Geoderma最新文献

{"title":"The influence of fine fraction content on storage and retention of soil organic carbon in Vertisols of subtropical Australia","authors":"Meghan Barnard ,&nbsp;Ram C. Dalal ,&nbsp;Zhe H. Weng ,&nbsp;Steffen A. Schweizer ,&nbsp;Peter M. Kopittke","doi":"10.1016/j.geoderma.2025.117269","DOIUrl":"10.1016/j.geoderma.2025.117269","url":null,"abstract":"<div><div>The proportion of fine mineral particles in soils is a broadly used predictor of soil organic carbon (SOC) storage based on the potential enhancement of organo-mineral associations with increasing mineral surface area. However, the influence of increasing fine fraction content on SOC pools remain understudied in high clay soils (&gt;50 % clay). We investigated SOC storage across paired native and cropped Vertisols from subtropical Australia, spanning a range of fine fraction (soil minerals &lt; 53 µm) contents from 481-927 g fine fraction kg⁻¹. The free particulate organic matter (fPOM), occluded POM (oPOM) and fine mineral-associated organic matter (fine-MAOM) were isolated by density and particle-size fractionation to assess SOC storage along the fine fraction gradient. The role of other mineral properties, such as specific surface area, was also examined. Overall, native soils revealed SOC in the unfractionated soil and the SOC fractions were poorly related to fine fraction content. Moreover, specific surface area increased substantially with fine fraction content, but SOC coverage on mineral surfaces was low (15–23 %), suggesting that MAOM formation is unrelated to the mineral surface area. By comparing native and cropped soils, we found that greater fine fraction contents did not enhance SOC retention in any fraction in the paired-cropped soils, indicating SOC retention is decoupled from fine fraction content in these Vertisols. We conclude that although fine-MAOM is important for SOC storage (storing 46–85 % of SOC in these soils), improved soil practices should prioritise the management of POM to maintain SOC in the fine-MAOM fraction of fine-textured Vertisols.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117269"},"PeriodicalIF":5.6,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of element release by weathering in soils of southern Ecuador: A comparison among different climatic and land-use regimes","authors":"Daniel Schöndorf ,&nbsp;Nuria Basdediós ,&nbsp;Andre Velescu ,&nbsp;Tobias Fabian ,&nbsp;Carlos Iván Espinosa ,&nbsp;Wolfgang Wilcke","doi":"10.1016/j.geoderma.2025.117263","DOIUrl":"10.1016/j.geoderma.2025.117263","url":null,"abstract":"<div><div>To predict future changes in nutrient availability in the young soils of the tropical Andes, it is important to study the response of weathering rates to climate and land-use change. This is particularly true in highly biodiverse tropical forests, where increasing nutrient availability can threaten their biodiversity. Hence, our objectives were to compare the kinetics of element release by weathering along an elevation gradient and between forest and pasture in a tropical montane forest region in south Ecuador. We collected soil samples from three plots in both natural forest and pasture, at elevations of 1000, 2000, and 3000 m above sea level (a.s.l., i.e., 18 in total). The sites at 2000 and 3000 m a.s.l. had similar parent material and allowed for evaluating the climatic effect. To assess element mobilization from the soil, we conducted a weathering experiment at a constant pH value (pH_stat). During the experiment, ions were released from the soil into solution at pH 3 and removed from the solution using an ion-exchange resin. We described the release of base cations (Ca, Mg, K), Mn, Al, and Fe with a two-step first-order reaction, distinguishing a fast-reacting pool (FP) and a slow-reacting pool (SP), with their associated rate constants. The FP of Ca, Mg, K, and Mn closely correlated with and corresponded in size to the concentrations of the exchangeable cations of these elements (<em>r</em> = 0.78 – 0.96). The FP of Ca, Mg, K, and Mn was significantly larger in the soils under pasture than under forest vegetation, likely because of the input of alkaline ashes during slash-and-burn practices. The sizes of the FP and the SP of all studied elements under both land covers/uses were not significantly different between the sites at 2000 and 3000 m a.s.l., possibly because the opposing effects of increasing precipitation and decreasing temperature canceled each other out. Metal release kinetics differed markedly among sites with different parent materials, indicating that weathering is strongly influenced by the chemical composition of the parent rocks. Our study illustrates that element release by weathering in the soils of south Ecuador is strongly influenced by differences in land cover/use and chemical composition of parent rocks.