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1. 题目: Effects of simulated nitrogen deposition on soil dissolved organic carbon leaching: Evidence from a 3-year field study in Abies georgei (Orr) woods of subtropical regions
文章编号: N26061304
期刊: Catena
作者: Jiyou Yuan, Yun Wang
更新时间: 2026-06-13
摘要: Dissolved organic carbon (DOC) is integral to carbon cycling in forest soils. However, research on DOC leaching in forest ecosystems remains limited, and several key mechanisms are poorly understood. This study investigated the direction, mechanisms, and seasonal dynamics of soil DOC leaching under nitrogen (N) enrichment through a field study spanning 2021 to 2023 in a subtropical Abies georgei (Orr) forest ecosystem. Four levels (0, 5, 15, and 30 kg N ha−1 yr−1) of NH4NO3 were applied to assess DOC leaching in both the organic (O) horizon and the combined O horizon plus 20–40 cm mineral (M) horizon. The results showed that low N input did not significantly influence DOC leaching in the O layer in the first two years, although a reduction was observed in the third year. In contrast, medium and high N additions consistently suppressed DOC leaching from the O layer throughout the study period. In the M layer, DOC leaching remained unaffected by all N treatments. DOC leaching in the O layer followed the seasonal pattern of spring > autumn > summer and was suppressed by medium and high N additions, with a low N effect observed only in 2023. In contrast, the M layer showed no response to N addition and lower DOC fluxes. Seasonal variation in DOC leaching in both layers was apparent and primarily influenced by abiotic variables, including thermal conditions, rainfall, and litter deposition. N enrichment promoted microbial biomass carbon accumulation and increased cellulase and phenol oxidase activities, implying that the observed DOC leaching reduction did not result from lower DOC generation. Although soil pH remained largely unaffected by N supplementation over the three-year period, a downward trend was observed, warranting longer-term monitoring. Overall, these findings indicate that the regulation of DOC leaching by N differs between soil layers, with N inputs reducing DOC leaching in the O layer and potentially improving the stabilization and accumulation of the soil carbon pool.

2. 题目: Low molecular weight organic acids regulated iron minerals activated persulfate system for sulfamethoxazole degradation
文章编号: N26061303
期刊: Chemical Engineering Journal
作者: Zhanghao Hu, Shixian Cheng, Xiaoping Gao, Wenfeng Huang, Jingyi Zhang, Yupeng Wang, Jun Liang, Xiaoyun Xu, Xinde Cao
更新时间: 2026-06-13
摘要: Persulfate (PS)-based in situ chemical oxidation in remediating organic-contaminated soils is significantly influenced by inherent soil constituents. However, the complex interactions between the various iron minerals and organic matter present in soils, and their combined impact on persulfate activation, are still not fully elucidated. Here, we investigated sulfamethoxazole (SMX) degradation by different Fe minerals and soil organic matter including low molecular weight organic acids (LMWOAs). Results showed that compared to lactic acid (LA), tartaric acid (TA) addition obviously enhanced SMX degradation in PS by goethite, chlorite, and magnetite. Specifically, SMX degradation was 98.3%, 83.8%, 99.0%, respectively, in goethite/TA/PS, chlorite/TA/PS, and magnetite/TA/PS systems. In goethite/TA/PS, stable Fe(IV)/SO4•- dual-active species was obtained through interfacial confinement reaction for SMX degradation despite its slower electron transfer; in magnetite/TA/PS system, •OH and SO4•- were the main reactive species though fast electron transfer and rapid release of aqueous Fe2+. Although magnetite exhibited fast electron transfer rate, its limited surface sites and weaker affinity restricted SMX degradation; in chlorite/TA/PS system, •OH was mainly responsible for SMX degradation due to low specific surface area and slow electron transfer. These were collectively examined by quenching experiment, ATR-FTIR analysis, electrochemical test, density functional theory calculations. Besides, Fe-bearing soils were effectively activated by TA to enhance SMX degradation by PS, further confirming the proposed mechanism. Therefore, outcomes of this work will advance the current knowledge on potential application of LMWOAs to enhance degradation of organics in soil/PS systems.

