This paper presents the results from a case study highlighting the difficulties of pile driving in diatomaceous soils.In the companion(first)paper to this article,results of an extensive laboratory and in situ testing...This paper presents the results from a case study highlighting the difficulties of pile driving in diatomaceous soils.In the companion(first)paper to this article,results of an extensive laboratory and in situ testing program were presented while the results from pile driving and further analysis of field observations were presented herein.Unexpected high pile rebound(HPR)was observed during driving of a closed-end pipe pile,with refusal occurring at a depth of less than 5 m.Subsequent open-ended piles were thus driven.Piezometer and case pile wave analysis program(CAPWAP)data were collected during driving of both closed-and open-end piles.Piezometer data indicated that negative pore water pressures(PWPs)were generated while the closed-ended pile exhibited high rebound.Results from in situ tests indicated change in material stiffness and strong dilative tendencies near the depth of refusal.A hypothesis for observed behavior was proposed that considers the soil beneath the pile as a medium with an effectively infinite bulk modulus.展开更多
Diatomaceous soils are comprised of the silica frustules of diatom microalgae that are present in marine and lacustrine environments throughout the world.Owing to their unique origin,diatomaceous soils are typically c...Diatomaceous soils are comprised of the silica frustules of diatom microalgae that are present in marine and lacustrine environments throughout the world.Owing to their unique origin,diatomaceous soils are typically characterized by high intraparticle porosity,complex particle shapes,and uniform mineralogy,causing them to exhibit atypical physical and engineering behaviors.A substantial deposit of diatomaceous silt was observed during site exploration for construction of the Buck Creek Bridge on OR140 near Klamath Falls,OR,USA.A comprehensive laboratory and in situ testing program indicated that the diatomaceous soil possessed“non-textbook”engineering properties.Specifically,tested samples had high liquid limits(≈100%-140%)with natural water contents at or near the liquid limit.Geologically,the soil is expected to be normally consolidated,yet high apparent overconsolidation ratios(OCR)(≈15-40)were observed both in oedometric consolidation tests and through cone penetration test(CPT)correlations.Standard penetration test(SPT)results show a corrected standard penetration resistance consistent with a medium-dense sand(i.e.(N1)_(60)≈25).CPT results include corrected tip resistances(qt)of approximately 7-10 MPa and excess pore pressures(u_(2))of up to 4 MPa.In CPT dissipation tests,pore water pressures(PWPs)returned to hydrostatic pressure in less than 1 h.In this work,we synthesize these seemingly disparate material properties in an attempt to infer appropriate engineering properties for the diatomaceous deposit at the Buck Creek Bridge and attempt to provide insight into the underlying reasons for the observed behavior.展开更多
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
[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucid...[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucidating the global response patterns of soil moisture to vegetation restoration and identifying research hotspots are critical for guiding ecological construction in arid regions.[Methods]We reviewed 6,152 articles concerning soil moisture and vegetation retrieved from the Web of Science platform.Using VOSviewer,we conducted analyses of keyword co-occurrence,publication trends,and research hotspots to systematically delineate the evolving trends in this field.[Results]The results indicate a significant increasing trend in the number of publications since 2000.Global research keywords are categorized into seven clusters,including vegetation,soil moisture,rainfall-erosion-infiltration,spatial heterogeneity,and climate change.In terms of highly cited papers in 2024,China and the United States maintain a significant lead.Global research demonstrates a strong dependency on typical regional geographical features(such as climate types and topography),exhibiting differentiated research focuses.Furthermore,studies extend beyond soil moisture itself to deeply couple with ecological processes such as vegetation restoration,soil respiration,carbon cycling,and hydrothermal conditions.[Conclusions]The long-term ecological effects of afforestation in arid regions remain unclear,and empirical data from key regions highlight the current urgency.Future research should integrate climate change dynamics,innovate monitoring methodologies,and deepen the understanding of regional differentiation to provide scientific support for the adaptive management of vegetation in arid regions.展开更多
39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.Ar...39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.ArcGIS inverse distance weight difference method was used to analyze the characteristics of pollution distribution,and single-factor pollution index,Nemerow comprehensive pollution index,ground accumulation index,and potential ecological risk index were selected to evaluate the characteristics of heavy metal pollution.Based on correlation analysis,the absolute principal component-multiple linear regression(APCS-MLR)and positive definite matrix factorization(PMF)models were used to analyze the sources of soil heavy metals.The results showed that the average concentrations of all eight heavy metals exceeded both national and Guangxi soil background values.Hg,Cd,and Zn exhibited high variation(greater than 0.5),indicating significant external disturbances,and their spatial distribution was closely related to mining activity locations.The single-factor pollution index evaluation indicated varying degrees of pollution risk for Cd,Zn,and As,with Cd and Zn being the most severe pollutants,as 69.23%and 30.77%of the samples fell into the moderate pollution or higher category.The geoaccumulation index analysis ranked the mean pollution levels of the eight elements as follows:Zn>Cd>Ni>Pb>Cu>Cr>Hg>As,with Cd and Zn showing the most severe contamination,and 51.28%of the samples exhibiting moderate or higher pollution levels.The Nemerow comprehensive pollution index evaluation showed that 74.35%of soil samples were classified as moderate to heavy pollution.The potential ecological risk index assessment indicated significant ecological risks posed by Cd and Zn,with 82.05%and 5.12%of the samples classified as causing strong to extreme ecological risks,respectively.The source apportionment analysis revealed minor differences between the two models.The APCS-MLR model identified three pollution sources and their contribution rates:anthropogenic mining sources(31.13%),parent material sources(40.38%),and unidentified sources(28.49%).The PMF model identified three pollution sources with contribution rates of anthropogenic mining sources(26.10%),parent material sources(46.96%),and a combined traffic and agricultural source(26.61%).Pb,Hg,Cd,and Zn mainly originated from mining activities;Cr,As,and Ni were primarily derived from the parent material,while Cu was predominantly attributed to traffic and agricultural sources.These findings provide a scientific basis for the prevention and control of heavy metal pollution in mining areas.展开更多
