Abstract:Traditional and emerging organochlorine pollutants (OCPs) are prone to form persistent sources of pollution, which adversely affect human health and the ecological environment. Although the usage of OCPs has been banned for many years, these pollutants could still be detected in soils, sediments and other environments where they have never been applied. Numerous studies have confirmed that anaerobic reduction dechlorination, the most efficient pathway for the complete removal of OCPs from soil, is essentially a process mediated by the metabolic activity of dechlorination bacteria. Under anaerobic conditions, the environmental fate of OCPs in the soil is abiotically and biotically attributed to biogeochemical redox processes, which are significantly influenced by the cycling of biogenic elements mediated by microbial-extracellular-respiration-initiated electron transfer. A better understanding of the microbial and geochemical interactions that occur during the environmental transformation of OCPs in anaerobic soils is required for improving soil pollution control and remediation. Owing to the global demand for “One Health”, it is quite necessary to illuminate the potential soil health risks of residual OCPs from the perspective of multi-process coupling. As such, this paper aims to briefly comb the research progress and current status of residual OCPs in soil in the past 42 years, and clarify the state-of-the-art research findings and academic frontiers. On this basis, the potential relationship between the reduction and dechlorination of OCPs and the biochemical cycle process of key elements like C, N, Fe and S in the soil is sorted out, to provide a new understanding of the ecological and health risks of underground environment polluted by residual OCPs. Finally, this paper puts forward suggestions and prospects for the future research direction of soil health risk in China, providing research ideas for facilitating pollution reduction of soil polluted by OCPs, thereby supporting the improvement of soil health theory.

Abstract:Heavy metal contamination of agricultural soils poses a great threat to food safety and human health. Heavy metals enter the human body mainly through exposure pathways such as direct ingestion of soil, inhalation of soil particles, dermal exposure and food chain ingestion, with direct ingestion of heavy metal-contaminated soil and eating agricultural products being the main exposure route. Human health risk assessment plays an important role in the classification of agricultural soil quality categories and environmental risk management. Therefore, this paper reviews the development of human health risk assessment of heavy metal contamination in agricultural soils in China, introduces the basic process and assessment techniques of human health risk assessment, and discusses the main factors affecting the accuracy of human health risk assessment and the optimization measures. The research indicates that in the health risk assessment of heavy metals in farmland soil, the coupled pollution source identification technology should be strengthened while the exposure route of food consumption needs more attention. Also, the exposure parameters of different sensitive receptors should be accurately identified, and the exposure parameters of localized sensitive receptors, and the bioavailability of heavy metals should be included to improve the accuracy of health risk assessment of heavy metals in farmland soil. In the future, the health risk assessment of heavy metals in farmland soil can be deepened from many aspects, such as strengthening technical methods to deal with the uncertainty of the health risk assessment process and considering the exposure pathways of various diets. This will help with establishing localized heavy metal toxicity standard data to promote the development of the theory and technology of human health risk assessment of heavy metals in agricultural soils of China.

Abstract:The rhizosphere microbial communities play a crucial role in assisting plants in dealing with soil-borne pathogens. When plants encounter specific soil pathogen invasions, they adapt the composition and quantity of root exudates to recruit beneficial microorganisms that can utilize these substances to resist soil pathogen infections. However, recent studies have revealed that certain root exudates can promote the occurrence of soil-borne diseases. This paper aims to provide a comprehensive review and summary of existing evidence regarding the role of root exudates in continuous cropping systems, which contribute to the occurrence and outbreaks of soil-borne diseases. The paper begins by presenting observations of soil-borne diseases exacerbated by continuous cropping and the accumulation of key root exudates. Subsequently, it summarizes the potential mechanisms through which some root exudates in continuous cropping promote the invasion of soil-borne pathogens. Considering the process of soil-borne pathogens causing plant diseases in continuous cropping involves introduction (soil to the rhizosphere), colonization (rhizosphere to root surface), and infection(root surface to root interior), the substances exacerbating soil-borne pathogen invasion in each stage are categorized into the following three groups based on their functions: 1)substances that facilitate the migration, proliferation, and pathogenicity of soil-borne pathogens from soil to the rhizosphere (“enriching pathogens”); 2)substances that disrupt the defense line of beneficial microbial communities in the rhizosphere (“suppressing beneficial microbes”); and 3) substances that hinder the root immune system (“self-toxic”). Subsequently, the paper explores the mechanisms of diversified cropping systems such as rotation, grafting, row intercropping, relay intercropping, and companion planting in alleviating soil-borne diseases from the perspective of root exudates. These mechanisms include: 1) enhancing the diversity of root exudates; 2) reducing the secretion of self-toxic substances by main crops; 3) secreting root exudates that suppress pathogens; 4) promoting the formation of a protective rhizosphere microbial community to enhance plant disease resistance and 5) regulating the synthesis pathways of metabolites to reduce the production of self-toxic substances. Finally, the paper outlines several green, efficient, safe, and comprehensive control strategies for soil-borne diseases. These strategies include: 1) identification of “enriching pathogens”, “suppressing beneficial microbes” and “self-toxic” root exudates; 2) application of diversified planting, rootstock grafting, biochar, and organic fertilizer to regulate root exudates, improve soil microbial community structure, enhance plant growth, and reduce diseases; and 3) establishment of biodegradation technologies for identifying, isolating, and culturing bacterial and fungal strains capable of decomposing the “enriching pathogens”, “suppressing beneficial microbes” and “self-toxic” plant root exudates.

Abstract:【Objective】Soil structure is the key to understanding physical, chemical, and biological processes that play a vital role in biodiversity and agricultural productivity. However, due to the mutual influence and simultaneous progress of these process, soil structure evolution has become irregular, unstable, and highly complex. With the development of computer technology on CT scanning images, different scaling and descriptive statistical analysis allow for a better study of soil pore structure or architecture. 【Method】Inthis study, the saline/sodic soil in the coastal reclamation area of JiangsuProvince was taken as the object of investigation. Based on multifractal and relative entropy theory, combined with Micro-CT technology, the scaling features of the pore structure of biochar-amended saline soil were revealed. 【Result】In this study, the surface soils (0-20 cm) were amended by thoroughly mixing with biochar atthree application rates (0%, 2% and 5% by mass of soil) in a completely randomized design. This experiment lasted for four years from 2017 to 2020. To reveal the scaling characteristics of CT pores, two methods were applied: multifractal analysis (MFA) and relative entropy (E). The results showed that different theoretical methods should be used to analyze the complex scaling behavior of soil pores. The multifractal method was suitable for grey images, while the relative entropy method was suitable for binary images. The pore complexity of all treatments increased from one year to the next. Also, the addition of biochar accelerated the developments of soil pore structure and induced a faster rate of increase in pore complexity. Among different biochar treatments, the pore complexity of 2% biochar treatment was the highest (Δα=0.061, RangeΔE=0.436)and the improvement effect was the best. The addition of high biochar(5% biochar treatment)reduced the pore complexity(Δα=0.045, RangeΔE=0.531), reducing the improvement effect of biochar. 【Conclusion】This study can provide a theoretical basis for the use of biochar to improve pore structure from a microscopic point of view.

