paid attention to for the green transformation of the industry. This study used Jingfen No.6 laying hens as the model to systematically evaluate the regulatory effect of compound microalgal powder(Chlorella vulgaris:Spirulina platensis:Haematococcus pluvialis = 3:1:1, 1:3:1, 1:1:3) on ammonia(NH3) emissions from laying hen manure.Results Through analysis of the static NH3production in manure, it was found that the NH3emissions within 24 h in the experimental group with 0.50% compound microalgal powder added were reduced to 6.27–16.84 mg(vs. control: 28.29 mg), achieving a 40.47%–77.84% reduction. GC/MS and 16S rRNA sequencing analyses indicated that the compound microalgal powder intervened in the remodeling of the microbial community and nitrogen metabolism network in manure, driving the transformation from inorganic nitrogen to organic nitrogen, mitigated the proliferation of NH3-producing bacteria(such as Escherichia coli, Klebsiella pneumoniae, Kurthia, and Proteus), and increased the abundance of acid-producing bacteria(such as Leuconostocaceae and Lactobacillaceae). The Spirulina platensis powder group had the best emission reduction effect(reduced by 77.84%), and its mechanism was closely related to the mitigation of Gram-negative bacteria activity by phycocyanin and increased synthesis of aromatic compounds, such as 2,3,5-trimethyl-6-ethylpyrazine.Conclusions This study revealed the mechanism by which the compound microalgal powder reduces NH3emissions by regulating the proliferation of acid-producing bacteria, reshaping the nitrogen metabolism network, and mitigating the activity of NH3-producing bacteria, while providing theoretical and data support for the development of environmentally friendly feed.展开更多
Hydrothermal carbonization(HTC)is a promising technology for the coversion of swine manure(SM)for hydrochars(HCs).Currently,information on the humification of organic matter is limited during the HTC of SM,and its pot...Hydrothermal carbonization(HTC)is a promising technology for the coversion of swine manure(SM)for hydrochars(HCs).Currently,information on the humification of organic matter is limited during the HTC of SM,and its potential correlation with the passivation of heavy metals(HMs)remains unclear,which is crucial referece for the land application of SM-derived HCs.This study systematically investigated the humification of organic matter and the passivation of HMs during the HTC of SM and then explored their intrinsic connection.The HTC treatment can enhance the humification of organic matter,and the HCs obtained at 240℃ had the best humification effect,with the highest content of humus(83.84 mg·g^(-1)versus 41.97 mg·g^(-1)in SM)and humification rate(28.89%versus 15.73%in SM).Dissolved organic carbons(DOC)and readily oxidized organic carbons(ROC)were more easily degraded in the HTC of SM,and part was further converted into inactive organic carbon.HMs(Cu,Zn,Pb,and Cr)were enriched in HCs,but all HMs were largely passivated.The ecological risk of multi-HMs was reduced from moderate risk in SM to low risk in HCs.The percentages of HMs in exchangeable/acid-soluble forms were positively correlated with the contents of DOC and negatively correlated with the ratio of humic acids to fulvic acids(P<0.05).It was inferred that the humification of organic matter promoted the passivation of HMs in the HTC of SM.This study provided deeper insights into the humification of organic matter and it's intrinsic correlation with HMs-passivation during the HTC of SM.展开更多
The land application of livestock manure has been widely acknowledged as a beneficial approach for nutrient recycling and environmental protection.However,the impact of residual antibiotics,a common contaminant of man...The land application of livestock manure has been widely acknowledged as a beneficial approach for nutrient recycling and environmental protection.However,the impact of residual antibiotics,a common contaminant of manure,on the degradation of organic compounds and nutrient release in Eutric Regosol is not well understood.Here,we studied,how oxytetracycline(OTC)and ciprofloxacin(CIP)affect the decomposition,microbial community structure,extracellular enzyme activities and nutrient release from cattle and pig manure using litterbag incubation experiments.Results showed that OTC and CIP greatly inhibited livestock manure decomposition,causing a decreased rate of carbon(28%-87%),nitrogen(15%-44%)and phosphorus(26%-43%)release.The relative abundance of gramnegative(G-)bacteria was reduced by 4.0%-13%while fungi increased by 7.0%-71%during a 28-day incubation period.Co-occurrence network analysis showed that antibiotic exposure disrupted microbial interactions,particularly among G-bacteria,G+bacteria,and actinomycetes.These changes in microbial community structure and function resulted in decreased activity of urease,β-1,4-N-acetyl-glucosaminidase,alkaline protease,chitinase,and catalase,causing reduced decomposition and nutrient release in cattle and pig ma-nures.These findings advance our understanding of decomposition and nutrient recycling from manure-contaminated antibiotics,which will help facilitate sustainable agricultural production and soil carbon sequestration.展开更多
Weeds have a negative impact on agricultural production by competing with cultivated crops for resources and fostering conditions conducive to disease and insect pest dissemination.Hence,optimal weed management is of ...Weeds have a negative impact on agricultural production by competing with cultivated crops for resources and fostering conditions conducive to disease and insect pest dissemination.Hence,optimal weed management is of paramount importance for sustainable agricultural.In this study,the ability of four distinct green manure species to suppress weeds was determined in a field experiment conducted in Chongqing,Southwest China.After cultivating the green manure species,the weed density and diversity were monitored over the following year.The findings highlight a notable trend in the suppressive ability of green manures,with increased suppression observed from November to March,an optimal level observed from March to May,and a gradual decline observed thereafter.Poaceae(Lolium perenne L.)demonstrated the highest efficacy in suppressing weeds.The meta-analysis underscore the exceptional suppressive effects of poaceous green manures on weed as well and prove sustained planting for three or more consecutive years yielded superior weed suppression outcomes.Green manure had the most prominent inhibitory effect on poaceae weeds,followed by Polygonaceae and Caryophyllaceae.The field experiment also investigated the effect of green manures on weed community composition,they increased in the proportion of perennial weeds within these communities.This study offers valuable insights that can guide policymakers,agricultural experts,and farmers in devising effective weed management strategies.By highlighting the potential benefits of green manures and unraveling their nuanced impact,this study contributes to the arsenal of sustainable agricultural practices.展开更多
Manure application as fertilizer can increase environmental exposure risk,as antibiotics,antibiotic resistance bacteria(ARB),and antibiotic resistant genes(ARGs)can be transmitted to agricultural fields,and adjacent n...Manure application as fertilizer can increase environmental exposure risk,as antibiotics,antibiotic resistance bacteria(ARB),and antibiotic resistant genes(ARGs)can be transmitted to agricultural fields,and adjacent natural systems.Understanding how specific antibiotics and ARGs respond within different manure fractions during on-farm management is limited.The study objective was to conduct a mass flow analysis determining the fate of antibiotic resistance factors(antibiotics,ARGs,and ARB)through solid-liquid separation,with the solid fraction continuing through a bedding recovery unit(BRU)via high temperature rotary composting for use of the manure solids as dairy cow bedding.The results show that most of the manure mass containing the antibiotic resistance factors went untreated following solid-liquid separation,with 95%of the mass leaving the separator as a liquid and pumped to a storage lagoon for field application and 5%proceeding to BRU processing.The tetracyclines and tulathromycin sorbed to the manure solids,while the beta lactams,ampicillin,and benzylpenicilloic acid were only found in the liquid fraction.The removal of antibiotic residuals during the BRU composting was insignificant,yet 40%-73%of the antibiotics were in the liquid fraction.The BRU composting was 100%effective in removing the ARB examined.Five of the eight ARGs(intl1,sul1,tetQ,tetX,and tetM)had significant reduction(>95%)following the BRU composting treatment.While the three other ARGs(tetW,ermB,and bla2)remained constant despite treatment.This study highlighted the importance of examining manure management from a mass balance perspective and understanding antibiotic resistance risk factors.展开更多