The 23rd World Congress of Soil Science(23rd WCSS),to be held on June 7-12,2026 in Nanjing,China,marks a historic coming of this century-old scientific gathering to one of the world's ancient agricultural civiliza...The 23rd World Congress of Soil Science(23rd WCSS),to be held on June 7-12,2026 in Nanjing,China,marks a historic coming of this century-old scientific gathering to one of the world's ancient agricultural civilizations.Since its inception in1927,this will be the first time the Congress is hosted in China,a land whose agricultural resilience has been nurtured by millennia of soil stewardship.展开更多
Phosphorus(P)leaching in alkaline soils,exacerbated by excessive fertilizer application,represents a significant pathway for P loss.While soil pore structure and texture critically regulate P transport,mechanisms gove...Phosphorus(P)leaching in alkaline soils,exacerbated by excessive fertilizer application,represents a significant pathway for P loss.While soil pore structure and texture critically regulate P transport,mechanisms governing P loss in texturally diverse alkaline soils remain unclear.This study investigated P leaching dynamics and transport parameters across four alkaline soil textures(silty clay,clay loam,loam,sandy loam)using a one-dimensional convective-diffusion equation(CDE)based on column experiments.Results indicated that phosphorus leaching kinetics were predominantly governed by diffusion transport,evidenced by low Peclet numbers(P_(e))(ranged from 0.02 to 0.31)across varying textures and initial P concentrations(C_(0)).Comparative analysis of transport parameters revealed significant textural effects on dispersion coefficient(D),retardation factor(R),pore water velocity(V),P_(e),and diffusion coefficient(λ)(F>523.42,p<0.001).Among these,only D,P_(e) andλexhibited substantial differences in response to variations in C_(0)(F>89.47,p<0.001).Saturated hydraulic conductivity(K_(s))(R^(2)=62.9%,p<0.01)and total pore area(A)(R^(2)=12.4%,p<0.01)emerged as primary regulators of P leaching.Enhanced clay content increased total pore area while reducing average pore diameter,concurrently decreasing pore water velocity and saturated infiltration rates.These textural modifications amplified diffusive P transport within soil matrices.The findings provide mechanistic insights into texturedependent P mobility in alkaline environments,informing targeted strategies for agricultural phosphorus management.展开更多
Soil respiration is the key process driving CO_(2) exchange between forest soils and the atmosphere and regulated by soil organic carbon(SOC)characteristics and extracellular enzyme activities.However,the direction an...Soil respiration is the key process driving CO_(2) exchange between forest soils and the atmosphere and regulated by soil organic carbon(SOC)characteristics and extracellular enzyme activities.However,the direction and magnitude of the effects of stand density on labile SOC fractions,extracellular enzymes,and soil respiration across plantation ages remain unclear.We constructed enhanced soil respiration models using heterogeneous soil data under density regulation to better characterize soil processes.Study plots encompassing stand-density gradients were implemented in Larix principis-rupprechtii plantations spanning three age-class strata.During the growing season,systematic measurements were conducted on soil respiration rates,labile organic carbon fractions,and extracellular enzyme activities.A process-driven soil respiration model was developed by integrating nonlinear mixed-effects modeling frameworks with measured data.The moderate density stands showed increases in soil respiration(Rs),microbial biomass carbon(MBC),light fraction organic carbon(LFOC),β-1,4-glucosidase(BGC),andβ-N-acetyl glycosaminidase+leucine aminopeptidase(NAG+LAP).In 36a and 48a stands,the moderate-density stands NAG+LAP had a~35%increase compared to other density levels,while readily oxidized carbon(ROC)concentrations showed a significant~30%-50%reduction.All labile organic carbon components were stable with age,so that soil microorganisms were promoted to acquire C,N,and P.Temperature,moisture,MBC,BGC,and NAG+LAP were essential factors that affected soil respiration.Stand density has important impacts on soil respiration as it regulates the soil organic carbon and activities of extracellular enzymes.The roles of temperature,microbial biomass carbon,soil organic carbon and dissolved organic carbon are complex and directly affect autotrophic and heterotrophic respiration and regulate soil respiration by influencing microbial C and N acquisition.A mixed-effects model with nested stand density and age mathematically optimized the soil respiration model,enabling enhanced characterization of covariation patterns of soil respiration with related soil carbon pool variables.展开更多
Soil science has remained basically an agricultural science since its establishment more than a century ago.However,given its multi-dimensional connections with human society and multi-functions and services to be uti...Soil science has remained basically an agricultural science since its establishment more than a century ago.However,given its multi-dimensional connections with human society and multi-functions and services to be utilized in the future,the theoretical and technological boundary of soil science is expanding from agricultural science to newly emerged soil science sectors,which can be termed as nontraditional soil science.To build a more comprehensive and up-to-date soil science system,new description methods,recommendation standards,interpretation principles,and criteria for non-agricultural applications should be developed.展开更多
Soil organic matter(SOM)is crucial for ecosystem carbon cycling,soil fertility,and environmental quality.As the main component of SOM,humic substances(HS)are considered a unique category of nonuniformly assembled subs...Soil organic matter(SOM)is crucial for ecosystem carbon cycling,soil fertility,and environmental quality.As the main component of SOM,humic substances(HS)are considered a unique category of nonuniformly assembled substances.展开更多
