Wildfire simultaneously disrupts ecosystem carbon, water, and soil processes, yet these coupled effects and post-fire recovery trajectories cannot be reliably assessed from spectral vegetation indices alone. Here, we developed a fine-scale, multi-dimensional framework to quantify wildfire impacts and post-fire ecohydrological recovery, using the 2016 megafire in Great Smoky Mountains National Park in the eastern United States as a testbed. This framework integrated gap-filled 30 m NASA Harmonized Landsat and Sentinel-2 surface reflectance with an expanded diagnostic ecosystem model (Coupled Carbon and Water Model) to generate spatially consistent estimation of gross primary productivity (GPP), evapotranspiration (ET), water yield (WY), and soil erosion (SE) from 2014 to 2024 within Google Earth Engine. Fire effects were isolated from climate variability using pixel-level counterfactual simulations that produced no-fire baselines under identical meteorological forcing. We found that GPP declined by 20.7%, ET by 20.0%, WY increased by 19.2%, and soil erosion increased 12.5 times in the first post-fire year. Recovery trajectories varied strongly with burn severity, with high-severity patches retaining persistent modeled functional deficits (−13% GPP, −9% ET, +9% WY, and 5× SE) after eight years despite full spectral recovery (NDVI +2%). Our findings reveal a distinct decoupling between spectral recovery and the modeled carbon, water, and erosion responses, driven by incomplete ecological succession, where high-severity areas remain in herb- and shrub-dominated stages rather than recovering to forest. The severity-stratified diagnostic framework we provide offers a directly applicable tool for post-fire vegetation assessment, hydrological response monitoring, and long-term restoration planning in fire-affected ecosystems.

Due to its inherent salt tolerance and high economic value, sunflower has become a promising crop for the development of saline–alkali lands, which constitute an important reserve of cultivable land. However, sunflowers exhibit differential responses to saline-alkali soils across various regions, primarily due to variations in soil salt composition. This study conducted a pot experiment to investigate the responses of sunflower seedlings to neutral salt, alkaline salt, and mixed salt stress (0, 60, 120,180,240 mmol L− 1), focusing on differences in growth indicators, physiological and biochemical parameters, nutrient uptake, and ion flux. Two-way ANOVA showed that both salt type and concentration significantly affected sunflower growth and physiology. Under neutral salt stress, survival remained at 100

Organic fertilizer substitution plays a crucial role in improving soil quality and reducing carbon emissions. However, the microbial mechanisms underlying effects on soil nutrient cycling and carbon emissions, especially in vegetable cultivation systems, remain poorly understood. A five-year field experiment (2019-2023) was conducted to evaluate the effects of fertilization strategies, including no fertilization (CK), inorganic fertilization (CF), bio-organic fertilization (OF), and their combination (COF). The impact of bio-organic fertilization on soil nutrient cycling, carbon emissions, and carbon-cycling microbial communities was analyzed. The highest multi-nutrient cycling index was observed in COF treatment. Compared to the CF treatment, the bio-organic fertilization treatments (OF, 35.9 %; COF, 12.1 %) significantly (P<0.05) reduced soil CO2 emissions. Bacterial diversity (Chao1 index and Shannon index) in the OF and COF treatments was significantly (P<0.05) higher than in the CF treatment, whereas fungal diversity (Shannon index) showed the opposite trend. Bacterial diversity played a crucial role in regulating soil nutrient status, as bacterial co-occurrence network exhibited a highly significant positive correlation with the multinutrient cycling index. Bio-organic fertilizer enhanced the activity of genes related to multiple systems (pccA), rTCA cycle (icd), reductive acetyl-CoA pathway (cooC), and Calvin cycle (cbbL/R), thereby promoting the conversion of CO2 into stable organic compounds. Furthermore, structural equation modeling confirmed that soil carbon fixation genes, bacterial diversity, and network stability were key factors influencing CO2 emissions. Overall, from a long-term perspective, organic fertilizer substitution can mitigate carbon emissions and promote nutrient cycling in greenhouse vegetable cultivation systems, representing a greener and more sustainable agricultural approach.

