Organic matter increases biological activity within the root zone because it contains beneficial microbes that stimulate vital processes.This study aimed to determine the effect of Ochrobactrum anthropi added to the s...Organic matter increases biological activity within the root zone because it contains beneficial microbes that stimulate vital processes.This study aimed to determine the effect of Ochrobactrum anthropi added to the soil as a single or mixed solution with different concentrations of organic matter on the vegetative growth of the zinnia plant and its content of nutrients.The study was conducted with a randomized complete block design(RCBD)with three replications.The plant was grown in soil with a high salinity level of 8 ds m^(–1).Plant characteristics were estimated 30 and 60 days after planting the plant.The treatment with the addition of bio-inoculum produced the best results;within 30 days,there was a 56.89%increase in plant length;after 60 days,there was a 52.56%increase;additionally,there was a 52.56%increase in leaf count within 30 days;after 60 days,there was a 53.50%increase;and finally,there was an increase in flower count.For plants after 60 days,it reached 3.66%.With the addition of bio-inoculum to soil at a level of 3 gm kg^(–1)of organic matter,the mixing treatment achieved the highest dry weight,29.86%.The addition of bio-inoculum resulted in the largest and most significant increase in chlorophyll content in leaves,reaching 18.76%.In the mixing addition of the biological inoculum treatment,the organic content of the plant showed an increase in nitrogen(14.38%),phosphorus(21.18%),and potassium(39.75%)at 2 and 3 gm kg^(–1)organic matter,respectively.展开更多
The release of essential nutrients from soil minerals for plant growth in calcareous soils,facilitated by organic extractants,is critical in semi-arid areas,particularly for elements affected by high soil pH.This stud...The release of essential nutrients from soil minerals for plant growth in calcareous soils,facilitated by organic extractants,is critical in semi-arid areas,particularly for elements affected by high soil pH.This study aims to investigate the release of calcium(Ca),magnesium(Mg),and phosphorus(P)through the application of wood vinegar extract in surface calcareous soils in Borojerd City,Lorestan Province,Iran.The experiment was conducted using a completely randomized design with three replications.The treatments included soils from three different land uses:vineyard,wheat field,and rangeland,each treated with 1.00%wood vinegar solution.Cumulative measurements of the specified elements were recorded over 10 consecutive 0.5 h intervals.The release data were analyzed using four various kinetic models(Elovich equation,parabolic diffusion law,power function equation,and zero-order kinetics).The highest concentrations recorded were for Ca(39,500.00 mg/kg),Mg(5880.00 mg/kg),and P(5.00 mg/kg)in grape cultivation.The findings revealed a significant difference in Ca release between grape cultivation and rangeland(P<0.01),while the Mg release showed a significant difference between both grape cultivation and rangeland and wheat cultivation(P<0.01).Additionally,the cumulative release of P showed significant differences between grape cultivation and both wheat and rangeland(P<0.01).The results indicated that the zero-order kinetics provided the best fit for the data(R^(2)=0.99).The maximum initial release amount was observed in grape cultivation when applying the zero-order kinetics,while the highest release rate was achieved using the parabolic diffusion law across three applications.Wood vinegar had the capacity to degrade various clay minerals,including vermiculite,smectite,palygorskite,and,to some extent,illite,resulting in the release of associated elements.Consequently,it can be concluded that wood vinegar can be effectively utilized in grape cultivation as an agent for reducing soil acidity,thereby enhancing the availability of soil nutrients and decreasing reliance on chemical fertilizers.展开更多
The effects of various biological soil crusts(BSCs)on soil properties have been extensively studied.However,the impacts of specific species such as Placidium squamulosum,Peccania terricola,and Grimmia ovalis on soil p...The effects of various biological soil crusts(BSCs)on soil properties have been extensively studied.However,the impacts of specific species such as Placidium squamulosum,Peccania terricola,and Grimmia ovalis on soil properties in arid regions have not been documented.Besides,the effects of soil parent rock on the extent of changes in soil properties caused by BSCs have not been thoroughly investigated.The objective of this study was to examine how BSCs including two different terricolous lichen species(Placidium squamulosum and Peccania terricola)and a moss species(Grimmia ovalis)could change major soil chemical and nutritional properties in an arid area under different parent rocks.Triplicate BSC-free surface soil and soil associated with the abovementioned BSCs were sampled from 13 different sites with sedimentary and igneous parent rocks in an arid area in Isfahan,Iran.Soil properties including p H,electrical conductivity(EC),organic matter(OM),calcium carbonate equivalent(CCE),total nitrogen,available phosphorus,and available potassium were determined in all the samples.The results indicated that the presence of lichens and mosses significantly changed the soil chemical and nutritional properties.Specifically,the content of total nitrogen,organic matter,and available potassium in the soil environment increased under the activity of these biological crusts developed on both sedimentary and igneous formations.Additionally,these biological crusts resulted in a significant reduction in soil p H,CCE,and available phosphorus.The electrical conductivity of soils slightly increased due to the activity of biological crusts.In general,biological crusts including both chlorolichen(Placidium squamulosum)and cyanolichen(Peccania terricola)species,as well as a moss species(Grimmia ovalis)appear to create a unique microenvironment in terms of biochemical and nutritional conditions,which is substantially different from those typically observed in drylands.展开更多
In addition to sequestering carbon in soil,biochars can also play a role in changing the potassium equilibration and dynamics of the soil.Nowadays,acidification of biochar is commonly used to improve its properties,wh...In addition to sequestering carbon in soil,biochars can also play a role in changing the potassium equilibration and dynamics of the soil.Nowadays,acidification of biochar is commonly used to improve its properties,which can impact the potassium content in the soil.Simultaneous application of acidified biochar and sodium bentonite can complicate this effect.In the present study,the effects of adding two types of biochars prepared from municipal waste and used coffee grounds and their acidified types,along with sodium bentonite at three levels(0.00%,1.00%,and 2.00%),on soil physical-chemical properties(pH,salinity,cation exchange capacity,concentration of soluble cations and their ratio,and sodium adsorption ratio)and the release of potassium from a calcareous soil were investigated.The results showed that the addition of coffee ground biochar increased the concentration of soluble potassium and decreased the ratio of calcium to potassium,while the acidified coffee ground biochar decreased the amount of soluble potassium and increased the ratio of calcium to potassium.Alkaline and acidified municipal waste biochars had no effect on soluble potassium and soluble cations ratio.Application of bentonite increased the amount of soluble calcium and sodium and the ratio of calcium to potassium.Addition of bentonite also increased the amount of exchangeable potassium and exchangeable sodium percentage,but use of different biochars reduced negative effect of bentonite.Use of bentonite also caused an increase in the exchangeable potassium and a decrease in the non-exchangeable potassium contents.Alkaline and acidified coffee ground biochars increased the amount of exchangeable,non-exchangeable,and total potassium,but this effect was greater by alkaline biochar.Application of municipal waste biochar did not affect the amount of exchangeable potassium but increased the amount of non-exchangeable and total potassium,with no significant difference observed between alkaline and acidified biochars.Potassium saturation percentage was not affected by bentonite,but coffee ground biochar increased its amount and municipal waste biochar had no effect on it.Acidified and alkaline coffee ground biochars were able to release more potassium from the soil(475 and 71 mg/kg,respectively),while alkaline municipal waste biochar did not affect it and acidified municipal waste biochar reduced it by 113 mg/kg.In general,it can be concluded that alkaline biochars in calcareous soils can improve potassium fertility by reduction of the ratio of calcium to potassium and increasing its various forms,while acidified biochars and bentonite may aggravate potassium deficiency in these soils.Considering the lack of significant change in the pH of calcareous soils with the use of different biochars,it is suggested to use alkaline biochars,which can improve the potassium status of the soil while reducing the costs associated with biochar modification.展开更多