The remediation of arsenic(As)-contaminated soil is essential for achieving sustainable environmental and agricultural development.Among various techniques,soil washing has emerged as a promising method due to its rap...The remediation of arsenic(As)-contaminated soil is essential for achieving sustainable environmental and agricultural development.Among various techniques,soil washing has emerged as a promising method due to its rapid,efficient,and thorough decontamination capabilities.This review critically examines the application of soil washing technology in the treatment of As-contaminated soil.Specifically,this paper discusses the mechanisms of four types of washing agents(inorganic detergents,chelating agents,surfactants,and microbial agents),focusing on processes such as acid dissolution,electrostatic interaction,ion exchange,and chelation,and the factors affecting washing efficiency.The concentration of washing agent and the initial p H are the key factors influencing the washing effect.The paper also summarizes the application conditions and the corresponding removal rates for different individual washing agents and compares their effectiveness,biodegradability,and environmental impacts.Among these,natural chelating agents are highlighted for their promising potential in As removal.While individual washing agents show certain effectiveness,the combined use of multiple washing agents and the optimization of washing sequence are necessary to achieve superior remediation outcomes.The synergistic effects of combining natural chelating agents with reducing agents,surfactants,and inorganic washing agents,as well as the integration of nanomaterials with chelating agents and microbial agents are summarized,demonstrating their efficiency and stability in soil remediation.By reviewing the current state of research,this paper provides essential insights for the selection of washing agents and the optimization of washing parameters in the remediation of As-contaminated soil.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
The excessive reliance on chemical inputs for managing soil nutrients and pathogens has raised concerns about their long-term sustainability and environmental impact.In contrast,the use of soil microbes offers an eco-...The excessive reliance on chemical inputs for managing soil nutrients and pathogens has raised concerns about their long-term sustainability and environmental impact.In contrast,the use of soil microbes offers an eco-friendly and efficient alternative for improving soil fertility and plant growth.Beneficial microorganisms,including plant growth-promoting rhizobacteria(PGPR),mycorrhizal fungi,and other soil organisms,play pivotal roles in nutrient cycling,organic matter decomposition,and nutrient availability improvement.This review explores the potential of leveraging microbial resources for sustainable soil nutrient management and resilient crop production.It delves into the intricate interactions between host plants and PGPR,particularly under nutrient-limited and fluctuating environmental conditions,with a focus on the molecular signaling pathways and mechanisms regulating these relationships.Furthermore,it emphasizes the role of advanced techniques and PGPR-responsive microRNAs to uncover the functional capabilities of microbial communities and their dynamic interactions with plants.These approaches pave the way for developing innovative,microbe-based strategies to optimize nutrient use efficiency,reduce dependency on synthetic fertilizers,and support sustainable agricultural practices.展开更多
Soil contaminated with heavy metals is a global health hazard.Nanomaterials,with their unique physical and chemical properties,hold significant potential for the remediation of soil polluted with heavy metals.They eff...Soil contaminated with heavy metals is a global health hazard.Nanomaterials,with their unique physical and chemical properties,hold significant potential for the remediation of soil polluted with heavy metals.They effectively reduce the mobility and bioavailability of heavy metals through various mechanisms such as adsorption,precipitation,and oxidation-reduction.This paper provides an in-depth exploration of the cuttingedge applications of various nanomaterials,including nanometallic,nano non-metallic materials,nanoclay and mineral materials,and nano modified biochar materials,in the remediation of heavy metal-contaminated soils.It specifically focuses on the key factors influencing the remediation efficacy of these nanomaterials,as well as the underlying remediation mechanisms and methods for performance optimization.The aims of this paper are to provide guidance for the further application of nanomaterials in the field of soil heavy metal remediation,and to offer insights that could promote the effective control of soil heavy metal pollution.展开更多
Soil organic carbon(SOC)dynamics significantly influence ecosystem carbon source-sink balance,particularly in agroecosystems.However,uncertainty remains regarding optimal land use types for maximizing farmland carbon ...Soil organic carbon(SOC)dynamics significantly influence ecosystem carbon source-sink balance,particularly in agroecosystems.However,uncertainty remains regarding optimal land use types for maximizing farmland carbon storage across different soil types,and identifying effective land management practices for enhanced carbon accumulation is essential for reducing agricultural emissions and strengthening carbon sinks.This study examined SOC variations in eastern Yunnan’s subtropical highlands(2,132 sites),analyzing topsoil(0–20 cm)across five land uses(dryland,irrigated land,forestland,grassland and plantation)of five soil types(red,yellow,yellowbrown,brown,purple).The investigation explored relationships between SOC and edaphic factors(26 elements)to determine SOC influencing factors.The study area demonstrated a mean SOC content of 27.78 g kg^(–1),with distinct spatial heterogeneity characterized by lower values in the southwestern sector and higher concentrations in the northeastern region.Brown soils displayed the highest SOC content(P<0.05),followed by yellow-brown then red,yellow,and purple soils.Irrigation significantly enhanced SOC storage,particularly in brown soils where irrigated land contained 2.2-,2.4-,and 1.6-times higher SOC than forestland,grassland,and dryland,respectively.Similar irrigation benefits occurred in purple,yellow,and yellow-brown soils,indicating moisture limitation as the primary SOC constraint.Notably,SOC exhibited strong positive correlations with nitrogen,sulfur,and selenium.Nitrogen fertilization demonstrated dual benefits:enhancing SOC sequestration and promoting Se enrichment in crops,potentially supporting specialty agriculture.Although land use impacts on SOC varied across soil types(P>0.05),irrigation consistently emerged as the optimal management for carbon sink enhancement.These findings suggest that targeted water management could effectively reduce farmland carbon emissions in moisture-limited subtropical highlands.Strategic nitrogen application offers co-benefits for soil fertility and selenium biofortification,providing practical pathways for climate-smart agriculture in similar ecoregions.展开更多