Long-term intensive tomato production accelerates soil organic carbon (SOC) loss thus soil structural degradation. Although the application of organic fertilizer is considered a key mitigation strategy, its effects on the mechanisms governing SOC quality and stability remain unclear. Herein, we present the field experiment that spans seven years and encompasses four treatments, including no fertilizer (NF), chemical fertilizer (CF), bio-organic fertilizer (BF), and chemical plus bio-organic fertilizer (CBF) in a typical intensive tomato production system. Soil aggregates were fractionated using a wet-sieving method, and SOC and humic fractionations in bulk soil and aggregates were characterized using Fourier transform infrared and sequential acid and base dissolution methods, alongside in-situ CO2 and CH4 emissions were monitored. The results showed that BF and CBF treatments markedly improved soil physical properties and significantly promoted the formation and stability (mean weight diameter increased by 50.0-69.4%) of macroaggregates (>0.25 mm). Bio-organic fertilizer also enhanced SOC concentrations (increased by 41.2-96.0%) and cold- and hot-water extractable C across different size of soil aggregates, particularly in macroaggregates. Notably, bio-organic fertilization reduced soil C emissions (by 7.7-36.6%) by increasing soil humic acid content, thereby contributing to greater SOC accumulation and stabilization. Partial least squares path modeling further revealed that enhanced macroaggregate formation was the primary pathway that strengthened SOC stability and reduced C loss. Overall, CBF treatment is the optimal measure for improving soil structure, while BF treatment exhibits greater advantages in carbon sequestration efficiency, offering a scientifically robust strategy for the sustainable management of intensive tomato production system.

Nitrous oxide (N2O) is a potent greenhouse gas pollutant, but the mechanisms by which different earthworm ecotypes regulate N2O emissions in latosolic red soils remain poorly understood. To address this issue, a microcosm incubation experiment was conducted using three earthworm ecological categories, epigeic Eisenia foetida, endogeic Pontoscolex corethrurus, and anecic Pheretima guillelmi, to investigate their effects on N2O emissions, soil nitrogen-cycling processes, microbial communities, and nitrogen-cycling functional genes in latosolic red soil. The results showed that the three earthworm ecological categories differentially affected N2O emissions by altering soil physicochemical properties, regulating related enzyme activities, and promoting inorganic nitrogen transformation, with endogeic and anecic earthworms exerting stronger stimulatory effects. Earthworm activity reshaped microbial community interactions and altered the relative abundances of key functional genes involved in nitrification, denitrification, assimilatory nitrate reduction, and dissimilatory nitrate reduction to ammonium (DNRA). Integrated analysis indicated that earthworms may jointly influence soil nitrogen transformation and N2O emissions by modifying the soil environment, promoting soil nitrogen transformation processes, and regulating microbial community structure and the relative abundance of nitrogen-cycling functional genes. Due to differences in activity patterns and disturbance intensity, the effects of different earthworm ecological categories varied substantially, with cumulative N2O emissions generally following the order: anecic > endogeic > epigeic.

Global cadmium (Cd) contamination threatens 30 % of agricultural lands, forcing unsustainable trade-offs between food safety and farmer livelihoods. This study establishes low accumulation crop (LAC) rotations as an eco-engineering platform that successfully decouples agricultural production from heavy metal pollution in contaminated agroecosystems. Through systematic validation of ten rotation patterns in severely Cd-polluted soils (3.32 mg/kg), we demonstrate how four optimized rotations-Rapeseed-Silage corn-Cherry tomato (CT), Rapeseed-Silage corn-Peanut (PN), Rapeseed-Silage corn-Silage corn (SC), and Rapeseed-Silage corn-Sunflower (SF)-achieve triple synergy: maintaining 100 % crop compliance rates while removing 66.78-91.34 g/ha/yr of Cd and generating 11,664-28,559 USD ha/yr net profits (270 %-590 % above conventional rice systems). Crucially, this framework propels self-sustaining circularity through Cd bio-sequestration in non-edible biomass, soil health restructuring via pH-driven bioavailability suppression (increased 0.59-1.48 units), and microbe-mediated reactivation evidenced by 8.44 %-24.3 % MBC enhancement, 61 %-117 % catalase surge, and 22.44 %-87.19 % urease amplification. By transforming remediation into an economically viable process where safe agricultural outputs fund ongoing contaminant drawdown, the system advances SDG 2 (Zero Hunger) and SDG 3 (Good Health) in subtropical contamination hotspots. This ecology-engineering blueprint offers a transferrable solution for 30 % of global agricultural ecosystems facing heavy metal degradation.

