Soil & Tillage Research最新文献

{"title":"Plastic film mulch mitigates soil respiration by reducing the duration of freeze-thaw transition","authors":"Yufei Li ,&nbsp;Kaiping Zhang ,&nbsp;Wucheng Zhao ,&nbsp;Yuling Li ,&nbsp;Ningning Zhang ,&nbsp;Pingxing Wan ,&nbsp;Zhongke Zhou ,&nbsp;Jianjun Yang ,&nbsp;Hongyuan Kan ,&nbsp;Feng Zhang","doi":"10.1016/j.still.2025.107038","DOIUrl":"10.1016/j.still.2025.107038","url":null,"abstract":"<div><div>Soil freeze–thaw cycles (FTCs) during the non-growing season influence soil respiration (R_s), yet the effect of widely used plastic film mulch (PFM) on FTCs remains unclear. Based on four years of high-frequency observations in the semi-arid Loess Plateau, we found that PFM shortened the freeze-thaw transition (F-T) period by 59 days per year and extended the freezing period by 42 days per year through reducing the daily soil temperature (ST) range by 2.5 °C during the non-growing season. Although microbial biomass carbon (MBC) decreased during the F-T period compared to the freeze period, increases in dissolved organic carbon (DOC) and the activities of β-glucosidase (BG), cellobiohydrolase (CBH) contributed to higher R_s under both treatments. PFM did not significantly influence R_s (relative to the control) within either period. PFM increased cumulative CO₂ emissions by 24 g C m⁻² due to the extended freezing period, while reducing emissions by 47 g C m⁻² owing to the shortened F-T period. PFM increased R_s by 24 % during the thaw period, causing only an 8 g C m⁻² rise. Overall, PFM reduced cumulative CO₂ emissions by 16 %. To investigate the regional effect of PFM on FTCs, we used a process-based model with good performance to simulate the spatiotemporal patterns of FTCs in PFM-applied cropland across northern China. Simulations showed that PFM shorten annual F-T periods by approximately 15 days, especially between 35°N and 45°N. Of the un-mulched cropland in northern China, 7 % showed an increasing F-T duration from 1990 to 2019, a figure which potentially increased to 11 % under PFM, mainly located in Northeast China. During the same period, 16 % of the un-mulched cropland showed a decreasing F-T events, which increase to 19 % under PFM, primarily in the central part of northern China. These results suggest that PFM effectively reduces F-T duration and may mitigate non-growing season R_s.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107038"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing water use efficiency and crop production through shallow- and deep-rooted crop strip intercropping in semi-arid regions","authors":"Yuhuan Wu ,&nbsp;Qianhu Ma ,&nbsp;Yanan Liu ,&nbsp;Zikui Wang","doi":"10.1016/j.still.2025.107043","DOIUrl":"10.1016/j.still.2025.107043","url":null,"abstract":"<div><div>In semi-arid dryland farming, continuous cultivation of perennial deep-rooted pastures can excessively deplete soil moisture, whereas annual crops underutilize precipitation. We hypothesize that intercropping these two types of plants has great potential for water resource conservation and efficient utilization. A field experiment on wheat-alfalfa strip intercropping was conducted over four seasons from September 2017 to September 2021 to examine root development and water use in three intercrops with wheat-to-alfalfa row ratios of 2:1 (I21), 4:2 (I42), and 8:4 (I84). We observed that wheat roots were primarily distributed within the 0–2 m soil profile, whereas alfalfa roots extended to 5-m-depth. Intercropping reduced vertical penetration while facilitating the lateral extension of wheat roots into alfalfa strips and promoting alfalfa roots distribution laterally below 2-m-depth in the wheat strip. Intercropping also increased root length and surface area of both species. Root plasticity enhanced the complementary use of soil water. Wheat in I21, I42, and I84 absorbed an average of 39.0, 33.1, and 14.7 mm yr⁻¹ of soil water from the alfalfa strip. In the dry year, 2021, alfalfa in I21, I42, and I84 absorbed 19.5, 20.2, and 62.4 mm of soil water from the wheat strip below 2-m-depth. Intercropping increased wheat grain yield by 18.4–22.3 % while maintaining the alfalfa biomass production. The wide-strip pattern, I84, achieved the highest production and water use advantages, averaging 9 % and 13 % respectively, over monocultures, with peaks of 14 % and 31 % in 2021. Our research confirms the feasibility of intercropping shallow- and deep-rooted crops to enhance water use efficiency in semi-arid regions, demonstrating a replicable and scalable approach that can be applied globally.