Improving crop yield and N utilization while mitigating environmental pollution is a key goal in sustainable agriculture.Integrating green manure with reduced chemical N application is a promising strategy to enhance ...Improving crop yield and N utilization while mitigating environmental pollution is a key goal in sustainable agriculture.Integrating green manure with reduced chemical N application is a promising strategy to enhance N utilization efficiency and minimize reactive N losses.However,the agronomic mechanisms through which green manure incorporation affects soil N retention and N loss under reduced N application remain unclear.This study aimed to uncover the compensatory mechanisms of green manure in improving wheat yield and N utilization under reduced N application,and to identify the principles behind reduced N loss in wheat fields.We conducted a split-plot experiment in the Hexi Oasis irrigation area of Northwest China from 2019 to 2024,using two cropping systems(W,fallow after wheat;W-G,green manure returning after wheat)combined with three N application levels(N1,local conventional N application rate;N2,N-reduction 15%;N3,N-reduction 30%).Our results demonstrated that green manure returning improved soil quality and compensated for the yield and N use efficiency losses caused by 15%chemical N reduction.Specifically,compared to the W-N1,W-GN2 increased soil organic matter content and soil water content by 6.5%and 9.4%,respectively,while reducing soil bulk density and pH by 8.9%and 6.7%.Meanwhile,W-GN2 increased soil nitrate N and total N content in the 0–40 cm soil layer by 8.4%and 8.7%,respectively.Moreover,W-GN2 reduced NH3 volatilization by 13.8%,N_(2)O emissions by 8.8%,and N leaching by 9.4%.It also enhanced microbial biomass N by 50.7%,urease activity by 10.2%,and decreased nitrate and nitrite reductase activities by 19.9%and 32.6%,respectively.Additionally,W-GN2 improved soil bacterialα-diversity and increased the abundance of functional bacteria.Green manure can sustain wheat yield and improve N utilization efficiency under reduced chemical N input by improving the soil environment,enhancing soil N retention and minimizing N losses,which presents a sustainable,yield-stabilizing strategy for Oasis agroecosystems in northwestern China.展开更多
Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(...Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(AMF)from different winter planting green manures on the soil properties and post-cropping rice production remain unclear.In this study,the soil AMF communities of three common winter planting patterns in southern China,winter fallow,winter ryegrass(Lolium multiflorum L.),and winter Chinese milk vetch(Astragalus sinicus L.),were explored and their effects on post-cropping rice production were investigated.Compared with winter fallow,the winter ryegrass and winter Chinese milk vetch patterns could alleviate soil acidification,significantly increase soil AMF spore density,and improve the soil AMF community structure.Based on sterilized soil,rice production indicators such as thousandseed weight,theoretical yield,and the grain amylose and total sugar contents of rice inoculated with AMF spores from winter Chinese milk vetch soil were 6.68–53.57%higher than those without AMF inoculation.Rice panicle weight,seed setting rate,and theoretical yield were 15.38–22.71%higher in the treatment with AMF spores from winter ryegrass soil than in the treatments with no AMF inoculation.In addition,the protein,amylose,and total sugar contents of rice grains were 14.92,104.82,and 802.23 mg kg^(–1),respectively,which were 31.31,14.25 and 34.47%higher than those without AMF inoculation.The AMF community dominated by Glomus and Acaulospora in winter Chinese milk vetch had a more positive effect on the improvement of rice yield,while the AMF community dominated by Glomus in winter ryegrass soil was more conducive to rice quality improvement.These findings have revealed the critical role of AMF communities from green manure in rice production,which lays the theoretical basis for a promising strategy to promote the sustainable development of southern winter agriculture.展开更多
As a renewable energy source,the thermal conversion of poultry manure,is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions.Currently,pr...As a renewable energy source,the thermal conversion of poultry manure,is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions.Currently,pressurized gasification of poultry manure is still a novel research field,especially when combined with a novel technological route of oxy-fuel gasification.Oxy-fuel gasification is a newly proposed and promising gasification technology for power generation that facilitates future carbon capture and storage.In this work,based on a commercially operated industrial-scale chicken manure gasification power plant in Singapore,we presented an interesting first exploration of the coupled pressurization technology for oxy-fuel gasification of poultry manure using CFD numerical simulation,analyzed the effects of pressure and oxygen enrichment concentration as well as the coupling mechanism between them,and discussed the conversion and emission of nitrogen-and sulfur-containing pollutants.The results indicate that under oxy-fuel gasification condition(Oxy-30,i.e.,30%O_(2)/70%CO_(2)),as the pressure increases from 0.1 to 0.5 MPa,the CO concentration in the syngas increases slightly,the H_(2)concentration increases to approximately 25%,and the CH4 concentration(less than 1%)decreases,resulting in an increase in the calorific value of syngas from 5.2 to 5.6 MJ·m^(-3).Compared to atmospheric pressure conditions,a relatively higher oxygen-enriched concentration interval(Oxy-40 to Oxy-50)under pressurized conditions is advantageous for autothermal gasification.Pressurization increases NO precursors production and also promotes homogeneous and heterogeneous reduction of NO,and provides favorable conditions for self-desulfurization.This work offers reference for the realization of a highly efficient and low-energy-consumption thermochemical treatment of livestock manure coupled with negative carbon emission technology.展开更多
A critical challenge for global food security and sustainable agriculture is enhancing crop yields while reducing chemical N inputs.Improving N use efficiency in crops is essential for increasing agricultural producti...A critical challenge for global food security and sustainable agriculture is enhancing crop yields while reducing chemical N inputs.Improving N use efficiency in crops is essential for increasing agricultural productivity.The aim of this study was to evaluate the impacts of intercropping maize with leguminous green manure on grain yield and N utilization under reduced N-fertilization conditions.A field experiment with a split-plot design was conducted in northwestern China from 2018 to 2021.The main plots consisted of two cropping systems:maize-common vetch intercropping(IM)and sole maize(SM).The subplots had three N levels:zero N application(N0,0 kg ha^(-1)),a 25%reduction from the traditional chemical N supply(N1,270 kg ha^(-1)),and the traditional chemical N supply(N2,360 kg ha^(-1)).The results showed that the negative effects of N reduction on maize grain yield and N uptake were compensated by intercropping leguminous green manure,and the improvements increased with cultivation years.The integrated system involving maize-leguminous green manure intercropping and a reduced N supply enhanced N translocation from maize vegetative organs to grains and increased the nitrate reductase and glutamine synthetase activities in maize leaves.The supercompensatory effect in maize leaves increased year by year,reaching values of 16.1,21.3,and 25.5%in 2019,2020,and 2021,respectively.These findings suggest that intercropping maize with leguminous green manure under reduced chemical N input can enhance N assimilation and uptake in maize.By using this strategy,chemical fertilizer is effectively replaced by leguminous green manure,thereby improving N use efficiency and maintaining stable yields in the maize-based intercropping system.展开更多
Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential.This work presents an innovative research exploration-coupling coal pressurized fluidiz...Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential.This work presents an innovative research exploration-coupling coal pressurized fluidized bed oxy-fuel combustion technology with energy utilization of poultry manure as a renewable and carbon-neutral fuel,in order to capture CO_(2)and solve the problem of poultry manure treatment simultaneously.In this study,a stable co-combustion of coal and chicken manure in a laboratory-scale pressurized fluidized bed under typical oxy-fuel condition(30%O_(2)/70%CO_(2),i.e.,Oxy-30)is achieved.The key parameters including the combustion pressure(0.1-0.5 MPa)and chicken-manure proportion(0%to 100%)and their impacts on fundamental combustion efficiency,carbon conversion,nitrogen and sulfur pollutant emissions,and residue ash characteristics have been investigated.The result show that pressurization favors an increase in the CO_(2)enrichment concentration and fluidized bed combustion efficiency.During co-combustion under 0.1 and 0.3 MPa,the CO_(2)concentration in the flue gas is the highest when the chicken manure blending ratio(M_(pm))is 25%.Although the NO emissions fluctuate and even increase as Mpm increases,the co-combustion of coal and chicken manure exhibits a synergistic effect in reducing NO conversion rate(XNO).The effect of pressurization on reducing NO emission is significant,XNO at M_(pm)=25%decreasing from 15%to 5%as the pressure(P)increases from 0.1 to 0.5 MPa.As P increases from 0.1 to 0.5 MPa and Mpm increases from 0%to 50%,the SO_(2) emissions and conversion rates decrease.The self-desulfurization process plays an important role in the reduction of SO_(2) emissions during pressurized oxy-fuel co-combustion.The aim of this work is to advance the development and application of pressurized fluidized bed oxy-fuel co-combustion technology and promote a circular bioeconomy and carbon-free waste management for biomass derived from livestock manure.展开更多
The effcacy of integrating green manure in arid irrigation regions to enhance maize yield and nitrogen(N)uptake effciency has been extensively explored.However,limited research has delineated the contribution of green...The effcacy of integrating green manure in arid irrigation regions to enhance maize yield and nitrogen(N)uptake effciency has been extensively explored.However,limited research has delineated the contribution of green manure N vs.soil N on crop N utilization effciency.This study integrated feld experiments with micro-plot experiments to examine green manure(common vetch)management practices for achieving high maize yield and N uptake.In a micro-plot experiment,^(15)N technology was utilized to label green manure crops.Five treatments were applied in the research methodology:conventional tillage without green manure as the control(CT),tillage with total green manure incorporation(TG),no-tillage with total green manure mulching(NTG),tillage with only root incorporation(T),and no-tillage with removal of aboveground green manure(NT).The results of the micro-plot experiment were consistent with those observed in the feld,demonstrating that the utilization of green manure substantially increased maize yield and nitrogen uptake effciency(NUPE)compared to CT.In particular,under NTG,N uptake by maize from green manure was higher than NT and T,accounting for 59.1%of maize N uptake.Furthermore,applying NTG boosted the NUPE of soil N in maize to 50.7%,higher than TG by 5.5%.Meanwhile,it decreased the proportion of soil N in the maize.The difference between NTG and TG was primarily shown in the maize grains.For N transport in the soil,NTG decreased N loss while increasing soil N retention.Also,it facilitated the mineralization of soil organic N before the fowering stage.In conclusion,adopting no-tillage with total green manure mulching increased N uptake from green manure and the soil and decreased the proportion of soil-derived N in maize.展开更多
Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures(3 chicken manures, 3 pig manures and 3 cattle manures) from different ...Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures(3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that significant(P〈0.01 or P〈0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.展开更多
[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis fo...[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis for cattle manure harmless treatment.[Method] Both experimental groups supplemented with 2.0% bacterial inhibitor and control groups without bacterial inhibitor were cultured under different temperatures(20,30,37,50,60 ℃)to determine the optimal composing temperature.Under 30 ℃,different bacterial inhibitor doses(0,2.0%,2.5%,3.0%)were added into the compost to obtain the optimal bacterial inhibitor addition dose.[Result] 30,50 and 60 ℃ were ideal temperatures for sterilization of E.coli.Under 30 ℃,E.coli couldn't be detected in 2.5% dose group and 3.0% dose group after culture for 48 h,demonstrating no less than 2.5% bacterial inhibitor should be added.[Conclusion] It has an important significance to enhance the sterilization effects on E.coli by adding CaCN2 into cattle manure compost especially in winter.展开更多
基金supported by National Key R&D Program of China (2022YFD1900104)。
文摘To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agricultural Experimental Station of Chinese Academy Sciences in the Low Plain of the North China Plain,comprising four irrigation treatments:irrigation once at the jointing stage for winter wheat with irrigation water containing salt at fresh water,3,4 and 5 g·L^(–1),and maize irrigation at sowing using fresh water.Manure application was conducted under all irrigation treatments,with treatments without manure application used as controls.The results showed that under long-term irrigation with saline water,the application of manure increased the soil organic matter content,exchangeable potassium,available phosphorus,and total nitrogen content in the 0–20 cm soil layer by 46.8%,117.0%,75.7%,and 45.5%,respectively,compared to treatments without manure application.The application of manure reduced soil bulk density.It also increased the proportion of water-stable aggregates and the abundance of bacteria,fungi,and actinomycetes in the tillage soil layer compared to the controls.Because of the salt contained in the manure,the application of manure had dual effects on soil salt content.During the winter wheat season,manure application increased soil salt content.The salt content was significantly reduced during the summer maize season,owing to the strong salt-leaching effects under manure application,resulting in a smaller difference in salt content between the manure and non-manure treatments.During the summer rainfall season,improvements in soil structure under manure application increased the soil desalination rate for the 1 m top soil layer.The desalination rate for 0–40 cm and 40–100 cm was averagely by 39.1%and 18.9%higher,respectively,under manure application as compared with that under the nomanure treatments.The yield of winter wheat under manure application was 0.12%lower than that of the control,owing to the higher salt content during the winter wheat season.In contrast,the yield of summer maize improved by 3.9%under manure application,owing to the increased soil nutrient content and effective salt leaching.The results of this study indicated that manure application helped maintain the soil physical structure,which is important for the long-term use of saline water.In practice,using manure with a low salt content is suggested to reduce the adverse effects of saline water irrigation on soil properties and achieve sustainable saline water use.
