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321. 题目: Meta-analysis reveals the processes and conditions of using biochar to control antibiotic resistance genes in soil.
文章编号: N25051801
期刊: Journal of Environmental Management
作者: Dishen Li, Pinjie Su, Mingbo Tang, Yanzhong Yao, Guohui Zhang
更新时间: 2025-05-18
摘要: Soil is a significant reservoir of antibiotic resistance genes (ARGs) and an important habitat for pathogens associated with many clinical infections and plant disease outbreaks. Although scientists have found that biochar can reduce ARGs in soil, the understanding of how biochar removes soil ARGs and the influencing factors remains limited. Here, a meta-analysis of 65 published studies was conducted to illuminate the mechanisms through which biochar remediates ARG-contaminated soils. In biochar-amended soil, the antibiotic content significantly decreased by 24.1 %, while the abundances of mobile genetic elements and ARG host bacteria declined by 23.5 % and 12.1 %, respectively. The reduced antibiotic content, suppressed mobile genetic elements, and altered bacterial community structure collectively led to a 41.8 % reduction in soil ARG abundance. In addition, wood-derived biochar pyrolyzed at 300-500 °C exhibited a substantial advantage in the remediation of ARGs. Furthermore, biochar application decreased the abundance of ARGs in alkaline and neutral soil more markedly than that in acidic soil. The results of this research confirmed the positive mitigating effect of biochar on ARGs in soil, providing valuable insights for the prevention and control of ARG pollution.

322. 题目: Observationally Constrained Wintertime Emission Fluxes and Atmospheric Lifetime of Black Carbon in South Asia
文章编号: N25051710
期刊: Environmental Science & Technology Letters
作者: Sanjeev Dasari, August Andersson, Sang-Woo Kim, Henry Holmstrand, Krishnakant Budhavant, Örjan Gustafsson
更新时间: 2025-05-17
摘要: Black carbon (BC) aerosols perturb the climate and affect air quality/human health. In the highly populated and heavily polluted South Asian region, the wintertime modeled atmospheric abundance of BC has remained underestimated relative to surface observations. We hypothesize this is linked to underestimated (i) atmospheric lifetime (τ_BC) and/or (ii) regional emission fluxes of BC. To address this hypothesis, we developed a novel inversion framework combining multiwinter (2018–2020) hourly resolved BC and carbon monoxide (CO) measurements from a wide footprint site in the North Indian Ocean, intercepting wintertime South Asian outflow. The average ΔBC/ΔCO ratio in this continental outflow of 14 ± 5 ng m^–3 ppb^–1 was 2–3 times higher than in East Asian outflow and shows a profound regional wintertime presence of BC. The empirically derived τ_BC of 8 ± 0.5 days was higher than global-mean τ_BC of 5.5 days employed in climate models and suggests greater regional longevity of wintertime BC. The ΔBC/ΔCO inversion-estimated ‘top-down’ BC emission flux of ∼200 Gg/month was in fact higher by a factor of ∼1.5 than wintertime monthly BC emission flux from scaled ‘bottom-up’ emission inventory (∼125 Gg/month). Taken together, assimilating higher BC emissions with greater longevity seems promising to reconcile the model-observation offset of wintertime BC abundance for South Asia.

323. 题目: Synergistic Power of Polyaniline Decorated Rauvolfia tetraphylla Fruit Biochar Hybrid in Smart Eriochrome Black T Remediation and Antibacterial Application
文章编号: N25051709
期刊: ACS ES&T Water
作者: Priyanka Priyadarsini Samal, Jhilirani Mohanta, Adrija Ghosh, Debashmita Mandal, Saumyashree Nayak, Banashree Dey, Dipankar Chattopadhyay, Soumen Dey
更新时间: 2025-05-17
摘要: Polymer-decorated composites for wastewater purification and bactericidal applications are of interest. Accordingly, the polyaniline decorated Rauvolfia tetraphylla fruit biochar (PANI@RTFB) composite was synthesized for Eriochrome black T (EBT) scavenging and bactericidal application. PANI@RTFB was characterized through BET surface area, SEM-EDX, FTIR, pH_zpc, and PXRD. A porous (BET surface area of 6.741 m²/g), quasi-crystalline nature, and COVID-19 virus-like architecture were seen from SEM. Polyaniline coating was confirmed from FTIR, and pH_zpc was found to be 8.59. A maximum removal of 93.37% EBT from simulated and 52.68% from wastewater was achieved within 60 min with 30 mL of 20 mg/L EBT, pH 7, and 298 K temperature. With an uptake capacity of 110.236 mg/g, PANI@RTFB enjoys an edge over reported adsorbents. The Langmuir (R²=0.996) and the pseudo-second-order (R² = 0.999) models were fitted best. The endothermic (ΔH = 16.302–18.188 kJ/mol) and favorable (ΔG = −1.182 to −5.346 kJ/mol) uptake occurred through H-bonding, electrostatic, and π-π interaction mechanisms. 50% methanol regenerates spent in up to 75.75%. The waste disposal issue was addressed by conversion to a new adsorbent with 64% efficiency. At a 20 mg/mL dose, PANI@RTFB reduced Staphylococcus aureus and Escherichia coli colonies by 56.90% and 73.17%. The PANI@RTFB ruptured the cell membranes of bacteria through electrostatic and hydrophobic interactions.