A field experiment was conducted on silty clay loam soil cultivated with wheat to evaluate the effects of bio-inoculation with the arbuscular mycorrhizal fungus Glomus mosseae and poultry manure on soil micronutrient ...A field experiment was conducted on silty clay loam soil cultivated with wheat to evaluate the effects of bio-inoculation with the arbuscular mycorrhizal fungus Glomus mosseae and poultry manure on soil micronutrient concentrations.Treatments included fungal inoculum alone,poultry manure alone,their combination,and a control,arranged in a randomized complete block design with three replications.The combined application of fungal inoculum and poultry manure significantly increased total concentrations of iron,manganese,zinc,molybdenum,copper,and boron in bulk soil to 5890.4,390.5,36.5,1.6,23.1,and 2.0 mg kg⁻¹,representing increases of 13%,20.3%,32.2%,84%,23.5%,and 175%over the control.In the rhizosphere,these elements reached 5650.8,380.7,33.2,3.8,21.4,and 3.5 mg kg⁻¹,with increases of 9.5%,26.4%,29.6%,92%,38.9%,and 90.1%.Available concentrations in bulk soil rose to 15.3,10.6,1.4,0.4,0.47,and 1.2 mg kg⁻¹,corresponding to increases of 51.6%,83%,42%,92.5%,65.9%,and 36.1%,while in the rhizosphere,available values reached 16.2,11.7,1.9,0.7,0.7,and 1.6 mg kg⁻¹,reflecting increases of 55%,30%,35.4%,90%,128%,and 93.7%,respectively.These enhancements are attributed to the synergistic effects of microbial activity,organic matter decomposition,and organic acid release,which improved nutrient solubility and accessibility in the root zone.The findings indicate that integrating Glomus mosseae inoculation with poultry manure is an effective and sustainable strategy to improve soil fertility,increase micronutrient availability,and enhance plant nutrient uptake,providing a practical recommendation for boosting wheat productivity while reducing reliance on chemical fertilizers.展开更多
A laboratory experiment was conducted to demonstrate the importance of improving the efficiency of six isolates of Aspergillus niger fungi.Four isolates were exposed to UV-rays radiation at a distance of 30 cm,a wavel...A laboratory experiment was conducted to demonstrate the importance of improving the efficiency of six isolates of Aspergillus niger fungi.Four isolates were exposed to UV-rays radiation at a distance of 30 cm,a wavelength of 254–255 nm during M15,M30,and M45 minutes.Exposure periods,both of wild(no UV-rays exposure)and no A.niger(C)as controls,all six isolates were identified molecularly by polymerase chain reaction technique extracted DNA of A.niger was analyzed to ensure gene completion through multiple sequence alignment by bioinformatic programs to study the improvement of dissolving efficiency of mutant and wild A.niger.They were incubated after the addition of superphosphate fertilizer(47%P2O5)at 90 mg P kg–1 applied to soil with controls(no A.niger or no superphosphate)for I,II,III,and IV weeks of incubation periods at 28±1°C.In addition,the DNA extraction and purification by NanoDrop of Thermo Scientific-200 A280/A260 ratio was 2.01 and confirmed that the sequences of nitrogenous bases by the method of multiple sequence alignment(MSA)as compared to the reference sequence of A.niger recorded in the gene bank under the accession number LC632396.Results proved that the M30 minutes exposure UV-rays radiation period was the superior dose when mutant Aspergillus niger obtained the highest amount of dissolved phosphate,reducing soil-pH with maximum biomass of A.niger during the M30 isolate during the third week(III).展开更多
This study was conducted to determine the content,distribution and transformation of iron oxides in the soils of the Middle Euphrates regions in Iraq.The study included four sites:Tuwairij area in Karbala Governorate,...This study was conducted to determine the content,distribution and transformation of iron oxides in the soils of the Middle Euphrates regions in Iraq.The study included four sites:Tuwairij area in Karbala Governorate,College of Agriculture at the University of Kufa in Najaf Governorate,College of Agriculture at the University of Qadisiyah in Diwaniyah Governorate,and the Nile District in Babylon Governorate.The results showed that the soils of Najaf and Qadisiyah were superior in terms of their content of total free iron oxides(Fet)compared to the soils of Karbala and Babylon.The relative distribution of free iron oxides was generally close among the studied sites,with a homogeneous pattern in the distribution of these oxides within the soil horizons.As for silicate iron oxides(Fes),a homogeneous pattern was observed in the soil of Babylon with its content increasing with depth,while these patterns varied in the soils of Karbala,Najaf and Qadisiyah.Regarding the ratios of crystalline iron oxides(Fed/Fet),the study showed that the Babylon and Qadisiyah soils recorded the highest values,while these values were lower in the Najaf and Karbala soils.On the other hand,amorphous iron oxides(FeO)showed similar values in the Najaf and Qadisiyah soils.In general,these results clearly showed the effect of environmental and geochemical factors of the study areas on the distribution and transformations of iron oxides in the soil of the Middle Euphrates regions.展开更多
Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine ...Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine Bangladesh,are generally low in organic matter status and deficient in necessary nutrient elements for crop production.Addressing this challenge,the present study was conducted to investigate the effects of various organic nutrient sources with inorganic fertilizers on crop yields,nutrient uptake,and soil fertility in farm(L1)and char land(L2)of Brahmaputra River in Mymensingh,Bangladesh from 2022(Y1)to 2023(Y2).For each location,eight treatments viz.T1(Control),T2[100%recommended fertilizer dose(RFD)],T3(75%RFD),T4(75%N from RFD 25%N from cow dung),T5(75%+N from RFD 25%N from poultry manure),T6(75%N from RFD 25%N from vermicompost),T7(75%N from++RFD 25%N from household compost)and T8(75%N from RFD 25%N from rice straw compost)were arranged in++a randomized complete block design with three replications using Wheat–Mungbean–T.Aman rice cropping pattern where three way interaction was considered for results.Treatment T5 performed the best in both years in both locations as it enhanced the yield components(p 0.05)and caused yield increment over control.The yield improvement in<Char land soils was higher than that in farm soils.For all three crops,treatment T5 consistently augmented the uptake of nitrogen,phosphorus,potassium,and sulphur by different parts of the crops and improved soil fertility properties such as organic matter status,cation exchange capacity,total nitrogen,available phosphorus,and sulphur as well as exchangeable potassium in both locations in both years.Cost and return analysis of different treatments for the whole cropping system showed that the highest marginal benefit-cost ratio(16.35 and 15.07)and gross return(about Tk 768,595/ha and 728,341/ha)were obtained from the T5 treatment in farm soils and Char land soils,respectively.Followed by poultry manure,vermicompost performed well in addition to mineral fertilizers for improving crop yield and soil fertility but its economic efficiency was less due to high input cost.These findings may be useful to the smallholder farmers in char areas,who could benefit from increased productivity,reduced reliance on chemical fertilizers,and improved soil health,contributing to the long-term sustainability of char land agriculture.展开更多
Cadmium(Cd)contamination in agricultural soils poses severe threats to human health and ecosystem integrity.While biochar is recognized for its ability to immobilize heavy metals,the impact of plant-derived low molecu...Cadmium(Cd)contamination in agricultural soils poses severe threats to human health and ecosystem integrity.While biochar is recognized for its ability to immobilize heavy metals,the impact of plant-derived low molecular weight organic acids(LMWOAs),such as citric acid(CA),on this process remains unclear.This study shows that CA and biochar synergistically immobilize Cd in alkaline soil from extensively polluted southeastern Hubei,China.Soils were amended with maize stover biochar at rates of 0,0.5%,1%,and 2%(W/W),with or without CA addition(1 mmol/L),and incubated for 80 days.Results show that biochar significantly reduced bioavailable Cd,with a 2%application decreasing extractable Cd by 26.84%.Unexpectedly,CA alone increased Cd mobility by 9.38%;however,when combined with high-dose biochar,CA and biochar synergistically enhanced Cd immobilization,reducing bioavailable Cd by 27.40%.Advanced analytical techniques,including BCR sequential extraction,X-ray diffraction,Fourier-transform infrared spectroscopy,and scanning electron microscopy with energy-dispersive X-ray spectroscopy,confirmed that the interaction between biochar and CA altered Cd speciation,promoting its stabilization.This study is the first to show that CA and biochar synergistically immobilize Cd in alkaline soils,disproving the idea that LMWOAs hinder biochar's metal remediation.Our findings show that biochar can prevent or even harness LMWOAs'activating effects on Cd,indicating its great potential for sustainable Cd remediation in alkaline soils.This study improves our understanding of biochar-soil interactions in organic acids and gives new scientific bases for enhancing heavy metal-contaminated soil remediation procedures.展开更多
The use of organic fertilizers can be an opportunity to increase crop yield and improve soil fertility in semi-arid regions,since soils from these regions usually have unfavourable conditions for plant growth.This res...The use of organic fertilizers can be an opportunity to increase crop yield and improve soil fertility in semi-arid regions,since soils from these regions usually have unfavourable conditions for plant growth.This research investigates the effects of organic and mineral fertilization on the impact of soil properties(pH,electrical conductivity and organic matter),availability of macro-(N,P and K),micro-nutrients(Fe,Mn,Cu and Zn)and the accumulation of heavy metals(Pb,Cd,Cr)in soil and potato tubers grown under semiarid conditions.A field experiment was conducted in Raqqa Governorate(Syria)using a randomized complete block design with six treatments:control,mineral fertilizer,fermented cow manure,municipal compost,sewage sludge and olive oil solid waste.At harvest,soil and plant samples were analyzed to assess nutrient dynamics in the soil and potato tubers,including metal uptake.The results showed that the highest yields were obtained with mineral fertilizer(22.87 t ha^(−1))and sewage sludge(22.15 t ha^(−1)).Organic amendments significantly improved soil organic matter,total nitrogen,and the bioavailability of phosphorus,potassium,and micronutrients after harvest.Compost and sewage sludge notably enhanced the soil and plant contents of Mn and Cu.However,these amendments also increased the amounts of Pb and Cd in soils and their uptake by plants,with Cd contents exceeding the Codex Alimentarius limit for potatoes(>0.1 mg kg^(−1)).These findings highlight the potential of treated organic waste as a valuable nutrient input for potato cultivation,especially in resource-limited areas.However,continuous monitoring is required due to the risk of heavy metal accumulation.Integrating organic fertilizers with mineral sources appears to be an effective strategy for improving crop productivity,soil health,and environmental sustainability.展开更多