基金supported financially by the National Key Research&Development Program of China(2021YFD1700200)the National Natural Science Foundation of China(32402686)+3 种基金the Earmarked Fund for China Agriculture Research System(CARS-22)the Fundamental Research Funds for Central Non-profit Scientific Institution,China(1610132022013)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciencesthe China National Crop Germplasm Resources Platform for Green Manure(NICGR-2024-19)。
文摘Green manuring is essential for improving soil quality and nutrient uptake.With the gradual depletion of phosphorus(P)resources,more attention is being paid to the role of green manures in cultivation systems,such as maize-green manure intercropping,to find possible pathways for enhancing soil P utilization.A maize-green manure intercropping experiment was started in 2009 to investigate the effects and mechanisms for enhancing P uptake and yield in maize.Three species of green manures(hairy vetch(HV),needle leaf pea(NP),sweet pea(SP))and a sole maize treatment(CK)were used,resulting in four treatments(CK,HVT,NPT,and SPT)in the experiment.During 2020-2023,the intercropping treatments enhanced maize yields in 2020 and 2021,particularly in HVT with increases of 13.7%(1.96 t ha^(-1))and 13.0%(2.13 t ha^(-1))compared with CK,respectively.Grain P accumulation of maize was significantly higher in the intercropping treatments than CK in 2020,2021,and 2023,and with an average increase of 10.6%over the four years(5.2% for NPT,10.8% for SPT and 15.9% for HVT)compared with CK.Intercropping promoted maize growth with a greater root length density and a higher organic acid release rate.HVT changed the soil properties more dramatically than the other treatments,with increases in the acid phosphatase and alkaline phosphatase activities of 29.8 and 38.5%,respectively,in the topsoil(0-15 cm),while the soil p H was reduced by 0.37 units compared to CK(p H=8.44).Intercropping treatments facilitated the conversion of non-labile P to mod-labile P and stimulated the growth of soil bacteria in the topsoil.Compared with CK,the relative abundance of Gemmatimonadota,known for accumulating polyphosphate,and Actinobacteriota,a prominent source of bioactive compounds,increased significantly in the intercropping treatments,especially in HVT and SPT.A PLS-PM analysis showed that intercropping promoted soil P mobilization and the enrichment of beneficial bacteria by regulating maize root morphology and physiology.Our results highlight that maize-green manure intercropping optimizes root traits,soil properties and bacterial composition,which contribute to greater maize P uptake and yield,providing an effective strategy for sustainable crop production.
基金supported by the National Key Research and Development Program of China(No.2024YFD1701101)the Fund for Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28010503)+2 种基金the National Natural Science Foundation of China(No.31971515)the Fund for National Key Research and Development Plan of China(No.2019YFC1804100)the Fund for Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(No.CAAS-ZDRW202110).
文摘Atrazine,a persistent triazine herbicide,poses environmental and health risks.This study examines the synergis-tic remediation of atrazine-contaminated soil using green manure plant(GMP)hairy vetch(Vicia villosa Roth,VV)and the exogenous atrazine-degrading bacterium Arthrobacter sp.ATR1.Soil samples contaminated with atrazine at 5 and 20 mg/kg were treated with control(CK),ATR1(CKatr),hairy vetch(VV),and combined hairy vetch and ATR1 remediation(VVatr).The results indicated that the VVatr treatment exhibited the most effective atrazine removal,achieving enhancements of 56.12%at 5 mg/kg and 54.51%at 20 mg/kg compared to CK after 28 days.Soil enzyme activities,including urease,sucrase,and alkaline phosphatase,were significantly elevated in the VV and VVatr treatments,contributing to improved soil quality.Additionally,the CKatr,VV,and VVatr treat-ments enhanced bacterial diversity and richness while altering the microbial community structure.The VV and VVatr treatments notably enriched indigenous atrazine-degrading bacteria and nitrogen-fixing bacteria in the rhizosphere.This microbial enrichment upregulated the Atrazine degradation and Nitrogen metabolism pathways,facilitating both atrazine removal and nitrogen cycling in the soil.And VVatr treatment promoted the stability of the microbial network and enhanced the cooperative relationship between key indigenous atrazine-degrading and nitrogen-fixing bacteria.These findings explain the mechanism of plantmicrobe combined remediation of atrazine-contaminated soil from the perspective of rhizosphere microorganisms and offer a theoretical basis for the practical application of this method.
基金funded by the Joint Funds of the National Natural Science Foundation of China (U20A20107 and U22A20562)the National Key Research and Development Program of China (2023YFD1900201-3)the International Cooperation Project,Ministry of Science and Technology of China (G2023019005L)。
文摘The lateral transport of labile organic carbon represents a critical pathway for soil organic carbon(SOC) loss,reducing organic carbon sequestration and increasing the risk of waterbody pollution.Livestock manure application on croplands serves as a common fertilizer reduction practice to sustain crop yields,enhance SOC sequestration,and reduce water erosion.However,limited quantitative assessments have examined the effects of livestock manure substitution on labile organic carbon lateral loss and fluxes in long-term experiments.This study conducted a three-year field investigation on subtropical sloping croplands to assess the impact of livestock manure substitution on dissolved organic carbon(DOC) and particulate organic carbon(POC) loss via surface runoff,interflow and eroded sediments.There are four treatments:no fertilization(CK);chemical nitrogen fertilizer(SF),40% nitrogen substitution with pig manure(PMF),and 100% nitrogen substitution from pig manure(PM).Compared to SF treatment,long-term livestock manure substitution in PMF and PM treatments significantly(P<0.05) reduced annual cumulative surface runoff fluxes by 13.5 and 21.6%,respectively.Manure applications decreased annual sediment fluxes by 12.9 and 19.1%,respectively.Soil water stable aggregates for mean weight diameter(MWD) increased significantly by 37.7 and 73.6%.Annual cumulative POC loss flux via eroded sediment under PMF and PM treatments increased significantly(P<0.05) by 61.1 and 47.9%,respectively.The labile organic carbon loss fluxes,including DOC and POC losses,under PMF and PM treatments increased significantly(P<0.05) by 11.9 and 31.4%,respectively.These results demonstrate that while water erosion intensity decreases due to enhanced soil aggregate stability,the risk of labile organic carbon loss increases after long-term livestock manure substitution in subtropical sloping croplands.Future research should examine labile organic carbon lateral migration under various soil types and slope gradients for livestock manure application in subtropical agricultural ecosystem croplands to better understand extreme rainfall effects.