324. 题目: Effects of nitrogen and phosphorus additions on soil particulate organic carbon through altering microbial decomposition in two tropical montane rainforests
文章编号: N25051708
期刊: Plant and Soil
作者: Kai Dong, Zixin Chen, Suhui Ma, Xuemei Yang, Wenao Wu, Danhua Zhang, Chen Yang, Fan Fan, Jiangling Zhu, Chengjun Ji, Jingyun Fang
更新时间: 2025-05-17
摘要:

Background and aims

Nutrient availability affects soil microbial activity, thereby regulating soil carbon (C) formation, turnover and storage. Anthropogenic nitrogen (N) and phosphorus (P) inputs are altering soil nutrients, but their consequences for soil organic carbon (SOC) and its components in P-limited tropical forests are poorly understood.

Methods

We conducted a 13-year-long nutrient addition experiment in two tropical montane forests to investigate the effects of N and P additions on soil particulate organic carbon (POC) and mineral-associated organic carbon (MAOC).

Results

Long-term high-N addition increased soil POC concentration and its contribution to SOC through altering edaphic conditions (i.e., soil acidification and nutrient imbalance) and suppressing microbial biomass C together with activity of lignin-modifying enzymes. However, P addition had minor effects on POC pool, which was mainly attributed to alleviate P limitation and stimulate microbial decomposition. In addition, N and P additions did not significantly change soil MAOC in both forests.

Conclusion

Our results indicated that soil microorganisms play key roles in regulating soil C cycling through extracellular enzymes under N and P additions, suggesting a necessity of incorporating it into the prediction of ecosystem C dynamics under global change.

325. 题目: Deciphering the Energy Use Channels in Soil Organic Matter: Impacts of Long-term Manure Addition and Necromass Revealed by LC-FT-ICR-MS
文章编号: N25051707
期刊: Soil Biology and Biochemistry
作者: Konstantin Stumpf, Carsten Simon, Anja Miltner, Thomas Maskow, Oliver J Lechtenfeld
更新时间: 2025-05-17
摘要: Manuring of arable soils has been reported to increase soil organic matter (SOM) contents, microbial activity, and abundance of microbial metabolites, suggesting an increasing abundance of necromass markers in general. SOM’s chemical complexity hampers our understanding of mechanistic links between SOM transformation, necromass imprints, and energy storage. Non-targeted molecular-levels techniques can provide insight into SOM’s molecular composition, energetic fingerprint and effects of manuring. We compared water-extractable organic matter (WEOM) from long-term manured soils with a set of fresh plant, bacterial and fungal necromass extracts by liquid chromatography Fourier transform ion cyclotron resonance mass spectrometry (LC-FT-ICR-MS). Manuring increased WEOM complexity in polar, unsaturated, oxidised and energy-poor compounds. These changes were linked to a 2-3-fold increase in necromass markers. In comparison to unfertilized soil, manured WEOM was dominated by bacterial necromass markers over fungal ones, suggesting bacterial control of changes in WEOM’s energetic properties. Although unfertilized soils showed a smaller necromass imprint, fungal N-containing markers were present, suggesting a more dominant fungal energy use channel, and potential N mining. Despite the parallel shifts in necromass imprints and NOSC between soils, 83% of formulas were not assigned to any necromass, but explained most of the shift to a more bioavailable, oxidized and energy-poor WEOM via long-term manuring. This could suggest that manuring promotes the oxidation of pre-existing SOM not associated to fresh necromass (“priming”). Alternatively, this could point to a missing coverage of necromass compositional variability in our study. We demonstrate the potential of LC-FT-ICR-MS to complement classical necromass marker studies by reporting ∼600 novel, readily soluble microbial necromass markers, thereby providing an avenue to build comprehensive databases for a more robust annotation of SOM sources and transformation processes in the future.