Very few studies have benefited from the synergetic implementation of visible,near-infrared,and shortwave infrared(VNIR-SWIR)spectra and terrain attributes in predicting Pb content in agricultural soils.To fill this g...Very few studies have benefited from the synergetic implementation of visible,near-infrared,and shortwave infrared(VNIR-SWIR)spectra and terrain attributes in predicting Pb content in agricultural soils.To fill this gap,this study aimed to predict lead(Pb)contents in agricultural soils by combining machine learning algorithms(MLAs)with VNIR-SWIR spectra or/and terrain attributes under three distinct approaches.Six MLAs were tested,including artificial neural network(ANN),partial least squares regression,support vector machine(SVM),Gaussian process regression(GPR),extreme gradient boosting(EGB),and Cubist.The VNIR-SWIR spectral data were preprocessed by methods of discrete wavelet transformation,logarithmic transformation-Savitzky Golay smoothing,standard normal variate(SNV),multiplicative scatter correction,first derivative(Fi D),and second derivative.In approach 1,MLAs were combined with the preprocessed VNIR-SWIR spectral data.The Cubist-Fi D combination was the most effective,achieving a coefficient of determination(R2)of 0.63,a concordance correlation coefficient(CCC)of 0.51,a mean absolute error(MAE)of 6.87 mg kg^(-1),and a root mean square error(RMSE)of8.66 mg kg^(-1).In approach 2,MLAs were combined with both preprocessed VNIR-SWIR spectral data and terrain attributes,and the EGB-SNV combination yielded superior results with R2of 0.75,CCC of 0.65,MAE of 5.48 mg kg^(-1),and RMSE of 7.34 mg kg^(-1).Approach 3 combined MLAs and terrain attributes,and Cubist demonstrated the best prediction results,with R^(2) of 0.75,CCC of 0.66,MAE of 6.18 mg kg^(-1),and RMSE of 7.71 mg kg^(-1).The cumulative assessment identified the fusion of terrain properties,SNV-preprocessed VNIR-SWIR spectra,and EGB as the optimal method for estimating Pb content in agricultural soils,yielding the highest R2value and minimal error.Comparatively,GPR,ANN,and SVM techniques achieved higher R2values in approaches 2 and 3 but also exhibited higher estimation errors.In conclusion,the study underscores the significance of using relevant auxiliary datasets and appropriate MLAs for accurate Pb content prediction with minimal error in agricultural soils.The findings contribute valuable insights for developing successful soil management strategies based on predictive modeling.展开更多
Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics o...Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.展开更多
The integration of machine learning(ML)into geohazard assessment has successfully instigated a paradigm shift,leading to the production of models that possess a level of predictive accuracy previously considered unatt...The integration of machine learning(ML)into geohazard assessment has successfully instigated a paradigm shift,leading to the production of models that possess a level of predictive accuracy previously considered unattainable.However,the black-box nature of these systems presents a significant barrier,hindering their operational adoption,regulatory approval,and full scientific validation.This paper provides a systematic review and synthesis of the emerging field of explainable artificial intelligence(XAI)as applied to geohazard science(GeoXAI),a domain that aims to resolve the long-standing trade-off between model performance and interpretability.A rigorous synthesis of 87 foundational studies is used to map the intellectual and methodological contours of this rapidly expanding field.The analysis reveals that current research efforts are concentrated predominantly on landslide and flood assessment.Methodologically,tree-based ensembles and deep learning models dominate the literature,with SHapley Additive exPlanations(SHAP)frequently adopted as the principal post-hoc explanation technique.More importantly,the review further documents how the role of XAI has shifted:rather than being used solely as a tool for interpreting models after training,it is increasingly integrated into the modeling cycle itself.Recent applications include its use in feature selection,adaptive sampling strategies,and model evaluation.The evidence also shows that GeoXAI extends beyond producing feature rankings.It reveals nonlinear thresholds and interaction effects that generate deeper mechanistic insights into hazard processes and mechanisms.Nevertheless,several key challenges remain unresolved within the field.These persistent issues are especially pronounced when considering the crucial necessity for interpretation stability,the demanding scholarly task of reliably distinguishing correlation from causation,and the development of appropriate methods for the treatment of complex spatio-temporal dynamics.展开更多
Degradation of the physical quality of the soil is a common problem encountered in agrosystems, particularly in the case of open field cropping systems in the northern areas of Côte d’Ivoire. Thus, the struc...Degradation of the physical quality of the soil is a common problem encountered in agrosystems, particularly in the case of open field cropping systems in the northern areas of Côte d’Ivoire. Thus, the structural stability of the soil, which is a good indicator of the sensitivity to threshing and to water erosion in relation to the accumulation of organic matter, was evaluated in two types of soil (Ferralsol and Cambisol) in cashew orchards, in two villages (Mahana and Sanankoro) producing cashew nuts, located the Department of Touba in the North West of Côte d’Ivoire. The objective of this study is to develop new technical routes that are better suited to further promote the sequestration of organic carbon in the soil. Soil samples were taken from open soil profiles at the two chosen sites to allow laboratory analyzes. The results indicate that the surface horizon of Cambisol (site 1) is more stable (Is = 0.78) than that of Ferralsol (site 2;Is = 1.08) with nevertheless relatively small thicknesses of horizons. The median horizons and those of depth, indicate a mediocre stability (Is vary from 1.03 to 1.62). In terms of the quantity of organic carbon, the estimated values vary from 1.96 to 4.53 t⋅ha−1 for Cambisol (site 1) and from 1.44 to 3.46 t⋅ha−1 for Ferralsol (site 2). These values remain relatively low especially at the level of the median horizons and those located in depths. Statistical tests have shown a very highly significant and negative association between the structural stability of soils and the amount of organic carbon in the different horizons. The relationship implies that organic carbon plays an important role in the structural stability of soil horizons under cashew tree orchards.展开更多
Labile soil organic carbon （SOC） pools, estimated through chemical fractionation techniques, are considered sensitive indicators of management-induced changes in quality and composition of soil organic matter. Altho...Labile soil organic carbon （SOC） pools, estimated through chemical fractionation techniques, are considered sensitive indicators of management-induced changes in quality and composition of soil organic matter. Although the impacts of organic manure and crop residue applications on C sequestration in rice-wheat system are fairly well documented, their influence on labile SOC pools is relatively less known. Impacts of organic manure, rice straw, and inorganic fertilizer nitrogen （N） applications on soil total organic carbon （TOC） and SOC pools including water-extractable organic C （WEOC）, hot water-soluble organic C （HWOC）, potassium permanganate- oxidizable organic C （KMnO4-C）, microbial biomass C （MBC）, mineralizable organic C （Cmin）, and the oxidizable fractions of decreasing oxidizability （easily-oxidizable, oxidizable, and weakly-oxidizable） were investigated in an ll-year field experiment under rice-wheat system. The field experiment included treatments of different combinations of farmyard manure, rice straw, and fertilizer N application rates, with C inputs estimated to be in the range from 23 to 127 Mg ha-1. After 11 years of experiment, WEOC, HWOC, and KMnO4-C were 0.32%-0.50%, 2.2%-3.3%, and 15.0%-20.6% of TOC, respectively. The easily-oxidizable, oxidizable, and weakly-oxidizable fractions were 43%-57%0, 22%-27%, and 10%-19% of TOC, respectively. The applications of farmyard manure and rice straw improved WEOC, HWOC, KMnO4-C, easily-oxidizable fraction, Cmin, and MBC, though the rates of change varied considerably from -14% to 145% and -1170 to 83% of TOC, respectively. At the C input levels between 29 and 78 Mg C ha-1 during the ll-year period, the greatest increase was observed in WEOC and the minimum in KMnO4-C. Water-extractable organic C exhibited a relatively greater sensitivity to management than TOC, suggesting that it may be used as a sensitive indicator of management-induced changes in soil organic matter under rice-wheat system. All the other labile SOC pools exhibited almost the same sensitivity to management as TOC. Most of the SOC pools investigated were positively correlated to each other though their amounts differed considerably. Long-term applications of farmyard manure and rice straw resulted in build-up of not only the labile but also the recalcitrant pool of SOC, emphasizing the need for continued application of organic amendments for permanence of the accrued C under the experimental conditions.展开更多