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117263"},"PeriodicalIF":5.6,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate and human activities alter coupling of soil macro- and micronutrients: Evidence from a long-term experiment in typical steppes","authors":"Yi Zhou ,&nbsp;Shenghua Chang ,&nbsp;Xiaojuan Huang ,&nbsp;Wenjun Wang ,&nbsp;Fujiang Hou ,&nbsp;Yanrong Wang ,&nbsp;Zhibiao Nan","doi":"10.1016/j.geoderma.2025.117250","DOIUrl":"10.1016/j.geoderma.2025.117250","url":null,"abstract":"<div><div>Soil nutrients are essential for ecosystem function and food production. However, the long-term dynamics and ecological drivers of soil macro- and microelements, as well as their relationships, remain virtually unknown, especially in varying precipitation contexts. Here, we conducted a long-term experiment in typical steppes to explore the universal and differential mechanisms of soil macro- and microelements along the precipitation gradient. Our results showed decreases in soil Zn and Fe stocks, alongside increases in Cu, SOC, and STN stocks over time. From north to south, the temporal stability of SOC, STN, Cu and Zn stocks generally increased. Additionally, compared to the humid site, soil macronutrients showed stronger coupling with micronutrients at the arid site, especially Fe, followed by Mn, Zn, Cu. The sensitivity of soil macro- and microelements to climate change and human activities were correlated with the local background precipitation. Precipitation fluctuation, GDP per capita and current precipitation were significant factors contributing to the variation in soil macro- and microelements stock in the north, center and south. Climate explained 46%, 19%, and 16% of nutrient coupling variation in the north, center, and south sites, respectively. Across all sites, human activities explained 74% of variation. Altogether, our findings provide an overview of long-term soil macro- and microelement distribution, their coupling relationships, and driving factors under different precipitation contexts, which is important for grassland management and food production in future global change scenarios.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117250"},"PeriodicalIF":5.6,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing soil quality in association with frozen ground in the source areas of the Yangtze and Yellow Rivers, Qinghai-Tibet Plateau","authors":"Shizhen Li ,&nbsp;Dongliang Luo ,&nbsp;Jinniu Wang ,&nbsp;Yanqiang Wei ,&nbsp;Ziqiang Yuan","doi":"10.1016/j.geoderma.2025.117264","DOIUrl":"10.1016/j.geoderma.2025.117264","url":null,"abstract":"<div><div>Frozen-ground environments represent one of the most fragile ecosystems in the source areas of the Yangtze and Yellow Rivers (SAYYR), characterized by persistently low temperatures and slow decomposition of soil organic matter, which sustains substantial soil organic carbon reserves. As climate warming intensifies, ecological stressors in the SAYYR increasingly threaten soil conditions. However, research on soil quality within the SAYYR remains scarce. This study systematically assessed soil quality through vegetation and soil surveys and analyses across 12 sites in the SAYYR. A soil quality index (SQI) was calculated using a selected minimum dataset comprising total nitrogen (TN), total phosphorus (TP), total kilocalorie (TK), available phosphorus (AP), available kilocalorie (AK), and total dissolved salt (TDS). Results revealed that the CLQ site, abundant in organic matter, exhibited the largest average SQI at 0.59, while the CMEH site located in seasonally frozen ground recorded the lowest value (0.26), highlighting the influence of frozen soil types on soil quality. The regional average SQI in the SAYYR was 0.44, indicating moderate soil quality. Diagnostic modeling identified TN as the primary constraint on soil quality in the SAYYR, with an average obstacle rate of 22.4%. Further analysis showed that fractional vegetation coverage and aboveground biomass were key determinants of soil quality in the SAYYR. The interaction between fractional vegetation coverage and mean annual ground temperature explained 58% of soil quality variability, the highest among tested factors. Additionally, the interactions of altitude with vegetation cover and vegetation cover with aboveground biomass accounted for 47.6% and 45.1% of variability, respectively. Results underscored the necessity of integrating vegetation characteristics, altitude, and frozen-ground thermal conditions to interpret soil quality variations in the SAYYR. This study provided valuable scientific insights and theoretical foundations for guiding ecological conservation, climate adaptation, and frozen-ground preservation in the SAYYR.