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
Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and th...Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.展开更多
The combined effects of macronutrients(Nitrogen,Phosphorus,and Potassium-N,P,K)and micronutrient fertilization on turmeric yield,soil enzymatic activity,microbial biomass,and nutrient dynamics remains poorly understoo...The combined effects of macronutrients(Nitrogen,Phosphorus,and Potassium-N,P,K)and micronutrient fertilization on turmeric yield,soil enzymatic activity,microbial biomass,and nutrient dynamics remains poorly understood,despite their significance for sustainable soil fertility management and optimizing crop productivity across diverse agroecosystems.To investigate,a net house experiment on sandy loam Haplic Chernozem was conducted to 03 fertilizer regimes,viz.N_(75)P_(50)K_(50)kg ha^(−1)(T-2),N_(12)5P_(100)K_(100)kg ha^(−1)(T-3),and N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg ha^(−1)(T-4).Furthermore,the influence of these treatments was systematically assessed on soil nutrient status(N,P,K),enzymatic activities(alkaline phosphomonoesterase,dehydrogenase,fluorescein diacetate hydrolysis),microbial biomass carbon(MBC)and soil organic carbon(SOC).Balanced fertilization significantly turmeric productivity and soil health.All three fertilizer treatments showed a clear yield increase compared to the unfertilized control.Compared to the control,N_(75)P_(50)K_(50)kg/ha T-2 increased rhizome number and biomass per plant by 44.7%and 16.3%,respectively,while N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg/ha T-4 further enhanced them by 86.6%and 27.7%.T-3 produced the most significant yield response by increasing the rhizome biomass by 38.0%and rhizome number per plant by 100%compared to the control.The nutrient availability was also substantially improved.T-2 enhanced the soil nitrogen contents by 83.3%with maximum N levels observed in T-3&T-4.Phosphorus increased by 61.5%in T-3 and 37.3%in T-4,while potassium was enhanced by 12.9%in T-3 relative to the control,respectively.Enzymatic activities were markedly enhanced as T-3 was recorded to improve alkaline phosphomonoesterase(APA),dehydrogenase(DHA)and fluorescein diacetate hydrolysis(FDA)by 50.6%,37.4%,and 43.4%,where T-4 increased by 32.2%,30.9%,and 35.9%,respectively compared to control.MBC and SOC also rose significantly,with SOC increased by 13.8%(T-2),41.6%(T-3),and 47.2%(T-3)relative to control.The result of this study demonstrates that the integrated macroµnutrient fertilization,particularly T-37 T-4 treatments,sustainably enhanced turmeric yield,soil nutrient availability,enzyme activity,microbial biomass,and organic carbon.These findings highlight the critical role of balanced nutrient management in sustaining soil fertility and crop productivity across agroecosystems.展开更多
Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics o...Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.展开更多
Soil greenhouse gas(GHG)emissions contribute profoundly to global warming;however,how plant detritus input alters GHG emissions is poorly understood.Here,we used detritus input and removal treatments(i.e.,DIRT:control...Soil greenhouse gas(GHG)emissions contribute profoundly to global warming;however,how plant detritus input alters GHG emissions is poorly understood.Here,we used detritus input and removal treatments(i.e.,DIRT:control,CK;double litter,DL;no roots with double litter,NRDL;no litter,NL;no roots,NR;no roots and no litter,NRNL)to assess the effects of litter and root inputs on soil CO_(2),CH_(4),and N_(2)O fluxes in soils in a coniferous(Pinus yunnanensis)and a broad-leaf forest(Quercus pannosa)in a subalpine region in southwestern China.Litter addition increased CO_(2) emissions on average 22.22%,but did not significantly alter CH_(4) uptake and N_(2)O emission compared to the CK.Litter removal(NL and NRNL)significantly reduced CO_(2) emissions on average 30.22%and N_(2)O emissions on average 31.16%from both forest soils,but did not significantly affect soil CH_(4) uptake.Root removal(NR and NRNL)generally decreased these three soil GHG fluxes.Changes inβ-1,4-glucosidase(BG)involved in C and phospholipid fatty acid(PLFAs)biomass were projected to influence CO_(2) emissions,while soil microclimates(temperature and moisture)combined with BG activity mainly regulated CH_(4) uptake.Alterations in dissolved organic nitrogen,microbial biomass nitrogen and BG were mainly responsible for changes in N_(2)O emissions.Interestingly,coniferous forest soil seemed to promote CH_(4) uptake more than the broad-leaf forest soil,but CO_(2) and N_(2)O fluxes were not significantly affected by the forest types.As expected,litter addition significantly increased the warming potential,while litter removal relatively lowered it.These findings revealed the divergent roles of plant detritus input and forest type in shaping soil GHG fluxes,thereby providing insights into forest management and predicting contributions of subalpine forests to global warming.展开更多
Elevation patterns and assembly processes of soil microbial community structures are essential for understanding biogeo-chemical processes in mountain systems.Differences in soil properties caused by elevation gradien...Elevation patterns and assembly processes of soil microbial community structures are essential for understanding biogeo-chemical processes in mountain systems.Differences in soil properties caused by elevation gradients can regulate the spatial distribu-tion and network complexity of the community structure.To explore the variations in soil microbial community structures and their as-sembly mechanisms across different elevations of the Changbai Mountains,as well as their responses to environmental factors,we col-lected microbial samples along an elevational gradient(seven elevations containing four vegetation zones)on the western slope of the Changbai Mountains using the method of metagenomic sequencing.The results showed a significant difference(P<0.05)for the Chao1 index across different elevations,but no significant difference was observed for the Shannon and Simpson indices.With increasing elev-ation,the number of nodes and links in the microbial network gradually decreased.Acidobacteria were highly connected to many nodes.The microbial communities indicated a significant distance-decay relationship(P<0.001)and were affected more by stochastic pro-cesses along the elevation gradient.The results of the Structural Equation Model(SEM)showed that elevation had direct significant ef-fect on carbon(C,P<0.01),nitrogen(N,P<0.01),and phosphorus(P,P<0.05)and weak negative effect on their ecological stoi-chiometry.Elevation was one of the major variables contributing to microbial network topology.The contribution of C and N to micro-bial network complexity was higher than that of P.Our study provides valuable insights into the responses of soil microbial communit-ies to elevation variations.展开更多
