Subsoiling is widely used to improve soil productivity in the North China Plain(NCP).However,its effects on pore network-based hydraulic properties and their relationship with water use efficiency(WUE)are far from cle...Subsoiling is widely used to improve soil productivity in the North China Plain(NCP).However,its effects on pore network-based hydraulic properties and their relationship with water use efficiency(WUE)are far from clear.In this study,we evaluated the effects of three tillage systems(rotary tillage at 15 cm depth,RT15;subsoiling at 40 cm depth,SS40;and subsoiling at 35 cm depth,SS35)on soil pore structure,hydraulic properties,and WUE during the 2022-2024 winter wheat seasons.Results showed that the effects of SS40 and SS35 were similar in optimizing the soil pore structure and hydraulic properties.Compared with RT15,SS40 and SS35 increased the soil macroporosity ratio,the soil pore connectivity,and the soil water storage.Structural equation modeling revealed that optimized soil pore structure under subsoiling directly and positively influenced the WUE or indirectly increasing the soil water storage.As a result,compared with RT15,SS40 and SS35 increased the spike number,kernel number per spike,and 1000-grain weight,and ultimately improved the yield(35.59% and 39.32%,respectively)and WUE(36.69% and 41.55%,respectively).Overall,the results revealed the mechanism of high-efficiency water use from the perspective of pore network-based hydraulic properties,providing a theoretical basis for food security.展开更多
The Gulf Cooperation Countries have the advantages of fundamental characteristics and abundant natural resources due to the high proportion of solar radiation, which helps to expand the transition to renewable energy,...The Gulf Cooperation Countries have the advantages of fundamental characteristics and abundant natural resources due to the high proportion of solar radiation, which helps to expand the transition to renewable energy, especially in solar projects. The Kuwait location was chosen for this research because of its high dust levels and average daily sunshine of 9.4 hours. The soiling map of Kuwait was then created using PVsyst software. A theoretical and mathematical model for 100 MW was developed based on many environmental and technical parameters. The model was run with Kuwait parameters and 100 MW solar PV power plant capacity. The results show that more than 25% of total generated electricity could be lost annually without any mitigation strategy. Furthermore, the efficiency loss could increase by around 50% during the seasons with sandstorms and high soiling rates. Additionally, manual and automatic cleaning methods were found to increase energy production from 112,092 MWh to 207,300 MWh. Moreover, manual cleaning reduced energy costs by 4.9%, but automated cleaning resulted in a 17.34% higher energy-saving cost than a system without cleaning. In addition, when using the automatic cleaning system, the system’s payback period was reduced from 9.22 to 7.86 years. Therefore, an automated cleaning system is recommended for use in Kuwait.展开更多
Compact!on layers are widely distributed in the Huang-Huai-Hai Plain,China,which restrict root growth and reduce yields.The adoption of subsoiling has been recommended to disrupt compacted soil layers and create a rea...Compact!on layers are widely distributed in the Huang-Huai-Hai Plain,China,which restrict root growth and reduce yields.The adoption of subsoiling has been recommended to disrupt compacted soil layers and create a reasonable soil structure for crop development.In this paper,the effects of subsoiling depth(30,35 and 40 cm),period interval(2 or 3 years)and combined pre-sowing tillage practice(rotary cultivation or ploughing)on soil condition improvement was studied on a tidal soil in the Huang-Huai-Hai Plain.Seve n tillage patter ns were desig ned by combini ng differe nt subsoili ng depths,period intervals and pre-sowing.The evaluation indicators for soil condition improvement were as follows:thickness of the plough layer and hard pan,soil bulk density,cone index,soil three-phase R values,alkali nitrogen content,crop yield,and economic ben efits.The results showed that subsoiling can sign ificantly improve the soil structure and physical properties.In all subsoiling treatments,the depth of 35 or 40 cm at a 2-year interval was the most significant.The thickness of the plough layer in creased from 13.67 cm before the test to 21.54-23.45 cm in 2018.The thick ness of the hard pan decreased from 17.68 cm before the test to 12.09-12.76 cm in 2018,a decrease of about 40.07%.However,the subsoiling combined presowing tillage practice,that is,rotary cultivation or ploughing,was not significant for soil structure and physical properties.For all subsoiling treatments,the soil bulk density,cone index and soil three-phase R values of the 15-25 cm soil layer were significantly lower compared to single rotary cultivation.Subsoiling was observed to increase the soil alkaline nitrogen and water conte nts.The tillage patter ns that had subsoiling at the depth of 35-40 cm at a 2-year in terval combi ned with rotary cultivation had the highest alkali nitrogen and water contents,which increased by 31.08-34.23%compared with that of the single rotary cultivati on.Subsoiling can sign ifica ntly in crease the yield both of wheat and corn,as well as the economic ben efits.The treatment of subsoili ng at the depth of 35 cm at an interval of 2 years com bined with rotary cultivation had the highest ann ual yield and economic benefits.For this treatme nt,the arinual yield and economic ben efits in creased by 14.55 and 62.87%in 2018,respectively.In con clusi on,the tillage patter ns that involved subsoili ng at a depth of 35 cm at a 2-year interval along with rotary cultivation are suitable for the Huang?Huai-Hai Plain.展开更多
Solar photovoltaic(PV)power represents one of the most promising future sources of energy in the world.Considered the cleanest form of energy,extensive research is being undertaken to widen its use.Notably,mega projec...Solar photovoltaic(PV)power represents one of the most promising future sources of energy in the world.Considered the cleanest form of energy,extensive research is being undertaken to widen its use.Notably,mega projects are being considered for installation in the Middle East and North Africa(MENA)region because of its high solar potential,with hopes of eventually feeding Europe from the PV electricity generated in this region and transported through high voltage direct current(DC)lines.However,current implementation of PV systems has shown that their reliability and efficiency depend upon surrounding environmental factors,such as the ambient temperature,wind,and rainfall,as well as soiling,pollution,and aging.The aim of this study was to investigate,through experimental tests,the effects of such factors on the power output of a grid connected PV station.The results showed that the output power and efficiency are deeply affected by various environmental factors,which are weather dependent.These findings may help us develop appropriate solutions to overcome these drawbacks.展开更多
In this paper,a detailed model of a photovoltaic(PV)panel is used to study the accumulation of dust on solar panels.The presence of dust diminishes the incident light intensity penetrating the panel’s cover glass,as ...In this paper,a detailed model of a photovoltaic(PV)panel is used to study the accumulation of dust on solar panels.The presence of dust diminishes the incident light intensity penetrating the panel’s cover glass,as it increases the reflection of light by particles.This phenomenon,commonly known as the“soiling effect”,presents a significant challenge to PV systems on a global scale.Two basic models of the equivalent circuits of a solar cell can be found,namely the single-diode model and the two-diode models.The limitation of efficiency data in manufacturers’datasheets has encouraged us to develop an equivalent electrical model that is efficient under dust conditions,integrated with optical transmittance considerations to investigate the soiling effect.The proposed approach is based on the use of experimental current-voltage(I-V)characteristics with simulated data using MATLAB/Simulink.Our research outcomes underscores the feasibility of accurately quantifying the reduction in energy production resulting from soiling by assessing the optical transmittance of accumulated dust on the surface of PV glass.展开更多
