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81. 题目: Chemical-biological suitability of biochar for peat, lime and fertilizer replacement in horticultural substrates
文章编号: N26090802
期刊: Journal of Cleaner Production
作者: Bart Vandecasteele, Simon Craeye, Kristof Gheysens, Peter Melis, Hanne Denaeghel, Krzysztof Kusnierek, Rianne Visser, Dries Vandamme
更新时间: 2026-09-08
摘要: Growing media in horticulture face sustainability challenges due to extensive use of non-renewable and single-use materials. Peat is an excellent bulk material but is under pressure for environmental and economic reasons. Existing peat replacements include wood fibers, coir and bark products. Potential peat replacements include biochars, composts and plant fibers, but their composition is highly variable depending on feedstock and production processes. The chemical and biological properties of biochars may therefore limit their potential use as bulk material in horticultural substrates. Insight is needed into the fit between biochar type in terms of feedstock and their use in horticulture, i.e., as peat replacement in growing media. More than 150 samples, including 75 biochar samples and more than 75 samples of peat, coir and feedstock materials to produce biochar, were scored based on eight chemical or biological characteristics. Suitability of biochars and their feedstocks for use in growing media blends was assessed using the Peat, Lime and Fertilizer replacement Index. Defining subcategories of feedstock and production process, assessed per batch, further refined the suitability assessment by reflecting the range of variability within the same type of material. Wood-based, fiber-based and bark-based biochars, organic spent growing media and straw-like plant fibers received the highest scores for the Peat, Lime and Fertilizer replacement Index, indicating high potential for use in horticultural substrates. Digestate-based or manure-based biochars and other nutrient-rich subcategories received low scores, with the inorganic C content and electrical conductivity being major bottlenecks for most nutrient-rich materials. The high acid buffering capacity of manure-based materials due to high content of inorganic C limits their application as peat replacement but indicates their potential to replace fossil lime and fertilizers when applied in a sufficiently low dose. In conclusion, different biochars should be selected according to their specific functional properties and intended role in growing media, rather than being considered interchangeable peat substitutes.

82. 题目: Temporal Amplification of Microbial Necromass Contribution to Soil Organic Carbon Under Nutrient Addition
文章编号: N26090801
期刊: Global Biogeochemical Cycles
作者: Peng Zhang, Yue Li, Chenyang Zhang, Nan Sun, Andong Cai, Minggang Xu
更新时间: 2026-09-08
摘要: Nutrient inputs can simultaneously regulate microbial necromass formation and soil organic carbon (SOC) accrual, but whether the contribution of microbial necromass to SOC changes over time under nutrient addition, and whether this temporal dependence differs among residue components remains unclear. We synthesized 303 paired observations of microbial necromass and SOC from 50 global studies to quantify the coupling between SOC responses and the responses of total necromass carbon (TNC), fungal necromass carbon (FNC), and bacterial necromass carbon (BNC), and to test how these relationships changed with experimental duration. Across nutrient input types, combined mineral and organic inputs produced the strongest responses, nitrogen, phosphorus, and potassium fertilization combined with manure increasing TNC, FNC, BNC, and SOC by 42.91%, 40.86%, 51.34%, and 44.01%, respectively. Microbial necromass responses were the strongest predictors of SOC responses, yet necromass increased more rapidly than SOC, indicating that enhanced residue production did not translate proportionally into persistent SOC accrual. The contribution of BNC to SOC was comparatively time independent and was mainly regulated by nutrient type. The contribution of FNC showed a convergent trend over time and was significantly influenced by ecosystem type. In contrast, the experimental duration significantly amplified the contribution of TNC to SOC. These findings indicate that long‐term SOC sequestration is an emergent system property arising from the time‐dependent coordination of distinct stabilization pathways. Accounting for this temporal dependence can refine microbial carbon pump theory and provide a globally relevant basis for improving long‐term soil carbon sink projections and nutrient‐management strategies under global change.

83. 题目: Co-application of biochar and microalgae improves soil quality and crop performance in saline-alkali soils
文章编号: N26090713
期刊: Environmental Technology & Innovation
作者: Chao Ma, Ranran Zhou, Yiwei Shang, Yule Sun, Ai Wang, Lei Wang, Xueru Pan, Prashanth Prasanna, Tao Tang, Zhongyi Qu
更新时间: 2026-09-07
摘要: Integrating stable organic amendments with microbial biofertilizers represents a promising strategy for soil health restoration and environmental sustainability. However, the specific mechanisms by which interactions between biochar and microalgae regulate crop growth and soil quality remain insufficiently understood, particularly in saline-alkali agroecosystems. Here, we conducted a three-year field experiment (2020–2022) in saline-alkali soils of Hetao Irrigation District, Inner Mongolia, to evaluate the individual and combined effects of biochar (0 and 30 t ha−1, denoted as B0 and B3) and microalgae (0, 30 and 60 L ha−1, denoted as M0, M3 and M6) on soil quality index (SQI) and plant growth, and to elucidate the mechanisms enhancing agroecosystem sustainability. Results showed that the co-application of biochar and microalgae fertilizer significantly improved soil physical properties, nutrient contents, and microbial activity by 5.2%-26.4%, 23.3%-86.8%, and 19.2%-26.9%, respectively, ultimately increasing SQI by 119.1% relative to untreated soil. Concurrently, the combined treatment increased plant growth and biomass accumulation to a greater extent than either amendment alone, indicating a beneficial combined effects on crop performance under saline-alkali conditions. Mechanistic analyses revealed plant growth-related traits were strongly and positively associated with SQI, underscoring the central role of soil quality in shaping crop performance, with carbon accumulation emerging as an important factor associated with these improvements. In parallel, the concurrent improvements in soil quality and crop performance contributed to a 58.0% increase in soil-crop system sustainability. Overall, our findings offer a scientific basis for developing effective management strategies to restore soil quality and advance sustainable agriculture in saline-alkali ecosystems.