3. 题目: Microbial Strategies Mediated by Diverse Agricultural Practices Stabilize Soil Organic Carbon Under Ultraviolet Radiation Stress
文章编号: N26061302
期刊: Environmental Science & Technology
作者: Wan-Rong Zhang, Quan Chen, Da Lin, Changping Zhao, Yi-Fei Wang, Yafeng Wang, Pengfei Wang, Min Wu, Dong Zhu, Bo Pan, Baoshan Xing
更新时间: 2026-06-13
摘要: Ultraviolet A (UVA) poses underexplored risks to organic carbon stability, particularly relevant to the fate of mineral-associated organic carbon (MAOC) and particulate organic carbon (POC) under diverse agricultural practices. To determine how UVA stress alters soil carbon stability, we conducted a 32 day microcosm experiment exposing agricultural soil to 0, 384.6, or 798.2 μW/cm2 UVA, with or without fulvic acid (FA, 0.4%, w/w), mulching, or their combination. Our study demonstrates that UVA acts as a genotoxic stressor, forcing microorganisms to undergo a metabolic trade-off. Specifically, UVA selectively stimulates decomposer taxa enriched in carbohydrate-active enzymes, such as Bacteroidota and Acidobacteriota, thereby supporting cellular repair. This “repair-driven hypermetabolism” accelerates the decomposition of recalcitrant substrates, significantly reducing stable MAOC content from 8.25 to 7.96 g/kg, whereas POC did not change significantly under UVA alone. Agricultural practices, such as fulvic acid (FA) preferentially promoted MAOC-related microbial communities and functions, whereas mulching enhanced extracellular polymeric substance production and supported POC stabilization. The combined Mulch-FA treatment redirected microbial strategies toward biosynthesis, increased soil organic carbon by 18.77% relative to the control, and reduced the relative abundances of genes involved in cellulose, mannan, xylan, and lactose degradation by 70.58%, 90.75%, 87.27%, and 81.40%, respectively. This study lays a scientific foundation for achieving sustainable agricultural development under accelerating UVA stress.

4. 题目: Research trajectory and long-term trends of dissolved organic carbon in freshwater systems
文章编号: N26061301
期刊: Environmental Science: Processes & Impacts
作者: Liping Hu, Kun Shi
更新时间: 2026-06-13
摘要: Dissolved organic carbon (DOC) is a major and dynamic carbon pool regulating carbon cycling in freshwater systems. Over the past two decades, research on freshwater DOC has moved beyond simple concentration monitoring to examine its sources, molecular composition, degradation potential, and interactions with climate change. Lake studies increasingly focus on DOC processing, long-term storage, and its role in greenhouse gas production, while river studies emphasize DOC mobilization, transport, and connectivity between terrestrial landscapes, inland waters, and downstream coastal environments. Long-term observations reveal increases in DOC concentrations in lakes and rivers, with mean growth rates of 0.042 and 0.015 mg L⁻¹ yr⁻¹, respectively. These trends are driven by multiple factors, including recovery from acid deposition, climate warming, extreme precipitation, and intensified human activities such as land-use change and wastewater discharge. Rising DOC concentrations leads to water browning, degraded water quality, biodiversity loss, and increased greenhouse gas emissions, with consequent socioeconomic impacts, particularly in fisheries and tourism. Addressing these challenges requires integrated strategies combining source control, long-term monitoring, and ecosystem restoration. Future research should prioritize global spatiotemporal dynamics of DOC concentration and composition by integrating field observations, remote sensing, and modeling to better understand and mitigate its ecological and socioeconomic impacts.

5. 题目: Spatial assessment of land use compensation potential for climate-based soil organic carbon stock losses in Poland by 2050
文章编号: N26061205
期刊: Agriculture, Ecosystems & Environment
作者: João Augusto Coblinski, Sylwia Pindral
更新时间: 2026-06-12
摘要: Climate changes affect the soil multifunctionality and the intensity of this impact can be determined by the land use type and its changes. Soil organic carbon (SOC) stock is one of the most important soil functions, and it is very sensitive to climate and land use changes. The objective of this study is to assess the importance of the land use changes in compensating the impacts of climate change on SOC stock losses. By 2050, climate change is projected to cause SOC stock losses across 34% of the Polish territory. Within this area, 17% will experience partial compensation of SOC stock losses and 12% may achieve total compensation. In contrast, 9% of the area will amplify the SOC stock losses. The changes from agriculture to conservative land uses, as forests and pasture, demonstrated a strong capacity to compensate the climate-based SOC stock losses. On the other hand, the changes from forest areas to agriculture resulted in the greatest amplification. Finally, the stable land use classes, are generally related with the absence of compensation or amplification effects. The land use changes had a limited capacity to influence the SOC stock losses on a national scale, demonstrating that the mitigation for SOC stock losses might depend on the type of soil management besides the land use types. The presented approach can guide for a mitigation and restoration strategies considering the climate change, prioritizing interventions in the most vulnerable areas and maintaining conservative practices in areas with partial or total compensation potential.