Intended for good productivity and perfect operation of the solar power grid a failure-free system is required.Therefore,thermal image processing with the thermal camera is the latest non-invasive(without manual conta...Intended for good productivity and perfect operation of the solar power grid a failure-free system is required.Therefore,thermal image processing with the thermal camera is the latest non-invasive(without manual contact)type fault identification technique which may give good precision in all aspects.The soiling issue,which is major productivity affecting factor may import from several reasons such as dust on the wind,bird mucks,etc.The efficient power production sufferers due to accumulated soil deposits reaching from 1%–7%in the county,such as India,to more than 25%in middle-east countries country,such as Dubai,Kuwait,etc.This research offers a solar panel soiling detection system built on thermal imaging which powers the inspection method and mitigates the requirement for physical panel inspection in a large solar production place.Hence,in this method,solar panels can be verified by working without disturbing production operation and it will save time and price of recognition.India ranks 3rd worldwide in the usage use age of Photovoltaic(PV)panels now and it is supported about 8.6%of the Nation’s electricity need in the year 2020.In the meantime,the installed PV production areas in India are aged 4–5 years old.Hence the need for inspection and maintenance of installed PV is growing fast day by day.As a result,this research focuses on finding the soiling hotspot exactly of the working solar panels with the help of Principal Components Thermal Analysis(PCTA)on MATLAB Environment.展开更多
In order to evaluate the effect of subsoiling on the soil physical properties and wheat yield in dry land conditions, this research was conducted in Mamassani area of Fars province in Iran. The experiment was laid dow...In order to evaluate the effect of subsoiling on the soil physical properties and wheat yield in dry land conditions, this research was conducted in Mamassani area of Fars province in Iran. The experiment was laid down in the form of a complete block experimental design with four treatments and four replications for three years. Treatments included： （1） conventional tillage without using subsoiler which was control treatment （So）; （2） using subsoiler with the shank space of 40 cm which was equal to the subsoiling depth （SO; （3） using subsoiler with the shank space of 60 cm which was 1.5 times of the subsoiling depth （S2）; and （4） using subsoiler with the shank space of 80 cm which was 2 times of the subsoiling depth （S3）. Subsoiling depth was set at 40 cm which was the lower limit of the hard pan depth in the soil. Soil cone index, soil bulk density, soil moisture content, wheat yield, and yield components were measured in this study and SAS software was used to analyze the collected data. Results showed that subsoiling decreased the soil bulk density and cone index, and increased water retention of the soil. Results also revealed that applying subsoiler increased wheat yield and yield components in our dry land conditions. Since subsoiling improved soil physical conditions and increases wheat yield, applying subsoiler in such a dry land conditions is therefore recommended. Results of this study also showed that subsoiling with the shank space of 40 cm and 60 cm had better performance compared to the shank space of 80 cm. On the other hand, shank space of 40 cm reduced the subsoiler effective working width and consequently effective field capacity. Therefore, subsoiler with a shank space of 60 cm is recommended for application in dry land soils of our type.展开更多
Sustainable agriculture in the Huang–Huai–Hai Plain of China is threatened by subsoil compaction and the decline of winter wheat productivity induced by inappropriate tillage regimes. We investigated the effects of ...Sustainable agriculture in the Huang–Huai–Hai Plain of China is threatened by subsoil compaction and the decline of winter wheat productivity induced by inappropriate tillage regimes. We investigated the effects of optimizing the tillage regime on grain filling and its relationship with flag leaf senescence post-anthesis in winter wheat. Four treatments were compared: rotary tillage, strip rotary tillage, strip rotary tillage with a 2-year subsoiling interval(STS), and conventional plowing tillage. STS produced higher chlorophyll content and leaf area indexes than other treatments, resulting in a greater photosynthetically active radiation capture ratio. The net photosynthesis rate of flag leaves from 14 to 28 days after anthesis and dry matter accumulation at maturity were higher in STS than in other treatments. Sucrose content and sucrose phosphate synthase activity of flag leaves first increased and then decreased during grain filling and were highest in STS. STS increased superoxide dismutase activity, increased soluble protein content, and reduced malondialdehyde concentrations in flag leaves after the middle grain-filling stages,resulting in reduced premature senescence. This consequence extended the active grain filling period and increased grain weight. The highest yields were observed in STS, reaching10,451 kg ha-1 in 2014–2015 and 10,074 kg ha-1 in 2015–2016, owing to increased spike numbers and 1000-kernel weight. Overall, our study suggested that STS could substantially increase photosynthetic capacity and delay leaf senescence, thus promoting grain filling rate and increasing winter wheat yields.展开更多
Eucalyptus harvesting,forwarding and soil tillage operations are among the main causes for compaction of forest soils,with potential impacts on productivity.This concern is especially important in areas with soils tha...Eucalyptus harvesting,forwarding and soil tillage operations are among the main causes for compaction of forest soils,with potential impacts on productivity.This concern is especially important in areas with soils that are naturally compacted(fragipans and duripans).In these soils,tillage operations include the use of subsoilers that can reach depths of more than one meter and require heavy tractors that exert high pressure on the soil.One of the ways to try to minimize the effect of this compaction is by retaining harvest residues.The objective of this study was to evaluate the impacts of eucalyptus harvesting on soil physical attributes,as well as to determine the potential of different types of residue management to reduce compaction from the soil tillage operation.Two experiments were conducted in the same area with a Yellow Argisol.In the first experiment,compaction caused by mechanized harvesting with harvester+forwarder was evaluated.In the second experiment,different managements of harvest residues were examined as potential modifiers of soil compaction during tillage for new plantings.For this,three managements systems were tested:(1)retention of all harvest residues and litter from the previous rotation(HR+L),(2)retention of litter from the previous rotation(L),and(3)removal of harvest residues and litter from the previous rotation(WR).Before and after harvest,sampling was carried out in the planting rows and inter-rows,and after tillage,samples were collected in the traffic line of the subsoiler-tractor set.In both experiments,undisturbed soil samples were collected from the center of the 0-10,10-20,20-40,40-60,and 60-100 cm layers to determine soil density and total porosity.In each period and site of evaluation,mechanical resistance to penetration up to the 60-cm depth was also determined.The harvesting operation increased soil density at 0-10 and 60-100 cm depths only in the inter-rows.Retention of harvest residues and litter(HR+L)after harvesting avoided increases in soil density and penetration resistance caused by machine traffic during tillage.The results indicate the importance of retaining harvest residues on forest soils for achieving sustainable utilization and for conserving soil quality.展开更多