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117264"},"PeriodicalIF":5.6,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Legume introduction increases soil organic carbon in grassland via regulation of microbial metabolism regardless of phosphorus fertilization","authors":"Meiqi Guo ,&nbsp;Tongtian Guo ,&nbsp;Gaowen Yang ,&nbsp;Nan Liu ,&nbsp;Jiqiong Zhou ,&nbsp;Yingjun Zhang","doi":"10.1016/j.geoderma.2025.117262","DOIUrl":"10.1016/j.geoderma.2025.117262","url":null,"abstract":"<div><div>Introducing legumes into grasslands can enhance soil organic carbon (SOC) storage, but high phosphorus (P) requirement of legume nitrogen (N) fixation may accelerate soil P depletion. As a result, P fertilizers are often applied to improve legume performance. However, the effects of legume introduction and P availability on SOC storage in grasslands remain poorly understood. In this study, we investigated how legume introduction and P fertilization influence SOC physical fractions and associated microbial metabolic activities, based on a ten-year field experiment. Our results showed that legume introduction increased mineral-associated organic carbon (MAOC) by 7.4 % and total SOC by 5.7 % compared to grasslands without legume introduction. This enhancement can be attributed to the improved soil substrate quality (lower carbon to nitrogen ratio) and enhanced microbial carbon (C) limitation (relative microbial nutrient limitation calculated using vector analysis based on ecoenzymatic stoichiometric theory models), which led to higher microbial carbon use efficiency (CUE) and lower microbial metabolic quotient (<em>q</em>CO₂). Phosphorus fertilization reduced microbial biomass and <em>q</em>CO₂ by increasing microbial C limitation, thereby leading to a 9.3 % increase in particulate organic carbon (POC); however, it did not affect SOC compared to no P fertilization. Moreover, the positive effect of P on POC was observed only when legume was not introduced, indicating legume introduction weakened this positive effect. In conclusion, introducing legumes to natural grasslands can enhance long-term SOC stabilization and storage by stimulating microbial metabolic activity, offering a sustainable strategy to improve soil fertility and agricultural productivity without the need for P fertilization.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117262"},"PeriodicalIF":5.6,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Field experiment reveals varied earthworm densities boost soil organic carbon more than they increase carbon dioxide emissions","authors":"Yufeng Qiu ,&nbsp;Ronggui Tang ,&nbsp;Yihong Liu ,&nbsp;Youchao Chen ,&nbsp;Yuye Shen ,&nbsp;Shoujia Zhuo ,&nbsp;Yanjiang Cai ,&nbsp;Scott X. Chang","doi":"10.1016/j.geoderma.2025.117251","DOIUrl":"10.1016/j.geoderma.2025.117251","url":null,"abstract":"<div><div>Earthworms play crucial roles in regulating soil organic carbon (SOC) and greenhouse gas emissions in forest soils. Laboratory studies have proven that they promote soil carbon dioxide (CO₂) emissions. However, the effects of earthworm activity on forest soil CO₂ emissions and organic carbon (C) have not yet been quantified in situ, and the impact of different earthworm densities remain unclear. In this study, we investigated how earthworm (<em>Pheretima guillelmi</em>) activity at three densities (no earthworms, original density, and double the original density) affected SOC, its labile fractions, C-related enzyme activities, and soil CO₂ emissions in a Moso bamboo (<em>Phyllostachys edulis</em>) forest ecosystem over a six-month field experiment. Our results showed that the original earthworm density resulted in a 23.4 % increase in soil CO₂ emissions, while double the original earthworm density resulted in a 9.6 % reduction in emissions compared to the original density. Additionally, earthworms at both densities significantly increased the concentration of SOC and its labile fractions. Notably, the increase in SOC density (SOCD, SOC stock per unit land area, kg C ha⁻¹) induced by earthworm activity far exceeded the increase in CO₂-C emissions. Specifically, the earthworms at double the original density led to an 8.8-fold increase in SOCD, while the original density resulted in a 3.7-fold increase. Furthermore, our findings identified dissolved organic C (DOC) as the most critical labile organic C fraction influencing soil CO₂ emissions associated with earthworm activity, while β-glucosidase (BG) was the most significant C-related enzyme affecting soil CO₂ emissions driven by earthworm activity. These results provide important insights into the role of earthworms in both CO₂ emissions and SOC accumulation in subtropical forests.