326. 题目: Constraining the Composition and Biochemical Activity of Organic Carbon in a Large Eutrophic Estuary using Size-Fractionated Analysis
文章编号: N25051706
期刊: Environmental Research
作者: Zongqing Lv, Xiaotian Liu, Ding He, Xiangbin Ran, Yao Feng, Wenxuan Gao, Xiaosong Zhong, Nianzhi Jiao
更新时间: 2025-05-17
摘要: The presence of refractory dissolved organic carbon (RDOC) can result in the misestimation of organic pollution, and documentation regarding the characteristics of organic carbon (OC) and its relationship with pollution is limited. This study employed physical separation, biological incubation, and chemical analysis to examine the size-fractionated composition and bioavailability of OC in the Yangtze River Estuary, one of the most polluted estuarine areas in China. Results revealed that OC chemical features were highly diverse, with RDOC constituting approximately 65.8% ± 9.2% of dissolved organic carbon (DOC). During incubation, less than 10% of CHO molecules (molecules composed solely of carbon, hydrogen and oxygen atoms) identified by ultra-high resolution mass spectrometry were degraded. A significant positive linear relationship between OC and RDOC in size-fractionated OC indicated greater recalcitrance in smaller size fractions. The OC present in the >0.45 μm fraction was notably important for labile OC, including the particulate share of OC, which is relevant to chemical oxygen demand (COD) assessments. Excluding RDOC allows for a more accurate estimation of the contribution of labile OC to COD, as represented by the equation: COD_Labile = 0.47×COD_Bulk - 0.03. Approximately 0.44 ± 0.10 Gt of refractory OC, including 0.31 ± 0.07 Gt of RDOC, is transported annually into the ocean via rivers. This linear relationship of COD reveals an overestimation in current assessments of organic pollution and a neglect of RDOC`s role in carbon preservation, thereby necessitating a revision of the COD evaluation practices in estuaries. This study highlights the differentiated impacts of refractory and labile OC on the quantification of OC pollution in a large eutrophic estuary.

327. 题目: Fresh tephra deposits from the Tajogaite Volcano boost thermophile proliferation and soil organic matter recovery
文章编号: N25051705
期刊: Biogeosciences
作者: Sara Gutiérrez-Patricio, Alba Gómez-Árias, Pedro Nolasco-Jiménez, Jorge Matáix-Solera, Javier Martínez-Martínez, Bruno Martínez-Haya, Juana Vegas, Nicasio T Jiménez-Morillo, Ana Z Miller
更新时间: 2025-05-17
摘要: . Tephra fallout deposition during volcanic eruptions overlays existing soils, profoundly altering their physical, chemical, and biological properties. This study investigates the impact of the newly deposited tephra blanket from the 2021 Tajogaite eruption (La Palma Island) on the molecular composition of soil organic matter and microbial diversity across different soil horizons. A combination of 16S and 18S rRNA gene sequencing, pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and elemental and isotope ratio mass spectrometry (EA/IRMS) was employed. Our results demonstrate that tephra deposits significantly modify the organic matter composition of the underlying soils, promoting microbial activity linked to the degradation and transformation of organic carbon and nitrogen compounds. The soil horizon directly beneath the tephra layer (horizon O) displayed a higher abundance of labile organic compounds and a reduced presence of recalcitrant compounds compared to the deeper horizons (A and Bw). This pattern is strongly associated with the predominance of thermophilic bacteria, which contribute actively to the breakdown of complex organic materials such as lignin and hydrocarbons, and drive key biogeochemical processes including nitrogen and carbon cycling. The continuous geothermal influence of nearby fumaroles further supports the persistence and ecological success of thermophilic communities in these volcanic soils. These findings underscore the critical role of volcanic activity not only in reshaping soil structure but also in enhancing soil fertility and resilience through microbial-mediated processes. Understanding these dynamics is essential for soil management and ecosystem recovery strategies in volcanic regions, providing new insights into the long-term effects of tephra deposition on soil health and the carbon cycle.