Monocolumn composite bucket foundation is a new type of offshore wind energy foundation.Its bearing characteristics under shallow bedrock conditions and complex geological conditions have not been extensively studied....Monocolumn composite bucket foundation is a new type of offshore wind energy foundation.Its bearing characteristics under shallow bedrock conditions and complex geological conditions have not been extensively studied.Therefore,to analyze its bearing characteristics under complex conditions-such as silty soil,chalky soil,and shallow bedrock-this paper employs finite element software to establish various soil combination scenarios.The load-displacement curves of the foundations under these scenarios are calculated to subsequently evaluate the horizontal ultimate bearing capacity.This study investigates the effects of shallow bedrock depth,the type of soil above the bedrock,the thickness of layered soil,and the quality of layered soil on the bearing characteristics of the monocolumn composite bucket foundation.Based on the principle of single-variable control,the ultimate bearing capacity characteristics of the foundation under different conditions are compared.The distribution of soil pressure inside and outside the bucket wall on the compressed side of the foundation,along with the plastic strain of the soil at the base of the foundation,is also analyzed.In conclusion,shallow bedrock somewhat reduces foundation bearing capacity.Under shallow bedrock conditions,the degree of influence on foundation bearing capacity characteristics can considerably vary on different upper soils.The thickness of each soil layer and the depth to bedrock in stratified soils also affect the bearing capacity of the foundation.The findings of this paper provide a theoretical reference for related foundation design and construction.In practice,the bearing performance of the foundation can be enhanced by improvingthe soil quality in the bucket,adjusting the penetration depth,adjusting the percentage of different types of soil layers in the bucket,and applying other technical construction methods.展开更多
Apart from being a clean source of energy,photovoltaic(PV)power plants are also a source of income generation for its investors and lenders.Therefore,mitigation of system losses is crucial for economic operation of PV...Apart from being a clean source of energy,photovoltaic(PV)power plants are also a source of income generation for its investors and lenders.Therefore,mitigation of system losses is crucial for economic operation of PV plants.Combined losses due to soiling,shading and temperature in PV plants go as high as 50%.Much of these losses are unaccounted initially,which can jeopardize the economic viability of PV projects.This paper aims to provide a model to determine losses due to soiling,shading and temperature using quantities like irradiance,cell temperature,DC power and current,which are readily available in PV yield data captured by the remote monitoring system,without involving any additional sensors or equipment.In this study,soiling,shading and thermal losses were calculated using PV yield data obtained from a 30-kWp PV plant located in Kharagpur,India.The results showed soiling and shading losses as high as 25.7%and 9.7%,respectively,in the month of December.Soiling loss was verified by measuring transmittance loss of coupon glasses installed in the vicinity of the plant.Shading loss was verified by shadow simulation using an architectural tool(SketchUp).Array thermal loss obtained using the proposed methodology was found to be in line with the estimated value obtained from PVsyst simulation.Additionally,using time-series data,the energy losses corresponding to soiling,shading and temperature effects were calculated by a numerical-integration technique.The monetary loss due to these energy losses thus obtained provides criteria for deciding when to mitigate the sources of these losses.展开更多
Installing internal bulkheads in a composite bucket foundation alters the rotational symmetry characteristic of a single-compartment bucket foundation,consequently influencing the stress distribution within the bucket...Installing internal bulkheads in a composite bucket foundation alters the rotational symmetry characteristic of a single-compartment bucket foundation,consequently influencing the stress distribution within the bucket and surrounding soil.During the seabed penetration of a spudcan from a jack-up wind turbine installation vessel,an angle may form between the spudcan’s axis and the axis of symmetry of the adjacent composite bucket foundation in the horizontal plane.Such a misalignment may affect load distribution and the non-uniform interaction between the foundation,soil,and spudcan,ultimately influencing the foundation’s stability.This study employs physical model tests to ascertain the trends in end resistance during spudcan penetration in sand,the extent of soil disturbance,and the backflow condition.The finite element coupled Eulerian-Lagrangian method is validated and utilized to determine the range of penetration angles that induce alterations in the maximum vertical displacement and tilt rate of the composite bucket foundation in sand.The differential contact stress distribution at the base of the bucket is analyzed,with qualitative criteria for sand backflow provided.Findings demonstrate that the maximum vertical displacement and tilt rate of the composite bucket foundation display a“wave-like”variation with the increasing spudcan penetration angle,peaking when the angle between the spudcan and bulkhead is the smallest.Stress distribution is predominantly concentrated at the base and apex of the bucket,becoming increasingly uneven as the penetration angle deviates from the foundation’s symmetry axis.The maximum stress gradually shifts to the junction of the bulkhead and bucket bottom on the side with the shortest net distance from the spudcan.Considering the in-place stability and stress state of the composite bucket foundation is therefore imperative,and particular attention should be paid to the foundation’s state when the angle between the spudcan and bulkhead is small.展开更多
We used solidification/stabilization methods to remediate highly concentrated Zn^(2+)-contaminated soil.An industrial waste mixture of red mud,carbide slag,and phosphogypsum is combined with cement as the curing agent...We used solidification/stabilization methods to remediate highly concentrated Zn^(2+)-contaminated soil.An industrial waste mixture of red mud,carbide slag,and phosphogypsum is combined with cement as the curing agent.The mixing ratios of the four materials are determined by comparing the strength,permeability coefficient,pH,and Zn^(2+)-leaching concentration of the solidified soil.Microscopic characteristics of the solidified uncontaminated soil and solidified Zn^(2+)-contaminated soil were observed using scanning electron microscopy,X-ray diffraction,and Fourier-transform infrared spectroscopy.Furthermore,the heavy metals speciation in both pure cement and mixed-material solidified soil was examined,demonstrating the beneficial role of the mixed-type curing agent in stabilizing heavy metals.The research results indicate that Zn^(2+)degrade the strength of the solidified soil by up to 90%.The permeability coefficient,pH,and Zn^(2+)-leaching concentration of the solidified soil easily meet standard,especially with Zn^(2+)leaching concentration well below the environmental protection limit.Furthermore,most Zn^(2+)exists in forms with lower biological and chemical reactivity.Both the solidified Zn^(2+)-contaminated soil and uncontaminated soil resulted in the formation of hydrated products containing elements such as silicon,aluminum,calcium,and sulfur.Additionally,the solidified Zn^(2+)-contaminated soil produced zinc-containing compounds and a large amount of rod-shaped ettringite.展开更多
Controlling heavy metal pollution in agricultural soil has been a significant challenge.These heavy metals seriously threaten the surrounding ecological environment and human health.The effective assessment and remedi...Controlling heavy metal pollution in agricultural soil has been a significant challenge.These heavy metals seriously threaten the surrounding ecological environment and human health.The effective assessment and remediation of heavy metals in agricultural soils are crucial.These two aspects support each other,forming a close and complete decisionmaking chain.Therefore,this review systematically summarizes the distribution characteristics of soil heavy metal pollution,the correlation between soil and crop heavy metal contents,the presence pattern and migration and transformation mode of heavy metals in the soil-crop system.The advantages and disadvantages of the risk evaluation tools and models of heavy metal pollution in farmland are further outlined,which provides important guidance for an in-depth understanding of the characteristics of heavymetal pollution in farmland soils and the assessment of the environmental risk.Soil remediation strategies involve multiple physical,chemical,biological and even combined technologies,and this paper compares the potential and effect of the above current remediation technologies in heavy metal polluted farmland soils.Finally,the main problems and possible research directions of future heavy metal risk assessment and remediation technologies in agricultural soils are prospected.This review provides new ideas for effective assessment and selection of remediation technologies based on the characterization of soil heavy metals.展开更多
Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production.With the ongoing...Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production.With the ongoing intensification of agricultural practices and negative natural factors,black soils are confronting enhanced degradation.The holistic overview of black soil degradation and the underlying mechanisms for soil health improvement will be key for agricultural sustainability and food security.In this review,the current status and driving factors of soil degradation in the four major black soil regions of the world are summarized,and effective measures for black soil conservation are proposed.The Northeast Plain of China is the research hotspot with 41.5%of the published studies related to black soil degradation,despite its relatively short history of agricultural reclamation,followed by the East European Plain(28.3%),the Great Plains of North America(20.7%),and the Pampas of South American(7.9%).Among the main types of soil degradation,soil erosion and soil fertility decline(especially organic matter loss)have been reported as the most common problems,with 27.6%and 39.4%of the published studies,respectively.In addition to the natural influences of climate and topography,human activities have been reported to have great influences on the degradation of black soils globally.Unsustainable farming practices and excess in agrochemical applications are common factors reported to accelerate the degradation process and threaten the sustainable use of black soils.Global efforts for black soil conservation and utilization should focus on standardizing evaluation criteria including real-time monitoring and the measures of prevention and restoration for sustainable management.International cooperation in technology and policy is crucial for overcoming the challenges and thus achieving the protection,sustainable use,and management of global black soil resources.展开更多
Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dyn...Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dynamic changes in soil communities,potential bacterial pathogens,and ARG profiles under various organicmaterial treatments during RSD,including distillers’grains,potato peel,peanut vine,and peanut vine combined with charcoal.Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens(P<0.05).The relative abundance of high-risk ARGs decreased by 10.7%-30.6%after RSD treatments,the main decreased ARG subtypeswere AAC(3)_Via,dfrA1,ErmB,lnuB,aadA.Actinobacteria was the primary host of ARGs and was suppressed by RSD.Soil physicochemical properties,such as total nitrogen,soil pH,total carbon,were crucial factors affecting ARG profiles.Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil.展开更多
Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vi...Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.展开更多
Pyrrolizidine alkaloids(PAs)and their N-oxides(PANOs)are phytotoxins produced by various plant species and have been emerged as environmental pollutants.The sorption/desorption behaviors of PAs/PANOs in soil are cruci...Pyrrolizidine alkaloids(PAs)and their N-oxides(PANOs)are phytotoxins produced by various plant species and have been emerged as environmental pollutants.The sorption/desorption behaviors of PAs/PANOs in soil are crucial due to the horizontal transfer of these natural products from PA-producing plants to soil and subsequently absorbed by plant roots.This study firstly investigated the sorption/desorption behaviors of PAs/PANOs in tea plantation soils with distinct characteristics.Sorption amounts for seneciphylline(Sp)and seneciphylline-N-oxide(SpNO)in three acidic soils ranged from 2.9 to 5.9μg/g and 1.7 to 2.8μg/g,respectively.Desorption percentages for Sp and SpNO were from 22.2%to 30.5%and 36.1%to 43.9%.In the mixed PAs/PANOs systems,stronger sorption of PAs over PANOs was occurred in tested soils.Additionally,the Freundlich models more precisely described the sorption/desorption isotherms.Cation exchange capacity,sand content and total nitrogen were identified as major influencing factors by linear regression models.Overall,the soils exhibiting higher sorption capacities for compounds with greater hydrophobicity.PANOs were more likely to migrate within soils and be absorbed by tea plants.It contributes to the understanding of environmental fate of PAs/PANOs in tea plantations and provides basic data and clues for the development of PAs/PANOs reduction technology.展开更多
Water level fluctuations in the reservoir deteriorate soils and rocks on the bank landslides by drying-wetting(D-W)cycles,which results in a significant decrease in mechanical properties.A comprehensive understanding ...Water level fluctuations in the reservoir deteriorate soils and rocks on the bank landslides by drying-wetting(D-W)cycles,which results in a significant decrease in mechanical properties.A comprehensive understanding of deterioration mechanism of sliding-zone soils is of great significance for interpreting the deformation behavior of landslides.However,quantitative investigation on the deterioration characteristics of soils considering the structural evolution under D-W cycles is still limited.Here,we carry out a series of laboratory tests to characterize the multi-scale deterioration of sliding-zone soils and reveal the mechanism of shear strength decay under D-W cycles.Firstly,we describe the micropores into five grades by scanning electron microscope and observe a critical change in porosity after the first three cycles.We categorize the mesoscale cracks into five classes using digital photography and observe a stepwise increase in crack area ratio.Secondly,we propose a shear strength decay model based on fractal theory which is verified by the results of consolidated undrained triaxial tests.Cohesion and friction angle of sliding-zone soils are found to show different decay patterns resulting from the staged evolution of structure.Then,structural deterioration processes including cementation destruction,pores expansion,aggregations decomposition,and clusters assembly are considered to occur to decay the shear strength differently.Finally,a three-stage deterioration mechanism associated with four structural deterioration processes is revealed,which helps to better interpret the intrinsic mechanism of shear strength decay.These findings provide the theoretical basis for the further accurate evaluation of reservoir landslides stability under water level fluctuations.展开更多
基金supported in part by the National Key Research and Development Plan(2023YFD1902605)the Natural Science Foundation of Shandong Province,China(ZR2021MC123)the Shandong Province First-class Discipline Construction“811”Project。
文摘Subsoiling is widely used to improve soil productivity in the North China Plain(NCP).However,its effects on pore network-based hydraulic properties and their relationship with water use efficiency(WUE)are far from clear.In this study,we evaluated the effects of three tillage systems(rotary tillage at 15 cm depth,RT15;subsoiling at 40 cm depth,SS40;and subsoiling at 35 cm depth,SS35)on soil pore structure,hydraulic properties,and WUE during the 2022-2024 winter wheat seasons.Results showed that the effects of SS40 and SS35 were similar in optimizing the soil pore structure and hydraulic properties.Compared with RT15,SS40 and SS35 increased the soil macroporosity ratio,the soil pore connectivity,and the soil water storage.Structural equation modeling revealed that optimized soil pore structure under subsoiling directly and positively influenced the WUE or indirectly increasing the soil water storage.As a result,compared with RT15,SS40 and SS35 increased the spike number,kernel number per spike,and 1000-grain weight,and ultimately improved the yield(35.59% and 39.32%,respectively)and WUE(36.69% and 41.55%,respectively).Overall,the results revealed the mechanism of high-efficiency water use from the perspective of pore network-based hydraulic properties,providing a theoretical basis for food security.