Iron sulfides (FexSy) possess excellent capacities for activating peroxydisulfate (PDS) to degrade organic pollutants from wastewater owing to their highly efficient circulation of Fe(III)/Fe(II), but the intrinsic facet-activity relations are still unclear to date. Herein, we employed the FLO-Fe3S4 with a flower-like structure and exposed [001] facet, and OCT-Fe3S4 with octahedral morphology and exposed [1-21] facet as catalysts for activating PDS to degrade clothianidin (CLO). Results show that FLO-Fe3S4 exhibits significantly enhanced catalytic activity, with a CLO degradation rate of 0.4270 min-1, which is 4.4 times higher than that of OCT-Fe3S4. The superior reactivity of FLO-Fe3S4 can be attributed to its longer Fe-S bonds, making them more prone to breaking and releasing more Fe ions for boosting homogeneous PDS activation. Moreover, the shorter Fe-S bond of OCT-Fe3S4 alleviates Fe dissolution, thereby enhancing its catalytic stability and heterogeneous catalytic reaction. Theoretical simulations reveal that the [001] facet of FLO-Fe3S4 favors the adsorption of PDS and provides more electrons to decompose PDS compared with the [1-21] facet of OCT-Fe3S4. Overall, this work delves into the intrinsic facet-activity relations for Fe3S4 crystals on PDS activation and further unravels the overlooked role of crystal Fe-S length on catalytic reaction.

Abstract Simultaneous removal of cationic metal and oxyanion-forming metalloid contaminants remains challenging because of their contrasting chemical behaviors. Polyzwitterionic hydrogels containing both cationic and anionic functional domains are promising for such cocapture, yet intranetwork electrostatic pairing often restricts site accessibility. Herein, carboxymethyl cellulose–chitosan polyzwitterionic hydrogel (CMC-CS) was used as a bio-derived precursor to construct Fe3+-crosslinked CMC-CS (Fe3+@CMC-CS) via Fe3+-induced semi-unzipping, followed by in situ reduction of the Fe3+ sites to generate recoverable nanoscale zero-valent iron (nZVI)-functionalized CMC-CS (nZVI@CMC-CS). This structural regulation loosened the compact charge-paired network and enlarged the average pore diameter from 5.14 to 19.47 nm, thereby improving the accessibility of interfacial binding sites. With the subsequent formation of nZVI-functionalized reactive interfaces, the capture capacities for Cd(II) and As(III) increased by 2.50- and 10.01-fold, respectively, compared with the pristine CMC-CS hydrogel. High uptake was also maintained in binary systems, reaching 91.95 mg/g for Cd(II) and 63.16 mg/g for As(III). Mechanistic analyses revealed that accessible interfacial binding sites favored Cd(II) capture through cation exchange, electrostatic attraction, and surface complexation, whereas Fe-based reactive interfaces promoted As(III) uptake via oxidation-associated immobilization, precipitation, and complexation. In a 30-day soil incubation experiment, nZVI@CMC-CS reduced the total contents of Cd and As by 3.87–13.62% and 4.24–9.11%, respectively, while altering their fraction distributions and maintaining high material recovery. These findings demonstrate that network unzipping offers an effective strategy for engineering recoverable reactive hydrogel interfaces for the cocapture of chemically distinct contaminants in soil.

To address the dual challenges of remediating cadmium (Cd)-arsenic (As) co-contaminated soil and utilizing mining waste resources, this study developed a novel remediation material from natural low-grade molybdenum tailings (MT). MT was subjected to high-temperature alkaline fusion to obtain amorphous silicate (ASi), onto which nanoscale zero-valent iron (nZVI) was subsequently loaded to form nZVI/ASi. Batch adsorption experiments were carried out evaluate its Cd(II) and As(III) adsorption capacities, while soil incubation tests assessed its effectiveness in reducing the bioavailability of Cd and As. Alkaline fusion disrupted the crystalline structures of quartz, mica, feldspar, and calcite in MT, increasing its surface area 37.83-fold and enhancing Cd(II) adsorption, whereas nZVI incorporation improved As(III) removal. nZVI/ASi exhibited maximum adsorption capacities of 139.10 mg·g− 1 for Cd(II) and 113.57 mg·g− 1 for As(III). Cd(II) immobilization occurred via coordination with Si-O/Si-OH, complexation with iron oxides/hydroxides, and ion exchange, while As(III) adsorption involved complexation, oxidation, and electrostatic interactions. Co-adsorption experiments revealed synergistic effects, where As(III) enhanced the adsorption rate of nZVI/ASi for Cd(II). Cd(II) notably boosted the ability of nZVI/ASi to adsorb As(III), attributed to electrostatic interactions and the creation of A-type ternary surface complexes. In soil, 2