328. 题目: Insight into the efficacy and mechanism of persulfate activation using KHCO3 modified biochar: The overlooked contribution of adsorption
文章编号: N25051704
期刊: Chemical Engineering Journal
作者: Xiting Yue, Xuantong Chen, Jin Kang, Yin Xu, Hui Zhang
更新时间: 2025-05-17
摘要: The annual production of waste herbal residue is substantial, and converting it into biochar for peroxydisulfate (PDS) activation to degrade emerging contaminants provides a promising approach for resource utilization. Whereas, the contribution of adsorption was frequently overlooked in this process. To address this issue, a family of KHCO₃ chemically modified waste-herb-derived biochars were prepared and KWBC-2 with KHCO₃ to waste herb residue mass ratio of 2: 1 shows an excellent adsorption and PDS activation performance. The adsorptive removal of bisphenol A (BPA) reached 97.0 % in 30 min at 0.3 g/L KWBC-2. By coupling with 1.0 mM PDS, the apparent removal of BPA increased to 98.3 %, from which 95.3 % of oxidative removal was distinguished. The BPA apparent removal is highly dependent on its liquid–solid mass transfer behavior with R² = 0.96. C–OH is identified as adsorption site of reactant (BPA or PDS) and active site for PDS activation by correlating the functional group content of biochar with mass transfer coefficient of reactant or oxidative removal of BPA. The KWBC-2/PDS system is dominated by electron transfer pathway and shows good tolerance to different water matrices. Its performance deteriorated to 45.5 % after three cycles, which could be largely recovered after thermal treatment, due to the complete regeneration of adsorption ability (96.7 %) and the partial restoration of catalytic activity (70.9 %). This study deepened the fundamental understanding on the adsorption and electron-transfer pathway in biochar activated persulfate advanced oxidation process.

329. 题目: Single-step synthesis of nitrogen and phosphorus co-doped biochar and its application in dye removal: synergistic effects of adsorption and peroxymonosulfate activation
文章编号: N25051703
期刊: Environmental Research
作者: Yixuan Shi, Mingfeng Yin, Dong Liu, Xingrui Gao, Xiao Liu, Tengteng Yang, Zuoping Zhao, Xiaohui Ji, Caibin Zhao, Xianzhao Shao
更新时间: 2025-05-17
摘要: In the field of advanced oxidation processes (AOPs), the development of catalysts with environmental friendliness and economic benefits faces multiple difficulties, mainly reflected in the catalytic efficiency, selection specificity, and complexity of the synthesis process. This study, we reported a nitrogen and phosphorus co-doped carbon catalyst (CANP800-1) synthesized by a one-step pyrolysis method. The co-doped catalyst was able to achieve 100% removal of Acid Orange 7 (AO7) in about 30 minutes and had a high apparent rate constant (k_obs = 0.125 min^-1), which is better than unmodified carbon and other single-doped comparative materials. Structural analyses pinpointed that N, P co-doped enhanced specific surface area (1179 m²/g), introduced abundant mesopores, and created a wealth of active sites (such as graphitic nitrogen, C-P bonds) synergistically promoting adsorption and peroxymonosulfate (PMS) activation. The CANP800-1/PMS system had significant adaptability to various water matrices, including pH, coexisting ions, natural organic matter, and real water conditions. A mechanistic investigation confirmed that singlet oxygen (¹O₂) was essential to the reaction process, while electrochemical studies and DFT simulations validated that N/P-induced enhancement of electron transfer and PMS adsorption took place. This study established an innovative metal-free catalytic system that exhibited remarkable effectiveness in sustainable water treatment, providing distinctive solutions and a theoretical basis for ongoing technical difficulties in industrial wastewater treatment.

330. 题目: Co-application of nitrification inhibitors with straw or biochar yielded varying effects on soil nitrification rate, N2O emissions, and ammonia oxidizers
文章编号: N25051702
期刊: Journal of Soils and Sediments
作者: Xiaoqian He, Jiaju He, Hongjie Shen, Zhuo Zeng, Di Zhao, Cen Cheng, Minghua Zhou, Ting Lan
更新时间: 2025-05-17
摘要:

Purpose

Nitrification inhibitors (NIs) are effective in reducing nitrification rates and nitrogen environmental losses. Yet, the combined effects of NIs with straw or biochar on soil nitrification and nitrous oxide (N₂O) production remain unclear.

Materials and methods

In this study, we performed an aerobic ¹⁵N microcosm incubation experiment to compare the effects of a biological nitrification inhibitor (methyl 3-(4-hydroxyphenyl) propionate, MHPP) and a synthetic nitrification inhibitor (3,4-dimethylpyrazole phosphate, DMPP), both in combination with straw or biochar, on gross N nitrification rates and N₂O production rates.

Results and discussion

DMPP and MHPP significantly reduced gross nitrification rates by 54.7% and 31.2%, respectively. Sole biochar application increased soil nitrification rates 1.2 times while having a negligible impact on short-term N₂O emissions. The co-application of nitrification inhibitors with biochar mitigated the stimulatory effects on nitrification. Straw inhibited nitrification slightly and stimulated N₂O emission significantly (p < 0.05), while co-application of DMPP and MHPP enhanced the inhibitory effect on nitrification by 41.4% and 62.3%, as well as reduced higher N₂O emission. Nitrification inhibitors inhibited the abundance of the amoA gene in both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), and the communities of AOB were more sensitive to nitrification inhibitors than AOA.