Abstract:【Objective】The objective of this study was to investigate the influence of fibrous and taproot plant root exudates, in terms of their relative composition and application rate, on soil penetration resistance (SPR) under specific compaction conditions (compaction, and compaction followed by wetting/drying), in order to evaluate the adverse effects of SPR on crop growth in clayey red soil.【Method】Fibrous root vetiver and taproot lucerne were selected to collect hydroponic secretions. These secretions were then analyzed to determine the root exudate composition, which was subsequently freeze-dried to obtain the original dry exudates. Clayey red soils (0～20 cm) were amended with different rates of dry root exudate materials (0, 0.02, 0.2, and 1 mg·g^-1, dry root exudates wt/soil wt), and left to equilibrate for one week in a 4℃ refrigerator. Soils amended with varying rates of dry root exudates were then compacted into steel cores (d= 5 cm and h= 5.1 cm) and subjected to two types of compaction. One subset of core samples was wetted to -33 kPa and compacted to 200 kPa stress (compaction), and another subset underwent 200 kPa stress followed by one cycle of saturation and drainage back to -33 kPa (compaction+w/d). The SPR, soil water content (SWC), aggregate properties, and bulk density (Bd) were determined. 【Result】 The results showed that: (1) The relative content of aromatic carbon, alkoxy carbon, and carbonyl carbon in the root exudates was higher in lucerne (3.23%, 6.83%, 55.09%) than that in vetiver (1.64%, 4.12%, 45.78%), whereas the ratio of hydrophobic to hydrophilic substances showed an opposite trend(0.52 for Lucerne and 0.86 for vetiver). (2) The SPR decreased as the exudate rate increased, with a significant decrease observed only when the root exudate application rate exceeded 0.2 mg·g^-1. For example, compared to the control, 0.2 mg·g^-1root exudates application from lucerne and vetiver resulted in reductions of 29.4% and 11.4% in SPR, respectively. (3) At the same root exudate application rate, lucerne showed a higher degree of SPR reduction than vetiver under both compaction conditions. (4) The SWC increased with increasing exudate rate compared to the control. For example, compared to the control, the application of 1 mg·g^-1root exudates resulted in an increase in SWC by 7.98% (compaction) and 21.65% (compaction + w/d) for lucerne, and 13.07% (compaction) and 11.15% (compaction + w/d) for vetiver. Furthermore, the aggregate mean weight diameter (MWD) also increased after root exudate treatments compared to the control. Correlation and regression analysis confirmed that a low ratio of hydrophobic to hydrophilic substances, a high proportion of alkoxy carbon, and a high exudate rate resulted in a low SPR value by improving SWC and aggregate MWD. 【Conclusion】In conclusion, taproot plants showed a more apparent effect in alleviating SPR than fibrous roots in clayey red soil. Therefore, selecting appropriate taproot green manure has the potential to effectively reduce SPR in clay red soil by improving SWC and aggregate MWD.

Abstract:【Objective】 Overuse of Nitrogen (N) fertilizer results in a low N use efficiency and intensive soil nitrate accumulation in arid farmland critical zone of China, which threatens eco-environmental safety. Elucidating characteristics of soil nitrate accumulation and its influencing factors can provide scientific reference for integrated management of water and fertilizers. 【Method】 The Aksu region, a typical arid region, was selected as the study area. Regolith core samples were collected from three drilling sites including XJ1 (40°36′48.7″N, 80°48′14.2″E), XJ2 (41°16′16.2″N, 80°19′9.1″E), and XJ3 (41°20′37.6″N, 80°17′11.0″E) along a topographic sequence from south to north, with depths of 7.75 m, 10.52 m, and 9.91 m, respectively. The drilling sites were located in a 60-year-old cotton field, a 32-year-old apple orchard, and a 15-year-old apple orchard, respectively. Key soil properties were measured and their relationship to soil nitrate concentration accumulation was analyzed using linear and nonlinear correlations. 【Result】 Significant accumulation of soil nitrate concentration was found under cotton fields with a low altitude and apple orchards with different planting years and a high altitude. Soil nitrate concentrations at depth can reach 44 mg·kg^-1 and soil nitrate accumulation occurs deeper than 10 m. Key soil properties including soil water content and soil particle (gravel, sand, silt and clay fractions) sizes could explain about 50% variations of soil nitrate concentrations with depth. Among key soil properties, soil water content and soil particle sizes were found to be the main factors determining soil nitrate accumulation at depth. Soil nitrate concentration was generally accumulated under conditions with a high soil water content and a fine soil particle. Notable denitrification below the groundwater table at a depth of 4 m occurred under cotton fields and led to a low nitrate concentration below 1 mg·kg^-1. Notable denitrification was not observed below 10 m under apple orchards with a deep groundwater table and soil nitrate concentration was intensively accumulated beyond the root zone deeper than 5 m. 【Conclusion】 Soil water content was found to be the below-ground direct factor determining soil nitrate accumulation at depth. Soil particle sizes were found to be the fundamental factor determining soil nitrate accumulation via controlling soil water content variations.