6. 题目: Biochar strengthens rainfall regime resistance of soil inorganic C by enhancing pH–bicarbonate and carbonic anhydrase regulation in dryland region
文章编号: N26061204
期刊: Agriculture, Ecosystems & Environment
作者: Yuhao Wang, Yanbo Ji, Shutong Guo, Lin Sun, Enke Liu, Zhikuan Jia, Kadambot H M Siddique, Rui Qian, Ting Wei, Peng Zhang
更新时间: 2026-06-12
摘要: Soil inorganic carbon (SIC) is a major carbon pool in drylands, yet its long-term response to agricultural management under interannual rainfall variability, and the mediating role of carbonic anhydrase (CA) as a key enzyme in SIC formation, remain poorly quantified. We conducted an eight year rainfed field experiment, comparing no fertilizer (CK), mineral fertilizer (F), fertilizer plus straw (FS), and fertilizer plus biochar (FB). Growing season precipitation was classified into dry, normal, and wet regimes by hierarchical clustering. We quantified annual changes in SIC and carbonate related variables, and evaluated CO2 emissions and maize productivity. Across rainfall regimes and 0–60 cm soil layer, FB consistently increased the SIC content (mean ΔSIC = 0.22 g kg−1), whereas FS caused net SIC loss (−0.04 g kg−1) and F showed little difference from CK (0.12 g kg−1). Wet years promoted topsoil SIC loss and HCO3- leaching to subsoil, while dry years generally favored net SIC accumulation. FS decreased soil pH, reduced HCO3-, increased CO2 emissions, and showed a stronger decline in CA activity, consistent with intensified carbonate dissolution and leaching. In contrast, FB increased pH, ΔHCO3-, and buffered CA declines across rainfall regimes. Biochar sustained CA related bicarbonate availability and favored bicarbonate mediated SIC formation. FB achieved the highest mean yield (10.75 × 103 kg ha−1) and smaller CO2 increase. Overall, long-term biochar application enhanced the rainfall regime resistance of SIC accumulation, particularly under high precipitation (504 mm), while improving crop production with a lower CO2 emission than straw in dryland region.

7. 题目: Global patterns of tree diversity effects on soil respiration and their linkages to soil organic carbon
文章编号: N26061203
期刊: Geoderma
作者: Junzhu Xiao, Zhenghu Zhou, Hanqi Hu, Binbin Li, Yuanyuan Li, Xiao Deng, Mingxiang Xu
更新时间: 2026-06-12
摘要: Forests are essential for sustaining global soil organic carbon (SOC) balance, particularly in species rich ecosystems. As the primary pathway of soil carbon (C) release, soil respiration profoundly influences SOC dynamics. However, the effects of tree diversity on soil respiration remain poorly understood. We conducted a meta-analysis based on 1119 paired observations from 228 publications to evaluate the effects of tree diversity on soil respiration (Rs), autotrophic respiration (Ra), heterotrophic respiration (Rh) and the temperature sensitivity of Rs (Q10), as well as the associations between these effects and SOC changes. On average, tree mixtures increased Rs and Rh by 16.25% and 14.91%, and reduced Q10 by 8.95%. These effects strengthened with increasing tree species richness and initial soil pH, particularly in mixtures with greater functional trait divergence and colder regions. Longer planting duration amplified the positive responses of Rs and Rh yet shifted the Q10 response from negative to positive. Notably, the linear relationship between changes in Rh and SOC shifted from positive in young mixtures to negative in old mixtures. This transition likely associated with intensified nitrogen limitation and long-term adjustments in microbial decomposition strategies in older mixtures. This first large-scale estimate of the relationship between changes in Rh and SOC in tree mixtures highlights the need to strengthen C sink management in mature mixtures to sustain their long-term C sequestration potential.

8. 题目: Contributions of iron-bound organic carbon to soil aggregation in a Luvisol
文章编号: N26061202
期刊: Soil and Tillage Research
作者: Wen Zhihao, Zhai Bingnian, Jia Hanzhong, Li Ziyan
更新时间: 2026-06-12
摘要: Iron-bound organic carbon (Fe-OC) is a key driver of soil aggregation formation. However, current research predominantly focuses on descriptive statistical analysis, and the mechanisms by which Fe-OC contributes to soil aggregation formation remain unclear. This study examined Fe-OC and aggregate formation in an experimental field receiving long-term fertilization treatments. A sequential selective extraction approach was employed to separate Fe-OC sub-pools. Our results show that the formation and stability of soil aggregates < 2 mm is dominated by Fe-OC. They also highlight that the three Fe-OC sub-pools form a continuous aging sequence corresponding to distinct stages of aggregate growth and suggest a graded cementation mechanism governed by different Fe-OC fractions. Among these, Feo-OC was the most critical cementing agent. More than 40% of Feo-OC is composed of carboxyl-rich CRAMs, which represent the key component responsible for its strong cementation capacity. Moderate nitrogen fertilization and manure application promoted the formation of Feo-OC by continuously supplying fresh organic carbon, which not only promotes soil aggregation but also promotes soil carbon stability. These findings contribute to a deeper understanding of how Fe-OC influences soil aggregate formation and the mechanisms by which it contributes to soil carbon storage.