文摘The Gulf Cooperation Countries have the advantages of fundamental characteristics and abundant natural resources due to the high proportion of solar radiation, which helps to expand the transition to renewable energy, especially in solar projects. The Kuwait location was chosen for this research because of its high dust levels and average daily sunshine of 9.4 hours. The soiling map of Kuwait was then created using PVsyst software. A theoretical and mathematical model for 100 MW was developed based on many environmental and technical parameters. The model was run with Kuwait parameters and 100 MW solar PV power plant capacity. The results show that more than 25% of total generated electricity could be lost annually without any mitigation strategy. Furthermore, the efficiency loss could increase by around 50% during the seasons with sandstorms and high soiling rates. Additionally, manual and automatic cleaning methods were found to increase energy production from 112,092 MWh to 207,300 MWh. Moreover, manual cleaning reduced energy costs by 4.9%, but automated cleaning resulted in a 17.34% higher energy-saving cost than a system without cleaning. In addition, when using the automatic cleaning system, the system’s payback period was reduced from 9.22 to 7.86 years. Therefore, an automated cleaning system is recommended for use in Kuwait.
基金This work was supported by the Agricultural Public Welfare Industry Research,Ministry of Agriculture,China(201503117)and the earmarked fund for China Agriculture Research System(CARS-02).
文摘Compact!on layers are widely distributed in the Huang-Huai-Hai Plain,China,which restrict root growth and reduce yields.The adoption of subsoiling has been recommended to disrupt compacted soil layers and create a reasonable soil structure for crop development.In this paper,the effects of subsoiling depth(30,35 and 40 cm),period interval(2 or 3 years)and combined pre-sowing tillage practice(rotary cultivation or ploughing)on soil condition improvement was studied on a tidal soil in the Huang-Huai-Hai Plain.Seve n tillage patter ns were desig ned by combini ng differe nt subsoili ng depths,period intervals and pre-sowing.The evaluation indicators for soil condition improvement were as follows:thickness of the plough layer and hard pan,soil bulk density,cone index,soil three-phase R values,alkali nitrogen content,crop yield,and economic ben efits.The results showed that subsoiling can sign ificantly improve the soil structure and physical properties.In all subsoiling treatments,the depth of 35 or 40 cm at a 2-year interval was the most significant.The thickness of the plough layer in creased from 13.67 cm before the test to 21.54-23.45 cm in 2018.The thick ness of the hard pan decreased from 17.68 cm before the test to 12.09-12.76 cm in 2018,a decrease of about 40.07%.However,the subsoiling combined presowing tillage practice,that is,rotary cultivation or ploughing,was not significant for soil structure and physical properties.For all subsoiling treatments,the soil bulk density,cone index and soil three-phase R values of the 15-25 cm soil layer were significantly lower compared to single rotary cultivation.Subsoiling was observed to increase the soil alkaline nitrogen and water conte nts.The tillage patter ns that had subsoiling at the depth of 35-40 cm at a 2-year in terval combi ned with rotary cultivation had the highest alkali nitrogen and water contents,which increased by 31.08-34.23%compared with that of the single rotary cultivati on.Subsoiling can sign ifica ntly in crease the yield both of wheat and corn,as well as the economic ben efits.The treatment of subsoili ng at the depth of 35 cm at an interval of 2 years com bined with rotary cultivation had the highest ann ual yield and economic benefits.For this treatme nt,the arinual yield and economic ben efits in creased by 14.55 and 62.87%in 2018,respectively.In con clusi on,the tillage patter ns that involved subsoili ng at a depth of 35 cm at a 2-year interval along with rotary cultivation are suitable for the Huang?Huai-Hai Plain.
文摘Solar photovoltaic(PV)power represents one of the most promising future sources of energy in the world.Considered the cleanest form of energy,extensive research is being undertaken to widen its use.Notably,mega projects are being considered for installation in the Middle East and North Africa(MENA)region because of its high solar potential,with hopes of eventually feeding Europe from the PV electricity generated in this region and transported through high voltage direct current(DC)lines.However,current implementation of PV systems has shown that their reliability and efficiency depend upon surrounding environmental factors,such as the ambient temperature,wind,and rainfall,as well as soiling,pollution,and aging.The aim of this study was to investigate,through experimental tests,the effects of such factors on the power output of a grid connected PV station.The results showed that the output power and efficiency are deeply affected by various environmental factors,which are weather dependent.These findings may help us develop appropriate solutions to overcome these drawbacks.