Soil particle size distribution(PSD) is a fundamental physical property affecting other soil properties. Characterizing spatial variability of soil texture is very important in environmental research. The objectives o...Soil particle size distribution(PSD) is a fundamental physical property affecting other soil properties. Characterizing spatial variability of soil texture is very important in environmental research. The objectives of this work were: 1) to partition PSD of 75 soil samples, collected from a flat field in the University of Guilan, Iran, into two scaling domains using a piecewise fractal model to evaluate the relationships between fractal dimensions of scaling domains and soil clay, silt, and sand fractions and 2) to assess the potential of fractal parameters as an index used in a geostatistical approach reflecting the spatial variability of soil texture. Features of PSD of soil samples were studied using fractal geometry, and geostatistical techniques were used to characterize the spatial variability of fractal and soil textural parameters. There were two scaling domains for the PSD of soil samples. The fractal dimensions of these two scaling domains(D_1 and D_2) were then used to characterize different ranges of soil particle sizes and their relationships to the soil textural parameters. There was a positive correlation between D_1 and clay content(R^2= 0.924), a negative correlation between D_1 and silt content(R^2= 0.801), and a negative correlation between D_2 and sand content(R^2= 0.913). The geometric mean diameter of soil particles had a negative correlation with D_1(R^2= 0.569) and D_2(R^2= 0.682). Semivariograms of fractal dimensions and soil textural parameters were calculated and the maps of spatial variation of D_1 and D_2 and soil PSD parameters were provided using ordinary kriging. The results showed that there were also spatial correlations between D_1 and D_2 and particle size fractions.According to the semivariogram models and validation parameters, the fractal parameters had powerful spatial structure and could better describe the spatial variability of soil texture.展开更多
In industry-oriented peri-urban areas, the heavy metal accumulation in soils caused by industrialization has become a potential threat. The top soil samples from 27 paddy fields and 75 vegetable fields were collected ...In industry-oriented peri-urban areas, the heavy metal accumulation in soils caused by industrialization has become a potential threat. The top soil samples from 27 paddy fields and 75 vegetable fields were collected from a typical industry- based peri-urban area of about 8 km^2 in Wuxi, China, to study the accumulation and distribution of As, Hg, Cu, Zn, Pb, Cr, and Cd in comparison with heavy metal contents in soils near developed industrial sites （Guangzhou, China; Wallsend Burn of Tyneside, UK; and Osnabrück, Germany）. Kriging interpolation was used to determine the metals, spatial distribution. The results showed that most soils, compared to the background values, contained elevated contents of As, Hg, Cu, Zn, and Pb with some having elevated contents of Cd and Cr. Except for less than 10% of the soil samples of Cu, Zn and Cd contents, these heavy metal contents were lower than the soil threshold levels of the Grade Ⅱ criteria for the Chinese environmental quality standard. Probably, because of the scattered distribution and diversity of industries in the study area, spatial distributions of these heavy metals from Kriging interpolation indicated little similarity. Nevertheless, when compared with other areas in the Taihu Lake region, mean contents of Cu, Zn, Pb, and Cd were relatively high in the Wuxi peri-urban area. Additionally, compared to soils in agricultural areas around Guangzhou, Osnabrück, or Wallsend Burn, contents of most heavy metals in soils from this area were lower.展开更多
It is noted that there has been little research to compare volume-based and number-based soil particle size distributions （PSDs）. Our objectives were to characterize the scaling properties and the possible connectio...It is noted that there has been little research to compare volume-based and number-based soil particle size distributions （PSDs）. Our objectives were to characterize the scaling properties and the possible connections between volume-based and number-based PSDs by applying single and joint multifractal analysis. Twelve soil samples were taken from selected sites in Northwest China and their PSDs were analyzed using laser diffractometry. The results indicated that the volume-based PSDs of all 12 samples and the number-based PSDs of 4 samples had multifractal scalings for moment order -6 〈 q 〈： 6. Some empirical relationships were identified between the extreme probability values, maximum probability （Pmax）, minimum probability （Pmin）, and Pmax/Pmin, and the multifractal indices, the difference and the ratio of generalized dimensions at q = 0 and 1 （Do - D1 and D1/Do）, maximum and minimum singularity strength （αmax and OZmin） and their difference （αmax - αmin, spectrum width）, and asymmetric index （RD）. An increase in Pmax generally resulted in corresponding increases of Do - D1, αmax, αmax - αmin, and RD, which indicated that a large Pmax increased the multifractality of a distribution. Joint multifractal analysis showed that there was significant correlation between the scaling indices of volume-based and number-based PSDs. The multifractality indices indicated that for a given soil, the volume-based PSD was more homogeneous than the number-based PSD, and more likely to display monofractal rather than multifractal scaling.展开更多
Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly base...Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly based on short-term studies has been encouraging and the trend obtained so far has raised many hopes. Biochar has been reported to positively impact an array of soil processes ranging from benefiting soil biology, controlling soil-borne pathogens, enhancing nitrogen fixation, improving soil physical and chemical properties,decreasing nitrate(NO-3) leaching and nitrous oxide(N2O) emission to remediation of contaminated soils. However, very little biochar is still utilized as soil amendment mainly because these benefits are yet to be quantified, and also the mechanisms by which the soil health is improved are poorly understood. Due to the infancy of research regarding this subject, there are still more questions than answers. The future research efforts must focus on carrying out long-term experiments and uncover the mechanisms underlying these processes so that key concerns surrounding the use of biochar are addressed before its large scale application is recommended.展开更多
The association of organic carbon with secondary particles （aggregates） results in its storage and retention in soil. A study was carried out at a catchment covering about 92 km2 to predict spatial variability of so...The association of organic carbon with secondary particles （aggregates） results in its storage and retention in soil. A study was carried out at a catchment covering about 92 km2 to predict spatial variability of soil water-stable aggregates （WSA）, mean weight diameter （MWD） of aggregates and organic carbon （OC） content in macro.- （〉 2 mm）, meso- （1-2 mm）, and micro-aggregate （〈 1 mm） fractions, using geostatistical methods. One hundred and eleven soil samples were eSlleeted at the 0 10cm depth and fractionated into macro-, meso-, and mlcro-aggregates by wet sieving. The OC content was determined for each fraction. A greater percentage of water-stable aggregates was found for micro-aggregates, followed by meso-aggregates. Aggregate OC content was greatest in meso-aggregates （9 g kg-1）, followed by micro-aggregates （7 g kg-1）, while the least OC content was found in macro-aggregates （3 g kg-1）. Although a significant effect （P = 0.000） of aggregate size on aggregate OC content was found, however, our findings did not support the model of aggregate hierarchy. Land use had a significant effect （P = 0.073） on aggregate OC content. The coefficients of variation （CVs） for OC contents associated with each aggregate fraction indicated macro-aggregates as the most variable （CV = 71%）. Among the aggregate fractions, the micro-aggregate fraction had a lower CV value of 27%. macro-aggregates to 84% for micro-aggregates. Geostatistical analysis differences in their spatial patterns in both magnitude and space at variance for most aggregate-associated properties was lower than 45%. The mean content of WSA ranged from 15% for showed that the measured soil variables exhibited each aggregate size fraction. The relative nugget The range value for the variogram of water-stable aggregates was almost similar （about 3 km） for the three studied aggregate size classes. The range value for the variogram of aggregate-associated OC contents ranged from about 3 km for macro-aggregates to about 6.5 km for meso-aggregates. Kriged maps of predicted WSA, OC and MWD for the three studied aggregate size fractions showed clear spatial patterns. However, a close spatial similarity （co-regionalization） was observed between WSA and MWD.展开更多
文摘Organic matter increases biological activity within the root zone because it contains beneficial microbes that stimulate vital processes.This study aimed to determine the effect of Ochrobactrum anthropi added to the soil as a single or mixed solution with different concentrations of organic matter on the vegetative growth of the zinnia plant and its content of nutrients.The study was conducted with a randomized complete block design(RCBD)with three replications.The plant was grown in soil with a high salinity level of 8 ds m^(–1).Plant characteristics were estimated 30 and 60 days after planting the plant.The treatment with the addition of bio-inoculum produced the best results;within 30 days,there was a 56.89%increase in plant length;after 60 days,there was a 52.56%increase;additionally,there was a 52.56%increase in leaf count within 30 days;after 60 days,there was a 53.50%increase;and finally,there was an increase in flower count.For plants after 60 days,it reached 3.66%.With the addition of bio-inoculum to soil at a level of 3 gm kg^(–1)of organic matter,the mixing treatment achieved the highest dry weight,29.86%.The addition of bio-inoculum resulted in the largest and most significant increase in chlorophyll content in leaves,reaching 18.76%.In the mixing addition of the biological inoculum treatment,the organic content of the plant showed an increase in nitrogen(14.38%),phosphorus(21.18%),and potassium(39.75%)at 2 and 3 gm kg^(–1)organic matter,respectively.