基金supported by the National Key Research and Development Program of China(2021YFD1700204)the National Natural Science Foundation of China(U21A20218 and 32372238)+1 种基金the Modern Agro-Industry Technology Research System of China(CARS-22-G-12)the“Innovation Star”Program of Graduate Students in 2025 of Gansu Province,China(2025CXZX-749)。
文摘Enhancing soil organic carbon(SOC)stocks is a key aspect of modern agriculture,but whether this can be achieved by incorporating legume green manure crops in cereal production to substitute synthetic N fertilizers is unknown.This study used a six-year(2017-2022)field study to explore the impacts of intercropping green manure with maize and reducing nitrogen fertilization on SOC stocks,while specifically focusing on the relationship between aggregate composition and carbon sequestration.Maize intercropped with common vetch(M/V),maize intercropped with rapeseed(M/R),and sole maize(M),were each tested at conventional(N2,360 kg ha^(-1))and reduced(N1,270 kg ha^(-1),25% reduced)N application rates.Soil was sampled in 2020,2021,and 2022.Compared with sole maize,intercropping with green manure(M/V and M/R)significantly increased SOC stocks which compensated for any negative effect due to the 25% reduction in N application.Based on 3-year averages,intercropping with M/V and M/R increased the SOC content compared to sole maize(M)by 12.1 and 9.1%,respectively,with intercropping further mitigating the negative impact of reduced nitrogen application.There was no significant difference between M/V and M/R.The SOC content at N1 was reduced by 9.3-10.5%compared to that at N2 in sole maize,but the differences in SOC stocks between N1 and N2 were not significant in the intercropping patterns(M/V and M/R).The intercropped M/V and M/R showed 20.9 and 16.3% higher SOC contents compared to sole maize at N1,with no differences at N2.Intercropping green manure led to a 5.3% greater SOC in the 0-20 cm depth soil in 2022 compared to that in 2020,due to the cumulative effect of two years of green manure intercropping.Intercropping green manure(M/V and M/R)increased the proportion of macroaggregates(>0.25 mm)and aggregate stability while reducing the proportion of microaggregates compared to sole maize under the N1 application.Structural equation modeling indicated that cropping patterns and nitrogen application levels mainly affect SOC indirectly by regulating the composition of macroaggregates and aggregate organic carbon(AOC).Correlation analysis further revealed that the composition of macroaggregates is significantly and positively correlated with the SOC content(R^(2)=0.64).In addition,intercropping green manure can maintain high crop yields by increasing SOC under reduced chemical nitrogen application.The results of this study show that intercropping green manure with grain crops can be a viable measure for increasing SOC sinks and maize productivity by optimizing the aggregate composition with reduced N application in the Hexi Oasis Irrigation Area.
基金financially supported by the National Science & Technology Fundamental Resources Investigation Project of China (2021FY100501)the Youth Innovation of Chinese Academy of Agricultural Sciences (Y2023QC16)。
文摘Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils.
基金funded by the Key Research and Development Project of Xinjiang Uygur Autonomous Region(2023A02002-2)the National Key Research and Development Program of China(2023YFD1901503)the Central Guidance Fund for Local Science and Technology Development of Xinjiang Uygur Autonomous Region(ZYYD2024CG03)。
文摘Biochar and animal manure application can improve crop yields in salt-affected soil.Previous studies have primarily applied biochar and animal manure either alone or at fixed ratios,while their combined effects with varying combination proportions are still unclear.To address this knowledge gap,we performed a 2-a experiment(2023-2024)in a salinized cotton field in Wensu County of Xinjiang Uygur Autonomous Region of China with the following 6 treatments:control;application of biochar(10t/hm^(2))alone(BC100%);application of cow manure(10 t/hm^(2))alone(CM100%);application of 70%biochar(7 t/hm^(2))combined with 30%cow manure(3 t/hm^(2))(BC70%+CM30%);application of 50%biochar(5 t/hm^(2))combined with 50%cow manure(5 t/hm^(2))(BC50%+CM50%);and application of 30%biochar(3 t/hm^(2))combined with 70%cow manure(7 t/hm^(2))(BC30%+CM70%).By measuring soil pH,electrical conductivity,soil organic matter,available phosphorus,available potassium,and available nitrogen at 0-20 and 20-40 cm depths,as well as yield components and cotton yield in 2023 and 2024,this study revealed that soil nutrients in the 0-20 cm depth were more sensitive to the treatment.Among all the treatments,BC50%+CM50%treatment had the highest value of soil pH(9.63±0.07)but the lowest values of electrical conductivity(161.9±31.8μS/cm),soil organic matter(1.88±0.27 g/kg),and available potassium(42.72±8.25 mg/kg)in 2024.Moreover,the highest cotton yield(5336.63±467.72 kg/hm^(2))was also observed under BC50%+CM50%treatment in 2024,which was 1.9 times greater than that under the control treatment.In addition,cotton yield in 2023 was jointly determined by yield components(density and number of cotton bolls)and soil nutrients(available phosphorus and available potassium),but in 2024,cotton yield was only positively related to yield components(density,number of cotton bolls,and single boll weight).Overall,this study highlighted that in salt-affected soil,the combination of biochar and cow manure at a 1:1 ratio is recommended for increasing cotton yield and reducing soil salinity stress.
基金supported by National Key Research and Development Program of China (Grant No.2023YFD1701700)approved by the Experimental Animal Ethics Committee of South China Agricultural University (Approval Number:2025f014)
文摘Background The rapid development of intensive layer breeding has intensified odor pollution that must be paid attention to for the green transformation of the industry. This study used Jingfen No.6 laying hens as the model to systematically evaluate the regulatory effect of compound microalgal powder(Chlorella vulgaris:Spirulina platensis:Haematococcus pluvialis = 3:1:1, 1:3:1, 1:1:3) on ammonia(NH3) emissions from laying hen manure.Results Through analysis of the static NH3production in manure, it was found that the NH3emissions within 24 h in the experimental group with 0.50% compound microalgal powder added were reduced to 6.27–16.84 mg(vs. control: 28.29 mg), achieving a 40.47%–77.84% reduction. GC/MS and 16S rRNA sequencing analyses indicated that the compound microalgal powder intervened in the remodeling of the microbial community and nitrogen metabolism network in manure, driving the transformation from inorganic nitrogen to organic nitrogen, mitigated the proliferation of NH3-producing bacteria(such as Escherichia coli, Klebsiella pneumoniae, Kurthia, and Proteus), and increased the abundance of acid-producing bacteria(such as Leuconostocaceae and Lactobacillaceae). The Spirulina platensis powder group had the best emission reduction effect(reduced by 77.84%), and its mechanism was closely related to the mitigation of Gram-negative bacteria activity by phycocyanin and increased synthesis of aromatic compounds, such as 2,3,5-trimethyl-6-ethylpyrazine.Conclusions This study revealed the mechanism by which the compound microalgal powder reduces NH3emissions by regulating the proliferation of acid-producing bacteria, reshaping the nitrogen metabolism network, and mitigating the activity of NH3-producing bacteria, while providing theoretical and data support for the development of environmentally friendly feed.