Abstract:【Objective】Soil is composed of different size particles, and the properties of each particle and their spatial position in the soil are different. However, prior studies focused on a small range of different aggregates or particle sizes. Thus, this study aimed to investigate different carbon changes in each particle with a wide range and evaluate the role of the turnover and stability of soil carbon for each particle in bulk soil. 【Method】After collecting soil samples from subtropical broad-leaved forest, the soil particles (> 2 000, 2 000-250, 250-53, < 53, 53-20, 20-2, < 2 μm) were obtained by physical fractionation. Moreover, the mineralization experiment was carried out with the same soil weight for each particle and bulk soil to study the difference in mineralization amount, carbon change trend and their relationship. Furthermore, after the dimension reduction of seventeen variables, a composite characteristic index was considered for each soil particle by principal component analysis. 【Result】 Although all soil particles were provided as the same amount for incubation to study their different carbon mineralization, their proportion in bulk soil was used to simulate their summation and compare them with bulk soil. The calculated sum values in cumulative CO₂ emissions, total carbon, C/N, aromatic index, and free oxide iron content for all soil particles according to the proportion of each particle in bulk soil are 95.0%-101.8% of the bulk soil. In addition, it was 132.6% and 116.7% for the calculated sum values of the proportion of specific surface area and total pore volume in bulk soil. It was also observed that the cumulative CO₂ emissions of <2 μm and 20-2 μm particles were significantly higher than those of other particles and bulk soil. The correlation analysis showed that the cumulative CO₂ emissions of bulk soil or particles were positively correlated with specific surface area, total pore volume, total carbon, DOC, MBC, readily oxidized carbon, and free iron oxide, but negatively correlated with C/N. Moreover, this correlation analysis would be altered when soil particles were considered as size group analysis rather than including all. The factor analysis of sixteen indexes for each particle showed that the composite characteristic index was the highest for < 2 μm and 20-2 μm particles, which means they have the most role in bulk soil. 【Conclusion】Physical fractionation of bulk soil facilitates the study by isolating the individual particle, but also amplifies the role of the individual, especially for < 2 μm and 20-2 μm. These different results in soil particles and bulk soil suggest that the carbon change in bulk soil can be traced back to the different changes in carbon in each particle and their relationships. The encapsulation of small-size particles (<2 μm and 20-2 μm) by large-size particles or aggregation might be one mechanism for reducing carbon mineralization, which is conducive to maintaining soil carbon stability or storage.

Abstract:The Mollisol in north-eastern China is rich in organic matter, which supports high crop yields and agricultural production. Soil organic carbon (SOC) is the largest carbon pool in terrestrial ecosystems, which responds to climate change directly affects the global carbon cycle. Understanding the response of SOC to increased hydrothermal conditions is important for soil conservation in the context of global climate change. 【Objective】This study aimed to analyze the response of SOC to long-term increasing hydrothermal conditions and their driving factors. 【Method】Based on a soil transplantation experiment, large transects of Mollisol in a cold temperate region (Hailun, HL) were translocated to warm temperate (Fengqiu, FQ) and mid-subtropical (Yingtan, YT) regions to simulate the increasing conditions of MAT and MAP. The experiment was started in 2005, soil samples were collected in August 2013. The SOC and microbial necromass C (MNC) were measured to investigate the changes and drivers of SOC after 8 years of increasing hydrothermal conditions.【Results】The results showed that the increased hydrothermal conditions increased plant biomass, litter C/N, and potential activities of hydrolytic enzymes while decreasing the content of SOC, MNC and soil activity minerals. Moreover, the contribution of MNC to SOC also decreased as hydrothermal conditions increased. The ratio of DMNC and DSOC was calculated to characterize the change in microbial necromass C per unit decrease in SOC, which could be considered a quantitative representation of necromass loss efficiency. DMNC/DSOC increased with increasing hydrothermal activity, with values of 72.50% ± 9.35% in FQ and 82.67% ± 2.37% in YT. The correlation and Random forest analysis showed that DMNC/DSOC positively correlated with the changes in MAT, MAP, α-D-Glucosidase, β-N-Acetyl Glucosaminidase, plant biomass and Straw C/N, while negatively correlated with the changes in pH, poorly crystalline Fe and Al oxyhydroxides, organically complexed Fe and Al, and exchangeable Ca. Structural equation modeling (SEM) indicated that DMNC/DSOC increased with increasing hydrothermal conditions, while decreased with soil mineral protection, with standardized coefficients of 0.64 and -0.24, respectively. It was confirmed in the variance partitioning analysis (VPA), which showed that hydrothermal conditions together with changes in soil mineral protection explained 83.69% of the variance in DMNC/DSOC. The above results indicate that hydrothermal conditions and soil mineral protection play decisive role in regulating DMNC/DSOC. 【Conclusion】In conclusion, long-term increases in hydrothermal conditions reduce the protection of MNC by soil minerals and/or stimulate the utilization of MNC by soil microorganisms. As evidenced by increased soil N limitation that allowed microbes to decompose more MNC and weakened the conservation capacity of minerals for MNC, contributing to the significant loss of SOC by reducing MNC.

Abstract:Counter tillage is a common soil and water conservation tillage practice, which can influence the soil erosion process by increasing storage and infiltration capacity on sloping farmland. However, studies about the effects of counter tillage on nutrient losses during soil erosion processes on sloping farmland are still limited. 【 Objective】 Therefore, this study aimed to reveal the characteristics of nutrient loss on sloping farmland. 【 Method】 In this study, the rainfall simulation was conducted with a rainfall intensity of 90 mm·hh^–1, five slope gradients (3°, 5°, 10°, 15°, 20°) and two types of slope treatments (counter tillage and flat slope) on runoff plots with projection length 4.5 m and projection width 1.5 m to explore the effects of counter tillage on the characteristics of soil erosion and nitrogen and phosphorus nutrient losses on sloping farmland of different slope gradient. 【 Result】 The results showed that: (1) When the slope gradient was less than 20°, counter tillage significantly reduced the amount of runoff and sediment on the sloping farmland and the amount of runoff and sediment reduced by a maximum of 95% and 99% respectively. When the slope gradient increased to 20°, a break in the ridge occurred on the counter tillage and the control effect on the runoff and sediment was gradually weakened. Also, the amount of runoff and sediment was close to or greater than that of the flat slope. (2) The effect of counter tillage on the concentration of nutrient loss was small, but it had a significant effect on the nutrient losses. When the slope gradient was less than 20°, the counter tillage had a better effect on controlling the nutrient losses on the sloping farmland. However, when the slope gradient increased to 20°, the effect of counter tillage on controlling nutrient losses was weakened. Additionally, TN losses were always greater than TP losses in runoff; except for the 10° slope gradient on CT, while TP losses were greater than TN in sediment. (3) The nutrient losses were mainly determined by the amount of runoff and sediment, while the nutrient loss rate and runoff rate or sediment production rate satisfied a linear positive correlation. In addition, the reduction benefits of nutrient losses on counter tillage in runoff and sediment can reach 45% to 100% and 59% to 100%, respectively. 【 Conclusion】 Our results show that counter tillage is an effective tillage practice to control soil erosion and nutrient losses.