Conclusion

Our findings indicated that combining nitrification inhibitors with straw or biochar can synergistically affect soil nitrification and N₂O emissions. Biochar co-applicated with DMPP showed the most significant effect on inhibiting nitrification and N₂O production, positively influencing soil inorganic N retention.

331. 题目: Transformation of dissolved organic matter during aquaculture wastewater treatment: Insights into the biological toxicity, spectral indices and molecular signatures
文章编号: N25051701
期刊: Water Research
作者: Feng Hu, Jianfeng Ye, Bingqing Wang, Wencan Zhang, Peipei Chen, Zhanzhan Yuan, Zuxin Xu
更新时间: 2025-05-17
摘要: China is a leading aquaculture producer globally and therefore, faces the critical challenge of effectively managing large volumes of aquaculture wastewater. In order to optimize treatment processes and evaluate the ecological risks from effluent discharge, it is important to understand the transformation of dissolved organic matter (DOM) and identify the key toxic components throughout the treatment process. This study focused on the ‘three ponds, two dams, one wetland’ (3P-2D-1W) treatment system, which has been widely adopted as an aquaculture wastewater treatment approach in China, investigating DOM transformation throughout the treatment process via spectroscopy, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and biotoxicity analyses. Correlation analysis indicated that biotoxicity was significantly positively correlated with dissolved organic carbon (DOC), chemical oxygen demand (COD), humification index (HIX) and modified aromaticity index (AImod_wa). Molecule-centered correlations identified aliphatic compounds and highly unsaturated phenolic compounds as the key contributors to DOM toxicity. In terms of treatment effect, the ‘three ponds, two dams’ (3P-2D) system was found to effectively reduce pollutants (59.4% DOC removal, 55.4% toxicity reduction) in aquaculture wastewater. After adding the constructed wetland module (3P-2D-1W), the treated effluent reached a DOC of 12.3 mg/L and an inhibition rate (represent for biotoxicity) of 7.16%, cleaner than the river water originally used for aquaculture (DOC 15.7 mg/L, inhibition rate 9.21%). However, the overall process showed limited selectivity for toxic compound removal. Additionally, the aeration pond exhibited redundancy and contributed to increased effluent toxicity. Analysis of potential reaction pairs revealed that the constructed wetland exhibited the highest diversity of reaction pairs (1953), with notable CHO group losses (489) and a significant increase in organic nitrogen transformation processes (±CHON, 293). This study provides novel insights into the rapid assessment indicators that can be leveraged to predict aquaculture wastewater pollution levels and offers strategic recommendations for optimizing the 3P-2D-1W treatment process.

332. 题目: Reclaiming saline-sodic land enhances soil organic carbon by altering network negative connectivity and complexity of specialists
文章编号: N25051610
期刊: Plant and Soil
作者: LiJun Zhang, Guixiang Zhou, Jiabao Zhang, Lin Chen, Donghao Ma, Congzhi Zhang
更新时间: 2025-05-16
摘要:

Background and aims

Increasing salinity and sodicity threaten soil fertility and crop yield worldwide and the accumulation of soil organic carbon (SOC) is a vital guarantee for soil improvement. However, there is still a gap in understanding how microbes influence the accumulation of SOC in saline-sodic land reclamation (converting saline-sodic land into cultivated land).

Methods

Herein, we conducted a survey of microbes in saline-sodic (solonetz) and cultivated soil collected from the Songnen Plain, and analyzed the impact of distribution patterns of niche breadth, microbial composition and multitrophic networks on SOC.

Results

Results showed saline-sodic land reclamation (reducing pH and EC) significantly increased SOC, niche breadth and microbial diversity of bacteria, fungi and protists. Microbes with significant narrow niche breadth (specialists), which associated over 85% underground connections especially negative connections, were extremely important of both network connectivity and SOC accumulation. SEM revealed that weakened negative connectivity and increased network complexity of specialists promoted the accumulation of SOC in saline-sodic land reclamation. Specialists explained 72.4% of the variance of SOC, higher than 61.3% of the whole community.

Conclusions

We demonstrated that specialists with high taxonomic diversity could facilitate SOC accumulation in saline-sodic land reclamation by strengthen multitrophic interactions. Our findings enhance the understanding of the effect of saline-sodic land reclamation on soil properties and microbial community and highlight the importance of integrating specialists into models of SOC accumulation, and these findings provide theoretical support for promoting SOC content in saline-sodic land reclamation.