文摘In this paper,a detailed model of a photovoltaic(PV)panel is used to study the accumulation of dust on solar panels.The presence of dust diminishes the incident light intensity penetrating the panel’s cover glass,as it increases the reflection of light by particles.This phenomenon,commonly known as the“soiling effect”,presents a significant challenge to PV systems on a global scale.Two basic models of the equivalent circuits of a solar cell can be found,namely the single-diode model and the two-diode models.The limitation of efficiency data in manufacturers’datasheets has encouraged us to develop an equivalent electrical model that is efficient under dust conditions,integrated with optical transmittance considerations to investigate the soiling effect.The proposed approach is based on the use of experimental current-voltage(I-V)characteristics with simulated data using MATLAB/Simulink.Our research outcomes underscores the feasibility of accurately quantifying the reduction in energy production resulting from soiling by assessing the optical transmittance of accumulated dust on the surface of PV glass.
文摘Intended for good productivity and perfect operation of the solar power grid a failure-free system is required.Therefore,thermal image processing with the thermal camera is the latest non-invasive(without manual contact)type fault identification technique which may give good precision in all aspects.The soiling issue,which is major productivity affecting factor may import from several reasons such as dust on the wind,bird mucks,etc.The efficient power production sufferers due to accumulated soil deposits reaching from 1%–7%in the county,such as India,to more than 25%in middle-east countries country,such as Dubai,Kuwait,etc.This research offers a solar panel soiling detection system built on thermal imaging which powers the inspection method and mitigates the requirement for physical panel inspection in a large solar production place.Hence,in this method,solar panels can be verified by working without disturbing production operation and it will save time and price of recognition.India ranks 3rd worldwide in the usage use age of Photovoltaic(PV)panels now and it is supported about 8.6%of the Nation’s electricity need in the year 2020.In the meantime,the installed PV production areas in India are aged 4–5 years old.Hence the need for inspection and maintenance of installed PV is growing fast day by day.As a result,this research focuses on finding the soiling hotspot exactly of the working solar panels with the help of Principal Components Thermal Analysis(PCTA)on MATLAB Environment.
文摘In order to evaluate the effect of subsoiling on the soil physical properties and wheat yield in dry land conditions, this research was conducted in Mamassani area of Fars province in Iran. The experiment was laid down in the form of a complete block experimental design with four treatments and four replications for three years. Treatments included： （1） conventional tillage without using subsoiler which was control treatment （So）; （2） using subsoiler with the shank space of 40 cm which was equal to the subsoiling depth （SO; （3） using subsoiler with the shank space of 60 cm which was 1.5 times of the subsoiling depth （S2）; and （4） using subsoiler with the shank space of 80 cm which was 2 times of the subsoiling depth （S3）. Subsoiling depth was set at 40 cm which was the lower limit of the hard pan depth in the soil. Soil cone index, soil bulk density, soil moisture content, wheat yield, and yield components were measured in this study and SAS software was used to analyze the collected data. Results showed that subsoiling decreased the soil bulk density and cone index, and increased water retention of the soil. Results also revealed that applying subsoiler increased wheat yield and yield components in our dry land conditions. Since subsoiling improved soil physical conditions and increases wheat yield, applying subsoiler in such a dry land conditions is therefore recommended. Results of this study also showed that subsoiling with the shank space of 40 cm and 60 cm had better performance compared to the shank space of 80 cm. On the other hand, shank space of 40 cm reduced the subsoiler effective working width and consequently effective field capacity. Therefore, subsoiler with a shank space of 60 cm is recommended for application in dry land soils of our type.
基金the National Natural Science Foundation of China(31771715,31401334,and 31601234)China Agriculture Research System(CARS-3-1-19).
文摘Sustainable agriculture in the Huang–Huai–Hai Plain of China is threatened by subsoil compaction and the decline of winter wheat productivity induced by inappropriate tillage regimes. We investigated the effects of optimizing the tillage regime on grain filling and its relationship with flag leaf senescence post-anthesis in winter wheat. Four treatments were compared: rotary tillage, strip rotary tillage, strip rotary tillage with a 2-year subsoiling interval(STS), and conventional plowing tillage. STS produced higher chlorophyll content and leaf area indexes than other treatments, resulting in a greater photosynthetically active radiation capture ratio. The net photosynthesis rate of flag leaves from 14 to 28 days after anthesis and dry matter accumulation at maturity were higher in STS than in other treatments. Sucrose content and sucrose phosphate synthase activity of flag leaves first increased and then decreased during grain filling and were highest in STS. STS increased superoxide dismutase activity, increased soluble protein content, and reduced malondialdehyde concentrations in flag leaves after the middle grain-filling stages,resulting in reduced premature senescence. This consequence extended the active grain filling period and increased grain weight. The highest yields were observed in STS, reaching10,451 kg ha-1 in 2014–2015 and 10,074 kg ha-1 in 2015–2016, owing to increased spike numbers and 1000-kernel weight. Overall, our study suggested that STS could substantially increase photosynthetic capacity and delay leaf senescence, thus promoting grain filling rate and increasing winter wheat yields.
基金The work is fully funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES,finance code 001)We also thank the Programa em Nutrição e Solos Florestais(NUTREE—UFV).
文摘Eucalyptus harvesting,forwarding and soil tillage operations are among the main causes for compaction of forest soils,with potential impacts on productivity.This concern is especially important in areas with soils that are naturally compacted(fragipans and duripans).In these soils,tillage operations include the use of subsoilers that can reach depths of more than one meter and require heavy tractors that exert high pressure on the soil.One of the ways to try to minimize the effect of this compaction is by retaining harvest residues.The objective of this study was to evaluate the impacts of eucalyptus harvesting on soil physical attributes,as well as to determine the potential of different types of residue management to reduce compaction from the soil tillage operation.Two experiments were conducted in the same area with a Yellow Argisol.In the first experiment,compaction caused by mechanized harvesting with harvester+forwarder was evaluated.In the second experiment,different managements of harvest residues were examined as potential modifiers of soil compaction during tillage for new plantings.For this,three managements systems were tested:(1)retention of all harvest residues and litter from the previous rotation(HR+L),(2)retention of litter from the previous rotation(L),and(3)removal of harvest residues and litter from the previous rotation(WR).Before and after harvest,sampling was carried out in the planting rows and inter-rows,and after tillage,samples were collected in the traffic line of the subsoiler-tractor set.In both experiments,undisturbed soil samples were collected from the center of the 0-10,10-20,20-40,40-60,and 60-100 cm layers to determine soil density and total porosity.In each period and site of evaluation,mechanical resistance to penetration up to the 60-cm depth was also determined.The harvesting operation increased soil density at 0-10 and 60-100 cm depths only in the inter-rows.Retention of harvest residues and litter(HR+L)after harvesting avoided increases in soil density and penetration resistance caused by machine traffic during tillage.The results indicate the importance of retaining harvest residues on forest soils for achieving sustainable utilization and for conserving soil quality.