84. 题目: Adsorption and immobilization of antimony (Sb) in aqueous and contaminated-soil by lanthanum-manganese modified biochar
文章编号: N26090712
期刊: Journal of Environmental Chemical Engineering
作者: Yi Li, Chijian Tang, Yu Gao, Ziang He, Fangming Yu, Rifeng Wu
更新时间: 2026-09-07
摘要: Lanthanum-manganese modified biochar (LM@PBC) was synthesized from peanut shell biochar via oxidative co-precipitation for antimony (Sb(III)/Sb(V)) adsorption in water and immobilization in soil. The material exhibited amorphous La(OH)3/Mn3O4 loading, with high surface area (176.83 m2/g) and abundant functional groups. LM@PBC showed maximum adsorption capacities of 36.68 mg/g for Sb(III) at pH 6.0 and 41.57 mg/g for Sb(V) at pH 2.0, representing 7.9- and 5.8-fold improvements over pristine biochar, respectively. Adsorption was effective across pH 2–10 and in the presence of coexisting anions. The adsorption kinetic followed the pseudo-second-order model, and isotherms were well described by both Langmuir and Freundlich models, indicating a predominantly monolayer chemisorption alongside heterogeneous multilayer adsorption. Mechanism studies revealed that Sb(V) was removed mainly through complexation with La/Mn hydroxyl groups and electrostatic attraction, whereas Sb(III) removal involved electrostatic attraction, complexation, and oxidation to Sb(V) by Mn (IV) followed by dissolution and re-adsorption. In soil, LM@PBC amendment (0.5–2.5 wt%) reduced acid-extractable Sb by 9.41–10.86% and increased residual Sb by 3.26–6.95%. Enhanced dehydrogenase (+57.9%) and catalase (+66.7%) activities indicated microbial redox processes promoted Sb transformation, while suppressed acid phosphatase (-24.91%) reduces competitive adsorption with phosphorus. The core immobilization mechanisms of Sb include complexation with surface hydroxyl groups, coprecipitation with lanthanum (oxyhydr)oxides, and Mn(IV)-driven oxidation of Sb(III) to Sb(V) with subsequent adsorption and stabilization. This work presents a synergistic “manganese oxidation-lanthanum fixation” composite effective in both aqueous and soil systems, revealing adsorption and immobilization pathways for Sb.

85. 题目: Inverse modeling and coupled analysis of soil moisture content and organic carbon in oasis areas of arid regions
文章编号: N26090711
期刊: Agricultural Water Management
作者: Zihan Zhang, Jinjie Wang, Jianli Ding, Jinming Zhang, Liya Shi, Xiangyu Ge
更新时间: 2026-09-07
摘要: Soil moisture content (SMC) and soil organic carbon (SOC) are important environmental factors influencing ecosystem stability and vegetation growth in arid regions. However, the synergistic evolution mechanisms of soil water and carbon, as well as the inversion of deep soil properties, remain insufficiently understood. This study selected the Weigan-Kuqa River Delta Oasis as the study area and integrated multi-source remote sensing data from Sentinel-1 and Landsat with field-measured samples, while combining the Bootstrap-Optimized Shrinkage (BOSS) feature selection algorithm to optimize variable combinations, Multi-layer soil water-carbon inversion models, including convolutional neural networks (CNN), long short-term memory (LSTM) networks, and CNN-LSTM, were constructed, and geographically weighted regression (GWR), bivariate Moran’s I, and coupling coordination degree models were used to analyze the spatial relationships between soil water and carbon.The results indicate that: (1) The CNN-LSTM model achieves the best performance in multi-depth inversion, with the highest accuracy at the 0–10 cm layer (SMC: R2=0.72; SOC: R2=0.74), and the accuracy gradually decreases with increasing depth; (2) Both SMC and SOC exhibit significant spatial heterogeneity, with SMC increasing and SOC decreasing with soil depth. The spatial distribution of both variables showed a pattern of “higher values in the oasis center and lower values at the edges.” (3) The soil water-carbon relationship exhibited clear vertical differences, with a significant correlation in the surface layer that gradually weakened with depth. The bivariate Moran’s I reached a maximum of 0.83, indicating strong spatial clustering between the two variables; however, the overall coupling coordination level still has room for improvement. This study provides methodological support for multi-depth remote sensing inversion of soil properties in arid regions and enhances the understanding of water-carbon interaction mechanisms in oasis ecosystems.