Soil compaction often imposes stress on root development and plant survival.However,root anatomical responses that enable persistent root growth and functioning under soil compaction remain unclear.We grew 10 herbaceo...Soil compaction often imposes stress on root development and plant survival.However,root anatomical responses that enable persistent root growth and functioning under soil compaction remain unclear.We grew 10 herbaceous species differing substantially in lateral root diameter,in soils with low(1.0 g cm^(-3))and high(1.4 g cm^(-3))bulk density,and assessed root traits including root biomass,anatomical structures,and respiration rates.Greater root thickening upon soil compaction was found in species with thicker first-order lateral roots,mainly due to larger cortical cell size.Both xylem vessel diameter and wall thickness increased more in compacted soils in these species.Despite these anatomical shifts,root respiration rate responded little to soil compaction across most species,likely due to the opposite investment in cortical cells and xylem vessels.Notably,root biomass,independent of root respiration rate and anatomical structures,determined whole-plant growth under soil compaction.Our study reveals two independent strategies of root response to soil compaction:anatomical remodeling for mechanical and metabolic maintenance,and root biomass investment for resource acquisition.These findings offer new insights for breeding and selecting species tolerant to soil compaction and highlight multidimensional strategies of plant adaptation to physical stress.展开更多
As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalen...As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalent parameters of SRMs,which are typically obtained through experimental and numerical methods.In contrasted to other numerical methods,the numerical manifold method(NMM)is more effective in addressing SRM problems.This is because the high-precision regular mathematical meshes in NMM can be used without aligning with the soil-rock interfaces and boundaries of SRMs.In the current research,the equivalent strength parameters of SRMs,i.e.the equivalent cohesion ce and internal friction angleϕ_(e),are determined using NMM.Initially,an NMM triaxial numerical model is established and validated based on triaxial experiments.Subsequently,the soil and rock parameters are derived through parameter inversion.Moreover,the impacts of rock content,size,shape and rock blocks'major-axis orientation on ce andϕ_(e) of SRMs are thoroughly examined using the NMM triaxial numerical model.Additionally,a fitting function is proposed to linkϕ_(e) to the rock content and size of SRMs.When other influencing factors are fixed,the above fitting model leads to the following conclusions:(1)the predictedϕ_(e) of SRMs increase with the increase of rock content;and(2)SRM samples with smaller rocks display a higher predictedϕ_(e).展开更多
Soil organic carbon(SOC):total nitrogen(TN):total phosphorus(TP)(C:N:P)stoichiometry can give important information about biogeochemical cycling in terrestrial ecosystems.The spatial patterns and driving mechanisms of...Soil organic carbon(SOC):total nitrogen(TN):total phosphorus(TP)(C:N:P)stoichiometry can give important information about biogeochemical cycling in terrestrial ecosystems.The spatial patterns and driving mechanisms of soil C:N:P ratios are still poorly understood on the Qinghai-Tibetan Plateau of China.In this study,we therefore combined data of the geography,climate,soil properties,and vegetation characteristics from 319 sites across the plateau to investigate their relationships with the horizontal and vertical patterns of SOC,TN,and TP concentrations and their stoichiometric ratios(C:N and N:P).We observed higher SOC(30.5–46.8 mg g^(-1)),TN(2.4–3.4 mg g^(-1)),C:N(14.7–18.0),and N:P(6.9–8.0)in alpine meadows,forests,and shrublands and higher TP(1.6 mg g^(-1))in croplands.Overall,SOC,TN,TP,C:N,and N:P showed decreasing trends(by 67%,64%,19%,12%,and 54%,respectively)along the whole soil profile(0–100 cm).Soil cation exchange capacity and bulk density were the stronger environmental drivers of SOC and TN.Soil TP showed latitudinal and longitudinal increasing trends in all soil layers.Soil properties explained most of the variations in SOC(67%–90%),TN(67%–87%),C:N(61%–89%),and N:P(64%–85%),with increasing impacts along the soil profile.Geography and climate influenced soil TP directly and indirectly through their impacts on soil properties,with geography being the predominant driver(46%–65%)along the soil profile.The variation in soil C:N was mostly driven by SOC and TN,and the direct and indirect effects of the environmental factors were relatively weak.Geography,climate,soil properties,and vegetation characteristics indirectly impacted soil N:P through their impacts on TN and TP in all the soil layers.Altogether,our findings illuminate the relative contributions of geography,climate,soil properties,and vegetation characteristics to soil C:N and N:P,thus enhancing our understanding of C,N,and P cycling across the Qinghai-Tibetan Plateau.展开更多
Both soil organic carbon (SOC) and iron (Fe) oxide content, among other factors, drive the formation and stability of soil aggregates.However, the mechanism of these drivers in greenhouse soil fertilized with organic ...Both soil organic carbon (SOC) and iron (Fe) oxide content, among other factors, drive the formation and stability of soil aggregates.However, the mechanism of these drivers in greenhouse soil fertilized with organic fertilizer is not well understood.In a 3-year field experiment, we aimed to investigate the factors which drive the stability of soil aggregates in greenhouse soil.To explore the impact of organic fertilizer on soil aggregates, we established four treatments:no fertilization (CK);inorganic fertilizer (CF);organic fertilizer (OF);and combined application of inorganic and organic fertilizers(COF).The application of organic fertilizer significantly enhanced the stability of aggregates, that is it enhanced the mean weight diameter, geometric mean diameter and aggregate content (%) of>0.25 mm aggregate fractions.OF and COF treatments increased the concentration of SOC, especially the aliphatic-C, aromatic-C and polysaccharide-C components of SOC, particularly in>0.25 mm aggregates.Organic fertilizer application significantly increased the content of free Fe(Fed), reactive Fe (Feo), and non-crystalline Fe in both bulk soil and aggregates.Furthermore, non-crystalline Fe showed a positive correlation with SOC content in both bulk soil and aggregates.Both non-crystalline Fe and SOC were significantly positively correlated with>2 mm mean weight diameter.Overall, we believe that the increase of SOC, aromatic-C, and non-crystal ine Fe concentrations in soil after the application of organic fertilizer is the reason for improving soil aggregate stability.展开更多
The continuous supply of phosphorus(P)is indispensable in crop production.However,P resources are non-renewable,and environmental concerns like eutrophication associated with its loss from agroecosystems make the sust...The continuous supply of phosphorus(P)is indispensable in crop production.However,P resources are non-renewable,and environmental concerns like eutrophication associated with its loss from agroecosystems make the sustainable management of P resources essential for ensuring global food security.This study was designed to reduce mineral P inputs through management practices.A field experiment comprising a wheat-maize rotation system was conducted in the Guanzhong Plain of Shaanxi Province,China from 2018-2023.The eight treatments included CK(without P),FP(conventional P application);RP(recommended P);RP80(20% reduction in RP);SRP80(20% reduction in RP with straw wrapping);ARP80(20% reduction in RP with ammonium sulfate instead of urea);SARP80(20% reduction in RP with straw wrapping and ammonium sulfate instead of urea);and SARP60(40% reduction in RP with straw wrapping and ammonium sulfate instead of urea).Crop yield,P uptake,and P fertilizer use efficiency were measured during harvest and throughout the entire period of the study.At the end of the experiment,P fractions were estimated using the Tiessen-Moir P classification method.The results revealed that the grain yields of all the treatments except for RP80 were significantly increased compared to CK,with increases of 14.9-28.8%.Furthermore,agronomic efficiency,apparent P use efficiency,P recovery rate,and partial factor productivity were significantly improved for the treatments that received 20% less P with straw wrapping.Moreover,the enhancement measures significantly increased labile and moderately labile P in the soil.Therefore,straw wrapping with ammonium sulfate instead of urea is one of the most effective ways to reduce mineral P inputs while increasing the efficiency of P in wheat-maize rotation systems.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
