Catena最新文献

{"title":"Understanding organic carbon dynamics in a river catchment through improved sediment fingerprinting","authors":"C. Wiltshire ,&nbsp;J. Meersmans ,&nbsp;T.W. Waine ,&nbsp;R.C. Grabowski ,&nbsp;S. Addy ,&nbsp;M. Glendell","doi":"10.1016/j.catena.2025.109216","DOIUrl":"10.1016/j.catena.2025.109216","url":null,"abstract":"<div><div>Agricultural practices accelerate the rates of soil erosion and organic carbon (OC) loss, increasing the input of nutrient rich sediment to surface waters. As climate change is increasing the frequency and intensity of hydrological disturbances that drive erosion, it is of vital importance to quantify the terrestrial to aquatic fluxes of OC to inform sustainable management strategies and mitigate the impacts of soil OC loss in river catchments. In this study, OC sediment fingerprinting was used to determine seasonal sources of sediment to a freshwater stream from different land uses in a river catchment. Multiple lines of evidence (soil and stream sediment sampling, local climate and agronomic data) were used to evaluate tracer properties and sources in order to improve the sediment fingerprinting technique. Within a mixed land-use catchment, four potential sources of sediment (arable, forest, pasture and moorland) were characterised between June 2018 and December 2019. Spatio-temporal differences in OC sources were observed at different times of year. Arable soil was the dominant contributor to suspended sediment OC, ranging from 37% to 61% at the catchment outlet. Increased rainfall, discharge, livestock poaching, and bare or sparsely vegetated areas were found to be the drivers of change in seasonal sources of sediment relative to land use. This study demonstrated a holistic approach to inform sustainable catchment management; using multiple lines of evidence to improve the characterisation of sediment sources and highlight remaining uncertainties in the sediment fingerprinting technique.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109216"},"PeriodicalIF":5.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262164","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":"Age and pedogenesis of alpine grassland soils on the northeastern Qinghai-Tibetan Plateau: Insights from optical dating","authors":"Jingjing Chen ,&nbsp;Haoran Zong ,&nbsp;Zihan Yan ,&nbsp;Yujie Guo ,&nbsp;Deguo Zhang ,&nbsp;Xiaoping Yang ,&nbsp;Yuxin He ,&nbsp;Xiao Fu","doi":"10.1016/j.catena.2025.109217","DOIUrl":"10.1016/j.catena.2025.109217","url":null,"abstract":"<div><div>Grassland soils in alpine regions of the Qinghai-Tibetan Plateau (QTP) constitute a crucial component of the QTP ecosystem. Understanding their formation requires accurate chronologies and insights into key pedogenic processes. This study applied multi-grain (MG) and single-grain (SG) post-infrared infrared stimulated luminescence (pIRIR) dating to alpine grassland soils around the Gonghe Basin in the northeastern (NE) QTP to gain new insights into their ages and pedogenic processes. In addition, ¹⁴C dating was performed on soil organic matter, with the resulting ¹⁴C ages compared with optical ages to evaluate their reliability for soil age determination. pIRIR dating showed that bioturbation-induced soil reworking is common in alpine grassland soils. SG pIRIR dating allows more accurate soil age estimation by effectively identifying grains associated with original deposition and pedoturbation, while ¹⁴C dating yields underestimated ages due to younger carbon contamination. We proposed an SG pIRIR-based approach that can be applied to alpine grassland soils to constrain their ages and quantify bioturbation. Combined with a synthesis of regional alpine loess and palaeosol/soil chronologies and a comparison with regional climatic records, the influence of climate on alpine soil pedogenesis and bioturbation was explored. Our results showed that pedogenesis in the studied profiles started at ∼11–5 ka, following an aeolian dust aggradation pedogenic mode. The intensity of soil mixing decreases with depth, with the most intensive mixing occurring in a near-surface zone of tens of centimetres depth. Integrating SG dating results with a new conceptual model, we for the first time estimated the recent and past downward soil mixing rates and the timing of intensified bioturbation for alpine soils on the QTP. Chronological synthesis revealed that alpine soil development on the NE-QTP was most pronounced since ∼6 ka. Effective moisture is a key factor that affects both soil development and bioturbation intensity in alpine grassland soils.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109217"},"PeriodicalIF":5.