Geoderma Regional最新文献

{"title":"Assessing the impact of soil use and management systems on soil health in Southern Brazil","authors":"Regiane Kazmierczak Becker ,&nbsp;Carolina Weigert Galvão ,&nbsp;Rafael Mazer Etto ,&nbsp;Daiane Hyeda ,&nbsp;Ariane Lentice de Paula ,&nbsp;Luis Miguel Schiebelbein ,&nbsp;Neyde Fabíola Balarezo Giarola","doi":"10.1016/j.geodrs.2025.e00932","DOIUrl":"10.1016/j.geodrs.2025.e00932","url":null,"abstract":"<div><div>The growing demand for adopting more sustainable agricultural management practices worldwide has prompted soil health assessment studies. In southern Brazil, there is a growing diversification in soil use and management systems. This study aimed to evaluate soil health under different soil use and management systems in this region using the Soil Management Assessment Framework. The study investigated secondary forest, no-tillage, and pasture across three mesoregions of Paraná State: West, Southwest, and Central East. Soil health was evaluated in the surface layer, and the Kruskal-Wallis test was used to assess the effect of soil use and management on soil health. Scores for bulk density, water-filled pore space, pH, phosphorus, potassium, microbial biomass carbon, and β-glucosidase activity were sensitive to detecting changes in soil conditions. However, other indicators, such as macroaggregate stability and total organic carbon, need refined algorithms for regional adaptation. Differences in soil health among soil use and management were observed. Secondary forest generally maintained optimal soil health indices, with values above 0.86. No-tillage showed good soil health indices in the evaluated layer, with values above 0.80. Notably, no-tillage with organic agricultural systems and the application of organic residues appeared to contribute positively to soil health improvement, with indices reaching 0.86 and 0.89, respectively. Pastures, especially silvopasture, showed potential for improving soil health through plant diversity, achieving an index of 0.88. We suggest that future studies compare different soil health indices to improve algorithms for interpreting soil health indicators on a regional scale.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00932"},"PeriodicalIF":3.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Importance of sampling frequency for the observed dynamics of SOC content in the Danish long-term monitoring network","authors":"Laura Sofie Harbo ,&nbsp;Rojina Lama ,&nbsp;Camilla Lemming ,&nbsp;Lars Elsgaard","doi":"10.1016/j.geodrs.2025.e00931","DOIUrl":"10.1016/j.geodrs.2025.e00931","url":null,"abstract":"<div><div>Monitoring soil organic carbon (SOC) content is crucial for understanding the role of agricultural soils in carbon sequestration and climate change mitigation. However, the influence of sampling frequency on the accuracy of SOC content trends remains an open question. This study investigates the effect of different sampling intervals using soils from the Danish long-term Soil Monitoring Network (SMN), which includes both decadal (every 10–12 years) and more frequent (7–11 times over 30 years) sampling since 1986, where the latter samples were originally collected (and archived) for analysis of soil mineral nitrogen. Our results show that decadal sampling effectively captures long-term SOC content trends, with no significant differences compared to more frequent sampling. Year-to-year variability in SOC content was high, suggesting that short-term fluctuations may mask long-term trends. This variability is reduced when SOC content trends are analysed over multi-year periods. To balance resource limitations with the need for temporal resolution, we suggest that a 3–5 year sampling scheme could be implemented, where a subset of SMN sites is sampled each year. This approach would provide finer temporal detail without the cost and effort of annual monitoring, while maintaining the ability to detect meaningful trends in SOC content dynamics. From an operational perspective, a rotational or rolling sampling strategy where only a fraction of sites (e.g., 20–30 %) are sampled each year such that all sites are eventually sampled in the monitoring period, would also help to maintain continuity of field expertise and laboratory capacity, ensuring consistent data quality over time.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00931"},"PeriodicalIF":3.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Land use change and forest management affect soil carbon stocks in the central hardwoods, U.S.","authors":"Lucas E. Nave ,&nbsp;Kendall DeLyser ,&nbsp;Grant M. Domke ,&nbsp;Scott M. Holub ,&nbsp;John M. Kabrick ,&nbsp;Adrienne B. Keller ,&nbsp;Patricia Leopold ,&nbsp;Matthew P. Peters ,&nbsp;Kevin A. Solarik ,&nbsp;Christopher W. Swanston","doi":"10.1016/j.geodrs.2025.e00930","DOIUrl":"10.1016/j.geodrs.2025.e00930","url":null,"abstract":"<div><div>Most research addressing land use change and forest management effects on soil carbon (C) is conducted at large or localized scales, rather than intermediate scales where management is planned and implemented. We assessed effects of land use and forest management on soil C stocks, for the Central Hardwoods ecoregion of the U.S., using meta-analysis, soil survey and national forest inventory databases