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117251"},"PeriodicalIF":5.6,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of Ca-bridged organic matter in an alkaline soil, as revealed by multimodal chemical imaging","authors":"Tamas Varga ,&nbsp;Ravi K. Kukkadapu ,&nbsp;Libor Kovarik ,&nbsp;Alice C. Dohnalkova ,&nbsp;Qian Zhao ,&nbsp;Mark H. Engelhard ,&nbsp;Swarup China ,&nbsp;Nurun Nahar Lata ,&nbsp;Anil K. Battu ,&nbsp;Rosalie K. Chu ,&nbsp;Matthew A. Marcus ,&nbsp;Thomas W. Wietsma ,&nbsp;Daniel E. Perea ,&nbsp;Lye Meng Markillie ,&nbsp;Hugh D. Mitchell ,&nbsp;Rene M. Boiteau ,&nbsp;James J. Moran ,&nbsp;Kirsten S. Hofmockel","doi":"10.1016/j.geoderma.2025.117256","DOIUrl":"10.1016/j.geoderma.2025.117256","url":null,"abstract":"<div><div>Mineral–organic matter (OM) studies have predominantly focused on acidic soils that are abundant in iron (Fe) oxides and aluminum (Al) oxides. We have probed mineral–OM interactions in an alkaline or calcareous soil of the Aridisols class. Unlike the role of Fe and Al, the role of Ca-minerals (particularly calcite), which are ubiquitous in alkaline soils, in OM sequestration is not well understood. Multiple recent model studies with aqueous Ca²⁺ or synthetic calcite and a suite of OM compounds have shown Ca-OM assemblages to be spatially correlated with calcite at the microscale. To study the chemical state of both Ca and Fe and their competing role in soil organic matter (SOM) stabilization, we performed laboratory characterization using x-ray diffraction, Mössbauer spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and scanning transmission electron microscopy, alongside synchrotron-based microscale chemical imaging using scanning transmission x-ray microscopy combined with near-edge x-ray absorption fine structure. Ca mineral–organic associations were found to be ubiquitous in this system and are likely critical for understanding SOM stabilization/degradation in alkaline soils. From our findings on mineralogy, speciation, and the nature of Ca-OM bridging, we identified differences in C and Ca chemistry based on the relative location of OM to Ca minerals. The OM near the calcite crystal was enriched in lipid and protein moieties, Ca-OM next to Fe minerals displayed a strong contribution from aromatic compounds, while on the surface of microbes, the carbonate was believed to be of microbial in origin, as also suggested by preliminary works reporting on the formation of amorphous calcite or nano-calcite. In Ca-OM admixed with carbonate, it was difficult to distinguish Ca-associated OM from amorphous calcite or nano-calcite.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117256"},"PeriodicalIF":5.6,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The predominance of root- and salt-marsh-derived soil organic carbon in a mangrove poleward range expansion front","authors":"Prakhin Assavapanuvat ,&nbsp;Joshua L. Breithaupt ,&nbsp;Ding He ,&nbsp;Ralph N. Mead ,&nbsp;Thomas S. Bianchi","doi":"10.1016/j.geoderma.2025.117249","DOIUrl":"10.1016/j.geoderma.2025.117249","url":null,"abstract":"<div><div>Due to global warming, temperate salt marshes (e.g., <em>Spartina alterniflora</em> and <em>Juncus roemerianus</em>) are being overtaken by poleward migrating mangroves (e.g., <em>Avicennia germinans</em> and <em>Rhizophora mangle</em>). While bulk soil organic carbon (SOC) stocks have been widely compared across mangrove and salt marsh habitats, differentiation of SOC derived from leaves and roots of each mangrove and salt marsh species remains a challenge. Hence, we used multiple biomarkers and proxies (stable isotopes, lignin oxidation products, <em>n</em>-alkanes, sterols, and triterpenoids) to quantify the relative contribution of leaves and roots of each plant taxon to bulk SOC in a mangrove-salt marsh ecotone in Apalachicola (Florida, USA). The shallow peaks of mangrove leaf biomarker (α-amyrin for <em>A. germinans</em>, taraxerol for <em>R. mangle</em>) suggested the deposition of mangrove leaf-OC over soil surface after the initial mangrove establishment, while the abundance of betulin and 3,5-dihydroxy benzoic acid in <em>A. germinans</em> and <em>R. mangle</em> deep soils, respectively, indicated subsurface contribution of mangrove root-OC, down to 45-cm depth. Based on mixing models, the principal source of SOC in mangrove habitats has shifted from <em>S. alterniflora</em> roots to mangrove roots. The total contribution of roots to the SOC pool in mangrove habitats was 69.0–86.1 %, highlighting that SOC was preferentially formed belowground. Interestingly, within ∼34 years after initial mangrove establishment, the majority (62.3–74.0 %) of SOC in mangrove habitats continues to be derived from pre-existing salt marshes. This emphasizes that comparing bulk SOC without considering their actual sources could result in an overestimation of the contribution of encroaching mangroves to SOC stocks.