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107043"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-frequency SAR and optical data integration for continental-scale digital mapping of soil chemical properties across Europe","authors":"Tao Zhou ,&nbsp;Yajun Geng ,&nbsp;Huijie Li ,&nbsp;Hongmin Zhang ,&nbsp;Hongchen Li ,&nbsp;Junming Liu ,&nbsp;Shuang Li ,&nbsp;Tingting Liu ,&nbsp;Jianjun Pan ,&nbsp;Bingcheng Si ,&nbsp;Angela Lausch","doi":"10.1016/j.still.2025.107034","DOIUrl":"10.1016/j.still.2025.107034","url":null,"abstract":"<div><div>Timely and accurate spatial information on soil properties is essential for addressing global challenges, including climate change, food security, and ecosystem degradation. Despite advances in digital soil mapping (DSM), current approaches remain limited by reliance on optical satellite data and insufficient exploration of synthetic aperture radar (SAR) potential at continental scales. Here, we advance DSM by integrating multi-frequency SAR and optical satellite observations to map four key soil chemical properties—soil organic carbon, pH, extractable potassium, and total nitrogen—across Europe. Eleven scenarios with different data integrations, combined with two machine learners (support vector machine and random forest algorithms) and measurements from the LUCAS 2018 soil module, were employed to construct prediction models. The results confirm that continental-scale DSM is feasible using long-term optical and SAR observations. For all soil properties, C-band Sentinel-1 outperformed <span>L</span>-band PALSAR-1/2, and the integration of multi-frequency SAR data achieved prediction accuracies comparable to or even exceeding those of optical data, with R² improvements of approximately 29 %–87 % compared with using only <span>L</span>-band backscatter bands. The joint use of radar and optical observations produced the best performance, improving predictions of all soil properties compared to using optical data alone, with R² values ranging approximately from 0.31 to 0.60—highest for soil pH and lowest for soil total nitrogen. The relative importance of SAR features in the predictions varied with specific polarization modes and band frequencies, and radar indices were found to be more influential in models than backscatter bands. The generated soil property maps showed spatial patterns consistent with previous efforts based on multi-source environmental data. This study demonstrates that multi-frequency SAR data can both substitute for and complement optical data in DSM, offering new insights and practical directions for future model development.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107034"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of continuous straw and equivalent straw-derived biochar application on soil multifunctionality, crop productivity, and greenhouse gas emissions","authors":"Junsheng Lu ,&nbsp;Wei Zhang ,&nbsp;Xuezhi Liu ,&nbsp;Xinyue Zhu ,&nbsp;Penghai Su ,&nbsp;Tiantian Hu","doi":"10.1016/j.still.2025.107033","DOIUrl":"10.1016/j.still.2025.107033","url":null,"abstract":"<div><div>Incorporating straw or straw-derived biochar is recognized as a promising strategy to enhance soil quality and promote sustainable agricultural development. However, the sustained effects of straw and biochar amendments on crop productivity, greenhouse gas (GHG) emissions and soil multifunctionality remain controversial, largely due to the lack of comparative studies between raw straw and biochar produced from an equivalent amount of straw. To address this issue, a five-year field experiment was conducted with three treatments—CK (no incorporation), SI (continuous raw straw incorporation), and BI (continuous incorporation of biochar derived from an equivalent amount of straw)—to evaluate whether converting raw straw into biochar for soil application provides greater benefits in mitigating GHG emissions and improving soil quality, crop yield, and water productivity. The results showed that both SI and BI significantly improved soil physical (bulk density, porosity, field capacity), chemical (pH, organic carbon, nutrient levels), and biological (microbial biomass carbon and nitrogen) properties, leading to increases in soil ecosystem multifunctionality by 222.8 % and 251.8 %, respectively, compared with CK. Additionally, SI consistently elevated N₂O emissions, whereas BI generally reduced N₂O emissions relative to CK. Both SI and BI increased CO₂ emissions and significantly enhanced crop yield, with SI and BI increasing grain yield by 8.3 % and 25.6 %, and water productivity by 12.2 % and 24.8 %, respectively, in the maize-wheat rotation system compared to CK. As a consequence, SI and BI increased the global warming potential (GWP) by 22.4 % and 6.1 %, respectively, while SI increased greenhouse gas intensity (GHGI) by 12.6 % and BI reduced it by 16.1 %, relative to CK. Notably, continuous incorporation of straw and biochar resulted in a cumulative effect (residual effect + current-season effect) on N₂O and CO₂ emissions. The residual effect on N₂O and CO₂ emissions persisted for 3 and 4 years, respectively, under SI, and extended up to 7 years for both gases under BI. Overall, these findings demonstrate that converting straw into biochar for soil incorporation not only enhances soil quality and sustains high crop productivity but also contributes to mitigating GHG emissions. This study highlights the importance of considering long-term dynamics in straw and biochar management and underscores biochar's potential as a sustainable strategy for climate change mitigation.