基金support of the Jiangxi Province Colleges and Universities Humanities and Social Science Key Research Base Project(JD23050)the Jiangxi Province Agricultural Key Core Technology Research Project(JXNK202307-03-01-02)the Natural Science Foundation of Jiangxi Province,China(20192BAB203019)。
文摘Hydrothermal carbonization(HTC)is a promising technology for the coversion of swine manure(SM)for hydrochars(HCs).Currently,information on the humification of organic matter is limited during the HTC of SM,and its potential correlation with the passivation of heavy metals(HMs)remains unclear,which is crucial referece for the land application of SM-derived HCs.This study systematically investigated the humification of organic matter and the passivation of HMs during the HTC of SM and then explored their intrinsic connection.The HTC treatment can enhance the humification of organic matter,and the HCs obtained at 240℃ had the best humification effect,with the highest content of humus(83.84 mg·g^(-1)versus 41.97 mg·g^(-1)in SM)and humification rate(28.89%versus 15.73%in SM).Dissolved organic carbons(DOC)and readily oxidized organic carbons(ROC)were more easily degraded in the HTC of SM,and part was further converted into inactive organic carbon.HMs(Cu,Zn,Pb,and Cr)were enriched in HCs,but all HMs were largely passivated.The ecological risk of multi-HMs was reduced from moderate risk in SM to low risk in HCs.The percentages of HMs in exchangeable/acid-soluble forms were positively correlated with the contents of DOC and negatively correlated with the ratio of humic acids to fulvic acids(P<0.05).It was inferred that the humification of organic matter promoted the passivation of HMs in the HTC of SM.This study provided deeper insights into the humification of organic matter and it's intrinsic correlation with HMs-passivation during the HTC of SM.
基金supported by the National Natural Science Foundation of China(No.U20A2047)the Key Research and Development Project for Tibet Autonomous Region(No.XZ202201ZY0003N)+2 种基金the National Key Research and Development Program of China(No.2022YFD1901402)the Lasa Science and Technology Bureau(No.LSKJ202206)the Foundation of Graduate Research and Innovation in Chongqing(No.CYB22127).
文摘The land application of livestock manure has been widely acknowledged as a beneficial approach for nutrient recycling and environmental protection.However,the impact of residual antibiotics,a common contaminant of manure,on the degradation of organic compounds and nutrient release in Eutric Regosol is not well understood.Here,we studied,how oxytetracycline(OTC)and ciprofloxacin(CIP)affect the decomposition,microbial community structure,extracellular enzyme activities and nutrient release from cattle and pig manure using litterbag incubation experiments.Results showed that OTC and CIP greatly inhibited livestock manure decomposition,causing a decreased rate of carbon(28%-87%),nitrogen(15%-44%)and phosphorus(26%-43%)release.The relative abundance of gramnegative(G-)bacteria was reduced by 4.0%-13%while fungi increased by 7.0%-71%during a 28-day incubation period.Co-occurrence network analysis showed that antibiotic exposure disrupted microbial interactions,particularly among G-bacteria,G+bacteria,and actinomycetes.These changes in microbial community structure and function resulted in decreased activity of urease,β-1,4-N-acetyl-glucosaminidase,alkaline protease,chitinase,and catalase,causing reduced decomposition and nutrient release in cattle and pig ma-nures.These findings advance our understanding of decomposition and nutrient recycling from manure-contaminated antibiotics,which will help facilitate sustainable agricultural production and soil carbon sequestration.
基金funding from the China Agriculture Research System(CARS-22,Green Manure)the Natural Science Foundation Project from Chongqing Municipal Science and Technology Bureau,China(4322300357)the Green Manure Cultivation Technology Project from Chongqing Agricultural Technology Extension Station。
文摘Weeds have a negative impact on agricultural production by competing with cultivated crops for resources and fostering conditions conducive to disease and insect pest dissemination.Hence,optimal weed management is of paramount importance for sustainable agricultural.In this study,the ability of four distinct green manure species to suppress weeds was determined in a field experiment conducted in Chongqing,Southwest China.After cultivating the green manure species,the weed density and diversity were monitored over the following year.The findings highlight a notable trend in the suppressive ability of green manures,with increased suppression observed from November to March,an optimal level observed from March to May,and a gradual decline observed thereafter.Poaceae(Lolium perenne L.)demonstrated the highest efficacy in suppressing weeds.The meta-analysis underscore the exceptional suppressive effects of poaceous green manures on weed as well and prove sustained planting for three or more consecutive years yielded superior weed suppression outcomes.Green manure had the most prominent inhibitory effect on poaceae weeds,followed by Polygonaceae and Caryophyllaceae.The field experiment also investigated the effect of green manures on weed community composition,they increased in the proportion of perennial weeds within these communities.This study offers valuable insights that can guide policymakers,agricultural experts,and farmers in devising effective weed management strategies.By highlighting the potential benefits of green manures and unraveling their nuanced impact,this study contributes to the arsenal of sustainable agricultural practices.
基金supported by the U.S.Department of Agriculture NIFA Award(No.2018-68003-27467).
文摘Manure application as fertilizer can increase environmental exposure risk,as antibiotics,antibiotic resistance bacteria(ARB),and antibiotic resistant genes(ARGs)can be transmitted to agricultural fields,and adjacent natural systems.Understanding how specific antibiotics and ARGs respond within different manure fractions during on-farm management is limited.The study objective was to conduct a mass flow analysis determining the fate of antibiotic resistance factors(antibiotics,ARGs,and ARB)through solid-liquid separation,with the solid fraction continuing through a bedding recovery unit(BRU)via high temperature rotary composting for use of the manure solids as dairy cow bedding.The results show that most of the manure mass containing the antibiotic resistance factors went untreated following solid-liquid separation,with 95%of the mass leaving the separator as a liquid and pumped to a storage lagoon for field application and 5%proceeding to BRU processing.The tetracyclines and tulathromycin sorbed to the manure solids,while the beta lactams,ampicillin,and benzylpenicilloic acid were only found in the liquid fraction.The removal of antibiotic residuals during the BRU composting was insignificant,yet 40%-73%of the antibiotics were in the liquid fraction.The BRU composting was 100%effective in removing the ARB examined.Five of the eight ARGs(intl1,sul1,tetQ,tetX,and tetM)had significant reduction(>95%)following the BRU composting treatment.While the three other ARGs(tetW,ermB,and bla2)remained constant despite treatment.This study highlighted the importance of examining manure management from a mass balance perspective and understanding antibiotic resistance risk factors.