文摘Monocolumn composite bucket foundation is a new type of offshore wind energy foundation.Its bearing characteristics under shallow bedrock conditions and complex geological conditions have not been extensively studied.Therefore,to analyze its bearing characteristics under complex conditions-such as silty soil,chalky soil,and shallow bedrock-this paper employs finite element software to establish various soil combination scenarios.The load-displacement curves of the foundations under these scenarios are calculated to subsequently evaluate the horizontal ultimate bearing capacity.This study investigates the effects of shallow bedrock depth,the type of soil above the bedrock,the thickness of layered soil,and the quality of layered soil on the bearing characteristics of the monocolumn composite bucket foundation.Based on the principle of single-variable control,the ultimate bearing capacity characteristics of the foundation under different conditions are compared.The distribution of soil pressure inside and outside the bucket wall on the compressed side of the foundation,along with the plastic strain of the soil at the base of the foundation,is also analyzed.In conclusion,shallow bedrock somewhat reduces foundation bearing capacity.Under shallow bedrock conditions,the degree of influence on foundation bearing capacity characteristics can considerably vary on different upper soils.The thickness of each soil layer and the depth to bedrock in stratified soils also affect the bearing capacity of the foundation.The findings of this paper provide a theoretical reference for related foundation design and construction.In practice,the bearing performance of the foundation can be enhanced by improvingthe soil quality in the bucket,adjusting the penetration depth,adjusting the percentage of different types of soil layers in the bucket,and applying other technical construction methods.
基金This work was supported by the Department of Science and Technology,Government of India under grants DST/RCUK/JVCCE/2015/02(C)DST/RCUK/SEGES/2012/04(G).
文摘Apart from being a clean source of energy,photovoltaic(PV)power plants are also a source of income generation for its investors and lenders.Therefore,mitigation of system losses is crucial for economic operation of PV plants.Combined losses due to soiling,shading and temperature in PV plants go as high as 50%.Much of these losses are unaccounted initially,which can jeopardize the economic viability of PV projects.This paper aims to provide a model to determine losses due to soiling,shading and temperature using quantities like irradiance,cell temperature,DC power and current,which are readily available in PV yield data captured by the remote monitoring system,without involving any additional sensors or equipment.In this study,soiling,shading and thermal losses were calculated using PV yield data obtained from a 30-kWp PV plant located in Kharagpur,India.The results showed soiling and shading losses as high as 25.7%and 9.7%,respectively,in the month of December.Soiling loss was verified by measuring transmittance loss of coupon glasses installed in the vicinity of the plant.Shading loss was verified by shadow simulation using an architectural tool(SketchUp).Array thermal loss obtained using the proposed methodology was found to be in line with the estimated value obtained from PVsyst simulation.Additionally,using time-series data,the energy losses corresponding to soiling,shading and temperature effects were calculated by a numerical-integration technique.The monetary loss due to these energy losses thus obtained provides criteria for deciding when to mitigate the sources of these losses.
文摘Installing internal bulkheads in a composite bucket foundation alters the rotational symmetry characteristic of a single-compartment bucket foundation,consequently influencing the stress distribution within the bucket and surrounding soil.During the seabed penetration of a spudcan from a jack-up wind turbine installation vessel,an angle may form between the spudcan’s axis and the axis of symmetry of the adjacent composite bucket foundation in the horizontal plane.Such a misalignment may affect load distribution and the non-uniform interaction between the foundation,soil,and spudcan,ultimately influencing the foundation’s stability.This study employs physical model tests to ascertain the trends in end resistance during spudcan penetration in sand,the extent of soil disturbance,and the backflow condition.The finite element coupled Eulerian-Lagrangian method is validated and utilized to determine the range of penetration angles that induce alterations in the maximum vertical displacement and tilt rate of the composite bucket foundation in sand.The differential contact stress distribution at the base of the bucket is analyzed,with qualitative criteria for sand backflow provided.Findings demonstrate that the maximum vertical displacement and tilt rate of the composite bucket foundation display a“wave-like”variation with the increasing spudcan penetration angle,peaking when the angle between the spudcan and bulkhead is the smallest.Stress distribution is predominantly concentrated at the base and apex of the bucket,becoming increasingly uneven as the penetration angle deviates from the foundation’s symmetry axis.The maximum stress gradually shifts to the junction of the bulkhead and bucket bottom on the side with the shortest net distance from the spudcan.Considering the in-place stability and stress state of the composite bucket foundation is therefore imperative,and particular attention should be paid to the foundation’s state when the angle between the spudcan and bulkhead is small.
基金Funded by the National Natural Science Foundation of China(Nos.52378360,51978438)。
文摘We used solidification/stabilization methods to remediate highly concentrated Zn^(2+)-contaminated soil.An industrial waste mixture of red mud,carbide slag,and phosphogypsum is combined with cement as the curing agent.The mixing ratios of the four materials are determined by comparing the strength,permeability coefficient,pH,and Zn^(2+)-leaching concentration of the solidified soil.Microscopic characteristics of the solidified uncontaminated soil and solidified Zn^(2+)-contaminated soil were observed using scanning electron microscopy,X-ray diffraction,and Fourier-transform infrared spectroscopy.Furthermore,the heavy metals speciation in both pure cement and mixed-material solidified soil was examined,demonstrating the beneficial role of the mixed-type curing agent in stabilizing heavy metals.The research results indicate that Zn^(2+)degrade the strength of the solidified soil by up to 90%.The permeability coefficient,pH,and Zn^(2+)-leaching concentration of the solidified soil easily meet standard,especially with Zn^(2+)leaching concentration well below the environmental protection limit.Furthermore,most Zn^(2+)exists in forms with lower biological and chemical reactivity.Both the solidified Zn^(2+)-contaminated soil and uncontaminated soil resulted in the formation of hydrated products containing elements such as silicon,aluminum,calcium,and sulfur.Additionally,the solidified Zn^(2+)-contaminated soil produced zinc-containing compounds and a large amount of rod-shaped ettringite.
基金supported by the National Natural Science Foundation of China(Nos.52100184,and U22A20617).