9. 题目: Proteomic perspectives on the effects of different iron valence states on the culture water quality of microalgae and the secretion of dissolved organic matter
文章编号: N26061201
期刊: Journal of Environmental Chemical Engineering
作者: Lin Qin, Zhihong Yin, Ziying Sun, Zhenning Wu, Liandong Zhu, Shaoqi Zhou
更新时间: 2026-06-12
摘要: The influence of iron sources on microalgae has been widely studied. This study specifically examined the effects of different iron valence states on culture water quality, as well as on dissolved organic matter (DOM) secretion by microalgae. The underlying molecular mechanisms were further elucidated using proteomics. The results indicated that both nanoscale zero-valent iron (Fe0) and ferric iron (Fe3+) increased the protein content, reaching concentrations of 98.43 and 99.40 mg/L, respectively. In addition, ferrous iron (Fe2+) and Fe3+ substantially promoted photosynthetic efficiency in the early stage, while its subsequent decline was due to the downregulation of LHCB1, LHCA2, and LHCA4 proteins, which reduced the microalgal light-harvesting capacity. The addition of Fe0 significantly enhanced chemical oxygen demand removal, reaching an efficiency of 60.93%. The ammonia nitrogen removal rate reached 88.05% under Fe3+, driven by the significant upregulation of CAH protein. The DOM secreted by microalgae induced by different valence states of iron mainly consisted of proteinoids, humus, and tryptophan. The reduced DOM, along with the absence of certain components from standard spectral libraries, is most likely attributable to protein folding defects, which downregulate functional proteins involved in endoplasmic reticulum activity and protein export (such as HUGT, HSPA5, SRPRB, and SPC2 proteins). Investigating the effects of different iron valences on microalgal water purification and DOM secretion contributes to the development of a microalgae–water interaction model, providing a theoretical foundation for the application of microalgae in aquatic ecological restoration.

10. 题目: How does biochar reduce N2O emission from soil? - a review of mechanisms
文章编号: N26061120
期刊: Soil Biology and Biochemistry
作者: Xiao Wang, Camille Nunes Leite, Bo Thamdrup, Sander Bruun, Hans Chr. Bruun Hansen
更新时间: 2026-06-11
摘要: Agricultural soils are a major source of nitrous oxide (N2O), a potent greenhouse gas. Biochar application has emerged as a promising mitigation strategy, but our understanding of the mechanisms behind its effects and the interplay between biochar properties, soil conditions, and microbial processes is still incomplete. This review synthesizes recent advances of our understanding of how biochar influences nitrogen transformations and N2O production, consumption and transport in soils and sediments. Biochar properties, governed by feedstock type and pyrolysis conditions, determine its surface area, porosity, functional groups, pH, and aromaticity, which in turn influence nitrogen cycling pathways involving both production and consumption of N2O. Mechanistically, biochar reduces N2O emissions primarily by altering the environmental conditions that regulate N2O production and consumption pathways rather than by directly suppressing a single microbial process. The most consistently supported mechanisms include increases in soil pH promoting N2O reduction to N2, changes in oxygen diffusion and redox conditions affecting the balance between nitrification and denitrification, modulation of carbon and nitrogen substrate availability, and electron transfer-mediated enhancement of denitrification. Despite substantial experimental evidence, knowledge gaps remain regarding the relative importance of mechanisms under specific soil contexts, the roles of critical alternative pathways (e.g., co-denitrification, chemodenitrification), and the electrochemical properties of biochar. Future research should integrate isotopic tracers, imaging, microsensors, light-based techniques and molecular tools, systematically characterize the electron donating and accepting capacity (EDC/EAC), and conduct cross-comparisons across diverse biochars to identify traits that consistently reduce N2O emissions. A mechanistic framework linking biochar properties to soil processes is essential to guide the design and targeted application of biochar for effective greenhouse gas mitigation in agriculture.