333. 题目: Simultaneous adsorption of cadmium and arsenic by goethite-modified rice straw-derived biochar in water and soil: interactive ion effects and co-adsorption mechanism
文章编号: N25051609
期刊: Environmental Monitoring and Assessment
作者: Iftikhar Ali Ahmad, Hongqing Hu, Md Shoffikul Islam, Qingling Fu, Jun Zhu, Fei Miao, Muhammad Mehran, Sharjeel Haider, Zaryab Murad, Ayaz Ali
更新时间: 2025-05-16
摘要:

The coexistence of cadmium (Cd(II)) and arsenic (As(III)) has long been an environmental problem. Green and cost-effective biochar (BC) shows considerable potential for addressing environmental issues, including the concurrent elimination of cadmium (Cd(II)) and arsenic (As(III)) from water and soil after nano-sized goethite modification. However, the behavior of goethite-modified rice straw-derived biochar (GBC) during co-adsorption of Cd (II)) and As (III)) in the presence of competing ions and anoxic vs oxic environments is unclear yet. This experiment (GBC) was successfully synthesized to study co-adsorption and the effects of environmental factors on it. The adsorption kinetics and isotherms for the mixed adsorption of Cd(II) and As(III) onto GBC showed that the pseudo-2nd-order model (R² Cd(II) = 0.998, R² As(III) = 0.996) and the Langmuir model (R² Cd(II) = 0.982, R² As(III) = 0.997) were both correctly portrayed. The highest adsorption of As(III) was 87.38 mg/g, and Cd(II) was 71.07 mg/g in a single adsorption system, which is considerably more significant than the values of 68.6 and 48.38 mg/g, correspondingly, in the co-adsorption system. The competitive adsorption of Cd(II) and As(III) on GBC was primarily driven by co-precipitation and ion exchange. Its efficacy in soil systems under aerobic and anaerobic situations remained undisturbed. At the same time, the anaerobic environment favors Cd adsorption, and the aerobic environment favors more As remediation in an aqueous system. The interactive ions Ca²⁺ and Mg²⁺ significantly enhanced the adsorption of As(III). On the other hand, phosphate and humic acid significantly promote Cd(II) adsorption. In summary, the different environmental conditions revealed by this study help a deeper understanding of the behaviors of As and Cd by GBC.

334. 题目: Biochar impact on soil properties and soil solution nutrient concentrations under cotton production.
文章编号: N25051608
期刊: Journal of Environmental Management
作者: Ramandeep Kumar Sharma, Gurbir Singh, Amrinder Jakhar, Jagmandeep Dhillon, Saseendran S Anapalli, Kelly A Nelson, Gurpreet Kaur
更新时间: 2025-05-16
摘要: Intensive tillage and unsustainable agricultural practices adversely impact soil health and the long-term sustainability of crop production in humid subtropics. Biochar, a soil amendment, can be used to improve soil properties and agricultural productivity. A field experiment evaluated the impact of biochar application rates (B) (0, 10, 20, and 40 Mg ha-1) on soil properties and soil solution chemistry under rainfed cotton (Gossypium hirsutum L.) production systems in the Lower Mississippi Delta from 2020 to 2022. An application of 40 Mg ha-1 of biochar significantly reduced bulk density and increased water content in 0-15 cm compared to other rates and depths. Biochar increased aggregate stability compared to the control in the topsoil layer for aggregate fractions of size 0.5-1 mm and 1-2 mm in 2021. Biochar application at 20 and 40 Mg ha-1 reduced NO3-N concentration in soil by 63 % and 53 %, respectively, compared to the control at a 0-15 cm depth in 2021. Biochar applications reduced soil solution NO3--N losses 49 %-87 % and 42 %-102 % during the fallow period compared to the control at a 46 and 81 cm depth, respectively. Biochar also reduced the soil solution PO43--P concentration 14 %-39 % compared to the control in the fallow period. Biochar improved soil properties while reducing nutrient losses in the soil solution and has the potential to be an alternative soil amendment strategy for sustainable cotton production.