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107033"},"PeriodicalIF":6.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term green manure incorporation increases soil carbon sequestration and improves aggregate stability by changing organic carbon components","authors":"Yulu Chen ,&nbsp;Li Huang ,&nbsp;Shaomin Huang ,&nbsp;Tengfei Guo ,&nbsp;Shuiqing Zhang ,&nbsp;Doudou Guo ,&nbsp;Xiao Song ,&nbsp;Shijie Ding ,&nbsp;Muhammad Mehran ,&nbsp;Yongqiang Yang ,&nbsp;Ke Yue ,&nbsp;Sumiao Su ,&nbsp;Mingjian Geng ,&nbsp;Huimin Zhang","doi":"10.1016/j.still.2025.107024","DOIUrl":"10.1016/j.still.2025.107024","url":null,"abstract":"<div><div>Dissolved organic carbon (DOC), the most labile fraction of soil organic carbon (SOC), plays a vital role in ecosystem functioning and soil productivity. However, the influence of long-term green manure application on DOC composition and its role in soil aggregate formation and carbon stabilization remains unclear. This study investigated changes in DOC composition and their effects on aggregate stability and carbon sequestration in two rice-green manure rotation trials long-5 years in Jingzhou (JZ) and 36 years in Qiyang (QY), China. Treatments included rice-winter fallow (WF), rice-Chinese milk vetch (MV), rice-oilseed rape (RP), and rice-ryegrass (RG). At the JZ test site, 5-year MV incorporation slightly improved aggregate stability, measured by mean weight diameter (MWD) and geometric mean diameter (GMD), but without significant changes. In contrast, at QY, 36-year MV and RG incorporation significantly enhanced both MWD and GMD. Green manure addition increased SOC and DOC contents and enhanced the molecular complexity of DOC, reflected by higher molecular weight, aromaticity, and humification degree. DOC was primarily derived from plant residues and microbial metabolites, with green manure application enhancing microbial contributions. Fluorescence spectroscopy identified three DOC components: bioavailable, humic-like, and protein-like. While DOC composition at JZ remained largely unchanged after 5 years of MV incorporation, 36 years of MV and RG incorporation at QY facilitated the transformation of protein-like into humic-like components. SOC, humic-like DOC, and the humification index (HIX), were the key drivers of aggregate stability, showing direct positive effects on aggregate MWD. Humic-like DOC indirectly promoted SOC accumulation through increased DOC aromaticity and enhanced humification. Our findings highlight the central role of humic-like DOC in enhancing SOC sequestration and soil aggregate stabilization, underscoring the long-term benefits of green manure in sustainable agriculture.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107024"},"PeriodicalIF":6.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unearthing profits: The impact of ripping depth on cost-benefit dynamics in south-eastern Australia's sandy soils","authors":"Muhammad Masood Azeem ,&nbsp;Therese McBeath ,&nbsp;Jackie Ouzman ,&nbsp;Chris Saunders ,&nbsp;Rick Llewellyn","doi":"10.1016/j.still.2025.107032","DOIUrl":"10.1016/j.still.2025.107032","url":null,"abstract":"<div><div>Deep ripping, a tillage practice that loosens compacted soil layers below 30 cm, has gained traction in south-eastern Australia's sandy soils due to recognition of its ability to overcome constraints to crop production and advances in machinery that allow the operation to be deeper and more effective. While it has the potential to improve productivity, deep ripping requires significant investment and exhibits variable effectiveness across locations, seasons, and timeframes. Despite its growing adoption, robust economic assessments of different ripping depths have been limited. This study evaluates the economic performance of deep ripping at varying depths using data from 162 treatment-site-years collected between 2014 and 2021 across on-farm trials in the southern Australian cropping zone (250–400 mm annual rainfall). Cost–benefit analysis combined with Monte Carlo simulations was used to estimate probabilistic outcomes under different scenarios and uncertainty levels. Results show that 73 % of cases yielded a positive net present value (NPV) and benefit–cost ratio (BCR), with NPV outcomes ranging from –$406 to $1218 per hectare. A cumulative grain yield gain of approximately 1 tonne per hectare was generally required to achieve a positive NPV. Ripping to depths between 40 and 60 cm—targeting the layers most restrictive to root exploration—produced higher economic returns than shallower ripping (e.g., 30 cm).