Abstract:【Objective】 Understanding the characteristics and differentiation of soil iron oxide in subtropical karst basins is crucial for comprehending the occurrence, development, and type evolution of soil in this unique regional complex. 【Method】 This study focused on 53 typical soil profiles in the Houzhai River Basin, Puding County, Guizhou Province. The research involved measuring the content of various forms of iron oxides in diagnostic surface and subsurface horizons, calculating their weathering indexes, and analyzing the characteristics and differentiation of soil iron oxides. Additionally, the study explored the impacts of soil-forming environments and soil attributes on the characteristic differentiation of iron oxides.【Result】The results revealed an increasing trend in the content of total iron and free iron from diagnostic surface to subsurface horizons, with average increments of 25.54% and 39.63%, respectively. Iron oxides exhibited enrichment in diagnostic subsurface horizons. The activation degree of iron in the diagnostic surface layer surpassed that in subsurface horizons, while free iron and the iron crystal gel rate showed an opposite trend. Most tested diagnostic tables' subsoil had over 30 g·kg^-1 of free iron, over 50% iron dissociation degree, and less than 30% iron activation degree, indicating that the soil was in the aluminization stage during the middle phase of desilication. Factors such as parent rock, land use, watershed position, organic matter, pH, clay CEC₇, and texture types significantly influenced the iron oxide content and weathering index of various soil forms. Geographical detector analysis highlighted the significant explanatory power of parent rock and organic matter on iron oxide index differences (excluding free iron degree), with the highest Q value observed in their interaction (total iron 41.9%, free iron 39.8%, amorphous iron 40.1%, iron activity 41%, iron crystal gel ratio 52.5%).【Conclusion】Apparently, parent rock and organic matter are the primary factors influencing the differentiation of soil iron oxide characteristics in subtropical karst watersheds.

Abstract:【Objective】The purpose of this study was to explore the optimum preparation conditions of bone biochars, their improvement effects on acid soil, and the influence on Al forms from the perspective of soil solid phase and liquid phase.【Method】The anaerobic pyrolysis of pig, chicken, ox, and sheep bone meals were used as raw materials to produce biochars(bone biochars)as ameliorants and three typical acid soils were used.【Result】The results showed that the bone biochars prepared by high-temperature anaerobic pyrolysis were rich in CaO, CaCO₃, and Ca₅(PO₄)₃(OH), contained alkaline substances such as NaO and MgO and characterized by many functional groups including -OH. Nevertheless, the alkali content of bone biochar was greatly affected by the pyrolysis temperature. The alkali content was close to the peak value and remained stable at 800 ℃ for chicken and cow bones, and the same at 900 ℃ for pig and sheep bones. Interestingly, the alkali content of these bone biochars was about 90% of the quicklime, which is the best preparation temperature. Also, the biochars effectively increased the pH of acidic red soils from Anhui, Jiangxi, and Guangdong with an original pH of lower than 6. The alkaline substances in bone biochars mainly existed in the form of H⁺ buffers and the magnitude of the increase in soil pH was inversely proportional to the initial soil pH. After adding 5 g·kg^-1 pig, chicken, sheep, and ox bone biochars to the red soils with pH = 4.40, the Al concentration in soil solution decreased by 33%, 34%, 47%, and 41%, respectively, compared with the control, and the content of organically bound Al in solid phase had no significant change(P > 0.05). Bone biochars increased the cation exchange capacity of acidic soil and reduced the content of soil solution Al and exchange Al by promoting the conversion of active Al to adsorbed hydroxyl Al and more stable Al in the soil solid phase.【Conclusion】Bone biochars are rich in nutrients required for plant growth, has the dual characteristics of inorganic and organic amendments, and are high-quality materials that can replace traditional lime as soil amendments for acidic farmlands.

Abstract:【Objective】 Reductive dechlorination is a key pathway for the degradation of hexachlorobenzene (HCB) which is a persistent organic pollutant. In anaerobic paddy soils, magnetite (Fe₃O₄) can enhance the direct dechlorination under the action of iron-reducing bacteria and their interacting microorganisms which have a dechlorination function. The process is characterized by an increased electron transfer rate and enhanced chemical reductive dechlorination of organic chlorinated pollutants by an acceleration in the production of adsorbed Fe(Ⅱ), which is an effective electron donor. To improve the dispersity of Fe₃O₄, this study attempted to load nano-Fe₃O₄ onto biochar and then clarified the effect of nano-Fe₃O₄/biochar composite material on the reductive dechlorination of HCB in anaerobic paddy soil and their possible mechanisms. 【Method】 First, nano-Fe₃O₄, biochar and nano-Fe₃O₄/biochar composite materials were prepared, and their surface morphologies, crystal structures, and characteristic functional groups were characterized. Then, the anaerobic incubation experiment was conducted in slurry systems with Hydragric Acrisols as the tested soil. The internal relationships between pH, Eh, adsorbed or dissolved Fe(Ⅱ), and the HCB dechlorination process in the reaction systems were analyzed. 【Result】 Results showed that the dechlorination degradation of HCB was negligible for the sterilized control treatment, indicating that the reductive dechlorination of HCB was mainly completed by microorganisms. The addition of single biochar accelerated the reductive dechlorination of HCB by increasing soil pH, enhancing the reducibility of the reaction system, and promoting the formation of adsorbed Fe(Ⅱ). The addition of exclusive nano-Fe₃O₄ presented a stronger effect on promoting the reductive dechlorination of HCB than the addition of biochar alone. This was mainly because nano-Fe₃O₄ could significantly enhance the production of adsorbed Fe(Ⅱ) through dissimilatory Fe reduction and adsorbed Fe(Ⅱ) as an effective electron donor to accelerate the chemical reductive dechlorination of HCB. Also, the application of nano-Fe₃O₄/biochar composite material presented a stronger effect on promoting the reductive dechlorination of HCB than the single nano-Fe₃O₄. This was attributed to the larger specific surface area of nano-Fe₃O₄/biochar composite material and better dispersity of nano-Fe₃O₄ on the biochar surface. This was more beneficial for the electron transfer process in the reaction system relative to the exclusive nano-Fe₃O₄ application. 【Conclusion】 In conclusion, the nano-Fe₃O₄/biochar composite material was a more efficient remediation additive for HCB-contaminated soil compared with single nano-Fe₃O₄ and biochar. In the future, the nano-Fe₃O₄/biochar composite material can be promoted and applied in the remediation and treatment of polychlorinated organic pollutants.