The source region of the Yellow River(SRYR),with its semi-humid to semi-arid climate,is crucial for understanding water resource dynamics.Precipitation is key for replenishing surface water and balancing the ecosystem...The source region of the Yellow River(SRYR),with its semi-humid to semi-arid climate,is crucial for understanding water resource dynamics.Precipitation is key for replenishing surface water and balancing the ecosystem’s water cycle.However,the soil moisture response to precipitation across climate zones and soil layers remains poorly understood due to limited long-term data.This study examines the response of soil moisture to precipitation at multiple time scales in the SRYR,using data from Maqu,Mado,Ngoring Lake sites,and the Maqu monitoring network(MMN),along with CN05.1 precipitation and GLEAM v3.8a soil moisture data.Results show that the semi-humid area requires more precipitation to trigger soil moisture responses compared to the semi-arid area in the SRYR.Surface soil at Maqu,MMN,Ngoring Lake,and Mado sites require at least 8.6,8.4,5.2,and 2.84 mm of precipitation,respectively,for effective replenishment.Significant responses to precipitation events were observed in soil layers at 40 cm and above in the semi-humid area,while at 20 cm and above in the semi-arid area.Precipitation volume is the primary factor influencing soil moisture,affecting both the increment and time lag to maximum moisture.Precipitation intensity and pre-rain moisture have no direct effect.In the central SRYR,accumulated precipitation has a greater impact.Root-zone soil moisture has a weaker correlation with precipitation compared to surface soil moisture but persists longer,responding for up to 10 days,while surface soil moisture responds more immediately but only lasts about 5 days.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 as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly base...Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly based on short-term studies has been encouraging and the trend obtained so far has raised many hopes. Biochar has been reported to positively impact an array of soil processes ranging from benefiting soil biology, controlling soil-borne pathogens, enhancing nitrogen fixation, improving soil physical and chemical properties,decreasing nitrate(NO-3) leaching and nitrous oxide(N2O) emission to remediation of contaminated soils. However, very little biochar is still utilized as soil amendment mainly because these benefits are yet to be quantified, and also the mechanisms by which the soil health is improved are poorly understood. Due to the infancy of research regarding this subject, there are still more questions than answers. The future research efforts must focus on carrying out long-term experiments and uncover the mechanisms underlying these processes so that key concerns surrounding the use of biochar are addressed before its large scale application is recommended.展开更多
Trees,mammals,and microbes relate to soil carbon(C)cycle.Trees capture C,and mammals consume plants and other animals,both contributing to organic remains that are then degraded by soil microbes.This organic C can be ...Trees,mammals,and microbes relate to soil carbon(C)cycle.Trees capture C,and mammals consume plants and other animals,both contributing to organic remains that are then degraded by soil microbes.This organic C can be stored in soils or released into the atmosphere through microbial mineralization.Yet,the simultaneous effects of mammals and trees on C consumption by soil microbes have not been investigated.For 30 sampling sites in a mixed forest-savanna environment in southern Guyana,we jointly analyzed observational data of mammal and tree communities along with soil organic matter(SOM)composition(using Fourier transform infrared spectroscopy combined with attenuated total reflectance,energy dispersive X-ray fluorescence spectrometry,and CNH elemental analyzer)and soil microbial C consumption(using Biolog EcoPlates).It was found that higher mammal functional richness(FRic)and functional evenness(FEve)were related to reduced overall C consumption by soil microbes(for FRic:regression coefficient(β)=-0.010,standard error(SE)=0.005,P=0.034;for FEve:β=-0.012,SE=0.005,P=0.010)with the coefficient of determination(R^(2))value of 0.359,explaining 36%of the variance in average well color development values,whereas a higher tree richness was associated with a reduced diversity of C sources consumed by soil microbial communities(β=-0.353,SE=0.172,P=0.041)with the R2 value of 0.290,explaining 29%of the variance in Shannon diversity index values.Our results indicate that mammal and tree communities have complementary effects on soil microbial C consumption,improving our understanding of the functioning of C cycle in the high-diversity Amazon biome.These findings are crucial in elucidating the intricate connections between above-and belowground biodiversity that influence the accumulation and stabilization of soil organic C.展开更多
Over the past six decades,the implementation of soil and water conservation measures has significantly reduced soil erosion and sediment yield on the Loess Plateau,China.However,while the overall reduction is well-doc...Over the past six decades,the implementation of soil and water conservation measures has significantly reduced soil erosion and sediment yield on the Loess Plateau,China.However,while the overall reduction is well-documented,the dynamic interplay between soil erosion potential and sediment connectivity,specifically how they spatially covary under land use/cover changes,remains insufficiently understood.To address this gap,this study established a model framework by integrating the revised universal soil loss equation(RUSLE),index of connectivity(IC),and sediment delivery ratio(SDR)to evaluate the spatio-temporal variations in soil erosion and sediment yield in the Hantaichuan Watershed,northern Loess Plateau,China,from 1995 to 2020 and to estimate the effects of land use/cover changes and check dam construction on sediment yield.The results revealed that the soil erosion in the Hantaichuan Watershed decreased by 43.90% from 1995 to 2020 and the sediment yield decreased by 69.28% under the combination of land use/cover changes and check dam construction.The IC and soil erosion(IC-SE)map revealed both the coupling and decoupling covariation relationships between sediment connectivity and soil erosion.By 2020,areas with high connectivity and high erosion(I-E)covered only 18.67% of the watershed,while contributed more than 40.00% to the total erosion.The I-E zones were mainly located in the central part of the watershed where aeolian sands derived from the Hobq Desert are concentrated and were identified as critical areas for soil and water conservation.This study provides support for priority management of watershed conservation measures as well as a valuable reference for future studies.展开更多