</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107032"},"PeriodicalIF":6.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of construction activities-altered soil bulk density on spoil heap rill erosion and morphological characteristics","authors":"Zhihua Zhang ,&nbsp;Yuhui Guo ,&nbsp;Li Li ,&nbsp;Honghu Liu ,&nbsp;Wenfeng Ding ,&nbsp;Wenjian Tang ,&nbsp;Jigen Liu","doi":"10.1016/j.still.2025.107026","DOIUrl":"10.1016/j.still.2025.107026","url":null,"abstract":"<div><div>Spoil heaps, resulting from excavation and backfilling at construction sites, are highly susceptible to soil detachment and transport, leading to rill development, while large-scale infrastructure activities continually alter the soil bulk density. However, the mechanisms by which soil bulk density affects rill erosion on spoil heaps remain poorly understood. This study aims to investigate how soil bulk density governs rill morphology and hydraulic parameters on spoil heaps by conducting multiple flume tests under different flow discharges (3, 5, and 7 L min⁻¹), slope gradients (10, 20, and 30°), and soil bulk densities (1.2, 1.5, and 1.8 g cm⁻³). Close-range digital photogrammetry was utilized to obtain surface elevation information, which was used for constructing a digital elevation model (DEM). The results showed: 1) soil bulk density significantly affected the soil erosion resistance of spoil heaps: as it increased from 1.2 to 1.8 g cm⁻³, soil erodibility decreased, while critical shear stress increased from 4.17 to 6.47 Pa and critical stream power from 1.23 to 2.13 N m⁻¹ s⁻¹; 2) soil bulk density significantly suppressed rill development as it increased from 1.2 to 1.8 g cm⁻³, reducing the mean rill density by 19.4 %, the mean rill width-depth ratio by 48.2 %, and the mean rill inclination angle by 30.5 %; 3) rill depth was the best morphological predictor of sediment yield (<em>P</em> &lt; 0.01), and among the four derived morphological indicators, the degree of rill dissection was the optimal predictor of rill erosion and morphology, followed by the rill inclination angle, the rill width-depth ratio, and the rill density. This study would enhance understanding of the complicated interactions between soil bulk density and morphological development on spoil heaps, and provides strategic erosion control plans for their management.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107026"},"PeriodicalIF":6.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron-bound organic-carbon dynamics in a fertilized Agriustoll","authors":"Wen Zhihao,&nbsp;Zhai Bingnian,&nbsp;Jia Hanzhong,&nbsp;Li Ziyan","doi":"10.1016/j.still.2025.107027","DOIUrl":"10.1016/j.still.2025.107027","url":null,"abstract":"<div><div>Iron-bound organic carbon (Fe-OC) is an important form of soil organic carbon (SOC), and understanding the mechanisms that underlie its formation is crucial for elucidating soil carbon cycling processes. Here, multiple inorganic leaching solutions were used to extract different types of iron minerals from soil under different nitrogen application rates. The results show that fertilization drives the activation of soil iron minerals by regulating root growth and microbial community composition. Iron mineral activation was highest under moderate nitrogen supplementation, but manure application also regulates iron mineral form. EEMs (Excitation-Emission-Matrix Spectra) analysis was also used to determine the molecular structure of Fe-OC, revealing that different types of iron minerals have a significant fractionation effect on organic carbon. To investigate the processes mediating this fractionation, FT-ICR MS (Fourier Transform Ion Cyclotron Resonance Mass Spectrometry) was employed to determine Fe-OC structure. This analysis revealed that fractionation was jointly determined by both iron-mineral and organic-carbon structure. This study reveals the mechanisms by which fertilization of regulates the formation of Fe-OC in temperate soils, improving understanding of the relationship between Fe-OC formation and fractionation.