Abstract:【Objective】The establishment of a spatial zoning system of soil pollution risk management indicates the concrete implementation of “classification, division and phased soil environmental management” claimed in Soil Pollution Prevention and Control Law. The high-resolution risk spatial mapping can undoubtedly provide scientific and effective decision-making guidance not only for delineating prior areas for soil pollution risk management but also for facilitating the overall deployment of soil pollution prevention and control works at a large scale.【Method】This study first adopted positive matrix factorization (PMF) model to identify emission sources and the corresponding contribution rate of Cr, Cu, As, Cd, Pb, Ni, Sb and Hg in an industrial agglomeration area in Ningbo City, Zhejiang Province. Then, a spatial zoning technical system for risk management on soil heavy metals pollution was developed based on the source-route-receptor relationship and mass balance theory.【Result】The results showed that: (1) the spatial distribution of soil heavy metals presented a significant heterogeneity and five factors were primarily determined as the emission sources of soil heavy metals including coal-fired power generation source(17.08%), other industrial sources(17.94%), natural source(28.61%), agricultural source(26.07%), and traffic source(10.31%); (2) five risk levels were clustered using the established spatial zoning technical system, including extremely high-, high-, medium-, low- and extremely low-risk accounting for 8.64%, 17.28%, 18.27%, 22.92%, and 32.89% of the total area, respectively. 【Conclusion】The quantification of the regional risk stress levels can effectively map high-risk hotspots to apply prior measures for precise soil pollution management.

Abstract:【Objective】This study aimed to investigate the input and output characteristics of cadmium (Cd), copper (Cu), and lead (Pb) in different atmospheric deposition areas.【Method】The arable soils (0-20 cm) of Guixi Smelter with main wind direction at 34 km (background site), 6 km (moderate deposition site) and 1 km (high deposition site) were selected as the research objects. The main input (atmospheric deposition, irrigation water, pesticides, and fertilizers) and output pathways (surface runoff, leaching water, and grain harvest) were monitored and quantitatively analyzed for three years by using the chemical mass balance (CMB) method.【Result】The results showed that the average annual input fluxes of Cd in the background, moderate, and high deposition sites by atmospheric deposition were 0.84, 2.26, 9.01 mg·m^-2·a^-1, accounting for 43.18%, 38.33%, and 100%, while the average annual input fluxes of Cu were 17.62, 99.68, 747.6 mg·m^-2·a^-1, accounting for 80.76%, 86.24%, 100%, respectively. Also, the average annual input fluxes of Pb were 13.93, 27.43, 73.17 mg·m^-2·a^-1, accounting for 97.75%, 92.36%, and 100%, respectively. Specifically, the average annual input fluxes of Cd in the background and moderate deposition sites due to irrigation water were 1.05 and 3.60 mg·m^-2·a^-1 and accounted for 54.62% and 60.82%, respectively, whereas the annual heavy metal input fluxes by pesticides and fertilizers accounted for less than 5%, which could be ignored. The main output pathways of arable soil in different atmospheric deposition areas were surface runoff and leaching water, with the output ratio ranging from 86.66% to 100%, and the output ratio of the grain harvest ranging from 2.88% to 13.34%. From 2019 to 2021, the average annual net input fluxes of Cd, Cu, and Pb were all greater than 0 in the background site, moderate deposition site, and high deposition site. For example, the average annual net input fluxes of Cd were 1.54, 1.96, and 4.38 mg·m^-2·a^-1, for Cu were 12.72, 28.02, and 184.0 mg·m^-2·a^-1, and for Pb were 13.03, 21.31, 55.04 mg·m^-2·a^-1 in the background site, moderate deposition site, and high deposition site, respectively. 【Conclusion】In general, it is advisable to strengthen the long-term supervision of atmospheric pollution sources and irrigation water quality in the study area and avoid the direct return of straw to the field. This study provided theoretical support for the remediation of heavy metal pollution and the protection of environmental quality in regional arable soils.

Abstract:【Objective】Yunnan Province is one of the typical high geological background regions in China. However, a few studies have focused on the phytoextraction of high geological soils for safe agricultural production. 【Method】This research was conducted to investigate cadmium (Cd) phytoextraction efficiency of the high geological background soils from Shilin, Fuyuan, and Luoping in Yunnan Province by the Cd/zinc (Zn) hyperaccumulator Sedum plumbizincicola and its effect on plant growth and Cd uptake by rice (Oryza sativa) through pot experiments. 【Result】After triple-cropping of S. plumbizincicola, the total Cd and available Cd concentrations in soils showed a substantial decrease, with the total Cd decreasing to 24.8%, 30.9%, and 58.8% of the original values for soils from Shilin, Fuyuan, and Luoping, respectively. S. plumbizincicola showed better growth when grown in soils from Fuyuan developed from basalt with more soil nutrients but presented a greater Cd phytoextraction efficiency when grown in soils from Shilin developed from limestone with higher soil pH, thereby greater Cd mobilization capacity. These significant differences indicated that plant growth and heavy metal accumulation of hyperaccumulators were affected by the comprehensive effects of soil parent materials, soil nutrients, and heavy metal availability in soils. After a triple-cropping of S. plumbizincicola, Cd concentration in brown rice and rice straw was significantly decreased under flooding conditions through the whole growth period, resulting in a Cd-safe production. However, the rice grain possessed a high Cd pollution risk without phytoextraction when grown under a dry cultivation system. 【Conclusion】The phytoextraction of high geological background soils by S. plumbizincicola combing with water management measures benefits greatly the safe production of rice crops, thereby providing a theoretical basis and technical support for the safe production of the high geological background soils.