Global grassland degradation necessitates the identification of sustainable grazing management strategies.In semi-arid regions,grazing exclusion(GE),cold-season grazing(CG),and free grazing(FG)represent common practic...Global grassland degradation necessitates the identification of sustainable grazing management strategies.In semi-arid regions,grazing exclusion(GE),cold-season grazing(CG),and free grazing(FG)represent common practices in grassland ecosystems,yet the long-term ecological consequences of these patterns on plant community structure and soil aggregate stability remain inadequately elucidated.In this study,we evaluated the effects of GE,CG,and FG on soil organic carbon,soil water content,soil bulk density,soil aggregates,and vegetation indicators in Xilamuren steppe,a semi-arid grassland in northern China through field sampling and laboratory analyses in 2024.Our findings revealed that,compared to CG and FG,GE significantly enhanced aboveground and belowground biomass,species diversity,and soil physical-chemical properties in the 0–30 cm layer.The dominant plant species in GE and CG sites were Stipa krylovii,Leymus chinensis,and Agropyron cristatum,whereas Stipa krylovii,Artemisia frigida,and Leymus chinensis were predominant in FG site.Different grazing patterns led to distinct soil aggregate distributions,with>2.00 and<0.25 mm aggregates exhibiting the highest content in different soil layers depending on the grazing patterns.All grazing management strategies significantly improved soil aggregate stability,with the overall stability following the order:GE>CG>FG.Furthermore,random forest modeling identified plant species diversity,plant growth traits,and grazing patterns as the primary determinants of soil aggregate stability.Collectively,these results offer valuable insights into the sustainable management and ecological restoration of semi-arid grasslands under different grazing pressures.展开更多
The dual-probe heat pulse(DPHP)is a well-established method for estimating soil moisture(θ)using soil thermal conductivity(λ)and volumetric heat capacity(C_(v)).Recently,monitoringθhas been improved by integrating ...The dual-probe heat pulse(DPHP)is a well-established method for estimating soil moisture(θ)using soil thermal conductivity(λ)and volumetric heat capacity(C_(v)).Recently,monitoringθhas been improved by integrating the DPHP method with distributed temperature sensing(DTS)technology.In the DPHP-DTS approach,a single fiber optic(FO)cable with embedded metallic constituents functions as a heating element,while a parallel cable serves to monitor the temperature.Despite ongoing advancements,challenges such as the difficulty in positioning heating and sensing cables and high energy requirements hinder the widespread adoption of the DPHP-DTS method.As alternative heating materials are seldom used,this study evaluated the feasibility of employing a resistive metallic alloy as the heating element in a laboratory DPHP-DTS application.Overall,higher errors were observed when assessing C_(v)andλat higherθvalues(>0.2),but using C_(v)data produced more accurateθestimates(with the root mean square error(RMSE)≤0.06).Based on C_(v)values,a low-power,long-duration heat pulse(8.07 W/m for 300 s)yielded more consistentθestimates(RMSE=0.04)than a high-power,shortduration pulse(15.93 W/m for 180 s,with RMSE=0.06).The findings of this study also indicated that variations in heating uniformity and electrical power fluctuations potentially affected measurement accuracy.Nevertheless,the resistive alloy proved advantageous for DPHP-DTS due to its independent power connection,ability to maintain linear positioning within the soil,and potential for energy savings,all while providing reliableθestimates.展开更多
The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new con...The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.展开更多
Soil erosion induced by water is one of the most common natural disasters.Microbially-induced calcite precipitation(MICP)technique was investigated as a possible method for improving soil hydro-mechanical characterist...Soil erosion induced by water is one of the most common natural disasters.Microbially-induced calcite precipitation(MICP)technique was investigated as a possible method for improving soil hydro-mechanical characteristics against erosion.Although many studies have been performed on hydraulic and mechanical properties of MICP-treated soils,they have mostly focused on sandy soils and less on clayey soils that are commonly susceptible to erosion.This study proposes a bio-mediated approach using MICP to construct a barrier on clayey soil surface with sand additive.Five groups of MICP-treated clayey soil samples with different sand contents(0%,10%,20%,30%,and 40%)and five control samples with the same sand contents were prepared.A series of slaking tests and penetration tests was conducted to characterize the soil hydro-mechanical properties.The experimental results show that MICP-treated samples exhibited better water stability than untreated samples.The penetration resistance of samples was increased significantly after MICP treatment.Sand additives significantly improve the MICP treatment effects,which becomes pronounced when sand content reaches 20%or more.This is mainly due to that sand additives provide relatively spacious pore structures facilitating MICP treatment solution infiltration.Furthermore,sand additives form a skeleton and significantly increase MICP-treated soil structure strength.Analyses of soil particle size distribution curves and SEM images indicate that a stable soil structure was formed contributing to sand skeleton,calcite precipitation,and clayey soil aggregations.The bridge and cementation effect of MICP and the skeleton effect of sand combine to provide prospective resistance against soil erosion.展开更多
Liquefaction occurs when loose,saturated sandy soils lose strength due to cyclic loads,like earthquakes,causing ground subsidence and structural collapse.While mitigation is possible,conventional cement-based methods ...Liquefaction occurs when loose,saturated sandy soils lose strength due to cyclic loads,like earthquakes,causing ground subsidence and structural collapse.While mitigation is possible,conventional cement-based methods have drawbacks,including carbon emissions and groundwater contamination.Consequently,there is a growing emphasis on the need for eco-friendly ground reinforcement materials.Research on biopolymer-treated soils lacks focus on underwater stability and performance degradation.This study used tannic acid to improve underwater durability,as confirmed through soil bonding experiments and cyclic shear tests.The optimal tannic acid formulation,based on gelatin content,enhanced liquefaction resistance and maintained stable strength during underwater curing.展开更多
文摘This paper presents the results from a case study highlighting the difficulties of pile driving in diatomaceous soils.In the companion(first)paper to this article,results of an extensive laboratory and in situ testing program were presented while the results from pile driving and further analysis of field observations were presented herein.Unexpected high pile rebound(HPR)was observed during driving of a closed-end pipe pile,with refusal occurring at a depth of less than 5 m.Subsequent open-ended piles were thus driven.Piezometer and case pile wave analysis program(CAPWAP)data were collected during driving of both closed-and open-end piles.Piezometer data indicated that negative pore water pressures(PWPs)were generated while the closed-ended pile exhibited high rebound.Results from in situ tests indicated change in material stiffness and strong dilative tendencies near the depth of refusal.A hypothesis for observed behavior was proposed that considers the soil beneath the pile as a medium with an effectively infinite bulk modulus.