基金financial support of the Science and Technology Program in Gansu province(25JRRA347,24ZDNA008)the Natural Science Foundation of China(32372238,U21A20218,32460547)+4 种基金the Industrial Support Project of Educational Committee of Gansu province(2025CYZC-037)the Research Program Sponsored by State Key Laboratory of Aridland Crop Science(GSCS-2023-Z03)the Agricultural Research System of China(CARS-22-G-12)China Agricultural University Corresponding Support Research Joint Fund(GSAU-DKZY-2024-001)the UPTAKE Project on EU Horizon(101081521).
文摘Improving crop yield and N utilization while mitigating environmental pollution is a key goal in sustainable agriculture.Integrating green manure with reduced chemical N application is a promising strategy to enhance N utilization efficiency and minimize reactive N losses.However,the agronomic mechanisms through which green manure incorporation affects soil N retention and N loss under reduced N application remain unclear.This study aimed to uncover the compensatory mechanisms of green manure in improving wheat yield and N utilization under reduced N application,and to identify the principles behind reduced N loss in wheat fields.We conducted a split-plot experiment in the Hexi Oasis irrigation area of Northwest China from 2019 to 2024,using two cropping systems(W,fallow after wheat;W-G,green manure returning after wheat)combined with three N application levels(N1,local conventional N application rate;N2,N-reduction 15%;N3,N-reduction 30%).Our results demonstrated that green manure returning improved soil quality and compensated for the yield and N use efficiency losses caused by 15%chemical N reduction.Specifically,compared to the W-N1,W-GN2 increased soil organic matter content and soil water content by 6.5%and 9.4%,respectively,while reducing soil bulk density and pH by 8.9%and 6.7%.Meanwhile,W-GN2 increased soil nitrate N and total N content in the 0–40 cm soil layer by 8.4%and 8.7%,respectively.Moreover,W-GN2 reduced NH3 volatilization by 13.8%,N_(2)O emissions by 8.8%,and N leaching by 9.4%.It also enhanced microbial biomass N by 50.7%,urease activity by 10.2%,and decreased nitrate and nitrite reductase activities by 19.9%and 32.6%,respectively.Additionally,W-GN2 improved soil bacterialα-diversity and increased the abundance of functional bacteria.Green manure can sustain wheat yield and improve N utilization efficiency under reduced chemical N input by improving the soil environment,enhancing soil N retention and minimizing N losses,which presents a sustainable,yield-stabilizing strategy for Oasis agroecosystems in northwestern China.
基金supported by the National Natural Science Foundation of China(32171683)the Shenzhen Science and Technology Program,China(JCYJ20220530145606015)+4 种基金the Agricultural and Social Development Project of Guangzhou Municipal Science and Technology Bureau,China(202206010058)the Special Fund for Agro-scientific Research in the Public Interest of China(201503122)the Natural Science Foundation of Guangdong Province,China(2020A1515010494)the Yangfan Innovative&Entrepreneurial Research Team Project,China(2015YT02H032)the Zhang Hong-da Science Research Fund of Sun Yat-sen University,China。
文摘Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(AMF)from different winter planting green manures on the soil properties and post-cropping rice production remain unclear.In this study,the soil AMF communities of three common winter planting patterns in southern China,winter fallow,winter ryegrass(Lolium multiflorum L.),and winter Chinese milk vetch(Astragalus sinicus L.),were explored and their effects on post-cropping rice production were investigated.Compared with winter fallow,the winter ryegrass and winter Chinese milk vetch patterns could alleviate soil acidification,significantly increase soil AMF spore density,and improve the soil AMF community structure.Based on sterilized soil,rice production indicators such as thousandseed weight,theoretical yield,and the grain amylose and total sugar contents of rice inoculated with AMF spores from winter Chinese milk vetch soil were 6.68–53.57%higher than those without AMF inoculation.Rice panicle weight,seed setting rate,and theoretical yield were 15.38–22.71%higher in the treatment with AMF spores from winter ryegrass soil than in the treatments with no AMF inoculation.In addition,the protein,amylose,and total sugar contents of rice grains were 14.92,104.82,and 802.23 mg kg^(–1),respectively,which were 31.31,14.25 and 34.47%higher than those without AMF inoculation.The AMF community dominated by Glomus and Acaulospora in winter Chinese milk vetch had a more positive effect on the improvement of rice yield,while the AMF community dominated by Glomus in winter ryegrass soil was more conducive to rice quality improvement.These findings have revealed the critical role of AMF communities from green manure in rice production,which lays the theoretical basis for a promising strategy to promote the sustainable development of southern winter agriculture.
基金supported by the National Natural Science Foundation of China(52306131)the Natural Science Foundation of Jiangsu Province(BK20230847)+2 种基金the Key Project of the National Natural Science Foundation of China(52336005)the Fundamental Research Funds for the Central Universities(2242024RCB0036)the Open Project Program of State Key Laboratory of Low-carbon Smart Coal-fired Power Generation and Ultra-clean Emission(D2024FK156).
文摘As a renewable energy source,the thermal conversion of poultry manure,is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions.Currently,pressurized gasification of poultry manure is still a novel research field,especially when combined with a novel technological route of oxy-fuel gasification.Oxy-fuel gasification is a newly proposed and promising gasification technology for power generation that facilitates future carbon capture and storage.In this work,based on a commercially operated industrial-scale chicken manure gasification power plant in Singapore,we presented an interesting first exploration of the coupled pressurization technology for oxy-fuel gasification of poultry manure using CFD numerical simulation,analyzed the effects of pressure and oxygen enrichment concentration as well as the coupling mechanism between them,and discussed the conversion and emission of nitrogen-and sulfur-containing pollutants.The results indicate that under oxy-fuel gasification condition(Oxy-30,i.e.,30%O_(2)/70%CO_(2)),as the pressure increases from 0.1 to 0.5 MPa,the CO concentration in the syngas increases slightly,the H_(2)concentration increases to approximately 25%,and the CH4 concentration(less than 1%)decreases,resulting in an increase in the calorific value of syngas from 5.2 to 5.6 MJ·m^(-3).Compared to atmospheric pressure conditions,a relatively higher oxygen-enriched concentration interval(Oxy-40 to Oxy-50)under pressurized conditions is advantageous for autothermal gasification.Pressurization increases NO precursors production and also promotes homogeneous and heterogeneous reduction of NO,and provides favorable conditions for self-desulfurization.This work offers reference for the realization of a highly efficient and low-energy-consumption thermochemical treatment of livestock manure coupled with negative carbon emission technology.