11. 题目: Microplastics identification framework: Integration of microplastic-derived dissolved organic matter fingerprints and machine learning
文章编号: N26061119
期刊: Water Research
作者: Ruxin Yang, Jinjiang Duan, Jianhao Song, Linhu Li, Xingnian Ren, Cheng Yang, Yu Xiang, Han Zhang, Mengli Chen
更新时间: 2026-06-11
摘要: Microplastics (MPs), ubiquitous in aquatic environments, pose ecological risks that depend fundamentally on their polymer composition. MPs can release dissolved organic matter (DOM) carrying polymer-specific chemical fingerprints, yet their integration into an accessible and interpretable framework for polymer-related MPs identification remains insufficiently developed. Here, we proposed an MP-DOM based MPs identification framework that integrates an interpretable machine learning model with MP-DOM fingerprints derived from aliphatic (polyethylene, polypropylene), aromatic (polystyrene, polyethylene terephthalate), and biodegradable MPs (polylactic acid) under controlled (Milli-Q) and environmental (river water) conditions. MP-DOM fingerprints were identified from dissolved organic carbon (DOC) levels, UV–Visible absorbance and fluorescence indices. Functional group analyses and molecular-scale simulations further supported that these fingerprints reflect polymer-dependent DOM compositions and release pathways. Specifically, aliphatic MP-DOM exhibited weak and uniform optical signatures linked to backbone-controlled release, aromatic MP-DOM showed enhanced aromaticity and a lower polymerization degree due to structure-selective release from aromatic units with higher local electronic activity, whereas biodegradable MP-DOM was characterized by high DOC release, strong bulk absorbance, and low aromaticity associated with ester-bond hydrolysis. After benchmarking multiple classifiers, an optimized random forest model incorporating seven MP-DOM fingerprints achieved high classification performance (AUC=0.953). When applied to MP-added river water samples, the model retained recognizable classification performance after background correction (AUC=0.903), with near-complete identification of biodegradable MPs and residual overlap mainly between aliphatic and aromatic MPs. This study demonstrates the feasibility of MP-DOM fingerprints for polymer-related MPs identification, providing an accessible approach to support source-related interpretation in aquatic environments.

12. 题目: Unraveling the organic phosphorus dynamics and its impact on internal phosphorus feedback during algal blooms senescence
文章编号: N26061118
期刊: Water Research
作者: Jia Pu, Shengrui Wang, Han Zhang, Zhaokui Ni, Yue Wu, Ying Guo, Xiaofei Liu
更新时间: 2026-06-11
摘要: Algal blooms (ABs) intensify the internal transformation of phosphorus, yet limited understanding of sedimentary organic phosphorus (SPo) and algal organic phosphorus (APo) has constrained insight into phosphorus feedback in eutrophication. In this study, we comprehensively characterized SPo and APo compositions during an incubation experiment using solution 31P nuclear magnetic resonance (31P-NMR), Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and complementary techniques. A marked decrease in bioavailable orthophosphate monoester and diester in APo (1223.7 mg/kg, 25.3%), contrasted with minimal variation in SPo (22.7 mg/kg, 1%), highlighted the high biodegradability of algal-derived compounds. Moreover, FT-ICR-MS results showed that NaHCO3-extracted one-phosphorus atom (NaHCO3-1P) exhibited a higher degradation rate than NaOH-1P with both fractions being dominated by aromatic compounds (condensed aromatic and tannin-like). In contrast, aliphatic compounds (lipid-like and protein-like) were primarily generated both in NaHCO3-extracted two-phosphorus atoms (NaHCO₃-2P) and NaOH-2P compounds. The net loss of 100 Molecular Labile Boundary (MLB) units in NaHCO3-1P, coupled with a net gain of 54 MLB units in NaHCO3-2P points to the synthesis of 2P-bearing compounds via phosphorylation or pyrophosphorylation reactions. These changes were accompanied by decrease in the weighted-average modified aromaticity index (AI mod, wa), double bond equivalence (DBEwa) and nominal oxidation state of carbon (NOSCwa). The transformation dynamics of APo and SPo by microbial activities (enzymatic hydrolysis and community succession) increased dissolved organic phosphorus (DPo) levels and enhanced the fluorescence and autochthonous character of dissolved organic matter in the overlying water. Overall, ABs enhanced internal organic phosphorus transformation, with 17.8% of APo partitioning into 13.3% DPo and 4.5% SPo, indicating a positive internal phosphorus feedback mechanism in lakes. This study elucidates the internal phosphorus cycling driven by frequent ABs and provides a basis for targeted eutrophication mitigation.

13. 题目: Impact of plastic pollution on agricultural soil: analysing extracellular polymeric substances (EPS) and morphological changes in microplastics with sludge amendments
文章编号: N26061117
期刊: Journal of Soils and Sediments
作者: Priyanka Singh, Murugesh Shivashankar, Natarajan Chandrasekaran
更新时间: 2026-06-11
摘要: This comparative study explores how microplastics (MPs) polyethylene (PE), polystyrene (PS) and polyvinyl chloride (PVC) affect soil properties, production and the constituents of extracellular polymeric substances (EPS) in agricultural soil (AS) and sludge-amended agricultural soil (SAS). EPS, made of sugars, proteins, nucleic acids, and lipids, helps microbes survive tough conditions.