基金This work was funded by the Oregon Department of Transportation(ODOT),which is gratefully acknowledged.
文摘Diatomaceous soils are comprised of the silica frustules of diatom microalgae that are present in marine and lacustrine environments throughout the world.Owing to their unique origin,diatomaceous soils are typically characterized by high intraparticle porosity,complex particle shapes,and uniform mineralogy,causing them to exhibit atypical physical and engineering behaviors.A substantial deposit of diatomaceous silt was observed during site exploration for construction of the Buck Creek Bridge on OR140 near Klamath Falls,OR,USA.A comprehensive laboratory and in situ testing program indicated that the diatomaceous soil possessed“non-textbook”engineering properties.Specifically,tested samples had high liquid limits(≈100%-140%)with natural water contents at or near the liquid limit.Geologically,the soil is expected to be normally consolidated,yet high apparent overconsolidation ratios(OCR)(≈15-40)were observed both in oedometric consolidation tests and through cone penetration test(CPT)correlations.Standard penetration test(SPT)results show a corrected standard penetration resistance consistent with a medium-dense sand(i.e.(N1)_(60)≈25).CPT results include corrected tip resistances(qt)of approximately 7-10 MPa and excess pore pressures(u_(2))of up to 4 MPa.In CPT dissipation tests,pore water pressures(PWPs)returned to hydrostatic pressure in less than 1 h.In this work,we synthesize these seemingly disparate material properties in an attempt to infer appropriate engineering properties for the diatomaceous deposit at the Buck Creek Bridge and attempt to provide insight into the underlying reasons for the observed behavior.
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.
文摘[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucidating the global response patterns of soil moisture to vegetation restoration and identifying research hotspots are critical for guiding ecological construction in arid regions.[Methods]We reviewed 6,152 articles concerning soil moisture and vegetation retrieved from the Web of Science platform.Using VOSviewer,we conducted analyses of keyword co-occurrence,publication trends,and research hotspots to systematically delineate the evolving trends in this field.[Results]The results indicate a significant increasing trend in the number of publications since 2000.Global research keywords are categorized into seven clusters,including vegetation,soil moisture,rainfall-erosion-infiltration,spatial heterogeneity,and climate change.In terms of highly cited papers in 2024,China and the United States maintain a significant lead.Global research demonstrates a strong dependency on typical regional geographical features(such as climate types and topography),exhibiting differentiated research focuses.Furthermore,studies extend beyond soil moisture itself to deeply couple with ecological processes such as vegetation restoration,soil respiration,carbon cycling,and hydrothermal conditions.[Conclusions]The long-term ecological effects of afforestation in arid regions remain unclear,and empirical data from key regions highlight the current urgency.Future research should integrate climate change dynamics,innovate monitoring methodologies,and deepen the understanding of regional differentiation to provide scientific support for the adaptive management of vegetation in arid regions.
文摘39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.ArcGIS inverse distance weight difference method was used to analyze the characteristics of pollution distribution,and single-factor pollution index,Nemerow comprehensive pollution index,ground accumulation index,and potential ecological risk index were selected to evaluate the characteristics of heavy metal pollution.Based on correlation analysis,the absolute principal component-multiple linear regression(APCS-MLR)and positive definite matrix factorization(PMF)models were used to analyze the sources of soil heavy metals.The results showed that the average concentrations of all eight heavy metals exceeded both national and Guangxi soil background values.Hg,Cd,and Zn exhibited high variation(greater than 0.5),indicating significant external disturbances,and their spatial distribution was closely related to mining activity locations.The single-factor pollution index evaluation indicated varying degrees of pollution risk for Cd,Zn,and As,with Cd and Zn being the most severe pollutants,as 69.23%and 30.77%of the samples fell into the moderate pollution or higher category.The geoaccumulation index analysis ranked the mean pollution levels of the eight elements as follows:Zn>Cd>Ni>Pb>Cu>Cr>Hg>As,with Cd and Zn showing the most severe contamination,and 51.28%of the samples exhibiting moderate or higher pollution levels.The Nemerow comprehensive pollution index evaluation showed that 74.35%of soil samples were classified as moderate to heavy pollution.The potential ecological risk index assessment indicated significant ecological risks posed by Cd and Zn,with 82.05%and 5.12%of the samples classified as causing strong to extreme ecological risks,respectively.The source apportionment analysis revealed minor differences between the two models.The APCS-MLR model identified three pollution sources and their contribution rates:anthropogenic mining sources(31.13%),parent material sources(40.38%),and unidentified sources(28.49%).The PMF model identified three pollution sources with contribution rates of anthropogenic mining sources(26.10%),parent material sources(46.96%),and a combined traffic and agricultural source(26.61%).Pb,Hg,Cd,and Zn mainly originated from mining activities;Cr,As,and Ni were primarily derived from the parent material,while Cu was predominantly attributed to traffic and agricultural sources.These findings provide a scientific basis for the prevention and control of heavy metal pollution in mining areas.