Polycyclic aromatic compounds (PACs) and heavy metals (HMs) frequently coexist in the soil of industrial areas, posing significant ecological risks. This study investigated the distribution and influencing factors of PACs and HMs in soil aggregates under co-contamination, as well as their interactive adsorption behavior and mechanisms with soil, with a focus on lead (Pb), phenanthrene (Phe), and 1-acenaphthenone (1-ACE). Soil samples were collected from an industrial area and fractionated into four aggregate sizes. soil properties and the contents of PACs and HMs in different aggregates were determined. Single and co-adsorption behaviors of Pb, Phe, and 1-ACE were examined through batch adsorption experiments, with isotherms modeled using Freundlich, Langmuir, and Linear models. Adsorption mechanisms were further explored by X-ray photoelectron spectroscopy (XPS) analysis. Most PACs and HMs mainly accumulated in the < 0.002 mm aggregates, with HMs influenced by multiple soil properties and PACs primarily influenced by soil organic matter (SOM). The Freundlich parameters (KF and 1/n) indicated that Pb exhibited heterogeneous multilayer adsorption, while Phe and 1-ACE exhibited homogeneous adsorption. The presence of Phe inhibited Pb adsorption by 7.94–19.28

Long-term intensive vegetable production degrades soil structure, alters microbial community composition, and induces imbalances between soil nutrient supply and demand, such as increased nitrate accumulation and reduced nutrient retention capacity. Although bio-organic fertilizer is widely regarded as an effective strategy for mitigating soil nutrient imbalances, its influence on microbial community and enzyme-mediated nutrient transformation processes at the aggregate scale is insufficiently understood. Four fertilization treatments were compared in a seven-year field experiment: control (CK, without fertilization), chemical nitrogen, phosphorus and potassium (NPK), bio-organic fertilizer (BF), and chemical added bio-organic fertilizer (BNPK), to evaluate their effects on soil microbial community, enzyme activity, and nutrient dynamics. The findings demonstrated that BF and BNPK significantly increased soil aggregate stability (MWD, 50.0

The Earth is currently in an era where massive deforestation and afforestation coexist. The impact of large-scale agricultural deforestation and the subsequent afforestation on soil biota multidiversity, ecosystem multifunctionality (EMF), and the relationship between soil biota multidiversity and EMF (BEFm) remain unclear. Here, we investigate 405 paired plots along a 4000 km south-north transect, spanning tropical, subtropical, temperate, and boreal zones. We measure 19 ecological functions and sequence soil biota (including bacteria, fungi, archaea, viruses, protists, and invertebrates) and metagenomes. We find that agricultural deforestation reduces soil multitrophic biodiversity by 25% and EMF by 58%, and afforestation has partially restored them, but pristine levels have not been reached. Agricultural deforestation decouples the positive BEFm relationship across four climatic zones, while afforestation restores the positive BEFm relationship in tropics and subtropics but not in temperate and boreal zones. Afforestation in the warmer zone triggers potential multitrophic cascades to enhance EMF, thereby strengthening BEFm relationship. The changes in biogeochemical-cycling genes induced by afforestation exert more significant driving effects on EMF in the warmer zone than the colder zone. Our study provides integrative evidence that climate modulates the recovery of BEFm relationship and offers multitrophic and metagenomic insights into the mechanisms underlying EMF.

Sulfamethoxazole (SMX) is a common antibiotic often found in water, and its presence poses a potential threat to the environment. However, a reliable strategy for SMX removal remains elusive. In this study, we developed biochar derived from piggery anaerobic digestate (Fe-ADBC) as a sustainable catalyst and investigated an Fe-ADBC-mediated peroxydisulfate (PDS) activation system for SMX degradation. Herein, Fe-ADBC samples with different iron contents were synthesized. The performance, stability, and resistance to environmental interferences of Fe-ADBC were evaluated systematically. The results showed that 2.0Fe-ADBC exhibited outstanding degradation efficiency over a wide pH range (3–11) and low Fe leaching (85.5 μg·L⁻¹). An electron-transfer mechanism via surface-confined complexes (Fe-ADBC-PDS*), rather than radical-based routes, dominated the SMX oxidation process, as supported by electrochemical tests, quenching experiments, and electron spin resonance spectroscopy. This work further demonstrates the potential of using biochar derived from piggery anaerobic digestate for wastewater treatment, elucidates the electron transfer pathway (ETP) for environmental pollutant oxidation, and provides fundamental insights into the resource utilization of digestate.