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117249"},"PeriodicalIF":5.6,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of vegetation restoration on soil organic carbon on the Loess Plateau, China using a combined remote sensing and process-based modeling approach","authors":"Xianlei Fan ,&nbsp;Yunqiang Wang ,&nbsp;Ying Qu ,&nbsp;Edith Bai","doi":"10.1016/j.geoderma.2025.117260","DOIUrl":"10.1016/j.geoderma.2025.117260","url":null,"abstract":"<div><div>A series of vegetation restoration programs (VRPs) have been implemented on the Loess Plateau, China to increase vegetation cover and soil organic carbon (SOC) content. Here, we used a Coupled Litter-Soil (CLS) model to estimate the spatiotemporal distribution of SOC change (0–100 cm) on the VRPs areas on the Loess Plateau from the vegetation restoration starting to 2100. The vertical transport process of SOC along the profile was considered in the model. Due to the starting time of VRPs varied across different areas on the Loess Plateau, we detected the implementation areas and starting times of VRPs from remote sensing data to constrain the model. Results indicate that between the restoration starting and the year 2022, VRPs areas increased a total of 0.8 Pg C of SOC (0–100 cm), showing an increasing trend of SOC from northwest to southeast on the Loess Plateau, China. Under the business-as-usual scenario (2022), our model predicts that SOC will reach a steady-state after 150 years of VRPs implementation, with a potential SOC storage of 2.9 Pg C (0–100 cm). The differences in SOC density among different future climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) were non-significant. Our study provides a platform for combining remote sensing techniques and a process-based model to better estimate and predict SOC change after the implementation of an ecological restoration program.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117260"},"PeriodicalIF":5.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The diversity, composition and potential function of bacterial size fractions from maize and soybean farmland soils","authors":"Xuemei Hu ,&nbsp;Chang Wang ,&nbsp;Siyuan Wang ,&nbsp;Yinghui Cao ,&nbsp;Haofei Zhang ,&nbsp;Chang Liu ,&nbsp;He Sun ,&nbsp;Yajun Gao ,&nbsp;Shanshan Yang ,&nbsp;Sanfeng Chen ,&nbsp;Sen Du ,&nbsp;Gehong Wei ,&nbsp;Weimin Chen","doi":"10.1016/j.geoderma.2025.117241","DOIUrl":"10.1016/j.geoderma.2025.117241","url":null,"abstract":"<div><div>Agricultural soil microbiomes, with their varied cell sizes and metabolic capabilities, contribute significantly to differences in soil ecosystem functions and services. However, the relationships among bacterial cell size, community structure and nutrient turnover in agricultural soils remain unclear. This study categorized bacterial cells from maize and soybean fields into five distinct size fractions—F1 (&gt;10 μm), F2 (3–10 μm), F3 (1–3 μm), F4 (0.4–1 μm) and F5 (0.2–0.4 μm)—using polycarbonate membrane filtration. High-throughput sequencing of the 16S rRNA gene and soil incubation subsequently revealed the taxonomic composition and potential functions of each size fraction. The results indicated that the bacterial diversity in maize field soil was greater than that in soybean field soil, with the F4 size fraction exhibiting the highest diversity and abundance in both soils, whereas the F1 size fraction showed the lowest. <em>Proteobacteria</em> dominated across all size fractions, and size-specific taxonomic distributions were observed: <em>Myxococcota</em>, <em>Entotheonellaeota</em> and <em>Cyanobacteria</em> were enriched in F1 and F2; <em>Planctomycetota</em> and <em>Chloroflexi</em> were enriched in F3; <em>Bacteroidota</em>, <em>Verrucomicrobiota</em>, <em>Actinobacteriota</em> and <em>Firmicutes</em> were enriched in F4 and F5. Before incubation, the qPCR of functional genes showed that the F1–F3 fractions exhibited highly active ammonia oxidation (F1, F2) and ammonification (F3), while the F4 fraction presented highly efficient organic P mineralization, when compared to other fractions. After incubation, qPCR and soil property analyses revealed that the F4 fraction exhibited highest increase in cell numbers and regulated C and P turnover through the secretion of BG and AKP, whereas the F1 fraction consistently maintained high ammonia oxidation capacity. These findings illustrate that bacterial taxa vary in cell size and nutrient turnover processes under different land-uses, thereby deepening our understanding of the bacterial ecology in farmlands.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"456 ","pages":"Article 117241"},"PeriodicalIF":5.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}