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253748","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":"Interactions and feedback mechanisms in oasis wetland hydrology–soil–vegetation systems, northwestern China","authors":"Bing Liu ,&nbsp;Ying Zhao ,&nbsp;Arash Malekian ,&nbsp;Xiao Wang ,&nbsp;Wenzhi Zhao ,&nbsp;Maliheh Behrang Manesh ,&nbsp;Bin Wang ,&nbsp;Changkun Yang ,&nbsp;Weihao Sun ,&nbsp;Wen Li ,&nbsp;Pouyan Dehghan Rahimabadi ,&nbsp;Yangyang Meng ,&nbsp;Chan Liu ,&nbsp;Zhaocen Zhu ,&nbsp;Rui Si","doi":"10.1016/j.catena.2025.109220","DOIUrl":"10.1016/j.catena.2025.109220","url":null,"abstract":"<div><div>Wetlands play a crucial role in maintaining the ecological balance and supporting the sustainable development of arid oases. However, the interactions and feedback mechanisms within oasis hydrology–soil–vegetation systems remain unclear. A five-year field study was conducted in northwestern China across swamp, riparian, grassland, shrubland, and reclaimed wetlands to analyze hydroclimatic processes, soil physicochemical properties, vegetation characteristics, and their interactions and feedback mechanisms. Precipitation in the study area was low (122.5 ± 12.3 mm yr⁻¹). Significant differences were observed among wetland types in hydrological variables: average annual evapotranspiration ranged from 598.2 to 654.53 mm yr⁻¹, groundwater depth ranged from 85.4 ± 5.3 to 130.1 ± 14.8 mm, and soil water content (SWC) ranged from 0.26 ± 0.03 to 0.39 ± 0.09. Groundwater depth significantly affected SWC, pH, electrical conductivity (EC), nutrient and ion concentrations, and microbial and vegetation diversity. Reclamation for agriculture significantly increased Cl⁻, CO₃²⁻, Mg²⁺, and K⁺ concentrations, while significantly decreasing SO₄²⁻, HCO₃⁻, Ca²⁺, and Na⁺ concentrations. The overall vegetation community comprised 17 families, 42 genera, and 46 species, with dicotyledonous species dominating, accounting for 56.52 % of the total species count. Path modelling showed that groundwater depth directly affected soil water content (88 %), soil ion content (56 %), and nutrient content (32 %), thereby indirectly affecting soil microbial and vegetation diversity. SWC exerted a stronger influence on vegetation diversity than did groundwater depth, with a total effect of 86.1 % (direct effect: 62.9 %, indirect effect: 23.2 %). These findings indicate that interactions among hydroclimatic processes, soil physicochemical properties, and human activities significantly affect species diversity and vegetation characteristics in oasis wetlands.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109220"},"PeriodicalIF":5.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264009","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":"Palaeosol structures and isotopic records of sulfates and carbonate horizons in Neogene Poznań clays of the Polish Lowlands, western Poland","authors":"Agata Duczmal-Czernikiewicz ,&nbsp;Beata Gebus-Czupyt ,&nbsp;Maciej Swęd","doi":"10.1016/j.catena.2025.109120","DOIUrl":"10.1016/j.catena.2025.109120","url":null,"abstract":"<div><div>This study examines two profiles of Neogene fossil soils within the Poznań clays formation in the Polish Lowlands, where well-developed carbonate and sulfate nodules are present. The clay fraction in these profiles indicates a mineral composition consistent with Vertisols, shaped by fluctuations in temperature and water availability that promoted the formation of carbonate nodules and gypsum crystallisation. Chemical analysis further elucidates the dominant hydrologic regime during palaeosol formation. Stable isotope data from gypsum horizons and carbonate concretions were crucial for characterising the sedimentary environments.</div><div>The δ³⁴S and δ¹⁸O values in gypsum ranged from + 1.1 to + 6.1 ‰ and − 6.0 to − 3.4 ‰, respectively, suggesting formation through sulfide oxidation, likely from pyrite. These sulfur and oxygen isotopic signatures indicate continental conditions with an arid to semi-arid climate during palaeosol development, along with gypsum recrystallisation and intercalations of clay minerals and organic matter.</div><div>Carbon isotopic composition (δ¹³C) ranges from − 37.7 to − 16.6 ‰, while oxygen isotopic composition (δ¹⁸O) ranges from − 6.1 to − 3.3 ‰, reflecting a combination of pedogenic and post-sedimentary processes. The δ¹³C values of pedogenic carbonates (PCs) (− 27.3 to − 23.3 ‰) suggest that the primary carbon source is likely the biomineralisation of C3 plants remains, with C3 photosynthesis contributing to carbonate precipitation in the topsoil. The minimal δ¹⁸O variability (approximately 1 ‰) in these carbonates may correspond to short-term environmental fluctuations. Additionally, some carbonates exhibit isotopic patterns indicative of modification by vegetation and contemporary weathering processes.