[Objectives]The soil permeability and its influencing factors in typical plantations were studied to provide a scientific basis for tending and managing plantations in the Haikou forest area of Kunming City.[Methods]W...[Objectives]The soil permeability and its influencing factors in typical plantations were studied to provide a scientific basis for tending and managing plantations in the Haikou forest area of Kunming City.[Methods]With three kinds of typical forest stands,i.e.,over-mature Pinus armandii Franch.,mid-mature Eucalyptus robusta Smith,and over-mature E.robusta Smith in this region as the research objects,soil infiltration changes and the effects on soil water retention in different stands,soil layers,and gap conditions under different moisture conditions were analyzed.[Results]①Under all three moisture conditions,the over-mature P.armandii forest demonstrated higher overall infiltration rates than the other two forest stands,which showed relatively similar infiltration rates.In all three stands,the soil infiltration rate decreased as the depth of the soil increased.Significant fluctuations in soil infiltration rate were observed during the initial 0-5 min,followed by gradual stabilization or regular fluctuations after 5 min.The infiltration process generally reached saturation after approximately 20 min.②The average infiltration rate was identified as the key factor affecting soil infiltration.Comprehensive evaluation of soil permeability revealed that the over-mature P.armandii forest exhibited optimal soil permeability.③Various soil physical and chemical properties significantly affected different indexes of soil permeability under varying conditions,with soil organic carbon content and water repellency demonstrating particularly notable effects on infiltration under different conditions.[Conclusions]Soil infiltration rates gradually decreased with the deepening of the soil layer.Principal component analysis(PCA)showed that the soil permeability of the over-mature P.armandii forest was stronger than that of the other two stands under the three moisture conditions,especially in non-gap positions.All soil indexes affected soil permeability,and soil organic carbon and water repellency were the key factors affecting soil permeability.展开更多
Oasis soils in Tunisia are characterized by low soil organic carbon(SOC)stocks,primarily due to their coarse texture and intensive irrigation practices.In the Gataaya Oasis,soils receive 3.000 to 4.000 L/m^(2) annuall...Oasis soils in Tunisia are characterized by low soil organic carbon(SOC)stocks,primarily due to their coarse texture and intensive irrigation practices.In the Gataaya Oasis,soils receive 3.000 to 4.000 L/m^(2) annually through submersion irrigation,leading to a rapid decline in SOC stocks.Despite their sandy texture,which promotes good water infiltration,these soils are enriched with clay,dissolved materials,and fertilizers in deeper horizons.This study aimed to assess SOC content in the Gataaya Oasis soils,investigate the transport of labile carbon in drainage water,and clarify the destiny of this transported carbon.Soil samples were collected systematically at three depths(0–10,10–20,and 20–30 cm),focusing on the top 30 cm depth,which is most affected by amendments.Two sampling points(P1 and P2)were selected,i.e.,P1 profile near the trunk of date palms(with manure input)and P2 profile between two adjacent date palms(without manure input).Water samples were collected from drainage systems within the oasis(W1,W2,and W3)and outside the oasis(W4).A laboratory experiment simulating manure application and irrigation was conducted to complement field observations.Physical-chemical analyses revealed a significant decrease in SOC stocks with soil depths.In P1 profile,SOC stocks declined from 17.71 t/hm^(2) at the 0–10 cm depth to 7.80 t/hm^(2) at the 20–30 cm depth.In P2 profile,SOC stocks were lower,decreasing from 6.73 t/hm^(2) at the 0–10 cm depth to 3.57 t/hm^(2) at the 20–30 cm depth.Labile carbon content in drainage water increased outside the oasis,with chemical oxygen demand(COD)values rising from 73 mg/L in W1 water sample to 290 mg/L in W4 water sample,indicating cumulative leaching effects from surrounding oases.The laboratory experiment confirmed field observations,showing a decline in soil organic matter(SOM)content from 3.27%to 2.62%after 12 irrigations,highlighting the vulnerability of SOC stocks to intensive irrigation.This study underscores the low SOC stocks in the Gataaya Oasis soils and their rapid depletion under successive irrigations.The findings provide insights into the dynamics of labile carbon transport and its contribution to regional carbon cycling,offering valuable information for sustainable soil management and ecological protection in arid ecosystems.展开更多
Artificial cyanobacteria crusts are formed by inoculating soil with cyanobacteria.These crusts help prevent soil erosion and restore soil functionality in degraded croplands.However,how fast the artificial cyanobacter...Artificial cyanobacteria crusts are formed by inoculating soil with cyanobacteria.These crusts help prevent soil erosion and restore soil functionality in degraded croplands.However,how fast the artificial cyanobacteria crusts can be formed is a key issue before their practical application.In addition,the effects of artificial cyanobacteria crusts on soil nutrients and plant growth are not fully explored.This study analyzed the effect of inoculation of cyanobacteria from local biological soil crusts on soil nutrients and Pak-choi(Brassica campestris L.ssp.Chinensis Makino var.communis Tsen et Lee;Chinese cabbage)growth in a cropland,northern China through field experiments by comparing with no fertilizer.The results showed that artificial cyanobacteria crusts were formed on the 18th d after inoculation with a coverage of 56.13%,a thickness of 3.74 mm,and biomass of 22.21μg chla/cm^(2).Artificial cyanobacteria crusts significantly improved the soil organic matter(SOM),NO_(3)^(-)-N,total nitrogen(TN)contents,and the activities of sucrase,alkaline phosphatase,urease,and catalase enzymes of plants on the 50th d after inoculation.Additionally,artificial cyanobacteria crusts led to an increase in plant biomass,improved root morphology,and raised the phosphorus and potassium contents in the plants.Furthermore,the biomass of plant grown with artificial cyanobacteria crusts was comparable with that of grown with chemical fertilizer.The study suggested that,considering plant biomass and soil nutrients,it is feasible to prevent wind erosion in the cropland of arid and semi-arid areas by inoculating cyanobacteria crusts.This study provides new perspectives for the sustainable development and environmental management of cropland in arid and semi-arid areas.展开更多
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funded by the National Key Research and Development Program of China(2024YFD1501602)the National Natural Science Foundation of China(42407437)conducted as part of the Coordinated Research Project D1.50.16,implemented by the Soil and Water Management and Crop Nutrition Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture,Department of Nuclear Sciences and Applications,Vienna,Austria。
文摘Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.