335. 题目: Temporal thresholds and depth-specific mechanisms of soil organic carbon stabilization during 65 years of revegetation in the Tengger Desert
文章编号: N25051607
期刊: Journal of Environmental Management
作者: Ting Zhang, Bin Niu, Yongli Wang, Zhifu Wei, Gen Wang, Xueyun Ma, Xinrong Li
更新时间: 2025-05-16
摘要: Revegetation is a widely adopted strategy to combat desertification and enhance soil organic carbon (SOC) storage in dryland ecosystems. However, the depth-dependent stabilization mechanisms of SOC and their temporal dynamics during long-term revegetation remain poorly understood, limiting accurate predictions of carbon sequestration potential. Here, we addressed this knowledge gap by applying sequential chemical extractions to quantify six operationally defined organic carbon (OC) fractions, reflecting different stabilization pathways, across three soil horizons over a 65-year revegetation chronosequence in the Tengger Desert. Our results show that the composition of SOC varies markedly with soil depth and revegetation age. In the organic horizon (Oh), SOC is primarily composed of residual OC (32 %–53 %) and metal-OC complexes (25 %–32 %). In the topsoil, the contribution of metal-bound OC (from 39 % to 22 %), carbonate-bound OC (from 26 % to 13 %), and iron oxide-bound OC (from 20 % to 6 %) decreases over time, while residual OC increases from 16 % to 54 %. In the subsoil, SOC consists mainly of carbonate-bound OC (27 %–58 %) and metal–OC complexes (21 %–34 %). We also identified clear temporal thresholds for accelerated SOC accumulation: after 34 years in the Oh and topsoil horizon, driven primarily by the increase in the residual OC, and after 57 years in the subsoil, due to higher contents of metal–OC complexes and residual OC. These thresholds are controlled by distinct factors across horizons—plants in the Oh horizon, biocrusts in the topsoil, and edaphic conditions in the subsoil. Our findings underscore the horizon-specific responses of SOC fractions to revegetation over time, offering mechanistic insights into SOC stabilization in drylands. This research provides a scientific basis for depth-targeted carbon management and emphasizes the importance of long-term revegetation in enhancing SOC storage in dryland ecosystems.

336. 题目: Carbon in river floodplains
文章编号: N25051606
期刊: Nature Climate Change
作者: Bronwyn Wake
更新时间: 2025-05-16
摘要:

Rivers play an important role in the transport and alteration of sediment and organic carbon. Yet, the role of floodplains in terrestrial carbon storage is poorly quantified as rivers vary in their erosion rates, transport and deposition of sediment, influenced by meanders, width and depth, among others.

To better understand what controls the timescales for carbon and sediment storage in river floodplains, Emily Geyman of the California Institute of Technology and co-authors used simulations, along with geomorphic mapping and dating techniques, applied to three Alaskan field sites with diverse characteristics. They show that the storage timescales can be predicted from the channel migration rate, channel width and the floodplain width.

337. 题目: Evaluating the potential of digestate-loaded biochar in improving soil biological health and plant nutrition with less greenhouse gas emissions
文章编号: N25051605
期刊: Environmental Pollution
作者: Yunyun Zheng, Lynette Abbott, Nanthi Bolan, Pankaj K Singh, Sasha N Jenkins, Bede S Mickan
更新时间: 2025-05-16
摘要: Digestate has a great potential as a carbon (C) and nitrogen (N) soil amendment. Loading digestate onto biochar can produce a C- and N- enriched biochar fertilizer (i.e., digestate-loaded biochar, DLB), and help to solve digestate-specific issues. This study aims to evaluate the potential of DLB at optimal application rates in keeping plant (annual ryegrass) nutrition level while mitigating greenhouse gas emissions and improving soil biological health compared to chemical fertilizers under liming or not. Soil biological health index was assessed through quantitative PCR and amplicon sequencing. The results showed that increasing DLB addition to 150 kg N ha^-1 resulted in a similar N uptake of ryegrass to that under urea despite lower mineral N provided by DLB. This application rate decreased greenhouse gas emissions relative to urea, through decreasing CO₂ emission despite increased CH₄ emission. Compared to urea, this DLB rate did not change N₂O emission, corresponding to the specifically increased abundance of nirK gene (1.3-fold) (and enriched denitrifier Dokdonella) for N₂O production and nosZ clade I and II genes (87%) for N₂O consumption. The DLB at 150 kg N ha^-1 enhanced soil biological health index by 1.4-fold relative to urea through increasing microbial abundances particularly fungi, enriching beneficial microbes (plant-growth-promoting bacteria, mycorrhiza and dark-septate-endophyte), and increasing fungal diversity; this effect was less pronounced under liming. This study concludes that DLB can serve as an organic-mineral fertilizer in maintaining plant nutrition while decreasing greenhouse gas emissions and enhancing soil biological health, offering a sustainable approach to managing organic waste.