86. 题目: ORYZA model development for soil organic carbon dynamics and greenhouse gas emissions: Module description and sensitivity analysis
文章编号: N26090710
期刊: Agricultural Water Management
作者: Tao Li, Emmali A Manalo, Hannah W Jose, Olivyn R Angeles, Ando M Radanielson, Ligia B Azevedo
更新时间: 2026-09-07
摘要: Rice cultivation contributes substantially to global greenhouse gas (GHG) emissions, accounting for ~10% of anthropogenic methane (CH₄), highlighting the need for process-based mitigation tools. Existing versions of ORYZA simulate crop growth, water and nitrogen dynamics, but do not explicitly represent soil carbon and nitrogen transformation and GHG emissions, limiting their use for mitigation planning and Tier 3 inventories. In this study, ORYZA was extended with soil carbon and nitrogen biogeochemical and GHG emission module. The resulting ORYZA 3.5 version concurrently simulates rice growth, soil organic carbon and nitrogen dynamics, and CH4/N2O/CO2 emissions. Using experimental data from irrigated rice systems at IRRI (2023–2024), the model was applied to (i) evaluate crop and soil parameter effects on yield, SOC, and GHG emissions; (ii) quantify sensitivities via Adaptive Sobol’ analysis; and (iii) characterize non-linear parameter effects and interactions using Shapley Additive exPlanations (SHAP). An ensemble was generated using ±25% parameter perturbations, and machine-learning surrogate models were trained to emulate model outputs. Results indicated that soil hydraulic properties exerted the strongest control on yield and biomass. Seasonal CH₄ emissions were primarily influenced by methanogenesis potential, soil bulk density, and decomposition parameters, whereas SOC dynamics were dominated by initial SOC/soil organic nitrogen (SON) stratification and crop carbon allocation. SHAP analysis revealed substatial nonlinearities and parameter interactions. Trade-off analysis showed that 22–38% of parameter combinations achieved higher yield with lower CH₄ emissions with statistically robust frequencies (SE = 0.0022–0.0026). The ORYZA v3.5 provides a basis for Tier 3 GHG estimation, carbon accounting, and climate-smart rice management.

87. 题目: Aromatic carbon from low-temperature biochar enhances bacterial phosphorus solubilization under saline-alkaline stress
文章编号: N26090709
期刊: Bioresource Technology
作者: Ziyi Ge, Shiyun Gan, Jiayi Li, Ziyue Xu, Siyu Wang, Xu Su, Yixuan Chen, Li Lin, Song Gao, Jun Meng
更新时间: 2026-09-07
摘要: Co-applying biochar with phosphate-solubilizing bacteria (PSB) holds promise for ameliorating severely degraded ecosystem productivity due to low phosphorus (P) bioavailability in saline-alkaline soils. However, their interaction on how biochar reshapes microbial metabolism function remains poorly understood. Here, low/high-temperature biochar (BC300 and BC700) were utilized to explore the possible mechanism on biochar derived carbon-driven cell's metabolic characteristics in terms of P-solubilization optimization. Specifically, BC300 at 15,000 mg/L was prominent in P-solubilization level over 37.0% of the control rather than BC700 (decreased by 21.4%). Consistent with this divergence, BC300 exhibited significantly higher DOC (108.9 vs. 21.5 mg/L) and SUVA254 values (4.3 vs. 0.9) than BC700. Metabolic-transcriptomic revealed up-regulated the PhoR/PhoB two-component system, enhancement of aromatic amino acid metabolism alongside suppressed ribosome biosynthesis and citrate cycle in BC300. Further detection on targeted LC-MS confirmed a 12.8-fold increase in extracellular maleic acid (28,571.2 ng/mL). Meanwhile, BC300 also improved stress defense supported by increase in extracellular polymeric substances and superoxide dismutase activity. Collectively, these findings suggest the pivotal role of low-temperature biochar in modulating microbial metabolic response to phosphorus deficiency under saltine-alkaline stress, which is possibly associated with aromatic-rich DOC that drives organic acid overflow and stress defense, thereby sustaining efficient P-solubilization.

88. 题目: Straw conversion to soil organic carbon: A global quantitative synthesis using isotopic tracers and machine learning
文章编号: N26090708
期刊: Soil and Tillage Research
作者: Wen-Sheng Liu, Zhi-Heng Qin, En-Ze Hu, Bai-Jian Lin, Cong He, Yash Pal Dang, Yakov Kuzyakov, Pete Smith, Rattan Lal, Xin Zhao, Hai-Lin Zhang
更新时间: 2026-09-07
摘要: Soil organic carbon (SOC) sustains ecosystem productivity, soil health, and sequesters atmospheric CO2. Straw return (StrawR) effectively compensates for carbon (C) losses by SOC mineralization in croplands. Quantifying the straw-derived SOC and straw conversion efficiency (SCE; the percentage of straw C converted to SOC) enables a direct assessment of C sequestration potential. This study integrates 13C isotopic tracer data with machine learning approaches to evaluate straw-derived SOC and SCE. A random forest model was further used to identify the key environmental and management drivers controlling straw-derived SOC and SCE, and to extrapolate their spatial patterns at the global scale. Straw-derived SOC content decreased over time, primarily due to the relative accumulation of recalcitrant compounds. Such dynamics are typically mediated by changes in microbial metabolic strategies in response to shifting resource availability. Random forest analysis identified StrawR amount, straw particle size, and soil bulk density (BD) as the key drivers of straw-derived SOC content (IncMSE percentages: 42%, 20%, and 19%, respectively). High soil BD potentially reduces soil aeration and suppresses microbial metabolic capacity, reducing C sequestration. Machine learning predictions indicate a straw C residual ratio of 17 ± 3.4% after 1 year and a global average SCE of 10 ± 1.1% after 5 years of StrawR, which supports our hypothesis that initial StrawR practices elevated C sequestration potential and SCE compared with prolonged StrawR application. Assuming 100% global adoption, StrawR offers a theoretical maximum biophysical potential of 1.7 Pg C yr−1 over five years. This maximum capacity would theoretically offset 52% of agricultural CO2 emissions and 16% of total anthropogenic CO2 emissions. This study addresses critical gaps in straw conversion dynamics and updated estimates of C sequestration capacity, highlighting the contribution of StrawR as a climate change mitigation strategy.