文摘The release of essential nutrients from soil minerals for plant growth in calcareous soils,facilitated by organic extractants,is critical in semi-arid areas,particularly for elements affected by high soil pH.This study aims to investigate the release of calcium(Ca),magnesium(Mg),and phosphorus(P)through the application of wood vinegar extract in surface calcareous soils in Borojerd City,Lorestan Province,Iran.The experiment was conducted using a completely randomized design with three replications.The treatments included soils from three different land uses:vineyard,wheat field,and rangeland,each treated with 1.00%wood vinegar solution.Cumulative measurements of the specified elements were recorded over 10 consecutive 0.5 h intervals.The release data were analyzed using four various kinetic models(Elovich equation,parabolic diffusion law,power function equation,and zero-order kinetics).The highest concentrations recorded were for Ca(39,500.00 mg/kg),Mg(5880.00 mg/kg),and P(5.00 mg/kg)in grape cultivation.The findings revealed a significant difference in Ca release between grape cultivation and rangeland(P<0.01),while the Mg release showed a significant difference between both grape cultivation and rangeland and wheat cultivation(P<0.01).Additionally,the cumulative release of P showed significant differences between grape cultivation and both wheat and rangeland(P<0.01).The results indicated that the zero-order kinetics provided the best fit for the data(R^(2)=0.99).The maximum initial release amount was observed in grape cultivation when applying the zero-order kinetics,while the highest release rate was achieved using the parabolic diffusion law across three applications.Wood vinegar had the capacity to degrade various clay minerals,including vermiculite,smectite,palygorskite,and,to some extent,illite,resulting in the release of associated elements.Consequently,it can be concluded that wood vinegar can be effectively utilized in grape cultivation as an agent for reducing soil acidity,thereby enhancing the availability of soil nutrients and decreasing reliance on chemical fertilizers.
文摘The effects of various biological soil crusts(BSCs)on soil properties have been extensively studied.However,the impacts of specific species such as Placidium squamulosum,Peccania terricola,and Grimmia ovalis on soil properties in arid regions have not been documented.Besides,the effects of soil parent rock on the extent of changes in soil properties caused by BSCs have not been thoroughly investigated.The objective of this study was to examine how BSCs including two different terricolous lichen species(Placidium squamulosum and Peccania terricola)and a moss species(Grimmia ovalis)could change major soil chemical and nutritional properties in an arid area under different parent rocks.Triplicate BSC-free surface soil and soil associated with the abovementioned BSCs were sampled from 13 different sites with sedimentary and igneous parent rocks in an arid area in Isfahan,Iran.Soil properties including p H,electrical conductivity(EC),organic matter(OM),calcium carbonate equivalent(CCE),total nitrogen,available phosphorus,and available potassium were determined in all the samples.The results indicated that the presence of lichens and mosses significantly changed the soil chemical and nutritional properties.Specifically,the content of total nitrogen,organic matter,and available potassium in the soil environment increased under the activity of these biological crusts developed on both sedimentary and igneous formations.Additionally,these biological crusts resulted in a significant reduction in soil p H,CCE,and available phosphorus.The electrical conductivity of soils slightly increased due to the activity of biological crusts.In general,biological crusts including both chlorolichen(Placidium squamulosum)and cyanolichen(Peccania terricola)species,as well as a moss species(Grimmia ovalis)appear to create a unique microenvironment in terms of biochemical and nutritional conditions,which is substantially different from those typically observed in drylands.
文摘In addition to sequestering carbon in soil,biochars can also play a role in changing the potassium equilibration and dynamics of the soil.Nowadays,acidification of biochar is commonly used to improve its properties,which can impact the potassium content in the soil.Simultaneous application of acidified biochar and sodium bentonite can complicate this effect.In the present study,the effects of adding two types of biochars prepared from municipal waste and used coffee grounds and their acidified types,along with sodium bentonite at three levels(0.00%,1.00%,and 2.00%),on soil physical-chemical properties(pH,salinity,cation exchange capacity,concentration of soluble cations and their ratio,and sodium adsorption ratio)and the release of potassium from a calcareous soil were investigated.The results showed that the addition of coffee ground biochar increased the concentration of soluble potassium and decreased the ratio of calcium to potassium,while the acidified coffee ground biochar decreased the amount of soluble potassium and increased the ratio of calcium to potassium.Alkaline and acidified municipal waste biochars had no effect on soluble potassium and soluble cations ratio.Application of bentonite increased the amount of soluble calcium and sodium and the ratio of calcium to potassium.Addition of bentonite also increased the amount of exchangeable potassium and exchangeable sodium percentage,but use of different biochars reduced negative effect of bentonite.Use of bentonite also caused an increase in the exchangeable potassium and a decrease in the non-exchangeable potassium contents.Alkaline and acidified coffee ground biochars increased the amount of exchangeable,non-exchangeable,and total potassium,but this effect was greater by alkaline biochar.Application of municipal waste biochar did not affect the amount of exchangeable potassium but increased the amount of non-exchangeable and total potassium,with no significant difference observed between alkaline and acidified biochars.Potassium saturation percentage was not affected by bentonite,but coffee ground biochar increased its amount and municipal waste biochar had no effect on it.Acidified and alkaline coffee ground biochars were able to release more potassium from the soil(475 and 71 mg/kg,respectively),while alkaline municipal waste biochar did not affect it and acidified municipal waste biochar reduced it by 113 mg/kg.In general,it can be concluded that alkaline biochars in calcareous soils can improve potassium fertility by reduction of the ratio of calcium to potassium and increasing its various forms,while acidified biochars and bentonite may aggravate potassium deficiency in these soils.Considering the lack of significant change in the pH of calcareous soils with the use of different biochars,it is suggested to use alkaline biochars,which can improve the potassium status of the soil while reducing the costs associated with biochar modification.