Tetracycline (TC) and cadmium (Cd(II)) often coexist in environments such as soil and water, posing synergistic toxicity risks. In this study, a Iron (II) sulfide-Enteromorpha prolifera carbohydrate hydrogel (FeS-EP-HD) was synthesized via direct precipitation for the simultaneous removal of TC and Cd(II) from water and soil. The maximum adsorption capacities for TC and Cd(II) were determined to be 213.6 mg/g and 213.8 mg/g, respectively. Mechanisms included precipitation, ion exchange, and coordination for Cd(II), while hydrogen bonding and pore filling for TC. In binary contamination system, FeS-EP-HD possesses co-adsorption sites for both TC and Cd(II). However, Cd(II) exhibited a stronger competitive adsorption affinity, rapidly occupying adsorption sites and consequently inhibiting TC uptake. The formation of FeS-CdS voltaic effect, which further accelerates the adsorption of TC. Additionally, adsorbed TC also provided additional sites for Cd(II) via cation-It interactions. In soil in-situ remediation trials, upon introducing 1.5 parts per thousand FeS-EP-HD into contaminated soil, reducted in TC and Cd (II) concentrations by 48 mu g/kg and 0.6 mg/kg, with removal efficiencies of 50.5 % and 47.9 %, respectively. This work demonstrates the potential of FeS-EP-HD as a efficient, eco-friendly material for co-contaminant remediation.

To investigate the effects of mealworm casting amendment on different land-use soils and find out the optimal soil moisture content for application, three distinct soils of different soil texture were selected for soil incubation experiment, one of which was set to two moisture levels. Soil samples were collected on days 14 and 28 of the incubation. Research findings indicate that soil mealworm casting amendemnt stimulates soil carbon and nitrogen cycling, facilitating the conversion of nutrients into forms readily absorbed by plants. The most pronounced effect is observed in soil ammonium nitrogen content, with an average increase of 620.7%; the average increases in soluble carbon and soluble organic carbon were 80.7% and 92.5%, respectively. Adding insect manure significantly increased the abundance of microorganisms involved in the soil carbon cycling, such as Proteobacteria and Bacteroidetes. The mealworm manure also increased beneficial taxa such as Chitinophaga and suppressed disease-associated microorganisms, thereby improving the soil microbial community structure. Moisture conditions and soil mechanical composition were key factors influencing the effectiveness of mealworm castings. The optimal moisture content for mealworm castings application is 60% of the field capacity, while higher moisture (80% of the field capacity) inhibits casting mineralization and reduces soil nitrate nitrogen content by 73.2% at day 28. Suitable moisture contents promoted mineralization of Tenebrio molitor castings, whereas excessive clay content constrained both mineralization and the frass-induced increase in soil pH.

Conventional sterilization limits smallholder mushroom cultivation in Papua New Guinea. This study evaluated alternative disinfection methods for Pleurotus ostreatus using coffee parchment and Juncao grass substrates. Twenty strains were screened; the superior strain PXF9 was selected. Three methods were compared: CSAI (T1 and T2), SSOI, (T3), and NSOI (T4). Growth, yield, nutrition, heavy metals, enzymes, and metabolites were assessed. Strain PXF9 showed superior growth. CSAI (T1) achieved the highest yield (3985 g/24 bags), biological efficiency (83.03%), protein (28.44 g/100g), and profit ($14.76), with fastest colonization (21 days). SSOI (T3) produced the largest fruiting bodies, while NSOI (T4) yielded the lowest heavy metal levels. All nutritional values met or exceeded literature standards. SSOI and NSOI generated profits of $9.88 and $5.96 per 24 bags, respectively. Bioactive compounds (naringenin, ergosterol peroxide) were detected across treatments. CSAI maximizes productivity, but SSOI and NSOI are viable low-cost alternatives for resource-limited farmers requiring no autoclave. These findings provide flexible, evidence-based options for sustainable mushroom cultivation using locally available agricultural wastes in tropical regions.