89. 题目: Differentiating molecular fingerprints of dissolved organic nitrogen between natural soil and iron-based sorption media for stormwater treatment
文章编号: N26090707
期刊: Water Research
作者: Jinxiang Cheng, Andrea Valencia, Diana Ordonez, Amy M McKenna, Ni-Bin Chang
更新时间: 2026-09-07
摘要: Dissolved organic nitrogen (DON) remains a significantly under-investigated component in the disruptive nitrogen cycle especially in different soils or specialty adsorbents that can efficiently remove inorganic nitrogen after pollution when simultaneously retaining, removing and remaking DON. The complexity of DON fate, transport, and transformation processes in low impact development infrastructure design is still a pending question for stormwater treatment. To compare different DON degradation pathways and clarify inherent complexity, we integrated paired influent–effluent column experiments with Fourier transform ion cyclotron resonance mass spectrometry, molecular descriptor and zonation analyses, fate-resolved reaction inference, Kendrick mass defect-based network analysis, and depth-resolved nitrogen-cycling gene profiling to examine DON transformation in natural soil, biosorption activated media (BAM), and two iron-filings-based green environmental media (IFGEM1 and IFGEM3) under three nitrate–phosphate loading conditions. Across the three nutrient-loading conditions, IFGEM1 and IFGEM3 achieved NOx-N (NO₃⁻-N + NO₂⁻-N) removal efficiencies of 98.6–99.2% and 98.9–99.9%, respectively, while their effluents showed systematic shifts in the assigned CHON formula pool. Relative to natural soil, IFGEM effluents showed lower relative contributions of condensed aromatic-like formulas and higher contributions of protein/amino sugar-like formulas, together with greater formula richness and stronger separation in molecular descriptor space, most notably for IFGEM3. Natural soil increasingly retained a lignin-rich, oxidizing–saturated DON pool as loading increased, whereas IFGEM3 promoted greater removed-to-produced turnover and concentrated newly produced DON in reducing–saturated chemical space under higher loading. Increasing N and P loading also redistributed inferred transformation portfolios: natural soil and BAM retained broader, more mixed reaction spectra, whereas IFGEM1 and IFGEM3 shifted towards more selective pathway combinations. KMD-derived formula-association networks showed broader cross-class connectivity in IFGEM3 than in natural soil, with the network edges interpreted as putative molecular linkages rather than confirmed transformations. Pre-spiking qPCR profiles showed depth-dependent differences in baseline nitrogen-cycling gene abundances. Overall, iron-based engineered media were associated with systematic restructuring of the detectable DON molecular composition across the tested nutrient-loading conditions.

90. 题目: Seasonal dynamics of dissolved organic matter along an intertidal gradient in semi-arid mangrove soils (New Caledonia)
文章编号: N26090706
期刊: Biogeosciences
作者: Naïna Mouras, Cyril Marchand, Maximilien Mathian, Hugues Lemonnier
更新时间: 2026-09-07
摘要: . Mangrove ecosystems play a key role in the global carbon cycle notably through the production, transformation, and export of dissolved organic matter (DOM). If DOM export to adjacent ecosystems is well studied, its dynamics in mangrove soils remain poorly understood. In this study, DOM quantity and quality were investigated in semi-arid mangroves with no external organic matter input, developing along an intertidal gradient: a salt-flat, an Avicennia marina stand, and a Rhizophora stylosa stand. Soil and porewater samples were collected during both wet and dry seasons, and analysed for physicochemical parameters, total and dissolved organic carbon (TOC, DOC), chromophoric and fluorescent dissolved organic matter (CDOM, FDOM), and mineralogical composition. Our result show distinct DOM quantity and quality between habitats. The Rhizophora stylosa stand, characterized by daily tidal immersion and the lowest salinity, presented high and stable DOC concentrations throughout the year. The dominance of one humic-like fluorescent component suggests that soil DOM is primarily mangrove-derived. In this stand, tidal fluctuations are a major cause for continuous Fe reduction-oxidation cycles, which can influence DOM dynamics. In the salt-flat and the Avicennia marina stand, which suffer from water stress due to their position, significant seasonal variations were measured with higher DOC concentrations during the wet and warm season as a result of enhanced microbial activity. In these stands due to a more open canopy cover, DOM shows a stronger contribution from microbial production, as evidenced by enhanced microbially-derived fluorescent component. In addition, photodegradation can occur. These findings provide new insights into DOM cycling in mangrove soils and highlight the combined effects of zonation and seasons.