基金supported by the‘Double First-Class’Key Scientific Research Project of Education Department in Gansu Province,China(GSSYLXM-02)the National Natural Science Foundation of China(U21A20218 and 32160765)+3 种基金the earmarked fund for China Agriculture Research System(CARS-22-G-12)the Science and Technology Project of Gansu Province,China(20JR5RA037 and 21JR7RA836)the Postdoctoral Research Start-up Foundation of Gansu Province,China(03824034)the Postdoctoral Research Start-up Foundation of Gansu Agricultural University,China(202403)。
文摘A critical challenge for global food security and sustainable agriculture is enhancing crop yields while reducing chemical N inputs.Improving N use efficiency in crops is essential for increasing agricultural productivity.The aim of this study was to evaluate the impacts of intercropping maize with leguminous green manure on grain yield and N utilization under reduced N-fertilization conditions.A field experiment with a split-plot design was conducted in northwestern China from 2018 to 2021.The main plots consisted of two cropping systems:maize-common vetch intercropping(IM)and sole maize(SM).The subplots had three N levels:zero N application(N0,0 kg ha^(-1)),a 25%reduction from the traditional chemical N supply(N1,270 kg ha^(-1)),and the traditional chemical N supply(N2,360 kg ha^(-1)).The results showed that the negative effects of N reduction on maize grain yield and N uptake were compensated by intercropping leguminous green manure,and the improvements increased with cultivation years.The integrated system involving maize-leguminous green manure intercropping and a reduced N supply enhanced N translocation from maize vegetative organs to grains and increased the nitrate reductase and glutamine synthetase activities in maize leaves.The supercompensatory effect in maize leaves increased year by year,reaching values of 16.1,21.3,and 25.5%in 2019,2020,and 2021,respectively.These findings suggest that intercropping maize with leguminous green manure under reduced chemical N input can enhance N assimilation and uptake in maize.By using this strategy,chemical fertilizer is effectively replaced by leguminous green manure,thereby improving N use efficiency and maintaining stable yields in the maize-based intercropping system.
基金supported by the National Natural Science Foundation of China(52306131)the Natural Science Foundation of Jiangsu Province(BK20230847)+1 种基金the Key Project of the National Natural Science Foundation of China(52336005)the Open Project Program of State Key Laboratory of Low-carbon Smart Coalfired Power Generation and Ultra-clean Emission(D2024FK156).
文摘Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential.This work presents an innovative research exploration-coupling coal pressurized fluidized bed oxy-fuel combustion technology with energy utilization of poultry manure as a renewable and carbon-neutral fuel,in order to capture CO_(2)and solve the problem of poultry manure treatment simultaneously.In this study,a stable co-combustion of coal and chicken manure in a laboratory-scale pressurized fluidized bed under typical oxy-fuel condition(30%O_(2)/70%CO_(2),i.e.,Oxy-30)is achieved.The key parameters including the combustion pressure(0.1-0.5 MPa)and chicken-manure proportion(0%to 100%)and their impacts on fundamental combustion efficiency,carbon conversion,nitrogen and sulfur pollutant emissions,and residue ash characteristics have been investigated.The result show that pressurization favors an increase in the CO_(2)enrichment concentration and fluidized bed combustion efficiency.During co-combustion under 0.1 and 0.3 MPa,the CO_(2)concentration in the flue gas is the highest when the chicken manure blending ratio(M_(pm))is 25%.Although the NO emissions fluctuate and even increase as Mpm increases,the co-combustion of coal and chicken manure exhibits a synergistic effect in reducing NO conversion rate(XNO).The effect of pressurization on reducing NO emission is significant,XNO at M_(pm)=25%decreasing from 15%to 5%as the pressure(P)increases from 0.1 to 0.5 MPa.As P increases from 0.1 to 0.5 MPa and Mpm increases from 0%to 50%,the SO_(2) emissions and conversion rates decrease.The self-desulfurization process plays an important role in the reduction of SO_(2) emissions during pressurized oxy-fuel co-combustion.The aim of this work is to advance the development and application of pressurized fluidized bed oxy-fuel co-combustion technology and promote a circular bioeconomy and carbon-free waste management for biomass derived from livestock manure.
基金supported by the National Natural Science Foundation of China(32160524)the National Key Research and Development Program of China(2022YFD1900200)+3 种基金the Industrial Support Project of Educational Committee of Gansu Province,China(2021CYZC-54)the China Agriculture Research System(CARS-22-G-12)the Fuxi Outstanding Talent Cultivation Program of Gansu Agricultural University,China(GAUfx-04J01)the“Innovation Star”Project of Gansu Province,China(2023CXZX-644)。
文摘The effcacy of integrating green manure in arid irrigation regions to enhance maize yield and nitrogen(N)uptake effciency has been extensively explored.However,limited research has delineated the contribution of green manure N vs.soil N on crop N utilization effciency.This study integrated feld experiments with micro-plot experiments to examine green manure(common vetch)management practices for achieving high maize yield and N uptake.In a micro-plot experiment,^(15)N technology was utilized to label green manure crops.Five treatments were applied in the research methodology:conventional tillage without green manure as the control(CT),tillage with total green manure incorporation(TG),no-tillage with total green manure mulching(NTG),tillage with only root incorporation(T),and no-tillage with removal of aboveground green manure(NT).The results of the micro-plot experiment were consistent with those observed in the feld,demonstrating that the utilization of green manure substantially increased maize yield and nitrogen uptake effciency(NUPE)compared to CT.In particular,under NTG,N uptake by maize from green manure was higher than NT and T,accounting for 59.1%of maize N uptake.Furthermore,applying NTG boosted the NUPE of soil N in maize to 50.7%,higher than TG by 5.5%.Meanwhile,it decreased the proportion of soil N in the maize.The difference between NTG and TG was primarily shown in the maize grains.For N transport in the soil,NTG decreased N loss while increasing soil N retention.Also,it facilitated the mineralization of soil organic N before the fowering stage.In conclusion,adopting no-tillage with total green manure mulching increased N uptake from green manure and the soil and decreased the proportion of soil-derived N in maize.
基金financially supported by the National Basic Research Program(973 Program) of China(2013CB127406)
文摘Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures(3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that significant(P〈0.01 or P〈0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.
基金Supported by Key Project of Natural Science Foundation of Inner Mongolia Autonomous Region(200607010403)National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology of China(2006BAD04A15)~~
文摘[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis for cattle manure harmless treatment.[Method] Both experimental groups supplemented with 2.0% bacterial inhibitor and control groups without bacterial inhibitor were cultured under different temperatures(20,30,37,50,60 ℃)to determine the optimal composing temperature.Under 30 ℃,different bacterial inhibitor doses(0,2.0%,2.5%,3.0%)were added into the compost to obtain the optimal bacterial inhibitor addition dose.[Result] 30,50 and 60 ℃ were ideal temperatures for sterilization of E.coli.Under 30 ℃,E.coli couldn't be detected in 2.5% dose group and 3.0% dose group after culture for 48 h,demonstrating no less than 2.5% bacterial inhibitor should be added.[Conclusion] It has an important significance to enhance the sterilization effects on E.coli by adding CaCN2 into cattle manure compost especially in winter.