文摘The 23rd World Congress of Soil Science(23rd WCSS),to be held on June 7-12,2026 in Nanjing,China,marks a historic coming of this century-old scientific gathering to one of the world's ancient agricultural civilizations.Since its inception in1927,this will be the first time the Congress is hosted in China,a land whose agricultural resilience has been nurtured by millennia of soil stewardship.
基金supported by the National Natural Science Foundation of China(Nos.42077067,42277329)the Projects of Talents Recruitment of GDUPT(No.XJ2005000301)。
文摘Phosphorus(P)leaching in alkaline soils,exacerbated by excessive fertilizer application,represents a significant pathway for P loss.While soil pore structure and texture critically regulate P transport,mechanisms governing P loss in texturally diverse alkaline soils remain unclear.This study investigated P leaching dynamics and transport parameters across four alkaline soil textures(silty clay,clay loam,loam,sandy loam)using a one-dimensional convective-diffusion equation(CDE)based on column experiments.Results indicated that phosphorus leaching kinetics were predominantly governed by diffusion transport,evidenced by low Peclet numbers(P_(e))(ranged from 0.02 to 0.31)across varying textures and initial P concentrations(C_(0)).Comparative analysis of transport parameters revealed significant textural effects on dispersion coefficient(D),retardation factor(R),pore water velocity(V),P_(e),and diffusion coefficient(λ)(F>523.42,p<0.001).Among these,only D,P_(e) andλexhibited substantial differences in response to variations in C_(0)(F>89.47,p<0.001).Saturated hydraulic conductivity(K_(s))(R^(2)=62.9%,p<0.01)and total pore area(A)(R^(2)=12.4%,p<0.01)emerged as primary regulators of P leaching.Enhanced clay content increased total pore area while reducing average pore diameter,concurrently decreasing pore water velocity and saturated infiltration rates.These textural modifications amplified diffusive P transport within soil matrices.The findings provide mechanistic insights into texturedependent P mobility in alkaline environments,informing targeted strategies for agricultural phosphorus management.
基金supported by the National Key Research and Development Program of China(2023YFD2200403)National Natural Science Foundation of China(No.32260382)the Natural Science Foundation of Guangxi(2025GXNSFBA069250).
文摘Soil respiration is the key process driving CO_(2) exchange between forest soils and the atmosphere and regulated by soil organic carbon(SOC)characteristics and extracellular enzyme activities.However,the direction and magnitude of the effects of stand density on labile SOC fractions,extracellular enzymes,and soil respiration across plantation ages remain unclear.We constructed enhanced soil respiration models using heterogeneous soil data under density regulation to better characterize soil processes.Study plots encompassing stand-density gradients were implemented in Larix principis-rupprechtii plantations spanning three age-class strata.During the growing season,systematic measurements were conducted on soil respiration rates,labile organic carbon fractions,and extracellular enzyme activities.A process-driven soil respiration model was developed by integrating nonlinear mixed-effects modeling frameworks with measured data.The moderate density stands showed increases in soil respiration(Rs),microbial biomass carbon(MBC),light fraction organic carbon(LFOC),β-1,4-glucosidase(BGC),andβ-N-acetyl glycosaminidase+leucine aminopeptidase(NAG+LAP).In 36a and 48a stands,the moderate-density stands NAG+LAP had a~35%increase compared to other density levels,while readily oxidized carbon(ROC)concentrations showed a significant~30%-50%reduction.All labile organic carbon components were stable with age,so that soil microorganisms were promoted to acquire C,N,and P.Temperature,moisture,MBC,BGC,and NAG+LAP were essential factors that affected soil respiration.Stand density has important impacts on soil respiration as it regulates the soil organic carbon and activities of extracellular enzymes.The roles of temperature,microbial biomass carbon,soil organic carbon and dissolved organic carbon are complex and directly affect autotrophic and heterotrophic respiration and regulate soil respiration by influencing microbial C and N acquisition.A mixed-effects model with nested stand density and age mathematically optimized the soil respiration model,enabling enhanced characterization of covariation patterns of soil respiration with related soil carbon pool variables.
基金supported by the National Natural Science Foundation of China(No.42130715)the National Key Research and Development Program of China(No.2023YFD1500101)。
文摘Soil science has remained basically an agricultural science since its establishment more than a century ago.However,given its multi-dimensional connections with human society and multi-functions and services to be utilized in the future,the theoretical and technological boundary of soil science is expanding from agricultural science to newly emerged soil science sectors,which can be termed as nontraditional soil science.To build a more comprehensive and up-to-date soil science system,new description methods,recommendation standards,interpretation principles,and criteria for non-agricultural applications should be developed.
基金financial support from the National Key Research and Development Program of China(No.2022YFD1500304)the Postdoctoral Fellowship Program of CPSF,China(No.GZC20232641)the Postdoctoral Science Foundation of China(No.2024M753215)。
文摘Soil organic matter(SOM)is crucial for ecosystem carbon cycling,soil fertility,and environmental quality.As the main component of SOM,humic substances(HS)are considered a unique category of nonuniformly assembled substances.