91. 题目: Qualitative transformations of dissolved organic matter along supra-permafrost flow: insights from Arctic subterranean estuaries
文章编号: N26090705
期刊: Biogeosciences
作者: Aude Flamand, Jean-François Lapierre, Gwénaëlle Chaillou
更新时间: 2026-09-07
摘要: . Increasing coastal erosion and permafrost thaw along the Arctic shoreline represent major lateral sources of dissolved organic matter (DOM) to the Arctic coastal ocean. One key and still underrecognized flow path is non-point source supra-permafrost groundwater flow discharging through sandy beaches in front of coastal bluffs. Here, we explore the qualitative transformations of DOM and dissolved organic carbon (DOC) along this flow path, with a focus on the beach discharge zone, where fresh supra-permafrost groundwater mixes with recirculated seawater. We sampled meltwater, beach groundwater, and seawater along coastal bluff transects extending up to 0.5–1 km offshore. Along these salinity and redox gradients, DOC and chromophoric DOM (CDOM) declined sharply, partially reflecting dilution. Optical indices (a350, SUVA254, HIX) and PARAFAC-based fluorescence analyses revealed a shift from humic-like, high molecular weight (HMW) DOM in meltwaters to protein-like, low molecular weight (LMW) DOM in nearshore waters. The inverse relationship between humic- and protein-like components, combined with reactive Fe-hydroxide coatings on sandy sediments, elevated dissolved iron (Fetot) and high dissolved inorganic carbon (DIC) under low oxygen conditions in beach groundwater, suggests that microbial degradation and mineral-organic interactions likely contribute to DOM transformation. Alongside these transformation processes, mixing governs bulk DOC behaviour. These findings suggest that nearshore and intertidal zones, particularly subterranean estuaries (STEs), are zones of DOM transformation along the Arctic coastline. However, whether they act primarily as transient filters, long-term carbon sinks, and/or dynamic biogeochemical reactors remains unresolved, highlighting the need for further research on their role in transferring permafrost-derived carbon to the ocean.

92. 题目: Organic carbon pathways across the fluvial-marine transition zone of the Mackenzie River Delta – Beaufort Sea region and implications on ocean color remote sensing
文章编号: N26090704
期刊: Biogeosciences
作者: Annabeth McCall, Martin Hieronymi, P Paul Overduin, Lisa Bröder, Julie Lattaud, Rüdiger Röttgers, Irina Overeem, Anne Morgenstern, Guido Grosse, Bennet Juhls
更新时间: 2026-09-07
摘要: . Arctic warming and hydrological intensification are accelerating permafrost thaw and increasing the export of terrestrial organic carbon (OC) and sediments from land via rivers and shallow coastal waters into marine waters, yet the fate of these materials in deltaic and coastal transition zones remains poorly understood. Here, we synthesize multiyear in-situ biogeochemical, optical, and radiometric observations (2009–2024) across the Mackenzie River Delta – southern Beaufort Sea land – ocean continuum. By using a compartmental approach (river, delta, coastal, marine) we quantify spatial and seasonal variability in dissolved organic carbon (DOC), particulate organic carbon (POC), and suspended particulate matter (SPM) and refine bio-optical relationships that support satellite retrievals in optically complex Arctic waters. Our results show that DOC concentrations declined from river to marine waters (mean 4.8 to 1.9 mg L−1), while POC and SPM showed more variability with marked reductions across the transition, consistent with retention and transformation processes in deltaic and nearshore zones. Across all compartments, DOC exhibited a strong non-linear relationship with CDOM absorption at 443 nm (aCDOM(443); r2=0.81), whereas POC related linearly to particulate absorption at 443 nm (aP(443); r2=0.73), with substantial compartment-dependent differences in slope and fit strength that indicate shifting OC composition and optical regimes along the salinity gradient. Optical Water Type (OWT) classification derived from remote sensing reflectance (Rrs) resolved transitions from turbid, particle-dominated waters to clearer coastal and marine regimes, providing a framework for guiding algorithm selection and improving retrieval performance. These results provide the first concurrent, Arctic fluvial-marine assessment of DOC, POC, SPM, and optical properties while demonstrating how land–sea connectivity governs both organic carbon processing and optical structure in Arctic coastal waters.