文摘A field experiment was conducted on silty clay loam soil cultivated with wheat to evaluate the effects of bio-inoculation with the arbuscular mycorrhizal fungus Glomus mosseae and poultry manure on soil micronutrient concentrations.Treatments included fungal inoculum alone,poultry manure alone,their combination,and a control,arranged in a randomized complete block design with three replications.The combined application of fungal inoculum and poultry manure significantly increased total concentrations of iron,manganese,zinc,molybdenum,copper,and boron in bulk soil to 5890.4,390.5,36.5,1.6,23.1,and 2.0 mg kg⁻¹,representing increases of 13%,20.3%,32.2%,84%,23.5%,and 175%over the control.In the rhizosphere,these elements reached 5650.8,380.7,33.2,3.8,21.4,and 3.5 mg kg⁻¹,with increases of 9.5%,26.4%,29.6%,92%,38.9%,and 90.1%.Available concentrations in bulk soil rose to 15.3,10.6,1.4,0.4,0.47,and 1.2 mg kg⁻¹,corresponding to increases of 51.6%,83%,42%,92.5%,65.9%,and 36.1%,while in the rhizosphere,available values reached 16.2,11.7,1.9,0.7,0.7,and 1.6 mg kg⁻¹,reflecting increases of 55%,30%,35.4%,90%,128%,and 93.7%,respectively.These enhancements are attributed to the synergistic effects of microbial activity,organic matter decomposition,and organic acid release,which improved nutrient solubility and accessibility in the root zone.The findings indicate that integrating Glomus mosseae inoculation with poultry manure is an effective and sustainable strategy to improve soil fertility,increase micronutrient availability,and enhance plant nutrient uptake,providing a practical recommendation for boosting wheat productivity while reducing reliance on chemical fertilizers.
文摘A laboratory experiment was conducted to demonstrate the importance of improving the efficiency of six isolates of Aspergillus niger fungi.Four isolates were exposed to UV-rays radiation at a distance of 30 cm,a wavelength of 254–255 nm during M15,M30,and M45 minutes.Exposure periods,both of wild(no UV-rays exposure)and no A.niger(C)as controls,all six isolates were identified molecularly by polymerase chain reaction technique extracted DNA of A.niger was analyzed to ensure gene completion through multiple sequence alignment by bioinformatic programs to study the improvement of dissolving efficiency of mutant and wild A.niger.They were incubated after the addition of superphosphate fertilizer(47%P2O5)at 90 mg P kg–1 applied to soil with controls(no A.niger or no superphosphate)for I,II,III,and IV weeks of incubation periods at 28±1°C.In addition,the DNA extraction and purification by NanoDrop of Thermo Scientific-200 A280/A260 ratio was 2.01 and confirmed that the sequences of nitrogenous bases by the method of multiple sequence alignment(MSA)as compared to the reference sequence of A.niger recorded in the gene bank under the accession number LC632396.Results proved that the M30 minutes exposure UV-rays radiation period was the superior dose when mutant Aspergillus niger obtained the highest amount of dissolved phosphate,reducing soil-pH with maximum biomass of A.niger during the M30 isolate during the third week(III).
文摘This study was conducted to determine the content,distribution and transformation of iron oxides in the soils of the Middle Euphrates regions in Iraq.The study included four sites:Tuwairij area in Karbala Governorate,College of Agriculture at the University of Kufa in Najaf Governorate,College of Agriculture at the University of Qadisiyah in Diwaniyah Governorate,and the Nile District in Babylon Governorate.The results showed that the soils of Najaf and Qadisiyah were superior in terms of their content of total free iron oxides(Fet)compared to the soils of Karbala and Babylon.The relative distribution of free iron oxides was generally close among the studied sites,with a homogeneous pattern in the distribution of these oxides within the soil horizons.As for silicate iron oxides(Fes),a homogeneous pattern was observed in the soil of Babylon with its content increasing with depth,while these patterns varied in the soils of Karbala,Najaf and Qadisiyah.Regarding the ratios of crystalline iron oxides(Fed/Fet),the study showed that the Babylon and Qadisiyah soils recorded the highest values,while these values were lower in the Najaf and Karbala soils.On the other hand,amorphous iron oxides(FeO)showed similar values in the Najaf and Qadisiyah soils.In general,these results clearly showed the effect of environmental and geochemical factors of the study areas on the distribution and transformations of iron oxides in the soil of the Middle Euphrates regions.
基金funded by Taif University,Saudi Arabia,Project No.(TU-DSPP-2025-30)The Science and Technology Fellowship Trust(SL No.39.00.0000.035.22.013.19.144)under the Ministry of Science and Technology of Bangladesh partially financed the current research。
文摘Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine Bangladesh,are generally low in organic matter status and deficient in necessary nutrient elements for crop production.Addressing this challenge,the present study was conducted to investigate the effects of various organic nutrient sources with inorganic fertilizers on crop yields,nutrient uptake,and soil fertility in farm(L1)and char land(L2)of Brahmaputra River in Mymensingh,Bangladesh from 2022(Y1)to 2023(Y2).For each location,eight treatments viz.T1(Control),T2[100%recommended fertilizer dose(RFD)],T3(75%RFD),T4(75%N from RFD 25%N from cow dung),T5(75%+N from RFD 25%N from poultry manure),T6(75%N from RFD 25%N from vermicompost),T7(75%N from++RFD 25%N from household compost)and T8(75%N from RFD 25%N from rice straw compost)were arranged in++a randomized complete block design with three replications using Wheat–Mungbean–T.Aman rice cropping pattern where three way interaction was considered for results.Treatment T5 performed the best in both years in both locations as it enhanced the yield components(p 0.05)and caused yield increment over control.The yield improvement in<Char land soils was higher than that in farm soils.For all three crops,treatment T5 consistently augmented the uptake of nitrogen,phosphorus,potassium,and sulphur by different parts of the crops and improved soil fertility properties such as organic matter status,cation exchange capacity,total nitrogen,available phosphorus,and sulphur as well as exchangeable potassium in both locations in both years.Cost and return analysis of different treatments for the whole cropping system showed that the highest marginal benefit-cost ratio(16.35 and 15.07)and gross return(about Tk 768,595/ha and 728,341/ha)were obtained from the T5 treatment in farm soils and Char land soils,respectively.Followed by poultry manure,vermicompost performed well in addition to mineral fertilizers for improving crop yield and soil fertility but its economic efficiency was less due to high input cost.These findings may be useful to the smallholder farmers in char areas,who could benefit from increased productivity,reduced reliance on chemical fertilizers,and improved soil health,contributing to the long-term sustainability of char land agriculture.
基金supported by the National Natural Science Foundation of China(No.U21A20237)。
文摘Cadmium(Cd)contamination in agricultural soils poses severe threats to human health and ecosystem integrity.While biochar is recognized for its ability to immobilize heavy metals,the impact of plant-derived low molecular weight organic acids(LMWOAs),such as citric acid(CA),on this process remains unclear.This study shows that CA and biochar synergistically immobilize Cd in alkaline soil from extensively polluted southeastern Hubei,China.Soils were amended with maize stover biochar at rates of 0,0.5%,1%,and 2%(W/W),with or without CA addition(1 mmol/L),and incubated for 80 days.Results show that biochar significantly reduced bioavailable Cd,with a 2%application decreasing extractable Cd by 26.84%.Unexpectedly,CA alone increased Cd mobility by 9.38%;however,when combined with high-dose biochar,CA and biochar synergistically enhanced Cd immobilization,reducing bioavailable Cd by 27.40%.Advanced analytical techniques,including BCR sequential extraction,X-ray diffraction,Fourier-transform infrared spectroscopy,and scanning electron microscopy with energy-dispersive X-ray spectroscopy,confirmed that the interaction between biochar and CA altered Cd speciation,promoting its stabilization.This study is the first to show that CA and biochar synergistically immobilize Cd in alkaline soils,disproving the idea that LMWOAs hinder biochar's metal remediation.Our findings show that biochar can prevent or even harness LMWOAs'activating effects on Cd,indicating its great potential for sustainable Cd remediation in alkaline soils.This study improves our understanding of biochar-soil interactions in organic acids and gives new scientific bases for enhancing heavy metal-contaminated soil remediation procedures.