基金supported by the Department of Biotechnology,Government of India(DBT),TWAS,and the Ministry of Innovative Development of Uzbekistan。
文摘The combined effects of macronutrients(Nitrogen,Phosphorus,and Potassium-N,P,K)and micronutrient fertilization on turmeric yield,soil enzymatic activity,microbial biomass,and nutrient dynamics remains poorly understood,despite their significance for sustainable soil fertility management and optimizing crop productivity across diverse agroecosystems.To investigate,a net house experiment on sandy loam Haplic Chernozem was conducted to 03 fertilizer regimes,viz.N_(75)P_(50)K_(50)kg ha^(−1)(T-2),N_(12)5P_(100)K_(100)kg ha^(−1)(T-3),and N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg ha^(−1)(T-4).Furthermore,the influence of these treatments was systematically assessed on soil nutrient status(N,P,K),enzymatic activities(alkaline phosphomonoesterase,dehydrogenase,fluorescein diacetate hydrolysis),microbial biomass carbon(MBC)and soil organic carbon(SOC).Balanced fertilization significantly turmeric productivity and soil health.All three fertilizer treatments showed a clear yield increase compared to the unfertilized control.Compared to the control,N_(75)P_(50)K_(50)kg/ha T-2 increased rhizome number and biomass per plant by 44.7%and 16.3%,respectively,while N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg/ha T-4 further enhanced them by 86.6%and 27.7%.T-3 produced the most significant yield response by increasing the rhizome biomass by 38.0%and rhizome number per plant by 100%compared to the control.The nutrient availability was also substantially improved.T-2 enhanced the soil nitrogen contents by 83.3%with maximum N levels observed in T-3&T-4.Phosphorus increased by 61.5%in T-3 and 37.3%in T-4,while potassium was enhanced by 12.9%in T-3 relative to the control,respectively.Enzymatic activities were markedly enhanced as T-3 was recorded to improve alkaline phosphomonoesterase(APA),dehydrogenase(DHA)and fluorescein diacetate hydrolysis(FDA)by 50.6%,37.4%,and 43.4%,where T-4 increased by 32.2%,30.9%,and 35.9%,respectively compared to control.MBC and SOC also rose significantly,with SOC increased by 13.8%(T-2),41.6%(T-3),and 47.2%(T-3)relative to control.The result of this study demonstrates that the integrated macroµnutrient fertilization,particularly T-37 T-4 treatments,sustainably enhanced turmeric yield,soil nutrient availability,enzyme activity,microbial biomass,and organic carbon.These findings highlight the critical role of balanced nutrient management in sustaining soil fertility and crop productivity across agroecosystems.
文摘Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.
基金supported by the National Natural Science Foundation of China(32130069)the National Key Research and Development Program of China(2024YFF1306700)the Scientific Research Foundation of Education Department of Yunnan Province(2024Y004).
文摘Soil greenhouse gas(GHG)emissions contribute profoundly to global warming;however,how plant detritus input alters GHG emissions is poorly understood.Here,we used detritus input and removal treatments(i.e.,DIRT:control,CK;double litter,DL;no roots with double litter,NRDL;no litter,NL;no roots,NR;no roots and no litter,NRNL)to assess the effects of litter and root inputs on soil CO_(2),CH_(4),and N_(2)O fluxes in soils in a coniferous(Pinus yunnanensis)and a broad-leaf forest(Quercus pannosa)in a subalpine region in southwestern China.Litter addition increased CO_(2) emissions on average 22.22%,but did not significantly alter CH_(4) uptake and N_(2)O emission compared to the CK.Litter removal(NL and NRNL)significantly reduced CO_(2) emissions on average 30.22%and N_(2)O emissions on average 31.16%from both forest soils,but did not significantly affect soil CH_(4) uptake.Root removal(NR and NRNL)generally decreased these three soil GHG fluxes.Changes inβ-1,4-glucosidase(BG)involved in C and phospholipid fatty acid(PLFAs)biomass were projected to influence CO_(2) emissions,while soil microclimates(temperature and moisture)combined with BG activity mainly regulated CH_(4) uptake.Alterations in dissolved organic nitrogen,microbial biomass nitrogen and BG were mainly responsible for changes in N_(2)O emissions.Interestingly,coniferous forest soil seemed to promote CH_(4) uptake more than the broad-leaf forest soil,but CO_(2) and N_(2)O fluxes were not significantly affected by the forest types.As expected,litter addition significantly increased the warming potential,while litter removal relatively lowered it.These findings revealed the divergent roles of plant detritus input and forest type in shaping soil GHG fluxes,thereby providing insights into forest management and predicting contributions of subalpine forests to global warming.
基金Under the auspices of the National Natural Science Foundation of China(No.42430511,U20A2083)the National Key Research and Development Program of China(No.2022YFF1300900)the Science and Technology Development Program of Jilin Province(No.20210509037RQ,20230101348JC)。
文摘Elevation patterns and assembly processes of soil microbial community structures are essential for understanding biogeo-chemical processes in mountain systems.Differences in soil properties caused by elevation gradients can regulate the spatial distribu-tion and network complexity of the community structure.To explore the variations in soil microbial community structures and their as-sembly mechanisms across different elevations of the Changbai Mountains,as well as their responses to environmental factors,we col-lected microbial samples along an elevational gradient(seven elevations containing four vegetation zones)on the western slope of the Changbai Mountains using the method of metagenomic sequencing.The results showed a significant difference(P<0.05)for the Chao1 index across different elevations,but no significant difference was observed for the Shannon and Simpson indices.With increasing elev-ation,the number of nodes and links in the microbial network gradually decreased.Acidobacteria were highly connected to many nodes.The microbial communities indicated a significant distance-decay relationship(P<0.001)and were affected more by stochastic pro-cesses along the elevation gradient.The results of the Structural Equation Model(SEM)showed that elevation had direct significant ef-fect on carbon(C,P<0.01),nitrogen(N,P<0.01),and phosphorus(P,P<0.05)and weak negative effect on their ecological stoi-chiometry.Elevation was one of the major variables contributing to microbial network topology.The contribution of C and N to micro-bial network complexity was higher than that of P.Our study provides valuable insights into the responses of soil microbial communit-ies to elevation variations.