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109120"},"PeriodicalIF":5.4,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253747","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":"The links between Na/K ratios in eolian sands and mean annual precipitation in the deserts of arid region, northern China","authors":"Jiaqi Wang,&nbsp;Shipei Dong,&nbsp;Zhuolun Li,&nbsp;Jiaming Qu,&nbsp;Yuhan Kuai,&nbsp;Dianjia Tan,&nbsp;Jie Luo","doi":"10.1016/j.catena.2025.109219","DOIUrl":"10.1016/j.catena.2025.109219","url":null,"abstract":"<div><div>The scarcity of precipitation and unique desert landscapes drive distinct surface processes, making the quantitative reconstruction of precipitation changes in deserts a challenge in past global change and landscape evolution studies. Establishing non-biological proxy–precipitation transfer functions not only provides new methods for quantitatively reconstructing desert hinterland environments but also offers an effective comparison and validation approach for the reliability of biological proxies. However, it remains uncertain whether the geochemistry element ratio can reliably serve as a proxy for precipitation in desert regions. In this study, 47 surface eolian sand samples were collected across the Alashan Desert in the arid region of northwestern China, and their bulk and 40 different grain size fractions (&gt; 250 μm and 125–250 μm) samples were analyzed for Na₂O and K₂O concentrations by X-ray fluorescence spectrometry. By combining previously published data in this region, we calculated and analyzed the spatial variation of the Na/K ratio using a total of 161 bulk eolian sand samples. The results show that the spatial variation of the Na/K ratio primarily reflects mean annual precipitation (MAP), rather than being influenced by source rocks or sedimentary sorting, with the Na/K ratio decreasing as precipitation increases. Furthermore, in the arid desert regions (the Alashan Desert, Taklimakan Desert, Qaidam Desert, and Kumtagh Desert, MAP &lt; 200 mm) of northern China, the Na/K ratio shows a strong and significant negative correlation with MAP (MAP = −156.84 × Na/K + 300.36, R² = 0.86, RMSE = 30 mm), indicating that Na/K ratios can provide valuable quantitative estimates of paleo-precipitation changes in the arid desert regions of northern China.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109219"},"PeriodicalIF":5.4,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240878","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":"Topographical effects on the interplay between soil organic carbon fractions, aggregate stability and water repellency at a small watershed scale","authors":"Filipe Behrends Kraemer ,&nbsp;Guadalupe Ares ,&nbsp;Joaquín Mozo ,&nbsp;Celio Chagas","doi":"10.1016/j.catena.2025.109182","DOIUrl":"10.1016/j.catena.2025.109182","url":null,"abstract":"<div><div>Soil erosion is one of the main environmental problems worldwide and even though there were many efforts in the scientific community to understand soil erosion drivers, the complexity of positive and negative feedbacks and thresholds of these drivers on the extent of soil erosion still requires further research. This study examines the influence of terrain attributes (Position: Shoulder, Back-slope, and Foot-slope), Sub-Position (Ridge and Valley), and Transect – summarizing shape, slope, and length – on the interplay between soil organic carbon fractions (SOC) −total, labile and very labile-, aggregate stability mechanisms (AS) by Le Bissonnais method, and soil water repellency (SWR) by water-drop penetration time, highlighted as important soil erosion drivers, within a no-tillage agricultural watershed. AS was predominantly stable, as assessed by micro-cracking (∼3.4 ± 0.10 mm MWD) and mechanical breakdown tests (3.2 ± 0.12 mm MWD) mainly due to high SOC content (mean total SOC: 3.5 % ±0.59 g kg⁻¹). Slaking tests (2.4 mm ± 0.58 mm MWD) revealed vulnerability in some areas, particularly influenced by terrain attributes and soil water repellency. SWR, categorized as slightly repellent (16.2 s ± 19.4), was positively correlated with slaking test showing a threshold where SWR increases no longer affected the slaking process. Slope position and shape, had significant effects on soil properties, especially on AS and SWR. In general Back-slope showed the lowest SOC and AS values, while the Foot-slope showed the opposite behavior. Valley showed low AS and SWR. Slope steepness and concavity affected SWR and SOC distribution probably due to its influence on soil water content. This study highlights the complex interplay between terrain attributes and soil properties, registering also thresholds between AS and SWR indirectly modulated by soil moisture. The magnitude of each soil property determined, among other factors by terrain attributes, plays a crucial role in soil erosion dynamics in agricultural landscapes.