14. 题目: Chemical structure of soil organic carbon governs formation, stability, and carbon accumulation of soil aggregates under contrasting land uses
文章编号: N26061116
期刊: Journal of Soils and Sediments
作者: Kiattisak Sonsri, Sudathip Kimsia, Penpichcha Sareewong, Yutthana Phankamolsil, Napaporn Phankamolsil, Akira Watanabe
更新时间: 2026-06-11
摘要: Purpose This study aimed to elucidate how the chemical structures of soil organic carbon (SOC) govern the formation, stability, and carbon accumulation of soil aggregates under different land uses. Methods Soil samples were collected from seven representative land uses: cassava plantation (CVP), orchard (OR), sugarcane plantation (SP), corn plantation (COP), forest (FR), pasture (PT), and abandoned land (AL). Soil aggregates were separated into distinct size classes (> 2000, 500–2000, 250–500, 53–250, and < 53 μm), aggregate stability was assessed using mean weight diameter (MWD) and geometric mean diameter (GMD), and SOC accumulation within aggregate fractions was quantified. The chemical composition of SOC was characterized using 13C cross-polarization/magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy. Results The results revealed pronounced land use-dependent differences in soil aggregation and SOC distribution. The PT land use exhibited a greater proportion of macroaggregates (> 2000 μm; 70% of total), higher aggregate stability (3.6 and 1.4 mm for MWD and GMD, respectively), and higher SOC accumulation in macroaggregate fractions (13.3 mg C g− 1). Whereas, the CVP resulted in greater SOC accumulation in microaggregates (53–250 μm; 10.9 mg C g− 1). The 13C CPMAS NMR results revealed that O-alkyl C was the major C group in the > 2000 μm fraction (23 − 42%), whereas aromatic C was the major C group in the 53 − 250 and < 53 μm fractions (29 − 47% and 35 − 54%, respectively). The formation, stability, and SOC accrual in macroaggregates were positively associated with O-alkyl C and alkyl C components, reflecting the importance of labile organic inputs and chemically hydrophobic features, respectively. Conversely, SOC accumulation in smaller aggregate fractions was positively correlated with aromatic C, suggesting preferential accumulation of recalcitrant compounds. Conclusions Overall, these findings suggest that land uses with perennial vegetation, such as PT, enhance soil structural stability and SOC accumulation compared to intensively managed croplands, with these advantages being associated with the chemical composition of SOC.

15. 题目: Biochar and Compost Amendments Reduce Heavy Metal Accumulation and Enhance Nutritional Quality in Tomato Fruits (Solanum Lycopersicum) under Contrasting Managements
文章编号: N26061115
期刊: Water, Air, & Soil Pollution
作者: Sara Gaida, Sondes Helaoui, Youssef Amor, Iteb Boughattas, Hanem Grissa, Mohamed Banni, Sabrine Hattab
更新时间: 2026-06-11
摘要: The use of organic amendments such as biochar and compost has gained increasing attention as a sustainable strategy to improve soil fertility, crop productivity, and reduce heavy metal accumulation in agricultural systems. This study evaluated the effects of biochar, compost, and their combination on the agronomic, biochemical, and physiological responses of tomato plants (Solanum lycopersicum) grown under field conditions in organic and conventional soils. Four treatments were applied: untreated soil (Control), soil amended with 2% w/w biochar, soil amended with 1% w/w compost, and a mixture of 2% biochar + 1% compost (w/w). A comprehensive assessment included soil physicochemical properties, vegetative growth traits, fruit micronutrient and heavy metal concentrations, and antioxidant enzyme activities. The results showed improvements in soil properties, particularly a 3% increase in soil organic matter under the combined treatment. Plant responses varied with treatment and soil type. Chlorophyll a and b increased under all amendments, while oxidative stress markers decreased in shoots and roots, indicating improved stress tolerance. Yield and fruit dry matter significantly increased in conventional soil under all treatments, with gains of 10–20% compared with the control. However, a slight yield reduction occurred under the combined treatment in organic soil. Compost application enhanced fruit micronutrient concentrations, whereas heavy metal levels decreased across all treatments. Overall, the combined application of biochar and compost shows strong potential as a sustainable fertilization strategy that improves soil quality, enhances tomato productivity, and reduces heavy metal accumulation in fruits under contrasting soil management systems.