Watersheds are natural units and meta-ecosystems of the earth's land surface providing multiple ecological functions. However, little is known about the biodiversity-ecological multifunctionality relationships of watersheds, particularly regarding how these relationships scale to large and complex landscapes. Here, we explore the impact of forest tree species richness on the ecological multifunctionality of watersheds in terms of carbon sequestration, carbon storage, water supply, water regulation, and soil conservation, by utilizing integrated ground-sourced forest inventory datasets comprising 846 forest watersheds from the Global Forest Biodiversity Initiative, the Global Streamflow Indices and Metadata Archive, and remote sensing data products. We find a consistently positive relationship between forest tree species richness and watershed ecological multifunctionality by accounting for factors such as forest structural characteristics and environmental conditions. Furthermore, we find that this biodiversity-multifunctionality link is dependent on spatial scale and climatic context, becoming stronger in larger watersheds but diminishing in arid climatic conditions. These insights enhance our understanding of ecosystem multifunctionality and underscore the importance of considering watershed-scale ecological processes and biodiversity in ecosystem management and conservation strategies.

To evaluate the actual effects of different ecological restoration technologies on high and steep rock slopes in the dry-hot valley area, we compared three typical slope ecological restoration techniques, vegetation concrete (VC), soilless spraying (SPF), and vegetation trough (VS) on the high and steep rock slope of Baihetan Hydropower Station. We conducted a one-year monitoring of soil physical and chemical indicators and vegetation characteristics from January to December 2022, and calculated the ecological restoration index (ERI) using the minimum dataset method, which were used to comprehensively evaluate the ecological restoration effects of each technique. The results showed that: 1) During the maintenance monitoring period, soil physical characteristics (bulk density, porosity, moisture content), soil organic matter, and nutrient (total nitrogen, total phosphorus, available phosphorus) contents of the three remediation techniques showed a fluctuating trend with seasons. Plant characteristics (plant height, plant diameter, vegetation coverage coefficient, aboveground biomass) increased from 3.6-9.3 cm, 0.98-2.16 mm, 0.12-0.61, and 42.80-163.56 g·m-2 to 11.5-14.7 cm, 2.85-4.05 mm, 0.68-0.98, and 368.00-421.12 g·m-2, respectively, while cation exchange capacity increased from 6.13-13.94 cmol·kg-1 to 13.94-20.42 cmol·kg-1. Soil pH decreased from 7.56-8.05 to 7.17-7.51. VC was generally superior to SPF and VS in enhancing soil structure and plant growth. 2) The minimum dataset consisted of plant height, available phosphorus, vegetation coverage, bulk density, and total nitrogen, which were significantly positively correlated with the entire dataset (R2=0.733) and could effectively replace the entire dataset for ecological restoration evaluation. 3) The restoration process of slopes presented a restoration path of "soil matrix construction plant growth and reproduction". The contribution rate of soil ERI of the three restoration techniques in spring was 66.3%-70.5%, that in summer was 43.7%-58.4%, with the contribution rate of vegetation to ERI being 41.6%-56.3%. The contribution rate of vegetation to ERI in autumn and winter exceeded that of soil, ranging from 54.7% to 64.1% and 55.6% to 61.0%, respectively. 4) The annual average ERI values of three typical slope ecological restoration techniques were ranked as VC (0.576)>SPF (0.549)>VS (0.452), and the final values showed the same trend (0.676>0.639>0.538), indicating that VC had the best ecological restoration effect.

Both soil organic carbon (SOC) and iron (Fe) oxide content, among other factors, drive the formation and stability of soil aggregates. However, the mechanism of these drivers in greenhouse soil fertilized with organic fertilizer is not well understood. In a 3-year field experiment, we aimed to investigate the factors which drive the stability of soil aggregates in greenhouse soil. To explore the impact of organic fertilizer on soil aggregates, we established four treatments: no fertilization (CK); inorganic fertilizer (CF); organic fertilizer (OF); and combined application of inorganic and organic fertilizers (COF). The application of organic fertilizer significantly enhanced the stability of aggregates, that is it enhanced the mean weight diameter, geometric mean diameter and aggregate content (%) of >0.25 mm aggregate fractions. OF and COF treatments increased the concentration of SOC, especially the aliphatic-C, aromatic-C and polysaccharide-C components of SOC, particularly in >0.25 mm aggregates. Organic fertilizer application significantly increased the content of free Fe (Fed), reactive Fe (Feo), and non-crystalline Fe in both bulk soil and aggregates. Furthermore, non-crystalline Fe showed a positive correlation with SOC content in both bulk soil and aggregates. Both non-crystalline Fe and SOC were significantly positively correlated with >2 mm mean weight diameter. Overall, we believe that the increase of SOC, aromatic-C, and non-crystalline Fe concentrations in soil after the application of organic fertilizer is the reason for improving soil aggregate stability.