Abstract:【Objective】The combined application of crop straw with chemical fertilizers and manure is an effective measure to improve soil quality, but its effect on wheat yield and its mechanism in the different textures of fluvo-aquic soils are still unclear. 【Method】Here, we examined shifts in soil quality and wheat grain yield when three soil textures (sandy, loam and clay) were subjected to different management strategies and through a 7-year field experiment at the Fengqiu Agro-Ecological Experimental Station of the Chinese Academy of Sciences. Five different treatments were used: no fertilizer or crop straw returning(N0S0), crop straw returning(N0S), traditional chemical fertilization(NS0), crop straw returning with chemical fertilizer(NS), and crop straw returning with chemical fertilizer and the nitrogen was substituted 20% by chicken manure(NSM). 【Result】The results showed that compared with the N0S0 treatment, the grain yield under the NS treatment was increased by 611.56%, 440.00%, and 403.55% while under the NSM treatment, it was increased by 676.56%, 546.67% and 492.86%, respectively. In sandy, loam, and clay soils, compared with the N0S0 treatment, the soil quality index(SQI) under the N0S and NS0 treatments was significantly increased, with that under the NS treatment being more significant. In sandy soil, the SQI of the NSM treatment was better than that of the NS treatment, but in loam and clay soils, the SQI of the NSM and NS treatments showed no significant differences. Random forest analysis indicated that in sandy soil, grain yield was significantly affected by pH, alkali-hydrolyzable nitrogen(AHN), dissolved organic nitrogen(DON), available phosphorus(AP), soil organic carbon(SOC), and available potassium(AK), in loam soil, it was significantly affected by AP, pH, AK, AHN, microbial biomass carbon(MBC), and SOC, while in clay soil, grain yield was significantly affected by AP, DON, AHN, and pH. The partial least squares path model(PLS-PM) showed that in sandy, loam, and clay soils, the soil properties significantly affecting grain yield were significantly regulated by management strategies, and all of these properties had significant effects on SQI, and SQI had direct significant effects on grain yield. The key soil properties affecting grain yield could be used as indicators to monitor the changes in soil quality and grain yield to select management strategies. In addition, in loam soil, SQI also indirectly affected the grain yield by affecting wheat yield components. 【Conclusion】The combined application of crop straw with chemical fertilizers and chicken manure improved soil quality and directly or indirectly affected grain yield through different action modes in the different textures of fluvo-aquic soils.

Abstract:【Objective】In order to reveal the response mechanism of microbial community and ecological network to straw returning process in typical fluvo-aquic soil, we experimented with different straw-returning treatments under long-term wheat-maize rotation.【Method】The high-throughput sequencing and ecological network methods were utilized to analyze the soil bacterial community composition, bacterial network co-occurrence and their relationships with soil nutrient concentrations.【Result】The results indicated that compared to straw removal and no nitrogen fertilizer treatment, straw returning with conventional fertilization treatments significantly reduced soil pH, while increasing the content of TN, SOC, AP, AK and NO₃^--N(P < 0.05). The treatments of straw burying with nitrogen fertilizers were beneficial for increasing soil nutrient content. Moreover, no significant difference in bacterial alpha diversity was observed between different straw-returning methods and different amounts of nitrogen fertilizers, but a significant difference was observed in bacterial community structure. Factors such as pH, SOC, and TN drove variations in bacterial community structure.Also, Acidobacteriota, Proteobacteria, Bacteroidota and Chloroflexi were the dominant phyla in the fluvo-aquic soil. Furthermore, co-occurrence network analysis revealed four main ecological clusters that were significantly correlated with soil nutrients. The abundances of taxa in module 1 were found to be inversely correlated with SOC, TN, TP, NO₃^--N, AP and AK(P < 0.001), and positively correlated with pH(P < 0.001). Conversely, the abundances of taxa in module 2 and module 3 were significantly positively correlated with most nutrient content, and negatively related to pH.【Conclusion】Therefore, it can be concluded that straw burying combined with nitrogen fertilizers can improve soil nutrient by regulating ecological relationships of microorganisms. The findings of this study can provide a scientific basis for the efficient utilization of straw and the efficient management of soil fertilization.

Abstract:【Objective】This study aimed to use different proportions of organic fertilizer instead of chemical fertilizer as organic matter compensation schemes to study their effects on garlic yield attenuation in long-term continuous cropping garlic fields in the main garlic-producing area of Jinxiang County, Shandong Province. 【Method】The representative fields with more than 25 years of continuous cropping history were selected in this experiment. The wheat field without garlic planting was used as the non-continuous cropping field control. Four treatments were set up : conventional chemical fertilizer fertilization (CF) and organic fertilizer to replace chemical fertilizer with 25% (M25), 50% (M50) and 100% ( M100) based on nitrogen (N).【Result】The results showed that in the long-term garlic continuous cropping soil, organic fertilizer instead of chemical fertilizer treatment had a significant effect on the increase(20%)of garlic yield in the current season. Also, the content of N in continuous cropping soil and the proportion of soil > 2 mm aggregates were increased, and the N nutrient supply status and soil aggregate structure in the soil were improved. Among the treatments, 25% organic fertilizer instead of chemical fertilizer treatment( N )had the best yield and economic benefit of garlic, and also had a better repair effect on the decline of soil productivity of continuously cropping garlic. However, in non-continuous cropping soil without organic matter deficit, organic substitution treatment did not have a direct effect on increasing production. 【Conclusion】This study clarified that the application of organic fertilizer(partial organic fertilizer instead of chemical fertilizer treatment)based on chemical fertilizer application can only promote the formation of large-grained soil aggregates and enhance the holding capacity of soil available nutrients during the whole growth period in the continuous cropping garlic soil with obvious deficiency of soil organic matter. It also has a significant restoration effect on the degradation of continuously cropping garlic soil productivity. This study provides a useful reference for alleviating similar soil degradation problems and maintaining the sustainability of soil productivity in continuous cropping systems.

Abstract:【Objective】Ammonia oxidizers make an important contribution to N₂O emissions. However, the composition of their relative contribution to N₂O emission in different soils and agricultural management systems has not been systematically studied.【Method】We studied the contributions of AOB, AOA + comammox and heterotrophic nitrifiers to the potential nitrification rate, net nitrification rate and N₂O emission in typical upland surface soils (fluvo-aquic soil, black soil, latosol, red soil), and in latosols from soil profile under organic fertilizer amendment.【Result】In the surface fluvo-aquic soil, black soil, latosol and red soil, potential nitrification rate significantly increased with soil pH (P < 0.05), and was 32.5, 6.6, 4.8 and 2.3 mg·kg^-1·d^-1, respectively. AOB dominated the potential nitrification rate in the above surface soils, with contributions ranging 58%-100%. Further analyses of the fluvo-aquic soil, black soil and latosol indicated that net nitrification rate and N₂O emission both significantly increased with soil pH (P < 0.05), which were consistent with potential nitrification rate. For the net nitrification rate, AOB and AOA + comammox contributed equally (30%-40%) in the fluvo-aquic soil and latosol, while AOB dominated in the black soil (72%). N₂O emissions from the fluvo-aquic soil, black soil and latosol were all dominated by AOB (58%-92%). For soils from the organic fertilizer-amended latosol profile, pH, potential nitrification rate, net nitrification rate and N₂O emission significantly increased from the subsurface to surface layer (P < 0.05). The increase in potential nitrification rate and net nitrification rate was dominated by AOA + comammox (contributing 63% and 54%) and the increase in N₂O emission was dominated by AOB (contributing 54%).【Conclusion】This study provides new evidence for developing reduction measures of N₂O emissions that match the soil ammonia oxidation characteristics and soil properties.