16. 题目: Synergistic Effects of Nano-Gypsum, Biochar, and Microbial inoculants on Salt Leaching and Soil Reclamation of Saline-Sodic Soils
文章编号: N26061114
期刊: Water, Air, & Soil Pollution
作者: Tirunima Patle, S K Sharma, H S Jatav, S K Trivedi
更新时间: 2026-06-11
摘要: To explore the potential of nanotechnology in soil reclamation and enhance gypsum efficiency for sustainable agriculture, we examined individual and combined treatments of nano-gypsum (NG), biochar, and microbial inoculants (Trichoderma harzianum and Pseudomonas fluorescens) for effective soil reclamation of saline-sodic soil. The experiment comprised nine treatments, with nano-gypsum (NG) applied at three levels, both alone and in combination with biochar and microbial inoculants, along with a conventional gypsum-based reference treatment (Control, GR). The treatments were incubated for 15, 30, and 45 days. Subsequently, a soil column leaching experiment was conducted to evaluate the synergistic effects of the different amendments on leachate and soil characteristics. Findings reveal that Treatment T9 (NG at 45% GR combined with biochar and microbial inoculants yielded a significant increase in leachate concentrations of Ca²⁺ (9.54%), Mg²⁺ (17.10%), Na⁺ (34.1%), and sodium adsorption ratio (35.01%) compared to GR as compared to individual treatment of biochar, microbial inoculants and NG. The increase in both Ca²⁺ and Na⁺ in the leachate indicates active dissolution and ion exchange, resulting in the release and removal of displaced Na⁺. Simultaneously, the combined amendments significantly reduce soil electrical conductivity, influencing the concentrations of Ca²⁺, Mg²⁺, and Na⁺ ions in the soil. An increase in cation exchange capacity accompanied the reduction in exchangeable sodium percentage and SAR, primarily attributed to biochar application, while nano-gypsum enhanced ion exchange processes through Ca²⁺ mediated Na⁺ displacement. This treatment was the most effective in reclaiming soil compared to the conventional gypsum treatment. The study highlights the potential for enhanced sodium-calcium balance in the soil, showcasing improved soil quality, mitigated salinity-related issues, and improved soil properties.

17. 题目: Soil indicators and changes in organic matter under organic, natural, and conventional coffee production in the Brazilian Atlantic Forest
文章编号: N26061113
期刊: Agriculture, Ecosystems & Environment
作者: Victória Alvarenga Rios, Vanessa Maria de Souza Barros, Hugo Felipe da Silva, Jônatas Pedro da Silva, Humberto Josué de Oliveira Ramos, Eric Batista Ferreira, Teogenes Senna de Oliveira
更新时间: 2026-06-11
摘要: This study evaluated of C and N stocks, organic matter fractions, molecular composition and microbial diversity of coffee plantations under conventional, natural and organic management, all 22 years old. The systems differed in inputs: mineral fertilization and herbicides (conventional), absence of external inputs and association with native vegetation and legumes (natural) and manure plus organic residues (organic). Soil was sampled under the canopy and between rows at multiple depths. Compared to natural vegetation, C and N stocks decreased by 25.66 and 29.67% in the conventional system, 33.71 and 31.35% in the natural system, and 24.53 and 21.17% in the organic system. Natural vegetation had the highest total C and N stocks, particularly in the mineral-associated and particulate organic matter fractions. Dissolved organic matter was lower in the organic system, which also had the highest litter biomass and root density. The stabilization of soil organic matter was associated with substrate quality, including the presence of lipids, cutin, lignin, and alkanes with C chains ranging from 14 to 26 atoms. Microbial diversity varied, with more fungi in natural system and gram-negative bacteria in organic and natural systems. Natural and organic management are viable alternatives to conventional management in coffee plantations following the conversion of forests in the Atlantic Forest biome.

18. 题目: Synergistic effects of biochar and probiotic fermentation agent on soil aggregate stability, carbon sequestration, and heavy metal(loid)s passivation in paddy fields
文章编号: N26061112
期刊: Agriculture, Ecosystems & Environment
作者: Keqi Zhao, Xue Yu, Xifeng Qin, Ruijie Li, Lin Luo, Xiaomei Yang, Liuqin He, Anwei Chen, Jiachao Zhang, Hongli Huang, Xichen Zhao
更新时间: 2026-06-11
摘要: Agricultural soils become more widely acknowledged as significant potential carbon sinks and pollution buffers. It is still a significant problem to concurrently improve soil carbon sequestration and immobilize heavy metal(loid)s through management strategies. This study employed the organic materials input strategies using biochar (B, rice husk biochar manufactured at 500℃, 1350 kg/ha), probiotic fermentation agent (PFA, major components are Bacillus subtilis and Bacillus licheniformis, 45 L/ha), and combination (BPFA) to investigate effects on carbon sequestration and passivation. Fertilization strategies improved soil physicochemical and biochemical properties, and promoted an increase in the distribution of macroaggregates. Probiotic fermentation agent enhanced carbon storage in macroaggregates and the mean weight diameter. Biochar had an average reduction in bioavailability (CaCl2-extractable) of 34.3% for Cr, 34.8% for Cd, and 23.5% for Pb. Probiotic fermentation agent decreased As, Pb, Cd, and Cr in grain by 18.8%, 10.9%, 23.2%, and 41.1%. The combination strategy reduced the bioavailability of Cd, Cr, and As by 14.5%, 94.9%, and 79.7%, and decreased the heavy metal(loid)s content in grain. Fertilization strategies modified the distribution of heavy metal(loid)s speciation in soil aggregates, making them more stable and less available to rice. PFA and BPFA mitigated soil carbon and nitrogen limitations. Soil carbon sequestration rate is linked to the stability of aggregates. Redundancy analysis showed that the primary factors that affected greenhouse gas emissions were the carbon- and nitrogen-acquisition enzyme, and microbial biomass phosphorus levels. Heavy metal contamination was the primary limiting factor, whereas enzyme activity was the key driver of carbon sink function. These findings provide a scientific basis for developing management practices aimed at carbon sequestration and pollution control in agricultural systems.