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109182"},"PeriodicalIF":5.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240290","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":"Explaining Dark Earth’s formation processes may help to understand the settlement strategy","authors":"Martin Petr Janovský ,&nbsp;Lenka Lisá ,&nbsp;Marek Hladík ,&nbsp;Manuel Arroyo-Kalin ,&nbsp;Marian Mazuch ,&nbsp;Pavel Samec ,&nbsp;Laszlo Ferenczi","doi":"10.1016/j.catena.2025.109185","DOIUrl":"10.1016/j.catena.2025.109185","url":null,"abstract":"<div><div>This study focuses on the geoarchaeological analysis of occupation deposits preserved at the edge of the early medieval site of Mikulčice, the centre of the Great Moravian proto-state (8th–10th century CE). The combination of soil geochemistry, grain size analyses and micromorphological observations applied to two sections and linked with wider sedimentological and archaeological context were applied to complicated archaeological structures. From the given data is obvious, that settling in this area was strongly influenced by the presence of increased underground water, so repeated terrain levelling with permeable sands was the necessary maintenance, followed by the deposition of sediments enriched by human waste, alongside episodes of soils formation. These sedimentary deposits condition were one of the most important factors for the formation of Dark Earth, driven by biological mixing of kitchen waste, charcoal, bone fragments, and excrements. The study presents one of the first descriptions of Dark Earth in Czechia outside a high medieval urban context, specifically identifying it as Endo-stagnic Arenic Technosols at an early medieval hillfort.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109185"},"PeriodicalIF":5.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240877","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":"Elevation gradients regulate microbial necromass and lignin phenols in alpine peatlands: Evidence from the Qinghai–Tibetan Plateau","authors":"Jianliang Liu ,&nbsp;Xinya Huang ,&nbsp;Dan Zhu ,&nbsp;Shaofei Jin ,&nbsp;Huai Chen","doi":"10.1016/j.catena.2025.109233","DOIUrl":"10.1016/j.catena.2025.109233","url":null,"abstract":"<div><div>Microbial necromass carbon (MNC) has recently been recognized as a critical contributor to soil organic C (SOC) sequestration and stabilization. Peatlands, which serve as important C sinks, are developed through the gradual accumulation of partially decomposed plant residues. However, the relative importance of and the key factors determining plant − and microbial − derived C for SOC accumulation remain poorly understood in peatlands. Here, we use amino sugars and lignin phenols as biomarkers to investigate the relative contributions of MNC and plant lignins to the SOC in the topsoil (0 − 15 cm) and subsoil (15 − 30 cm) layers of four alpine peatlands on the Qinghai − Tibetan Plateau. The results revealed that the contributions of MNC to SOC decreased significantly from an average of 283 mg g⁻¹ SOC (213 − 335 mg g⁻¹ SOC) in the topsoil to 229 mg g⁻¹ SOC (142 − 277 mg g⁻¹ SOC) in the subsoil. Conversely, lignin phenols exhibited the opposite trend, with contributions increasing from an average of 21.5 mg g⁻¹ SOC (19.6 − 25.5 mg g⁻¹ SOC) in the topsoil to 24.6 mg g⁻¹ SOC (18.7 − 26.9 mg g⁻¹ SOC) in the subsoil. Among the peatlands, the contributions of MNC to SOC at both depths and the contribution of lignin phenols in the subsoil varied significantly and were significantly positively correlated with the elevation gradient. This pattern was partly attributed to the decline in the activities of C − oxidizing enzymes with increasing elevation, which in turn slowed the decomposition of microbial necromass and plant lignins. Moreover, stoichiometric imbalances, particularly the C-to-phosphorus (P) imbalances, likely stimulate the decomposition of labile organic components to alleviate microbial nutrient limitations, thereby increasing the proportions of MNC and lignin phenols in the SOC pools. Our findings provide important insights into the mechanism of soil C sequestration and stabilization in peatland ecosystems, as well as their feedback to climate change.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109233"},"PeriodicalIF":5.