Abstract:【Objective】Rhizosphere beneficial microorganisms can enhance plant salt stress tolerance through multiple pathways, including re-establishing ion and osmotic homeostasis, preventing damage to plant cells, and resuming plant growth in saline soil. This study aimed to obtain plant growth-promoting rhizobacteria that can improve salt tolerance of rice and to explore its application effects.【Method】Two rice cultivars were used in this study, of which one is salt-tolerant cultivar Hunanxian and the other is salt-sensitive cultivar Nanjing 46. The physiological characteristics of rice seedlings were compared after planting in sterile and non-sterile saline soils. Then, the key rhizobacterial groups associated with salt tolerance, which were enriched in the rhizosphere of salt-tolerant rice cultivars, were identified by compositional differences and co-occurrence network analyses based on the 16S rRNA gene amplicon sequencing. Subsequently, the culturable strains of the key rhizobacterial groups were isolated through the high-throughput cultivation and identification method of rhizobacteria. Finally, pot experiments were conducted to evaluate the beneficial effects of the strains on enhancing the salt tolerance of salt-sensitive rice cultivar.【Result】The height of shoot and root length of salt-tolerant rice were significantly higher while the content of proline was significantly lower when cultivated in non-sterile soil than in sterile soil under salt stress. This indicates that the rhizosphere microbial community of salt-tolerant rice cultivars may play a crucial role in enhancing the salt tolerance of the host plant. Amplicon sequencing results demonstrated that the composition of the rhizosphere microbial communities of salt-tolerant and salt-sensitive rice cultivars was significantly different. The bacterial families of Flavobacteriaceae and Pseudomonadaceae were the key rhizobacterial groups that were both enriched in the rhizosphere of the salt-tolerant rice. Several bacterial strains affiliated with Flavobacteriaceae and Pseudomonadaceae were isolated, in which two strains of Pseudomonas punonensis P34 from Pseudomonadaceae and Chryseobacterium taeanense C18 from Flavobacteriaceae were screened to be the most efficient strains in improving the salt tolerance of rice by germination and hydroponics tests using salt-sensitive rice under salt stress. Finally, the efficient strains of C18 and P34 were applied as direct inoculants and seed-coating agents in pot experiments, and the results demonstrated that they were able to promote the growth of salt-sensitive rice under salt stress. 【Conclusion】Two rhizobacterial strains of C18 and P34 showed great capacity to enhance the salt tolerance of rice and they could be developed as bacteriological agents for seed coating or microbial fertilizer for application in saline lands.

Abstract:【Objective】A large number of studies have found that changing from dry to wet significantly affects soil microbial communities and greenhouse gas emissions. However, the transient dynamic of active microorganisms and greenhouse gas emissions of soils under dry to wet fluctuations are still unclear. 【Method】In this study, the dynamic of bacterial communities and greenhouse gas emissions under dry, wet, and dry-wet changes conditions in paddy soil were investigated. The diversity, assembly, and potential functions of active bacterial communities under dry-wet change conditions were further revealed by combining ¹⁸O-based DNA stable isotope probing technology (DNA-SIP) and high-throughput sequencing. 【Result】Dry-wet change treatment significantly promoted emissions of carbon dioxide and contained significantly higher relative abundances of Actinobacteria and planctomycetes compared with those in the dry and/or wet treatments. The relative abundances of Proteobacteria, Actinobacteria, and planctomycetes increased significantly along with the incubation. DNA-SIP experiment showed that the alpha diversity of active bacteria in the dry-wet change treatment decreased significantly along with the incubation. Proteobacteria and Actinobacteria dominated the active bacterial communities, and the relative abundance of Myxococcales in Proteobacteria increased significantly along with the incubation. The assembly of active bacteria was dominated by determinism, and the contribution of determinism was increased along with the incubation. Functional prediction of active bacteria further found that carbohydrate metabolic potential decreased significantly during the incubation. 【Conclusion】In conclusion, the dry-wet change treatment significantly changed the soil bacterial community and promoted carbon dioxide emission in paddy soil. The active bacteria in the dry-wet change treatment were dominated by Proteobacteria and Actinobacteria, and their assembly was dominated by a deterministic process.

Abstract:【Objective】Microbial biomass carbon(C)metabolism is vital in the formation and stabilization of organic C in soil, constituting a critical parameter in the models of terrestrial ecosystems. Yet, the variances in the microbial C metabolism indices in soils developed from different lithological origins remain undefined. 【Method】To address the scientific gap in the characteristics and driving factors of microbial biomass C metabolism in soils developed from different rocks, we sampled forest soils developed from limestone and clastic rocks as research objects. Using ¹⁸O-H₂O labeling, we measured the microbial growth rate, respiration rate, carbon use efficiency (CUE), and turnover time. Combined with soil physicochemical properties, soil organic matter mineral protection characteristics, soil enzyme activity, and microbial biomass and community composition, we clarified the influencing mechanism of lithology on forest soil microbial biomass C metabolism. 【Result】The findings indicate that the pH and the 0.002～0.05 mm particle content in limestone-derived soils surpass those in clastic rock-derived soils, whereas soil organic carbon (SOC), total nitrogen (TN), dissolved organic carbon(DOC), C: P and N: P ratios were lower in limestone-derived soils (P<0.05). The limestone-developed soils had a higher content of exchangeable calcium and magnesium (Ca/Mg) and free iron and aluminum ((Fe+Al)_d) than the clastic rock-developed soils, but the content of amorphous iron and aluminum((Fe+Al)_o)was lower than that in the clastic rock-developed soils. Furthermore, the enzyme activity related to C, N, and P cycling in limestone-developed soils was significantly lower than that in clastic rock-developed soils (P< 0.05). In addition, the microbial biomass phosphorus (MBP) in limestone-developed soils was higher than that in clastic rock-developed soils, but microbial biomass carbon(MBC), fungi: bacteria ratio (F: B), and Gram-positive to Gram-negative bacteria ratio (G⁺: G^-)were significantly lower than those in clastic rock-developed soils (P<0.05). The microbial growth rate and turnover rate in limestone-derived soils were significantly higher than in clastic rock-derived soils (P<0.05), but there was no significant difference in the microbial respiration rate and CUE between the two types of soils. Correlation analysis revealed that the soil microbial growth rate and turnover rate were significantly positively correlated with soil pH, (Ca+Mg): (Fe+Al)_o, (Ca+Mg): SOC, (Fe+Al)_d: SOC, and Gram-negative bacteria(P<0.05), and significantly negatively related to DOC, organic C bound to iron and aluminum, enzyme activity, MBC: MBN, F: B, and G⁺: G^- ratio(P<0.05). The soil CUE was significantly negatively correlated with MBC and MBC: MBN (P<0.05) while microbial respiration rate was only significantly negatively correlated with phenol oxidase activity (P<0.05). In summary, the higher pH, weaker amorphous iron-aluminum mineral protection, lower microbial resource limitation, and larger bacterial biomass (especially Gram-negative bacteria) in limestone-derived soils may lead to greater microbial motility in these soils and stronger substrate availability, resulting in larger microbial growth and turnover rates. However, there was no difference in the soil microbial biomass CUE between the two rock types, which may be due to the similar soil C: N ratio. 【Conclusion】The microbial biomass C metabolism of forest soils developed from two types of rocks is controlled by biological and non-biological factors. These research results provide a new mechanism for explaining the differences in organic carbon pools in forest soils developed from different rocks.