基金funded by the National Natural Science Foundation of China(32471824,32171746,31870522,42477227,and 32560282)the leading talents of basic research in Henan Province(24XM0375)+6 种基金Excellent Youth Creative Research Group Project in Henan Province(252300421002)Foreign Scientists Studio in Henan Province(GZS2025011)MOHRSS National Foreign Expert Individual Projectsand(110000264820258001)Natural Science Foundation of Henan(242300420604)supported by the Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control(2023B1212060002)the High-level University Special Fund(G03050K001)the China Postdoctoral Science Foundation(No.2021M690922).
文摘Soil compaction often imposes stress on root development and plant survival.However,root anatomical responses that enable persistent root growth and functioning under soil compaction remain unclear.We grew 10 herbaceous species differing substantially in lateral root diameter,in soils with low(1.0 g cm^(-3))and high(1.4 g cm^(-3))bulk density,and assessed root traits including root biomass,anatomical structures,and respiration rates.Greater root thickening upon soil compaction was found in species with thicker first-order lateral roots,mainly due to larger cortical cell size.Both xylem vessel diameter and wall thickness increased more in compacted soils in these species.Despite these anatomical shifts,root respiration rate responded little to soil compaction across most species,likely due to the opposite investment in cortical cells and xylem vessels.Notably,root biomass,independent of root respiration rate and anatomical structures,determined whole-plant growth under soil compaction.Our study reveals two independent strategies of root response to soil compaction:anatomical remodeling for mechanical and metabolic maintenance,and root biomass investment for resource acquisition.These findings offer new insights for breeding and selecting species tolerant to soil compaction and highlight multidimensional strategies of plant adaptation to physical stress.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272393 and 52130905).
文摘As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalent parameters of SRMs,which are typically obtained through experimental and numerical methods.In contrasted to other numerical methods,the numerical manifold method(NMM)is more effective in addressing SRM problems.This is because the high-precision regular mathematical meshes in NMM can be used without aligning with the soil-rock interfaces and boundaries of SRMs.In the current research,the equivalent strength parameters of SRMs,i.e.the equivalent cohesion ce and internal friction angleϕ_(e),are determined using NMM.Initially,an NMM triaxial numerical model is established and validated based on triaxial experiments.Subsequently,the soil and rock parameters are derived through parameter inversion.Moreover,the impacts of rock content,size,shape and rock blocks'major-axis orientation on ce andϕ_(e) of SRMs are thoroughly examined using the NMM triaxial numerical model.Additionally,a fitting function is proposed to linkϕ_(e) to the rock content and size of SRMs.When other influencing factors are fixed,the above fitting model leads to the following conclusions:(1)the predictedϕ_(e) of SRMs increase with the increase of rock content;and(2)SRM samples with smaller rocks display a higher predictedϕ_(e).
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program of China(No.2019QZKK0306-02)the National Natural Science Foundation of China(Nos.42322102 and 42271058)+1 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2021310)the Science&Technology Fundamental Resources Investigation Program of China(No.2022FY100202)
文摘Soil organic carbon(SOC):total nitrogen(TN):total phosphorus(TP)(C:N:P)stoichiometry can give important information about biogeochemical cycling in terrestrial ecosystems.The spatial patterns and driving mechanisms of soil C:N:P ratios are still poorly understood on the Qinghai-Tibetan Plateau of China.In this study,we therefore combined data of the geography,climate,soil properties,and vegetation characteristics from 319 sites across the plateau to investigate their relationships with the horizontal and vertical patterns of SOC,TN,and TP concentrations and their stoichiometric ratios(C:N and N:P).We observed higher SOC(30.5–46.8 mg g^(-1)),TN(2.4–3.4 mg g^(-1)),C:N(14.7–18.0),and N:P(6.9–8.0)in alpine meadows,forests,and shrublands and higher TP(1.6 mg g^(-1))in croplands.Overall,SOC,TN,TP,C:N,and N:P showed decreasing trends(by 67%,64%,19%,12%,and 54%,respectively)along the whole soil profile(0–100 cm).Soil cation exchange capacity and bulk density were the stronger environmental drivers of SOC and TN.Soil TP showed latitudinal and longitudinal increasing trends in all soil layers.Soil properties explained most of the variations in SOC(67%–90%),TN(67%–87%),C:N(61%–89%),and N:P(64%–85%),with increasing impacts along the soil profile.Geography and climate influenced soil TP directly and indirectly through their impacts on soil properties,with geography being the predominant driver(46%–65%)along the soil profile.The variation in soil C:N was mostly driven by SOC and TN,and the direct and indirect effects of the environmental factors were relatively weak.Geography,climate,soil properties,and vegetation characteristics indirectly impacted soil N:P through their impacts on TN and TP in all the soil layers.Altogether,our findings illuminate the relative contributions of geography,climate,soil properties,and vegetation characteristics to soil C:N and N:P,thus enhancing our understanding of C,N,and P cycling across the Qinghai-Tibetan Plateau.
基金supported by the Shenyang Municipal Science and Technology Project,China(23-409-2-03)the Liaoning Provincial Department of Science and Technology Project,China(Z20230183)the Liaoning Provincial Applied Basic Research Program,China(2022JH2/101300173).
文摘Both soil organic carbon (SOC) and iron (Fe) oxide content, among other factors, drive the formation and stability of soil aggregates.However, the mechanism of these drivers in greenhouse soil fertilized with organic fertilizer is not well understood.In a 3-year field experiment, we aimed to investigate the factors which drive the stability of soil aggregates in greenhouse soil.To explore the impact of organic fertilizer on soil aggregates, we established four treatments:no fertilization (CK);inorganic fertilizer (CF);organic fertilizer (OF);and combined application of inorganic and organic fertilizers(COF).The application of organic fertilizer significantly enhanced the stability of aggregates, that is it enhanced the mean weight diameter, geometric mean diameter and aggregate content (%) of>0.25 mm aggregate fractions.OF and COF treatments increased the concentration of SOC, especially the aliphatic-C, aromatic-C and polysaccharide-C components of SOC, particularly in>0.25 mm aggregates.Organic fertilizer application significantly increased the content of free Fe(Fed), reactive Fe (Feo), and non-crystalline Fe in both bulk soil and aggregates.Furthermore, non-crystalline Fe showed a positive correlation with SOC content in both bulk soil and aggregates.Both non-crystalline Fe and SOC were significantly positively correlated with>2 mm mean weight diameter.Overall, we believe that the increase of SOC, aromatic-C, and non-crystal ine Fe concentrations in soil after the application of organic fertilizer is the reason for improving soil aggregate stability.