基金supported by the National Key R&D Program of China(No.2023YFC3706703)the National Natural Science Foundation of China(No.51874018)。
文摘The remediation of arsenic(As)-contaminated soil is essential for achieving sustainable environmental and agricultural development.Among various techniques,soil washing has emerged as a promising method due to its rapid,efficient,and thorough decontamination capabilities.This review critically examines the application of soil washing technology in the treatment of As-contaminated soil.Specifically,this paper discusses the mechanisms of four types of washing agents(inorganic detergents,chelating agents,surfactants,and microbial agents),focusing on processes such as acid dissolution,electrostatic interaction,ion exchange,and chelation,and the factors affecting washing efficiency.The concentration of washing agent and the initial p H are the key factors influencing the washing effect.The paper also summarizes the application conditions and the corresponding removal rates for different individual washing agents and compares their effectiveness,biodegradability,and environmental impacts.Among these,natural chelating agents are highlighted for their promising potential in As removal.While individual washing agents show certain effectiveness,the combined use of multiple washing agents and the optimization of washing sequence are necessary to achieve superior remediation outcomes.The synergistic effects of combining natural chelating agents with reducing agents,surfactants,and inorganic washing agents,as well as the integration of nanomaterials with chelating agents and microbial agents are summarized,demonstrating their efficiency and stability in soil remediation.By reviewing the current state of research,this paper provides essential insights for the selection of washing agents and the optimization of washing parameters in the remediation of As-contaminated soil.
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 project OLP116.CSIR-NBRI allotted the manuscript number CSIR-NBRI_MS/2025/06/15。
文摘The excessive reliance on chemical inputs for managing soil nutrients and pathogens has raised concerns about their long-term sustainability and environmental impact.In contrast,the use of soil microbes offers an eco-friendly and efficient alternative for improving soil fertility and plant growth.Beneficial microorganisms,including plant growth-promoting rhizobacteria(PGPR),mycorrhizal fungi,and other soil organisms,play pivotal roles in nutrient cycling,organic matter decomposition,and nutrient availability improvement.This review explores the potential of leveraging microbial resources for sustainable soil nutrient management and resilient crop production.It delves into the intricate interactions between host plants and PGPR,particularly under nutrient-limited and fluctuating environmental conditions,with a focus on the molecular signaling pathways and mechanisms regulating these relationships.Furthermore,it emphasizes the role of advanced techniques and PGPR-responsive microRNAs to uncover the functional capabilities of microbial communities and their dynamic interactions with plants.These approaches pave the way for developing innovative,microbe-based strategies to optimize nutrient use efficiency,reduce dependency on synthetic fertilizers,and support sustainable agricultural practices.
基金the Natural Science Research Initiation Fund Project of China West Normal University(No.23KE001)the National Natural Science Foundation of China(Nos.42407186,42277033,and 42171045)+1 种基金the Basic Research Foundation of Yunnan Province(No.202401AT070304)the Central Public-interest Scientific Institution Basal Research Fund(No.Y2024QC28)for their financial support。
文摘Soil contaminated with heavy metals is a global health hazard.Nanomaterials,with their unique physical and chemical properties,hold significant potential for the remediation of soil polluted with heavy metals.They effectively reduce the mobility and bioavailability of heavy metals through various mechanisms such as adsorption,precipitation,and oxidation-reduction.This paper provides an in-depth exploration of the cuttingedge applications of various nanomaterials,including nanometallic,nano non-metallic materials,nanoclay and mineral materials,and nano modified biochar materials,in the remediation of heavy metal-contaminated soils.It specifically focuses on the key factors influencing the remediation efficacy of these nanomaterials,as well as the underlying remediation mechanisms and methods for performance optimization.The aims of this paper are to provide guidance for the further application of nanomaterials in the field of soil heavy metal remediation,and to offer insights that could promote the effective control of soil heavy metal pollution.
基金funded by the Yunnan Provincial Key Programs for Basic Research Project,China(202301AS070087)the Yunnan Provincial R&D Program,China(202405AF140014 and 202302AO370015)the National Natural Science Foundation of China(42307058).
文摘Soil organic carbon(SOC)dynamics significantly influence ecosystem carbon source-sink balance,particularly in agroecosystems.However,uncertainty remains regarding optimal land use types for maximizing farmland carbon storage across different soil types,and identifying effective land management practices for enhanced carbon accumulation is essential for reducing agricultural emissions and strengthening carbon sinks.This study examined SOC variations in eastern Yunnan’s subtropical highlands(2,132 sites),analyzing topsoil(0–20 cm)across five land uses(dryland,irrigated land,forestland,grassland and plantation)of five soil types(red,yellow,yellowbrown,brown,purple).The investigation explored relationships between SOC and edaphic factors(26 elements)to determine SOC influencing factors.The study area demonstrated a mean SOC content of 27.78 g kg^(–1),with distinct spatial heterogeneity characterized by lower values in the southwestern sector and higher concentrations in the northeastern region.Brown soils displayed the highest SOC content(P<0.05),followed by yellow-brown then red,yellow,and purple soils.Irrigation significantly enhanced SOC storage,particularly in brown soils where irrigated land contained 2.2-,2.4-,and 1.6-times higher SOC than forestland,grassland,and dryland,respectively.Similar irrigation benefits occurred in purple,yellow,and yellow-brown soils,indicating moisture limitation as the primary SOC constraint.Notably,SOC exhibited strong positive correlations with nitrogen,sulfur,and selenium.Nitrogen fertilization demonstrated dual benefits:enhancing SOC sequestration and promoting Se enrichment in crops,potentially supporting specialty agriculture.Although land use impacts on SOC varied across soil types(P>0.05),irrigation consistently emerged as the optimal management for carbon sink enhancement.These findings suggest that targeted water management could effectively reduce farmland carbon emissions in moisture-limited subtropical highlands.Strategic nitrogen application offers co-benefits for soil fertility and selenium biofortification,providing practical pathways for climate-smart agriculture in similar ecoregions.
基金supported by the National Key Research and Development Program of China(2024YFF1306305)the Inner Mongolia Autonomous Region Natural Science Foundation Project(2025QN03106)+1 种基金the Research Start-up Project for the Introduction of High-level and Outstanding Doctoral Talent at Inner Mongolia Agricultural University(NDYB2024-42)the National Natural Science Foundation of China(42201012).