基金ARS would like to acknowledge their JdCi research contract(IJC2020-044197-I)funded by MICIU/AEI/10.13039/501100011033 and European Union EU/PRTR。
文摘The use of organic fertilizers can be an opportunity to increase crop yield and improve soil fertility in semi-arid regions,since soils from these regions usually have unfavourable conditions for plant growth.This research investigates the effects of organic and mineral fertilization on the impact of soil properties(pH,electrical conductivity and organic matter),availability of macro-(N,P and K),micro-nutrients(Fe,Mn,Cu and Zn)and the accumulation of heavy metals(Pb,Cd,Cr)in soil and potato tubers grown under semiarid conditions.A field experiment was conducted in Raqqa Governorate(Syria)using a randomized complete block design with six treatments:control,mineral fertilizer,fermented cow manure,municipal compost,sewage sludge and olive oil solid waste.At harvest,soil and plant samples were analyzed to assess nutrient dynamics in the soil and potato tubers,including metal uptake.The results showed that the highest yields were obtained with mineral fertilizer(22.87 t ha^(−1))and sewage sludge(22.15 t ha^(−1)).Organic amendments significantly improved soil organic matter,total nitrogen,and the bioavailability of phosphorus,potassium,and micronutrients after harvest.Compost and sewage sludge notably enhanced the soil and plant contents of Mn and Cu.However,these amendments also increased the amounts of Pb and Cd in soils and their uptake by plants,with Cd contents exceeding the Codex Alimentarius limit for potatoes(>0.1 mg kg^(−1)).These findings highlight the potential of treated organic waste as a valuable nutrient input for potato cultivation,especially in resource-limited areas.However,continuous monitoring is required due to the risk of heavy metal accumulation.Integrating organic fertilizers with mineral sources appears to be an effective strategy for improving crop productivity,soil health,and environmental sustainability.
基金supported by an institutional Ph.D.grant(No.21130/1312/3131)from the Faculty of Agrobiology,Food,and Natural Resources at the Czech University of Life Sciences Prague(CZU),Czech Republic。
文摘Very few studies have benefited from the synergetic implementation of visible,near-infrared,and shortwave infrared(VNIR-SWIR)spectra and terrain attributes in predicting Pb content in agricultural soils.To fill this gap,this study aimed to predict lead(Pb)contents in agricultural soils by combining machine learning algorithms(MLAs)with VNIR-SWIR spectra or/and terrain attributes under three distinct approaches.Six MLAs were tested,including artificial neural network(ANN),partial least squares regression,support vector machine(SVM),Gaussian process regression(GPR),extreme gradient boosting(EGB),and Cubist.The VNIR-SWIR spectral data were preprocessed by methods of discrete wavelet transformation,logarithmic transformation-Savitzky Golay smoothing,standard normal variate(SNV),multiplicative scatter correction,first derivative(Fi D),and second derivative.In approach 1,MLAs were combined with the preprocessed VNIR-SWIR spectral data.The Cubist-Fi D combination was the most effective,achieving a coefficient of determination(R2)of 0.63,a concordance correlation coefficient(CCC)of 0.51,a mean absolute error(MAE)of 6.87 mg kg^(-1),and a root mean square error(RMSE)of8.66 mg kg^(-1).In approach 2,MLAs were combined with both preprocessed VNIR-SWIR spectral data and terrain attributes,and the EGB-SNV combination yielded superior results with R2of 0.75,CCC of 0.65,MAE of 5.48 mg kg^(-1),and RMSE of 7.34 mg kg^(-1).Approach 3 combined MLAs and terrain attributes,and Cubist demonstrated the best prediction results,with R^(2) of 0.75,CCC of 0.66,MAE of 6.18 mg kg^(-1),and RMSE of 7.71 mg kg^(-1).The cumulative assessment identified the fusion of terrain properties,SNV-preprocessed VNIR-SWIR spectra,and EGB as the optimal method for estimating Pb content in agricultural soils,yielding the highest R2value and minimal error.Comparatively,GPR,ANN,and SVM techniques achieved higher R2values in approaches 2 and 3 but also exhibited higher estimation errors.In conclusion,the study underscores the significance of using relevant auxiliary datasets and appropriate MLAs for accurate Pb content prediction with minimal error in agricultural soils.The findings contribute valuable insights for developing successful soil management strategies based on predictive modeling.
文摘Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.
文摘The integration of machine learning(ML)into geohazard assessment has successfully instigated a paradigm shift,leading to the production of models that possess a level of predictive accuracy previously considered unattainable.However,the black-box nature of these systems presents a significant barrier,hindering their operational adoption,regulatory approval,and full scientific validation.This paper provides a systematic review and synthesis of the emerging field of explainable artificial intelligence(XAI)as applied to geohazard science(GeoXAI),a domain that aims to resolve the long-standing trade-off between model performance and interpretability.A rigorous synthesis of 87 foundational studies is used to map the intellectual and methodological contours of this rapidly expanding field.The analysis reveals that current research efforts are concentrated predominantly on landslide and flood assessment.Methodologically,tree-based ensembles and deep learning models dominate the literature,with SHapley Additive exPlanations(SHAP)frequently adopted as the principal post-hoc explanation technique.More importantly,the review further documents how the role of XAI has shifted:rather than being used solely as a tool for interpreting models after training,it is increasingly integrated into the modeling cycle itself.Recent applications include its use in feature selection,adaptive sampling strategies,and model evaluation.The evidence also shows that GeoXAI extends beyond producing feature rankings.It reveals nonlinear thresholds and interaction effects that generate deeper mechanistic insights into hazard processes and mechanisms.Nevertheless,several key challenges remain unresolved within the field.These persistent issues are especially pronounced when considering the crucial necessity for interpretation stability,the demanding scholarly task of reliably distinguishing correlation from causation,and the development of appropriate methods for the treatment of complex spatio-temporal dynamics.
文摘Degradation of the physical quality of the soil is a common problem encountered in agrosystems, particularly in the case of open field cropping systems in the northern areas of Côte d’Ivoire. Thus, the structural stability of the soil, which is a good indicator of the sensitivity to threshing and to water erosion in relation to the accumulation of organic matter, was evaluated in two types of soil (Ferralsol and Cambisol) in cashew orchards, in two villages (Mahana and Sanankoro) producing cashew nuts, located the Department of Touba in the North West of Côte d’Ivoire. The objective of this study is to develop new technical routes that are better suited to further promote the sequestration of organic carbon in the soil. Soil samples were taken from open soil profiles at the two chosen sites to allow laboratory analyzes. The results indicate that the surface horizon of Cambisol (site 1) is more stable (Is = 0.78) than that of Ferralsol (site 2;Is = 1.08) with nevertheless relatively small thicknesses of horizons. The median horizons and those of depth, indicate a mediocre stability (Is vary from 1.03 to 1.62). In terms of the quantity of organic carbon, the estimated values vary from 1.96 to 4.53 t⋅ha−1 for Cambisol (site 1) and from 1.44 to 3.46 t⋅ha−1 for Ferralsol (site 2). These values remain relatively low especially at the level of the median horizons and those located in depths. Statistical tests have shown a very highly significant and negative association between the structural stability of soils and the amount of organic carbon in the different horizons. The relationship implies that organic carbon plays an important role in the structural stability of soil horizons under cashew tree orchards.
基金supported by the Indian Council of Agricultural Research (ICAR) National Professor Project
文摘Labile soil organic carbon （SOC） pools, estimated through chemical fractionation techniques, are considered sensitive indicators of management-induced changes in quality and composition of soil organic matter. Although the impacts of organic manure and crop residue applications on C sequestration in rice-wheat system are fairly well documented, their influence on labile SOC pools is relatively less known. Impacts of organic manure, rice straw, and inorganic fertilizer nitrogen （N） applications on soil total organic carbon （TOC） and SOC pools including water-extractable organic C （WEOC）, hot water-soluble organic C （HWOC）, potassium permanganate- oxidizable organic C （KMnO4-C）, microbial biomass C （MBC）, mineralizable organic C （Cmin）, and the oxidizable fractions of decreasing oxidizability （easily-oxidizable, oxidizable, and weakly-oxidizable） were investigated in an ll-year field experiment under rice-wheat system. The field experiment included treatments of different combinations of farmyard manure, rice straw, and fertilizer N application rates, with C inputs estimated to be in the range from 23 to 127 Mg ha-1. After 11 years of experiment, WEOC, HWOC, and KMnO4-C were 0.32%-0.50%, 2.2%-3.3%, and 15.0%-20.6% of TOC, respectively. The easily-oxidizable, oxidizable, and weakly-oxidizable fractions were 43%-57%0, 22%-27%, and 10%-19% of TOC, respectively. The applications of farmyard manure and rice straw improved WEOC, HWOC, KMnO4-C, easily-oxidizable fraction, Cmin, and MBC, though the rates of change varied considerably from -14% to 145% and -1170 to 83% of TOC, respectively. At the C input levels between 29 and 78 Mg C ha-1 during the ll-year period, the greatest increase was observed in WEOC and the minimum in KMnO4-C. Water-extractable organic C exhibited a relatively greater sensitivity to management than TOC, suggesting that it may be used as a sensitive indicator of management-induced changes in soil organic matter under rice-wheat system. All the other labile SOC pools exhibited almost the same sensitivity to management as TOC. Most of the SOC pools investigated were positively correlated to each other though their amounts differed considerably. Long-term applications of farmyard manure and rice straw resulted in build-up of not only the labile but also the recalcitrant pool of SOC, emphasizing the need for continued application of organic amendments for permanence of the accrued C under the experimental conditions.