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107027"},"PeriodicalIF":6.8,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover cropping and minimum tillage improved microbial functional resilience to compaction stress in an acidic soil","authors":"Apsara Amarasinghe ,&nbsp;Chengrong Chen ,&nbsp;Lukas Van Zwieten ,&nbsp;Michael T. Rose ,&nbsp;Mehran Rezaei Rashti","doi":"10.1016/j.still.2025.107031","DOIUrl":"10.1016/j.still.2025.107031","url":null,"abstract":"<div><div>Sustainable agriculture requires maintaining soil health, yet conventional management (CM) practices may not protect soils from stresses such as compaction. This study compared microbial resilience to compaction in two soils collected from sugarcane farms under improved management (IM: minimum tillage, cover cropping and stubble retention) and CM (conventional tillage, no cover crop and stubble retention) practices. Samples were placed in 96-well deep-well plates and compacted using a bespoke device to achieve bulk densities of 0.9 (control), 1.1 (low), and 1.2 g cm⁻³ (moderate). Microbial resistance was assessed 14 days after compaction, and resilience 14 days after stress relief. Under low and moderate compaction, IM soils showed 49.5 % and 45.7 % higher CO₂ emission resistance indices (i.e., the ability of soil to maintain microbial respiration under compaction stress) than CM, indicating greater stability. Microbial biomass carbon and nitrogen were 56.2 % and 47.9 % higher in IM soils under low compaction, compared to CM. Soil microbial metabolic quotient (<em>q</em>CO₂) was similar across compaction levels within each system, but was 19.5 %–36.3 % lower in IM soils than CM at equivalent compaction, indicating lower microbial stress under IM. Fourteen days after stress relief, <em>q</em>CO₂ in moderately compacted CM soil increased by 41.1 % and 25.0 % compared to control and low compaction. In contrast, IM soil under moderate compaction had 40.6 % lower <em>q</em>CO₂ than CM. The CM showed no effects of compaction on hot water extractable organic carbon content, while compaction of IM showed a 13 % decline compared to its control. Hot water extractable total nitrogen did not vary with compaction within the management systems but was 12 %–15 % higher in IM than CM under the same compaction during the resistance phase. Total mineral nitrogen was unaffected by compaction treatments under each system but was 11 %–13 % higher in IM than CM during resistance phase. These findings highlight the potential of improved management practices to sustain soil health and resilience under compaction stress.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107031"},"PeriodicalIF":6.8,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron fractionation-directed mechanisms of soil organic carbon: A geochemically-grounded hypothesis and validation","authors":"Fei Xie ,&nbsp;Yuanqing Tang ,&nbsp;Jin-E. Wei ,&nbsp;Yangzheng Liu ,&nbsp;Weifang Chen ,&nbsp;Chengmei Liao ,&nbsp;Changwei Lü","doi":"10.1016/j.still.2025.107029","DOIUrl":"10.1016/j.still.2025.107029","url":null,"abstract":"<div><div>The stabilization of soil organic carbon (SOC) by reactive iron (Fe) minerals is a critical yet poorly quantified process in the global carbon cycle. To elucidate the specific mechanisms of Fe-mediated OC (organic carbon) fractionation, we employed a sequential chemical extraction protocol on &lt; 53 μm soil fractions to isolate distinct Fe phases. This method was rigorously validated using X-ray diffraction (XRD) to correlate the extracted Fe species with specific mineral phases. A key methodological advancement was the developmen of a novel approach to quantify OC co-extracted with each Fe phase, enabling the first direct assessment of MAOC (mineral-associated organic carbon) partitioning to specific mineral hosts. Operationally, citrate-bicarbonate-dithionite (CBD) extraction targeted reactive Fe (Fe_HR) minerals (e.g., lepidocrocite, goethite, maghemite), while 12 M HCl dissolved poorly reactive Fe (Fe_PR) phases (e.g., ankerite, magnetite, illite, montmorillonite). The residual silicate-bound Fe (Fe_U), such as grossular, riebeckite, mica, and orthoclase remained in the final residue. Our results revealed a quantitative partitioning of MAOC: Fe_U-OC dominated (47.9 %), indicative of long-term geological inheritance via physical occlusion within silicate matrices. Fe_PR-OC (36.3 %) was stabilized predominantly by micropore confinement in low-activity minerals and cation bridging, effectively shielding OC from redox-driven dissolution. In contrast, Fe_HR-OC constituted the smallest fraction (15.8 %) but was the most dynamic, with its concentration strongly correlated with precipitation-induced Fe (oxyhydr)oxide transformation and vegetation diversity, leading to the formation of mineral-organic complexes. Mechanistically, we identified three distinct stabilization pathways: (1) reactive Fe/Al-(hydr)oxides bound OC mainly through chemical complexation or co-precipitation at high-surface-area mineral surfaces; (2) low-activity Fe/Al-(hydr)oxides associated with OC via physical adsorption; and (3) Fe_U-OC through physical encapsulation within silicate mineral frameworks and lattice-defects. These findings provide a mechanistic and quantitative framework for predicting the persistence of Fe-OC associations under changing environmental conditions.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107029"},"PeriodicalIF":6.8,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}