文摘Global grassland degradation necessitates the identification of sustainable grazing management strategies.In semi-arid regions,grazing exclusion(GE),cold-season grazing(CG),and free grazing(FG)represent common practices in grassland ecosystems,yet the long-term ecological consequences of these patterns on plant community structure and soil aggregate stability remain inadequately elucidated.In this study,we evaluated the effects of GE,CG,and FG on soil organic carbon,soil water content,soil bulk density,soil aggregates,and vegetation indicators in Xilamuren steppe,a semi-arid grassland in northern China through field sampling and laboratory analyses in 2024.Our findings revealed that,compared to CG and FG,GE significantly enhanced aboveground and belowground biomass,species diversity,and soil physical-chemical properties in the 0–30 cm layer.The dominant plant species in GE and CG sites were Stipa krylovii,Leymus chinensis,and Agropyron cristatum,whereas Stipa krylovii,Artemisia frigida,and Leymus chinensis were predominant in FG site.Different grazing patterns led to distinct soil aggregate distributions,with>2.00 and<0.25 mm aggregates exhibiting the highest content in different soil layers depending on the grazing patterns.All grazing management strategies significantly improved soil aggregate stability,with the overall stability following the order:GE>CG>FG.Furthermore,random forest modeling identified plant species diversity,plant growth traits,and grazing patterns as the primary determinants of soil aggregate stability.Collectively,these results offer valuable insights into the sustainable management and ecological restoration of semi-arid grasslands under different grazing pressures.
基金funded in part by the Coordination for the Improvement of Higher Education Personnel(CAPES,Finance Code 001)in part by the Brazilian National Council for Scientific and Technological Development(CNPq,Grant No.131511/2020-3)/Ministry of Science,Technology and Innovation(MCTI)in part by the State of São Paulo Research Foundation(FAPESP)(Grant Nos.2015/03806-1 and 2023/08756-9).
文摘The dual-probe heat pulse(DPHP)is a well-established method for estimating soil moisture(θ)using soil thermal conductivity(λ)and volumetric heat capacity(C_(v)).Recently,monitoringθhas been improved by integrating the DPHP method with distributed temperature sensing(DTS)technology.In the DPHP-DTS approach,a single fiber optic(FO)cable with embedded metallic constituents functions as a heating element,while a parallel cable serves to monitor the temperature.Despite ongoing advancements,challenges such as the difficulty in positioning heating and sensing cables and high energy requirements hinder the widespread adoption of the DPHP-DTS method.As alternative heating materials are seldom used,this study evaluated the feasibility of employing a resistive metallic alloy as the heating element in a laboratory DPHP-DTS application.Overall,higher errors were observed when assessing C_(v)andλat higherθvalues(>0.2),but using C_(v)data produced more accurateθestimates(with the root mean square error(RMSE)≤0.06).Based on C_(v)values,a low-power,long-duration heat pulse(8.07 W/m for 300 s)yielded more consistentθestimates(RMSE=0.04)than a high-power,shortduration pulse(15.93 W/m for 180 s,with RMSE=0.06).The findings of this study also indicated that variations in heating uniformity and electrical power fluctuations potentially affected measurement accuracy.Nevertheless,the resistive alloy proved advantageous for DPHP-DTS due to its independent power connection,ability to maintain linear positioning within the soil,and potential for energy savings,all while providing reliableθestimates.
基金supported by the National Natural Science Foundation of China(U2243235)the Shaanxi Provincial Department of Water Resources,China(2022slkj-6)。
文摘The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.
基金supported by the National Natural Science Foundation of China(Grant Nos.42525201 and 42230710).
文摘Soil erosion induced by water is one of the most common natural disasters.Microbially-induced calcite precipitation(MICP)technique was investigated as a possible method for improving soil hydro-mechanical characteristics against erosion.Although many studies have been performed on hydraulic and mechanical properties of MICP-treated soils,they have mostly focused on sandy soils and less on clayey soils that are commonly susceptible to erosion.This study proposes a bio-mediated approach using MICP to construct a barrier on clayey soil surface with sand additive.Five groups of MICP-treated clayey soil samples with different sand contents(0%,10%,20%,30%,and 40%)and five control samples with the same sand contents were prepared.A series of slaking tests and penetration tests was conducted to characterize the soil hydro-mechanical properties.The experimental results show that MICP-treated samples exhibited better water stability than untreated samples.The penetration resistance of samples was increased significantly after MICP treatment.Sand additives significantly improve the MICP treatment effects,which becomes pronounced when sand content reaches 20%or more.This is mainly due to that sand additives provide relatively spacious pore structures facilitating MICP treatment solution infiltration.Furthermore,sand additives form a skeleton and significantly increase MICP-treated soil structure strength.Analyses of soil particle size distribution curves and SEM images indicate that a stable soil structure was formed contributing to sand skeleton,calcite precipitation,and clayey soil aggregations.The bridge and cementation effect of MICP and the skeleton effect of sand combine to provide prospective resistance against soil erosion.
基金supported by a National Research Foundation of Korea(NRF)grant,funded by the Korean government(MSIT)(Grant Nos.2022R1A4A3029737 and RS-2024-00353644).
文摘Liquefaction occurs when loose,saturated sandy soils lose strength due to cyclic loads,like earthquakes,causing ground subsidence and structural collapse.While mitigation is possible,conventional cement-based methods have drawbacks,including carbon emissions and groundwater contamination.Consequently,there is a growing emphasis on the need for eco-friendly ground reinforcement materials.Research on biopolymer-treated soils lacks focus on underwater stability and performance degradation.This study used tannic acid to improve underwater durability,as confirmed through soil bonding experiments and cyclic shear tests.The optimal tannic acid formulation,based on gelatin content,enhanced liquefaction resistance and maintained stable strength during underwater curing.