基金supported by the National Key Research and Development Program of China(2023YFD1900300 and 2017YFD0200205)the Agricultural Key-scientific and Core-technological Project of Shaanxi Province,China(2024NYGG011)。
文摘The continuous supply of phosphorus(P)is indispensable in crop production.However,P resources are non-renewable,and environmental concerns like eutrophication associated with its loss from agroecosystems make the sustainable management of P resources essential for ensuring global food security.This study was designed to reduce mineral P inputs through management practices.A field experiment comprising a wheat-maize rotation system was conducted in the Guanzhong Plain of Shaanxi Province,China from 2018-2023.The eight treatments included CK(without P),FP(conventional P application);RP(recommended P);RP80(20% reduction in RP);SRP80(20% reduction in RP with straw wrapping);ARP80(20% reduction in RP with ammonium sulfate instead of urea);SARP80(20% reduction in RP with straw wrapping and ammonium sulfate instead of urea);and SARP60(40% reduction in RP with straw wrapping and ammonium sulfate instead of urea).Crop yield,P uptake,and P fertilizer use efficiency were measured during harvest and throughout the entire period of the study.At the end of the experiment,P fractions were estimated using the Tiessen-Moir P classification method.The results revealed that the grain yields of all the treatments except for RP80 were significantly increased compared to CK,with increases of 14.9-28.8%.Furthermore,agronomic efficiency,apparent P use efficiency,P recovery rate,and partial factor productivity were significantly improved for the treatments that received 20% less P with straw wrapping.Moreover,the enhancement measures significantly increased labile and moderately labile P in the soil.Therefore,straw wrapping with ammonium sulfate instead of urea is one of the most effective ways to reduce mineral P inputs while increasing the efficiency of P in wheat-maize rotation systems.
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 the National Natural Science Foundation of China(Grant No.42325502,and 42275045)the West Light Foundation of the Chi-nese Academy of Sciences(Grant No.xbzg-zdsys-202215)+1 种基金the Sci-ence and Technology Research Plan of Gansu Province(Grant Nos.23JRRA654 and 20JR10RA070)iLEAPs(Integrated Land Ecosystem-Atmosphere Processes Study).
文摘The source region of the Yellow River(SRYR),with its semi-humid to semi-arid climate,is crucial for understanding water resource dynamics.Precipitation is key for replenishing surface water and balancing the ecosystem’s water cycle.However,the soil moisture response to precipitation across climate zones and soil layers remains poorly understood due to limited long-term data.This study examines the response of soil moisture to precipitation at multiple time scales in the SRYR,using data from Maqu,Mado,Ngoring Lake sites,and the Maqu monitoring network(MMN),along with CN05.1 precipitation and GLEAM v3.8a soil moisture data.Results show that the semi-humid area requires more precipitation to trigger soil moisture responses compared to the semi-arid area in the SRYR.Surface soil at Maqu,MMN,Ngoring Lake,and Mado sites require at least 8.6,8.4,5.2,and 2.84 mm of precipitation,respectively,for effective replenishment.Significant responses to precipitation events were observed in soil layers at 40 cm and above in the semi-humid area,while at 20 cm and above in the semi-arid area.Precipitation volume is the primary factor influencing soil moisture,affecting both the increment and time lag to maximum moisture.Precipitation intensity and pre-rain moisture have no direct effect.In the central SRYR,accumulated precipitation has a greater impact.Root-zone soil moisture has a weaker correlation with precipitation compared to surface soil moisture but persists longer,responding for up to 10 days,while surface soil moisture responds more immediately but only lasts about 5 days.
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.
文摘Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly based on short-term studies has been encouraging and the trend obtained so far has raised many hopes. Biochar has been reported to positively impact an array of soil processes ranging from benefiting soil biology, controlling soil-borne pathogens, enhancing nitrogen fixation, improving soil physical and chemical properties,decreasing nitrate(NO-3) leaching and nitrous oxide(N2O) emission to remediation of contaminated soils. However, very little biochar is still utilized as soil amendment mainly because these benefits are yet to be quantified, and also the mechanisms by which the soil health is improved are poorly understood. Due to the infancy of research regarding this subject, there are still more questions than answers. The future research efforts must focus on carrying out long-term experiments and uncover the mechanisms underlying these processes so that key concerns surrounding the use of biochar are addressed before its large scale application is recommended.
文摘Trees,mammals,and microbes relate to soil carbon(C)cycle.Trees capture C,and mammals consume plants and other animals,both contributing to organic remains that are then degraded by soil microbes.This organic C can be stored in soils or released into the atmosphere through microbial mineralization.Yet,the simultaneous effects of mammals and trees on C consumption by soil microbes have not been investigated.For 30 sampling sites in a mixed forest-savanna environment in southern Guyana,we jointly analyzed observational data of mammal and tree communities along with soil organic matter(SOM)composition(using Fourier transform infrared spectroscopy combined with attenuated total reflectance,energy dispersive X-ray fluorescence spectrometry,and CNH elemental analyzer)and soil microbial C consumption(using Biolog EcoPlates).It was found that higher mammal functional richness(FRic)and functional evenness(FEve)were related to reduced overall C consumption by soil microbes(for FRic:regression coefficient(β)=-0.010,standard error(SE)=0.005,P=0.034;for FEve:β=-0.012,SE=0.005,P=0.010)with the coefficient of determination(R^(2))value of 0.359,explaining 36%of the variance in average well color development values,whereas a higher tree richness was associated with a reduced diversity of C sources consumed by soil microbial communities(β=-0.353,SE=0.172,P=0.041)with the R2 value of 0.290,explaining 29%of the variance in Shannon diversity index values.Our results indicate that mammal and tree communities have complementary effects on soil microbial C consumption,improving our understanding of the functioning of C cycle in the high-diversity Amazon biome.These findings are crucial in elucidating the intricate connections between above-and belowground biodiversity that influence the accumulation and stabilization of soil organic C.