93. 题目: The Stratified Microbial Carbon Pump: Thermal Stratification Enhances Refractory Dissolved Organic Carbon Production and Stabilizes Carbon in Alkaline Karst Waters through Keystone Microbial Interaction Networks
文章编号: N26090703
期刊: Biogeosciences
作者: Yikun Jia, Junbing Pu, Zaihua Liu, Qiufang He, Xinlu Su, Tao Zhang, Jianhong Li, Sibo Zeng
更新时间: 2026-09-07
摘要: . Recalcitrant dissolved organic carbon (RDOC) represents a persistent fraction of the carbon pool and contributes substantially to regional carbon budgets in terrestrial aquatic ecosystems. Given the substantial carbon sequestration potential of karst waters, elucidating the dynamics and persistence of RDOC is essential for understanding carbon retention in these geologically distinctive environments. Karst reservoirs represent important yet highly complex components of regional carbon cycling. Here, RDOC accumulation and its underlying mechanisms were examined in the Dalongdong (DLD) Reservoir, a dissolved-carbon-rich karst water body, over three contrasting thermal phases: incubating thermal stratification (ITS), obvious thermal stratification (OTS), and mixing (MX). Our results revealed that RDOC dynamics were predominantly regulated by microbial processes rather than benthic carbon inputs. The establishment of thermal stratification generated pronounced physicochemical gradients that facilitated vertical niche partitioning among keystone taxa, thereby regulating DOM bioavailability through taxon-specific metabolic pathways. Bacterial network analysis further indicated that facilitative interactions favored the generation of labile carbon, whereas competitive interactions under environmental stress promoted RDOC accumulation. Notably, the distinctive geochemical conditions of the karst system facilitated Ca–P co-precipitation, resulting in persistent phosphorus limitation and an elevated C:P ratio in the water column. This nutrient imbalance reduced microbial carbon use efficiency and suppressed extracellular enzyme activities, consequently favoring the conversion of autochthonous labile carbon into more persistent RDOC. Collectively, these findings suggest that the synergistic coupling of the biological carbon pump (BCP) and microbial carbon pump (MCP), reinforced by geochemical phosphorus sequestration, represents an important mechanism underlying long-term carbon retention in alkaline, calcium-rich aquatic systems. Our findings further demonstrate that karst-specific geochemical conditions interact with thermal stratification to regulate microbial processes governing carbon persistence. In particular, MCP efficiency appears to be modulated by carbonate-weathering-derived dissolved inorganic carbon (DIC), providing mechanistic insights into the enhanced carbon sequestration capacity of geologically distinctive inland waters. Protecting these highly efficient carbon-sequestering ecosystems may therefore contribute to atmospheric CO2 removal and provide an additional pathway for advancing global climate mitigation.

94. 题目: Terrestrial organic carbon processing and dispersal on a high-energy, river-dominated margin
文章编号: N26090702
期刊: Biogeosciences
作者: Evan R Flynn, Valier Galy, Manuel Colombo, Steven A Kuehl
更新时间: 2026-09-07
摘要: . The Ayeyarwady and Thanlwin Rivers deliver ~1.9 Mt y-1 of particulate terrestrial organic carbon (TerrOC) to the Northern Andaman Sea making them one of the largest sources of TerrOC to the world ocean. Offshore, fluvial material is extensively mixed by tides and estuarine circulation in the Gulf of Martaban, concurrently incorporating marine organic carbon. While previous bulk stable isotope analyses have suggested that frequent resuspension enhances TerrOC degradation, limiting burial on high-energy margins, in this study we use ramped pyrolysis/oxidation (RPO) and radiocarbon analysis to identify high and uniform TerrOC content (by Wt. %) in continental shelf sediments offshore of the Ayeyarwady Delta. By analyzing sediment samples from the river mouths and across the shelf, RPO results demonstrate consistent radiocarbon and stable carbon isotope composition (δ13C) of TerrOC from the Gulf of Martaban to the mid-shelf clinoform depocenter, suggesting that extensive degradation does not occur during shelf transport. Instead, rapid remineralization and processing of labile material likely occurs near-shore, while refractory terrestrial components are efficiently transported to the mid-shelf depocenter. Given δ13C values of refractory TerrOC fractions that mimic marine sources, we suggest that offshore TerrOC content has been substantially underestimated by bulk δ13C-based mixing models. Providing a new conceptual framework for organic carbon preservation in this globally significant offshore delta, these findings indicate the necessity of re-evaluating our understanding of TerrOC processing on high-energy, river-dominated margins, and support recent hypotheses that these systems provide a larger sink for TerrOC than previously suggested.

95. 题目: Radical-enhanced humification of straw-impregnated biogas slurry toward artificial humic acid fertilizer
文章编号: N26090701
期刊: Bioresource Technology
作者: Shisheng Song, Hui Qin, Tangjuan Zhang, Yixuan Jia, Wenjuan Niu, Aibin Hu, Ping Ai
更新时间: 2026-09-07
摘要: The residual biogas slurry (BS) generated after straw impregnation contains dissolved lignocellulosic fragments and other humification precursors but remains insufficiently utilized. Here, a mild radical-enhanced humification strategy was developed to convert post-impregnation BS into a humic acid (HA)-like product at room temperature. An alkaline persulfate (PS) activation system using citrate (CA)-chelated Fe2+ was established to promote the oxidative transformation and subsequent condensation of soluble organic precursors. Under the selected conditions (1.0 g KOH, 3.0 g PS, 0.75 g Fe2+, and 1.0 g CA per 100 mL BS), the HA yield reached approximately 13.3 g/L. Electron paramagnetic resonance and quenching experiments confirmed that sulfate and hydroxyl radicals were the dominant reactive species. Spectroscopic analyses demonstrated that radical oxidation preferentially transformed labile proteinaceous, polysaccharide-derived, and aliphatic fractions into reactive oxygenated intermediates, which subsequently underwent aromatic coupling, condensation, and polymerization to form humic-like macromolecules. In a bok choy pot experiment, the HA product produced greater plant length, root development, and biomass than untreated BS and mineral HA. Overall, this study provides a rapid, room-temperature approach for upgrading residual BS into a value-added HA-like product and supports the integrated utilization of straw and anaerobic-digestion effluents.