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240876","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":"Differential responses in topsoil and subsoil: N2O, CO2, and CH4 dynamics under extreme rainfall","authors":"Mengdi Yang ,&nbsp;Yufei Cui ,&nbsp;Xiaomin Li ,&nbsp;Ning Zhang ,&nbsp;Shengli Guo ,&nbsp;Rui Wang","doi":"10.1016/j.catena.2025.109214","DOIUrl":"10.1016/j.catena.2025.109214","url":null,"abstract":"<div><div>The production and diffusion of greenhouse gases (GHG) in soil layers play a crucial role in surface emissions. However, the impact of subsoil GHG dynamics on surface emissions remains largely unclear. Here, differential dynamics between topsoil and subsoil of N₂O, CO₂, and CH₄ were determined during rainfall events in a soil-column experiment. Soil oxygen (O₂), nitrate nitrogen (NO₃^–-N), ammonium nitrogen (NH₄⁺-N), and dissolved organic carbon (DOC) were measured, and gas diffusivity was calculated during experimental period. The peak N₂O concentration in topsoil was 23.8 % higher than in subsoil. Under short-term hypoxic conditions (15.1–15.3 % O₂ concentration), higher NO₃^–-N concentration in topsoil (53.6–57.8 mg kg⁻¹) was key factor influencing pulsed N₂O concentrations compared to subsoil (31.2–42.2 mg kg⁻¹). N₂O downward diffused from topsoil to subsoil, ranging from 0.0299 to 0.0581 kg ha⁻¹ due to nitrogen topdressing. CO₂ concentration in topsoil was 7.4–25.0 % lower than in subsoil, with extreme rainfall events amplifying these differences by a factor of 3.4. Subsoil contributed 11.1–17.6 % of the cumulative CO₂ emissions during rainfall events. In contrast, CH₄ concentrations showed no significant differences between topsoil and subsoil. These findings underscore the importance of understanding GHG dynamics across soil layers, offering new insights into the role of subsoils in GHG emissions.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109214"},"PeriodicalIF":5.4,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240289","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":"Controls on soil organic matter stability and composition of neutral-to-alkaline topsoil and subsoil across Indo-Gangetic plains","authors":"Ruohan Zhong ,&nbsp;Han Lyu ,&nbsp;Monika Kumari ,&nbsp;Ajay Kumar Mishra ,&nbsp;M.L. Jat ,&nbsp;Randy A. Dahlgren ,&nbsp;Shinya Funakawa ,&nbsp;Tetsuhiro Watanabe","doi":"10.1016/j.catena.2025.109215","DOIUrl":"10.1016/j.catena.2025.109215","url":null,"abstract":"<div><div>Elusive controls over soil organic carbon (SOC) in neutral-to-alkaline soils limit long-term carbon dynamic predictions across vast agricultural areas such as Indo-Gangetic Plain (IGP). We studied the causes of low SOC content in neutral-to-alkaline topsoil and subsoil under tropical to subtropical climates by identifying factors controlling soil organic matter (SOM) fractions, SOC pools, and SOM molecular composition. We investigated topsoil and subsoil from six paired forest and agricultural fields within 12 sites across IGP, using SOM fractionation, 196-day soil incubation, and pyrolysis-GC/MS. A three-pool kinetic model estimated labile, intermediate, and stable SOC pools from respiration curves, with non-hydrolyzable SOC as the stable pool. Measured soil properties include pH, exchangeable cations, CEC, inorganic/organic C, texture, oxalate-extractable Al/Fe (active Al/Fe), and dithionite-extractable Al/Fe. SOC turnover over decades is regulated by the intermediate SOC pool, which is closely associated with mineral-associated SOM. Active Al/Fe, rather than exchangeable Ca²⁺, clay, or agricultural activity, controlled the stability of intermediate pool in both topsoil and subsoil. In topsoil, agricultural activity reduced light fraction carbon by 38 % and intermediate pool size by 34 %, but had no significant effect in subsoil or on more stable fractions/pools. Active Al/Fe had a stronger effect on stabilizing carbon in less carbon-saturated subsoil. SOM degradation was intense (e.g., high abundance of N-containing compounds) and was attributed to low active Al/Fe levels under drier conditions, and to elevated microbial activity driven by neutral-to-alkaline soil pH. Cultivation had a non-significant influence on SOM composition. In conclusion, the low SOC in neutral-to-alkaline IGP soils is primarily due to drying and elevated pH, which limits active Al/Fe formation, thereby reducing SOC stability and intensifying SOM degradation. Cultivation further exacerbates SOC loss in topsoil. This highlights the need for understanding and targeted management of these SOM regulating factors to enhance ecological and agricultural sustainability in neutral-to-alkaline soils.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"258 ","pages":"Article 109215"},"PeriodicalIF":5.4,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240879","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}