基金supported by the National Natural Science Foundation of China (42077076, 42177323)the National Natural Science Foundation of ChinaYellow River Water Science Research Joint Fund (U2243211)。
文摘Over the past six decades,the implementation of soil and water conservation measures has significantly reduced soil erosion and sediment yield on the Loess Plateau,China.However,while the overall reduction is well-documented,the dynamic interplay between soil erosion potential and sediment connectivity,specifically how they spatially covary under land use/cover changes,remains insufficiently understood.To address this gap,this study established a model framework by integrating the revised universal soil loss equation(RUSLE),index of connectivity(IC),and sediment delivery ratio(SDR)to evaluate the spatio-temporal variations in soil erosion and sediment yield in the Hantaichuan Watershed,northern Loess Plateau,China,from 1995 to 2020 and to estimate the effects of land use/cover changes and check dam construction on sediment yield.The results revealed that the soil erosion in the Hantaichuan Watershed decreased by 43.90% from 1995 to 2020 and the sediment yield decreased by 69.28% under the combination of land use/cover changes and check dam construction.The IC and soil erosion(IC-SE)map revealed both the coupling and decoupling covariation relationships between sediment connectivity and soil erosion.By 2020,areas with high connectivity and high erosion(I-E)covered only 18.67% of the watershed,while contributed more than 40.00% to the total erosion.The I-E zones were mainly located in the central part of the watershed where aeolian sands derived from the Hobq Desert are concentrated and were identified as critical areas for soil and water conservation.This study provides support for priority management of watershed conservation measures as well as a valuable reference for future studies.
文摘[Objectives]The soil permeability and its influencing factors in typical plantations were studied to provide a scientific basis for tending and managing plantations in the Haikou forest area of Kunming City.[Methods]With three kinds of typical forest stands,i.e.,over-mature Pinus armandii Franch.,mid-mature Eucalyptus robusta Smith,and over-mature E.robusta Smith in this region as the research objects,soil infiltration changes and the effects on soil water retention in different stands,soil layers,and gap conditions under different moisture conditions were analyzed.[Results]①Under all three moisture conditions,the over-mature P.armandii forest demonstrated higher overall infiltration rates than the other two forest stands,which showed relatively similar infiltration rates.In all three stands,the soil infiltration rate decreased as the depth of the soil increased.Significant fluctuations in soil infiltration rate were observed during the initial 0-5 min,followed by gradual stabilization or regular fluctuations after 5 min.The infiltration process generally reached saturation after approximately 20 min.②The average infiltration rate was identified as the key factor affecting soil infiltration.Comprehensive evaluation of soil permeability revealed that the over-mature P.armandii forest exhibited optimal soil permeability.③Various soil physical and chemical properties significantly affected different indexes of soil permeability under varying conditions,with soil organic carbon content and water repellency demonstrating particularly notable effects on infiltration under different conditions.[Conclusions]Soil infiltration rates gradually decreased with the deepening of the soil layer.Principal component analysis(PCA)showed that the soil permeability of the over-mature P.armandii forest was stronger than that of the other two stands under the three moisture conditions,especially in non-gap positions.All soil indexes affected soil permeability,and soil organic carbon and water repellency were the key factors affecting soil permeability.
基金financially supported by the Ministry of Higher Education and Scientific Research of Tunisia.
文摘Oasis soils in Tunisia are characterized by low soil organic carbon(SOC)stocks,primarily due to their coarse texture and intensive irrigation practices.In the Gataaya Oasis,soils receive 3.000 to 4.000 L/m^(2) annually through submersion irrigation,leading to a rapid decline in SOC stocks.Despite their sandy texture,which promotes good water infiltration,these soils are enriched with clay,dissolved materials,and fertilizers in deeper horizons.This study aimed to assess SOC content in the Gataaya Oasis soils,investigate the transport of labile carbon in drainage water,and clarify the destiny of this transported carbon.Soil samples were collected systematically at three depths(0–10,10–20,and 20–30 cm),focusing on the top 30 cm depth,which is most affected by amendments.Two sampling points(P1 and P2)were selected,i.e.,P1 profile near the trunk of date palms(with manure input)and P2 profile between two adjacent date palms(without manure input).Water samples were collected from drainage systems within the oasis(W1,W2,and W3)and outside the oasis(W4).A laboratory experiment simulating manure application and irrigation was conducted to complement field observations.Physical-chemical analyses revealed a significant decrease in SOC stocks with soil depths.In P1 profile,SOC stocks declined from 17.71 t/hm^(2) at the 0–10 cm depth to 7.80 t/hm^(2) at the 20–30 cm depth.In P2 profile,SOC stocks were lower,decreasing from 6.73 t/hm^(2) at the 0–10 cm depth to 3.57 t/hm^(2) at the 20–30 cm depth.Labile carbon content in drainage water increased outside the oasis,with chemical oxygen demand(COD)values rising from 73 mg/L in W1 water sample to 290 mg/L in W4 water sample,indicating cumulative leaching effects from surrounding oases.The laboratory experiment confirmed field observations,showing a decline in soil organic matter(SOM)content from 3.27%to 2.62%after 12 irrigations,highlighting the vulnerability of SOC stocks to intensive irrigation.This study underscores the low SOC stocks in the Gataaya Oasis soils and their rapid depletion under successive irrigations.The findings provide insights into the dynamics of labile carbon transport and its contribution to regional carbon cycling,offering valuable information for sustainable soil management and ecological protection in arid ecosystems.
基金supported by the National Key Research and Development Program of China(2022YFF1300802)the National Natural Science Foundation of China(42377357).
文摘Artificial cyanobacteria crusts are formed by inoculating soil with cyanobacteria.These crusts help prevent soil erosion and restore soil functionality in degraded croplands.However,how fast the artificial cyanobacteria crusts can be formed is a key issue before their practical application.In addition,the effects of artificial cyanobacteria crusts on soil nutrients and plant growth are not fully explored.This study analyzed the effect of inoculation of cyanobacteria from local biological soil crusts on soil nutrients and Pak-choi(Brassica campestris L.ssp.Chinensis Makino var.communis Tsen et Lee;Chinese cabbage)growth in a cropland,northern China through field experiments by comparing with no fertilizer.The results showed that artificial cyanobacteria crusts were formed on the 18th d after inoculation with a coverage of 56.13%,a thickness of 3.74 mm,and biomass of 22.21μg chla/cm^(2).Artificial cyanobacteria crusts significantly improved the soil organic matter(SOM),NO_(3)^(-)-N,total nitrogen(TN)contents,and the activities of sucrase,alkaline phosphatase,urease,and catalase enzymes of plants on the 50th d after inoculation.Additionally,artificial cyanobacteria crusts led to an increase in plant biomass,improved root morphology,and raised the phosphorus and potassium contents in the plants.Furthermore,the biomass of plant grown with artificial cyanobacteria crusts was comparable with that of grown with chemical fertilizer.The study suggested that,considering plant biomass and soil nutrients,it is feasible to prevent wind erosion in the cropland of arid and semi-arid areas by inoculating cyanobacteria crusts.This study provides new perspectives for the sustainable development and environmental management of cropland in arid and semi-arid areas.