文摘Soil particle size distribution(PSD) is a fundamental physical property affecting other soil properties. Characterizing spatial variability of soil texture is very important in environmental research. The objectives of this work were: 1) to partition PSD of 75 soil samples, collected from a flat field in the University of Guilan, Iran, into two scaling domains using a piecewise fractal model to evaluate the relationships between fractal dimensions of scaling domains and soil clay, silt, and sand fractions and 2) to assess the potential of fractal parameters as an index used in a geostatistical approach reflecting the spatial variability of soil texture. Features of PSD of soil samples were studied using fractal geometry, and geostatistical techniques were used to characterize the spatial variability of fractal and soil textural parameters. There were two scaling domains for the PSD of soil samples. The fractal dimensions of these two scaling domains(D_1 and D_2) were then used to characterize different ranges of soil particle sizes and their relationships to the soil textural parameters. There was a positive correlation between D_1 and clay content(R^2= 0.924), a negative correlation between D_1 and silt content(R^2= 0.801), and a negative correlation between D_2 and sand content(R^2= 0.913). The geometric mean diameter of soil particles had a negative correlation with D_1(R^2= 0.569) and D_2(R^2= 0.682). Semivariograms of fractal dimensions and soil textural parameters were calculated and the maps of spatial variation of D_1 and D_2 and soil PSD parameters were provided using ordinary kriging. The results showed that there were also spatial correlations between D_1 and D_2 and particle size fractions.According to the semivariogram models and validation parameters, the fractal parameters had powerful spatial structure and could better describe the spatial variability of soil texture.
基金Project supported by the RURBIFARM (Sustainable Farming at the Rural-Urban Interface) project of the European Union (No. ICA4-CT-2002-10021)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX3-SW-427)the National Key Basic Research Support Foundation of China (No. 2002CB410810).
文摘In industry-oriented peri-urban areas, the heavy metal accumulation in soils caused by industrialization has become a potential threat. The top soil samples from 27 paddy fields and 75 vegetable fields were collected from a typical industry- based peri-urban area of about 8 km^2 in Wuxi, China, to study the accumulation and distribution of As, Hg, Cu, Zn, Pb, Cr, and Cd in comparison with heavy metal contents in soils near developed industrial sites （Guangzhou, China; Wallsend Burn of Tyneside, UK; and Osnabrück, Germany）. Kriging interpolation was used to determine the metals, spatial distribution. The results showed that most soils, compared to the background values, contained elevated contents of As, Hg, Cu, Zn, and Pb with some having elevated contents of Cd and Cr. Except for less than 10% of the soil samples of Cu, Zn and Cd contents, these heavy metal contents were lower than the soil threshold levels of the Grade Ⅱ criteria for the Chinese environmental quality standard. Probably, because of the scattered distribution and diversity of industries in the study area, spatial distributions of these heavy metals from Kriging interpolation indicated little similarity. Nevertheless, when compared with other areas in the Taihu Lake region, mean contents of Cu, Zn, Pb, and Cd were relatively high in the Wuxi peri-urban area. Additionally, compared to soils in agricultural areas around Guangzhou, Osnabrück, or Wallsend Burn, contents of most heavy metals in soils from this area were lower.
基金Supported by the National Natural Science Foundation of China (No. 50709028)the Basic Foundation for Scientific Researchof Northwest Agriculture and Forestry Sci-Tech University,China (No. QN2009087)
文摘It is noted that there has been little research to compare volume-based and number-based soil particle size distributions （PSDs）. Our objectives were to characterize the scaling properties and the possible connections between volume-based and number-based PSDs by applying single and joint multifractal analysis. Twelve soil samples were taken from selected sites in Northwest China and their PSDs were analyzed using laser diffractometry. The results indicated that the volume-based PSDs of all 12 samples and the number-based PSDs of 4 samples had multifractal scalings for moment order -6 〈 q 〈： 6. Some empirical relationships were identified between the extreme probability values, maximum probability （Pmax）, minimum probability （Pmin）, and Pmax/Pmin, and the multifractal indices, the difference and the ratio of generalized dimensions at q = 0 and 1 （Do - D1 and D1/Do）, maximum and minimum singularity strength （αmax and OZmin） and their difference （αmax - αmin, spectrum width）, and asymmetric index （RD）. An increase in Pmax generally resulted in corresponding increases of Do - D1, αmax, αmax - αmin, and RD, which indicated that a large Pmax increased the multifractality of a distribution. Joint multifractal analysis showed that there was significant correlation between the scaling indices of volume-based and number-based PSDs. The multifractality indices indicated that for a given soil, the volume-based PSD was more homogeneous than the number-based PSD, and more likely to display monofractal rather than multifractal scaling.
文摘Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly based on short-term studies has been encouraging and the trend obtained so far has raised many hopes. Biochar has been reported to positively impact an array of soil processes ranging from benefiting soil biology, controlling soil-borne pathogens, enhancing nitrogen fixation, improving soil physical and chemical properties,decreasing nitrate(NO-3) leaching and nitrous oxide(N2O) emission to remediation of contaminated soils. However, very little biochar is still utilized as soil amendment mainly because these benefits are yet to be quantified, and also the mechanisms by which the soil health is improved are poorly understood. Due to the infancy of research regarding this subject, there are still more questions than answers. The future research efforts must focus on carrying out long-term experiments and uncover the mechanisms underlying these processes so that key concerns surrounding the use of biochar are addressed before its large scale application is recommended.
基金Supported by Shahrekord University, Shahrekord, Iran
文摘The association of organic carbon with secondary particles （aggregates） results in its storage and retention in soil. A study was carried out at a catchment covering about 92 km2 to predict spatial variability of soil water-stable aggregates （WSA）, mean weight diameter （MWD） of aggregates and organic carbon （OC） content in macro.- （〉 2 mm）, meso- （1-2 mm）, and micro-aggregate （〈 1 mm） fractions, using geostatistical methods. One hundred and eleven soil samples were eSlleeted at the 0 10cm depth and fractionated into macro-, meso-, and mlcro-aggregates by wet sieving. The OC content was determined for each fraction. A greater percentage of water-stable aggregates was found for micro-aggregates, followed by meso-aggregates. Aggregate OC content was greatest in meso-aggregates （9 g kg-1）, followed by micro-aggregates （7 g kg-1）, while the least OC content was found in macro-aggregates （3 g kg-1）. Although a significant effect （P = 0.000） of aggregate size on aggregate OC content was found, however, our findings did not support the model of aggregate hierarchy. Land use had a significant effect （P = 0.073） on aggregate OC content. The coefficients of variation （CVs） for OC contents associated with each aggregate fraction indicated macro-aggregates as the most variable （CV = 71%）. Among the aggregate fractions, the micro-aggregate fraction had a lower CV value of 27%. macro-aggregates to 84% for micro-aggregates. Geostatistical analysis differences in their spatial patterns in both magnitude and space at variance for most aggregate-associated properties was lower than 45%. The mean content of WSA ranged from 15% for showed that the measured soil variables exhibited each aggregate size fraction. The relative nugget The range value for the variogram of water-stable aggregates was almost similar （about 3 km） for the three studied aggregate size classes. The range value for the variogram of aggregate-associated OC contents ranged from about 3 km for macro-aggregates to about 6.5 km for meso-aggregates. Kriged maps of predicted WSA, OC and MWD for the three studied aggregate size fractions showed clear spatial patterns. However, a close spatial similarity （co-regionalization） was observed between WSA and MWD.