19. 题目: Adsorption and oxidation of Mn(II) at the organo-ferrihydrite coprecipitate-water interfaces: Implications for Mn geochemical behavior and carbon stability
文章编号: N26061111
期刊: Geoderma
作者: Xing Xia, Chenxi Zhou, Yongyi Zhang, Huaiyan Zhao, Guodong Fang, Jianjun Yang, Xiangwei Wu
更新时间: 2026-06-11
摘要: Adsorption and oxidation of Mn(II) on Fe oxides plays a crucial role in controlling the behavior of Mn in soils. Additionally, Fe oxides are often associated with ubiquitous organic matter (OM) through coprecipitation to form organo-Fe oxide coprecipitates, which improves the stability of OM. However, the adsorption and oxidation of Mn(II) at the coprecipitate-water interfaces and its impact on the stability of OM fraction in the coprecipitates remain unclear. Here, citric acid (CA), a common OM in soil, was used to synthesize CA-ferrihydrite coprecipitates (CFCs), and the interactions between Mn(II) and CFCs were investigated using batch experiments and multiple spectroscopies. Results suggested that the coprecipitated CA promoted Mn(II) adsorption by ferrihydrite under anoxic conditions, but it decreased Mn(II) removal by ferrihydrite under oxic conditions through inhibiting Mn(II) oxidation, particularly at high Mn(II) concentration and CA loading. This was attributed to the fact that the CA suppressed the electron transfer from adsorbed Mn(II) to O2 by complexing with Mn(II) and increasing the charge transfer resistance of ferrihydrite, and reduced the formed Mn oxides (e.g., hausmannite and manganite). In turn, 8.2%-16.0% of OM in the CFCs was oxidized into CO2 after Mn(II) removal under oxic conditions. However, the stability of remaining OM in the CFCs was improved, as suggested by the increase of nonextractable C. This was due to additional OM binding sites and physical protection provided by the formed Mn oxides or Mn(II) bridging. These findings facilitate the understanding of Mn(II) adsorption-oxidation at the organo-Fe oxide composite–water interfaces, which aids in assessing the geochemical behavior of Mn and OM stability in soils.

20. 题目: Bayesian uncertainty analysis of soil organic carbon stocks and stock changes from croplands in the U.S. Midwest
文章编号: N26061110
期刊: Geoderma
作者: Ram B Gurung, Stephen M Ogle, F.Jay Breidt, Shannon Spencer
更新时间: 2026-06-11
摘要: Quantifying uncertainty in process-based model predictions is essential for evaluating confidence in model predictions and identifying priorities for model improvements. This study applied a Bayesian model analysis framework to quantify and partition multiple sources of uncertainty in DayCent model estimates of soil organic carbon (SOC) stocks and stock changes (0–30 cm) for croplands across the U.S. Midwest from 1990 to 2020. The region gained SOC at an average rate of 10.38 (95% prediction interval (PI) of 4.37–17.83) Tg C year−1, equivalent to 0.27 (95% PI of 0.11–0.46) t C ha−1 year−1 or a relative increase of 0.46% (95% PI of 0.42%–0.57%). Using Monte Carlo simulation, total predictive uncertainty was decomposed into four components: composite structural uncertainty, parameter uncertainty, input uncertainty associated with management practice adoption, and spatial scaling uncertainty associated with National Resources Inventory (NRI) sample design. At the point level, uncertainties for SOC stocks and stock changes were 29.5 and 11.7 t C ha−1, respectively, while at the regional scale they were 10.6 and 0.09 t C ha−1. Uncertainty decomposition showed that the composite structural component was the dominant source of uncertainty for regional SOC stock changes (57.5%), followed by parameters (38.8%), inputs (3.2%), and scaling (0.5%). For SOC stocks, parameter uncertainty dominated at the regional scale (69.8%), followed by composite structural uncertainty (26.0%), inputs (3.7%), and scaling (0.6%). Furthermore, temporal aggregation substantially reduced uncertainty, stabilizing the level of reduction after approximately five years of averaging, whereas spatial uncertainty required aggregation of a relatively large number of sites, about 5,000 to 10,000 sites, to reduce the uncertainty to a stable level. These findings highlight two approaches to reduce parameter and composite structural uncertainties in model-based assessments: advance model development to improve process representation and expand the quantity and quality of SOC observations.