Abstract:【Objective】The effect of warming on the accumulation dynamics of microbial necromass is of great significance to the balance of soil carbon(C)pool. However, the impact of climate warming on microbial necromass is poorly understood. Thus, the objective of this study was to evaluate the responses of microbial necromass to climate warming and the main factors controlling this feedback.【Method】In this study, a meta-analysis was conducted to reveal general patterns of climate warming on amino sugars (microbial necromass biomarkers) in soils under grasslands, forests, and croplands. Here, 12 published publications from international and domestic journals were collected and extracted independent observations that met our criteria (29 for total amino sugars, 35 for glucosamine, 39 for muramic acid, and 25 for galactosamine).【Result】The results showed that the overall effects of warming could promote the accumulation of microbial necromass. However, warming effect sizes on microbial necromass were not consistent across different ecosystems, with the most sensitive responses occurring in cropland. The response of fungal and bacterial necromass differed under climate warming. Specifically, warming significantly increased the content of galactosamine and muramic acid, with an increase of 10.3% and 5.0%, respectively. Together with the significant decline in the ratio of glucosamine to muramic acid, the results suggested that warming benefited the accumulation of bacterial necromass compared to fungi. Also warming significantly increased the proportion of bacterial necromass to soil organic carbon (SOC), while the contribution of fungal and total necromass to SOC did not change significantly, suggesting that the contribution of fungal-derived C to SOC was weakened under warming scenarios. Warming magnitude was a key factor affecting the accumulation of microbial necromass. For instance, the accumulation of microbial necromass increased by 2.7%-14.6%, when the warming magnitude was less than or equal to 2℃ relative to unwarmed control. However, when the warming amplitude was greater than 2℃, the accumulation of microbial necromass was decreased by 8.0%-14.3%. Interestingly, the duration of warming was an important factor affecting the accumulation of microbial necromass.【Conclusion】The results demonstrate that warming has significant effects on the accumulation dynamics of microbial necromass and their contribution SOC pool. The intensity and direction of the warming impact are largely dependent upon ecosystem type and soil depth, in which warming amplitude, warming duration, and mean annual precipitation are important factors controlling the sequestration of the microbial-derived C under global climate warming.

Abstract:【Objective】Long-term mining activities have caused serious damage to the ecological environment in the mining area. Soils near mining areas have reduced quality, decreased vegetation cover, and changed microbial habitats. Stripped soil and coal gangue are mixed to form hillocks and the exposed surface of the hillocks is highly susceptible to wind and water erosion, which has resulted in increasingly severe damage to the ecosystems, including changes in plant species composition and community structure, reduced biodiversity and productivity, deterioration of soil and microenvironment, and changes in the relationships between organisms. Hence, the ecological restoration of the coal mines is an urgent task. Interestingly, vegetation types may affect the composition and diversity of microbial communities in rhizosphere soil owing to the growth conditions, vegetation cover, root turnover rates, and the chemical composition of root exudates. Therefore, it is important to explore the response of microbial community composition and diversity under different vegetation types in mining ecological restoration areas.【Method】The rhizosphere soils of five vegetation types (Platycladus orientalis, Picea asperata, Pinus sylvestris, Pinus tabuliformis, and Sabina chinensis) were collected in this study to detect the soil physicochemical properties, enzyme activities, and bacterial community structure. Also, we identified key environmental factors affecting rhizosphere bacterial communities using redundancy analysis and conducted a mantel-test analysis between dominant bacterial phyla and environmental factors. Structural equation models were established to explore the interactions between plants, soil, and microbes. Furthermore, the soil-integrated fertility index was calculated to analyze the ecological restoration effectiveness of different vegetation types.【Result】Vegetation types had significant effects on soil physicochemical properties, enzyme activities, bacterial community composition, and diversity. The P. sylvestris field had significantly higher total carbon content, total nitrogen contents, bacterial abundance, and diversity, while soil alkaline phosphatase and soil urease activities were significantly higher in the P. asperata field. The Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla of soil bacterial communities. Also, the dominant genera were RB41, Streptomyces, MND1, Ferruginibacter, and Variovorax. Total sulfur, soil bulk density, and soil alkaline protease were the key factors affecting the structure of rhizosphere soil bacterial communities. Our analysis revealed that vegetation types can directly affect soil physicochemical properties, soil enzyme activities, and bacterial community structure, as well as indirectly affect rhizosphere soil bacterial community structure through soil physicochemical properties and soil enzyme activities. Soil integrated fertility index indicated that P. sylvestris and P. asperata were superior to other vegetation in the ecological restoration of mining areas.【Conclusion】Vegetation types have significant effects on soil physicochemical properties, soil enzyme activity, and bacterial community in the rhizosphere. P. sylvestris and P. asperata can improve the rhizosphere soil bacterial diversity and soil fertility, which is beneficial to the ecological restoration of the coal mine reclamation area. This study provides a scientific basis for vegetation selection for ecological restoration of coal mine reclamation areas in semiarid regions.