96. 题目: Application-dependent effects of tea waste biochar on PFAS mobility and N2O and CH4 emissions in agricultural soil
文章编号: N26090615
期刊: Waste Management
作者: Liting Hao, Dongdong Zhang, Ziheng Zhao, Jun Wang, Ruofei Wang, Miao Li
更新时间: 2026-09-06
摘要: Per- and polyfluoroalkyl substances (PFAS) in agricultural soils can migrate into crops and may alter soil greenhouse gas emissions, yet remediation strategies rarely address these risks simultaneously. This study evaluated tea waste biochar (TWB) produced at 400, 500, and 600 °C and applied at 5–20 g per pot by whole-soil mixing or surface-layer placement in a simulated PFAS-contaminated soil-leachate-plant system. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) distributions, nitrous oxide (N2O) and methane (CH4) fluxes, and microbial responses were examined. TWB produced at 500 °C showed the most favorable combination of pore accessibility, surface hydrophobicity, and interfacial charge, with material-associated PFOS and PFOA enrichments of 0.12 and 0.57 μg/g, respectively. Whole-soil mixing with TWB-500 lowered soil and leachate PFAS levels and reduced PFAS concentrations in plant shoots by approximately 36% relative to the contaminated control. TWB treatments also reduced cumulative N2O emissions and enhanced net CH4 uptake. Metagenomic analysis showed lower relative abundances of genes associated with nitrogen fixation, ammonia oxidation, and several N2O-producing pathways, whereas CH4-cycling genes responded differently to the two application methods. Organic fluorine transformation genes were not enriched, indicating that PFAS control mainly resulted from physicochemical retention rather than enhanced microbial defluorination. Overall, TWB-500 can integrate PFAS stabilization with greenhouse gas management, but the optimal placement depends on the remediation objective: whole-soil mixing favors PFAS immobilization, whereas surface-layer application provides greater greenhouse gas mitigation.

97. 题目: Phosphate-solubilizing bacteria-loaded biochar alleviates microplastic–cadmium co-contamination by reshaping the soil phosphorus cycling network
文章编号: N26090614
期刊: Journal of Environmental Chemical Engineering
作者: Meng Wang, Yan Chen, Yue-Liang Meng, Shan-Shan Gao, B Larry Li, Yu-Ying Li, Xue-Min Ren, Hui Han, Ling Liu, Zhao-Jin Chen
更新时间: 2026-09-06
摘要: Phosphorus (P) is essential for soil–plant–microbe interactions. However, increasing co-contamination by heavy metals and microplastics (HMs–MPs) severely disrupts soil phosphorus cycling. Although microbial–biomaterial-based remediation has emerged as an environmentally friendly strategy for soil restoration, its performance under combined HMs–MPs stress remains largely unexplored. In this pot experiment, we investigated the effects of phosphate-solubilizing bacteria (PSB)-loaded biochar on rhizosphere microbial communities and phosphorus cycling under polyethylene (PE), cadmium (Cd), and combined PE–Cd contamination. Under combined PE–Cd contamination, PSB-loaded biochar significantly increased plant biomass, reduced Cd concentrations in plant tissues, improved soil physicochemical properties, and enhanced phosphorus availability by increasing TP, labile P, and moderately labile P fractions. Metagenomic analysis revealed that PSB-loaded biochar reshaped the rhizosphere microbial community, enriched phosphorus-cycling taxa, and increased the abundance of phosphorus-cycling genes under contaminated conditions. Among the six major phosphorus-cycling pathways, Gaiella was strongly associated with polyphosphate synthesis and organic phosphorus mineralization, whereas Sphingomicrobium, Sphingomonas, and Luteitalea were positively associated with polyphosphate degradation and phosphorus transport. Spearman correlation analysis demonstrated coordinated responses between phosphorus-cycling functional genes and dominant bacterial genera, both positively correlated with soil nutrients and crop biomass but negatively correlated with Cd contamination indicators. Mantel tests further revealed significant associations between key bacterial genera (Gaiella and Nocardioides) and soil phosphorus pools, suggesting that these taxa coordinately regulate soil remediation and crop growth. Overall, PSB-loaded biochar effectively mitigated the adverse effects of combined PE–Cd contamination by enhancing phosphorus cycling and reshaping the rhizosphere microbiome, providing a promising strategy for remediating microplastic–heavy metal co-contaminated soils.