338. 题目: Dissolved black carbon in full-scale drinking water treatment plants: Occurrence and contribution to disinfection byproducts formation and cytotoxicity
文章编号: N25051604
期刊: Journal of Hazardous Materials
作者: Haoran Chen, Jianwei Li, Chuze Chen, Xiating Zhao, Zongcheng Yao, Yuting Wang, Zhigang Li, Qiming Xian
更新时间: 2025-05-16
摘要: Dissolved black carbon (DBC) is a crucial precursor to disinfection byproducts (DBPs) in the drinking water disinfection process. However, the understanding of the presence and transformation of DBC within drinking water treatment plants (DWTPs) is still limited. This article systematically examined the presence and transport of DBC, in combination with the contribution to disinfection byproducts formation and cytotoxicity along the full-scale DWTPs. The results indicated that DBC concentrations varied from 70.0–199.4 μg/L in source water, 28.7–122.7 μg/L in sedimentation, 22.5–68.5 μg/L in carbon filter, 27.8–116.7 μg/L in sand filter and 7.2–23.0 μg/L in finished water. Sedimentation and disinfection processes resulted in higher DBC removal rates of 57% and 71% on average, respectively. DBC components with high aromaticity were predominantly removed during sedimentation, while DBC with low aromaticity was more likely to be removed during chlorination. DBC concentration had a significantly positive correlation with UV₂₅₄ absorbance throughout the entire treatment process. Additionally, although DBC in the source water constituted only 1–10% of the dissolved organic matter, DBC was estimated to contribute to 1–25% of the DBP formation and 1–20% of the cytotoxicity in the finished water. Hence, it is crucial to consider the possible risk of DBPs generated in the disinfection of DBC along the full-scale DWTPs.

339. 题目: Global Change Modulates Microbial Carbon Use Efficiency: Mechanisms and Impacts on Soil Organic Carbon Dynamics
文章编号: N25051603
期刊: Global Change Biology
作者: Jingwei Shi, Lei Deng, Jianzhao Wu, Yuanyuan Huang, Yajing Dong, Josep Peñuelas, Yang Liao, Lin Yang, Xingyun Huang, Hailong Zhang, Jiwei Li, Zhouping Shangguan, Yakov Kuzyakov
更新时间: 2025-05-16
摘要: Microbial carbon use efficiency (CUE) is a key parameter of initial microbial utilization of organic matter in soil. The responses of CUE to global change factors (GCFs) remain unclear due to their multiple effects and interactions. Here, this study generalized 385 observations obtained using various methods, including ¹³C-/¹⁴C-labeled substrates, ¹⁸O-labeled water, stoichiometric modeling, and others. The effects of climate change (drought, precipitation, warming), fertilization (nitrogen addition, phosphorus addition, potassium addition, and nitrogen fertilization combined with phosphorus and potassium), land use conversion, and natural restoration, were evaluated along with their 16 associated GCFs on CUE. CUE was insensitive to climate change factors and most fertilization practices, maintaining a mean value of 0.36 under global change scenarios. Farmland conversion to forest and vegetation restoration decreased CUE by 11% and 17%, respectively. Grassland restoration increased CUE by 41%, indicating that grasslands have high potential for soil carbon accrual. Nitrogen fertilization combined with phosphorus and potassium increased CUE by 18% because the combined application of nutrients allows plants to produce organic matter sources with high-quality and decreases nutrient limitations for microorganisms. Increase in soil pH induced by GCFs leads to higher CUE. The CUE was decoupled from soil organic carbon content under several global change scenarios (e.g., warming, fertilization), suggesting that this relationship is not universally consistent across GCFs. This study provides a new perspective on the responses of CUE to GCFs and deepens our understanding of the global change effects on microbial physiology with consequences for soil carbon cycling.

340. 题目: Parent material geochemistry – and not plant input – as the primary element shaping soil organic carbon stocks in European alpine grasslands
文章编号: N25051602
期刊: Biogeosciences
作者: Annina Maier, Maria E Macfarlane, Marco Griepentrog, Sebastian Doetterl
更新时间: 2025-05-16
摘要: . Soils represent the largest terrestrial carbon (C) reservoir on Earth. Within terrestrial ecosystems, soil geochemistry can be a strong driver of plant-soil-carbon dynamics, especially in young, less weathered soils. Here, we investigate the impact of potential plant biomass input, soil fertility parameters, and soil organic carbon (SOC) stabilization mechanisms on the distribution of SOC in European alpine grasslands across gradients of geochemically distinct parent materials. We demonstrate that SOC stock accrual in geochemically young, developing alpine soils is dependent on soil mineralogy as a result of parent material weathering, and is not strongly linked to plant biomass input. We show potential differences in the importance of SOC stabilization mechanisms, with universally large relative contributions (≥ 50 %) of the microaggregate soil fraction to bulk SOC. We further show that concentrations of Fe, Al and Mn pedogenic oxides coincide with SOC stock magnitude across an alpine soil geochemical gradient, where SOC stocks range between 8.1–23.2 kg C m⁻². Our results highlight that soil fertility, which governs plant C inputs, and soil mineralogical characteristics, which control C stabilization, play equally crucial roles in predicting SOC contents in alpine soils at an early development stage, corroborated by soil fraction modern (F14C) values ranging from 0.77–1.06.