文摘Controlling heavy metal pollution in agricultural soil has been a significant challenge.These heavy metals seriously threaten the surrounding ecological environment and human health.The effective assessment and remediation of heavy metals in agricultural soils are crucial.These two aspects support each other,forming a close and complete decisionmaking chain.Therefore,this review systematically summarizes the distribution characteristics of soil heavy metal pollution,the correlation between soil and crop heavy metal contents,the presence pattern and migration and transformation mode of heavy metals in the soil-crop system.The advantages and disadvantages of the risk evaluation tools and models of heavy metal pollution in farmland are further outlined,which provides important guidance for an in-depth understanding of the characteristics of heavymetal pollution in farmland soils and the assessment of the environmental risk.Soil remediation strategies involve multiple physical,chemical,biological and even combined technologies,and this paper compares the potential and effect of the above current remediation technologies in heavy metal polluted farmland soils.Finally,the main problems and possible research directions of future heavy metal risk assessment and remediation technologies in agricultural soils are prospected.This review provides new ideas for effective assessment and selection of remediation technologies based on the characterization of soil heavy metals.
基金funded by the Science and Technology Plan for the Belt and Road Innovation Cooperation Project of Jiangsu Province,China(No.BZ2023003)the National Key Research and Development Program of China(No.2021YFD1500202)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA28010100)the“14th Five-Year Plan”Self-Deployment Project of the Institute of Soil Science,Chinese Academy of Sciences(No.ISSAS2418)the National Natural Science Foundation of China(No.42107334)。
文摘Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production.With the ongoing intensification of agricultural practices and negative natural factors,black soils are confronting enhanced degradation.The holistic overview of black soil degradation and the underlying mechanisms for soil health improvement will be key for agricultural sustainability and food security.In this review,the current status and driving factors of soil degradation in the four major black soil regions of the world are summarized,and effective measures for black soil conservation are proposed.The Northeast Plain of China is the research hotspot with 41.5%of the published studies related to black soil degradation,despite its relatively short history of agricultural reclamation,followed by the East European Plain(28.3%),the Great Plains of North America(20.7%),and the Pampas of South American(7.9%).Among the main types of soil degradation,soil erosion and soil fertility decline(especially organic matter loss)have been reported as the most common problems,with 27.6%and 39.4%of the published studies,respectively.In addition to the natural influences of climate and topography,human activities have been reported to have great influences on the degradation of black soils globally.Unsustainable farming practices and excess in agrochemical applications are common factors reported to accelerate the degradation process and threaten the sustainable use of black soils.Global efforts for black soil conservation and utilization should focus on standardizing evaluation criteria including real-time monitoring and the measures of prevention and restoration for sustainable management.International cooperation in technology and policy is crucial for overcoming the challenges and thus achieving the protection,sustainable use,and management of global black soil resources.
基金supported by the Key Research and Development Program of Shandong Province,China(No 2021CXGC010803)Pan’an County Chinese Medicine Industry Project(No.PZYF202103).
文摘Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dynamic changes in soil communities,potential bacterial pathogens,and ARG profiles under various organicmaterial treatments during RSD,including distillers’grains,potato peel,peanut vine,and peanut vine combined with charcoal.Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens(P<0.05).The relative abundance of high-risk ARGs decreased by 10.7%-30.6%after RSD treatments,the main decreased ARG subtypeswere AAC(3)_Via,dfrA1,ErmB,lnuB,aadA.Actinobacteria was the primary host of ARGs and was suppressed by RSD.Soil physicochemical properties,such as total nitrogen,soil pH,total carbon,were crucial factors affecting ARG profiles.Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil.
基金funded by the National Natural Science Foundation of China(No.41962016)the Natural Science Foundation of NingXia(Nos.2023AAC02023,2023A1218,and 2021AAC02006).
文摘Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.
基金supported by the earmarked fund for the Modern Agro-Industry Technology Research System (No.CARS-19)the Innovative Research Team in Chinese Academy of Agricultural Sciences (No.CAAS ASTIP-2014-TRICAAS).
文摘Pyrrolizidine alkaloids(PAs)and their N-oxides(PANOs)are phytotoxins produced by various plant species and have been emerged as environmental pollutants.The sorption/desorption behaviors of PAs/PANOs in soil are crucial due to the horizontal transfer of these natural products from PA-producing plants to soil and subsequently absorbed by plant roots.This study firstly investigated the sorption/desorption behaviors of PAs/PANOs in tea plantation soils with distinct characteristics.Sorption amounts for seneciphylline(Sp)and seneciphylline-N-oxide(SpNO)in three acidic soils ranged from 2.9 to 5.9μg/g and 1.7 to 2.8μg/g,respectively.Desorption percentages for Sp and SpNO were from 22.2%to 30.5%and 36.1%to 43.9%.In the mixed PAs/PANOs systems,stronger sorption of PAs over PANOs was occurred in tested soils.Additionally,the Freundlich models more precisely described the sorption/desorption isotherms.Cation exchange capacity,sand content and total nitrogen were identified as major influencing factors by linear regression models.Overall,the soils exhibiting higher sorption capacities for compounds with greater hydrophobicity.PANOs were more likely to migrate within soils and be absorbed by tea plants.It contributes to the understanding of environmental fate of PAs/PANOs in tea plantations and provides basic data and clues for the development of PAs/PANOs reduction technology.
基金funding support from the NSFC Key Projects of International Cooperation and Exchanges (Grant No.42020104006)the National Key Research and Development Program of China (Grant No.2023YFC3007001)the National Natural Science Foundation of China (Grant No.42307227).
文摘Water level fluctuations in the reservoir deteriorate soils and rocks on the bank landslides by drying-wetting(D-W)cycles,which results in a significant decrease in mechanical properties.A comprehensive understanding of deterioration mechanism of sliding-zone soils is of great significance for interpreting the deformation behavior of landslides.However,quantitative investigation on the deterioration characteristics of soils considering the structural evolution under D-W cycles is still limited.Here,we carry out a series of laboratory tests to characterize the multi-scale deterioration of sliding-zone soils and reveal the mechanism of shear strength decay under D-W cycles.Firstly,we describe the micropores into five grades by scanning electron microscope and observe a critical change in porosity after the first three cycles.We categorize the mesoscale cracks into five classes using digital photography and observe a stepwise increase in crack area ratio.Secondly,we propose a shear strength decay model based on fractal theory which is verified by the results of consolidated undrained triaxial tests.Cohesion and friction angle of sliding-zone soils are found to show different decay patterns resulting from the staged evolution of structure.Then,structural deterioration processes including cementation destruction,pores expansion,aggregations decomposition,and clusters assembly are considered to occur to decay the shear strength differently.Finally,a three-stage deterioration mechanism associated with four structural deterioration processes is revealed,which helps to better interpret the intrinsic mechanism of shear strength decay.These findings provide the theoretical basis for the further accurate evaluation of reservoir landslides stability under water level fluctuations.