98. 题目: Microbial inoculation and temperature regulate mineral-associated organic carbon formation in technosols: molecular-level insights into distiller’s grains transformation
文章编号: N26090613
期刊: Geoderma
作者: Yujia Tang, Hui Sun, Jiang Yu, Shuangchao Wang, Wenqing Chen, Junxi Li
更新时间: 2026-09-06
摘要: Whether mineral-associated organic carbon (MAOC) formation follows the same molecular pathways when the organic input is a pre-fermented industrial residue — already enriched in microbial metabolites — as when it is fresh plant litter remains unknown. Here, we investigated MAOC formation during transformation of distiller’s grains (DG; C/N = 3.78), a pre-fermented baijiu waste, in Technosols with a defined mineral matrix (quartz, montmorillonite, goethite, boehmite) under factorial manipulation of microbial inoculation and temperature (15, 25, 35 °C) over 120 days. Multi-analytical characterisation (density fractionation, Py-GC/MS, FTIR, selective dissolution, amino sugar biomarkers, amplicon sequencing) revealed three principal findings. First, microbial inoculation at 25 °C increased MAOC by 23.6 % (to 18.85 g C/kg), with microbial necromass carbon most strongly associated with MAOC in exploratory analyses. Notably, the MNC/MAOC ratio (0.50–0.60) substantially exceeded values reported for natural soils (0.30–0.45), consistent with a shortened microbial processing sequence in which DG’s pre-existing metabolites elevate the MNC/MAOC ratio. Second, MAOC formation showed a mineral-selective pattern not previously reported in model soil systems: organo-iron complexes (Fep) correlated strongly with MAOC (r = 0.84, p < 0.01), while aluminium phases showed no significant treatment response, indicating that iron oxide transformation — not aluminium — was the mineral phase most strongly associated with MAOC stabilisation under fermentation waste inputs. Third, elevated temperature (35 °C) not only reduced net MAOC through substrate depletion but shifted necromass composition (FNC/BNC declined from 1.32 to 1.64 to 0.92–0.95) and triggered necromass decline after Day 60. Partial-correlation analysis further indicated that MAOC was preferentially associated with bacterial necromass despite a fungal-dominated pool, and TG-DSC thermal-stability data indicated that the inoculated, N-rich MAOC was thermally the least stable, consistent with an early, transient accumulation state rather than long-term stabilisation. These results suggest that the MCP framework, while fundamentally applicable, requires a “substrate processing history” dimension to account for pre-fermented inputs, and that iron-bearing minerals should be prioritised in Technosol design for fermentation waste valorisation.

99. 题目: Vertical convergence of soil dissolved organic matter composition across Central European landscapes
文章编号: N26090612
期刊: Geoderma
作者: Christina Fasching, Mansour Ahmadi Foroushani, Kyle Sampson Boodoo, Annika Feld-Golisnki, Nikolai Späth, Christian Reinhardt-Imjela, Peter Chifflard
更新时间: 2026-09-06
摘要: Soil dissolved organic matter (DOM) plays a critical role in terrestrial carbon cycling and its transfer to aquatic systems, yet its vertical dynamics, particularly in deeper soil layers, remain poorly understood. We investigated water-soluble organic matter (WSOM) composition, used here as a proxy for soil DOM composition, in ∼1,500 soil samples from 330 cores across four Central European regions (Ore Mountains, Tyrolean Alps, Black Forest, Sauerland). Samples were collected from profiles extending to 4 m and analyzed using absorbance and fluorescence spectroscopy coupled with Parallel Factor Analysis (PARAFAC). Dissolved organic carbon (DOC) concentrations declined with depth, while DOM composition shifted toward greater protein-like contributions, consistent with intensified microbial reworking of organic matter. DOM exhibited vertical structuring: upper layers differed regionally, mid-depth layers (11–100 cm) showed the highest compositional heterogeneity, and deeper layers (101–400 cm) converged toward remarkably similar signatures across all regions. Depth was the dominant driver of DOM composition, outweighing regional context, land use, and topography. The observed convergence is consistent with microbial reworking of DOM at depth. These findings highlight deep soils as a reservoir of transformed DOM that likely influences groundwater chemistry and baseflow DOM export to streams. These depth-dependent patterns underscore the importance of subsoil processes in shaping the composition of terrestrial–aquatic carbon fluxes. By combining extensive spatial coverage with deep soil profiles, our study provides a comprehensive assessment of vertical DOM composition in temperate soils and highlights the need to incorporate deep soil dynamics into models of carbon cycling and hydrological connectivity.

100. 题目: Techno-economic analysis of farmer-scale biochar production from agricultural residues in the U.S. Corn Belt: A comparison of three low-cost kiln architectures
文章编号: N26090611
期刊: Bioresource Technology
作者: Francis Asare, Rado Gazo, Jue Mo, Eva Haviarova, Henry J Quesada, Shams R Rahmani, Francis W Owusu, Shristi S Saraugi, Winny Routray
更新时间: 2026-09-06
摘要: Decentralized, farmer-scale biochar production can valorize agricultural residues for soil amendment and carbon storage while avoiding the feedstock-transport burden of centralized pyrolysis. This study compared three low-capital, field-deployable kiln architectures for an on-farm self-supply user: an open flame-curtain Traditional Oregon Kiln (TOK, Type A), a Controlled-Draft Flame-Curtain Kiln (CDFC, Type B), and an Indirect-Heat Fine-Feedstock Retort (IHFRt, Type C). A unified techno-economic model was parameterized with experimental yields and charring times for corn cob, corn stalk, and sorghum stover (n=15 batches per kiln). At a 50kg batch, 100dyr−1 of operation, a wage of 16.50USDh−1, and a 7% discount rate over a 10-yr life, the estimated minimum selling prices (MSP, oven-dry basis) were 3.06USDkg−1 (Type A), 2.60USDkg−1 (Type B), and 1.74USDkg−1 (Type C). Capital cost was small (876–1416 USD, <3% of levelized cost), whereas labor contributed more than 95% and dominated sensitivity. Type C achieved the lowest MSP because its passive charring phase decoupled operator hours from conversion time, raising biochar output per labor hour by 80%. Against the 3USDkg−1 to 5USDkg−1 U.S. retail price for comparable specialty biochar, Type C undercut even the low end and Type A remained competitive at the upper end. A 10,000-draw Monte Carlo preserved the Type C < Type B < Type A ranking in 99.9% of draws. A paired life-cycle assessment of kiln emissions and the soil-organic-carbon foregone by residue removal is the necessary next step before net climate benefits can be claimed.