to examine baseline controls on soil C stocks and their responses to land use and forest management. Biotic and geologic factors drive baseline variation in soil C stocks across the ecoregion, with forest type and productivity being most important in surface horizons and parent material dominating at the whole profile level. Among forest management treatments, prescribed fire is most noteworthy, decreasing O horizons to an extent determined by place and practice (mean: −53 %). Coal mine reclamation is extensive in the region, and while there is no effect of forest vs. herbaceous reclamation, distinct overburden types have different effects on soil C stocks (mean: +183 %). Land use change effects on soil C are difficult to determine due to the preferential use of the most favorable soils for agriculture, the relegation of forests to the least productive soils, and the tendency for reforestation to occur on marginal soils. Overall, our results can help forest managers anticipate the C outcomes of typical burn prescriptions in this region of extensive prescribed fire, and help landowners and planners understand how parent material and soil properties influence soil C stocks under agriculture and mine reclamation.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00930"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing soil multifunctionality of coastal peat grasslands","authors":"C.T. Kraamwinkel ,&nbsp;J.A. Beaulieu ,&nbsp;S.C. Feron ,&nbsp;C. Vazquez ,&nbsp;W. de Haan ,&nbsp;R.A. Howison","doi":"10.1016/j.geodrs.2025.e00929","DOIUrl":"10.1016/j.geodrs.2025.e00929","url":null,"abstract":"<div><div>Soils have the capacity to provide a wide range of soil functions that can help address socio-environmental challenges, such as climate change and biodiversity loss. Here, we apply the Functional Land Management framework aimed at optimally balancing supply and demand of soil functions at a landscape-scale to drained coastal peat (<em>Histosols</em>) in Friesland, The Netherlands. We focus on the supply side by assessing the capacity of grassland peat soils with different topsoil types to provide five soil functions: climate regulation, habitat provision, nutrient cycling, water storage, and primary productivity. A field campaign was conducted in March 2022 to collect data on soil, water, vegetation, and management from 30 grasslands mapped as peat on the national soil map (Basisregistratie Ondergrond). Results revealed significant differences in above and belowground field conditions between peat with different topsoil types. Peat soils with a mineral cover are predominantly used as grasslands for dairy farming, with a clear differentiation in functioning between fields managed by organic and conventional farmers. Peat soils without a mineral cover are generally owned by nature organizations and managed as semi-natural grasslands aimed at optimizing aboveground habitat provision. Our results show that conventional agricultural management, including deep drainage and high fertilizer inputs, results in moderate to high nutrient cycling and primary productivity, along with low climate regulation, water storage and habitat provision. Extensification results in a decrease in primary productivity and nutrient cycling along with a strong increase in climate regulation, water storage, and habitat provision. To optimize landscape-scale provision of soil functions, we recommend promoting soil multifunctionality while maintaining moderately high yields on peat with a mineral cover. To benefit from the unique and yet unmet potential of peat soil for climate regulation and water storage, we recommend tailoring management of peat soils without a mineral cover to fully restore natural peatlands.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00929"},"PeriodicalIF":3.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Better management zoning with elevation than with three soil classifications in a periodically waterlogged plot","authors":"Tibor Tóth ,&nbsp;Szilárd Szabó ,&nbsp;Tibor Novák ,&nbsp;Szabolcs Czigány ,&nbsp;Mihály Kocsis ,&nbsp;András Makó ,&nbsp;Bence Gallai ,&nbsp;Mátyás Árvai ,&nbsp;János Mészáros ,&nbsp;Kitti Balog","doi":"10.1016/j.geodrs.2025.e00927","DOIUrl":"10.1016/j.geodrs.2025.e00927","url":null,"abstract":"<div><div>Following a comparison of the practical applicability of USDA Soil Taxonomy (ST), Hungarian soil classification (HU), and WRB in a slightly saline alluvial plot (Tóth et al., 2021), in this study, we compared the polygon alignment derived from the three systems, relative to the pattern of elevation and mean NDVI. The final objective focused on delineating potential management zones. The study plot is the largest salt-affected plot in the country (0.9 km^{<strong>2</strong>}). Within this plot, 85 undisturbed, 1 m deep profiles were collected, sampled, described and classified using a 100 × 100 m grid. We described the polygon alignment qualitatively and through the use of landscape metrics. Additionally, we evaluated number of classes and polygons, and delineated potential management zones based on environmental variables.</div><div>Large dominant polygons were found at level 1, the least detailed of all three classifications. The polygons became increasingly fragmented at levels 2, 3 and 4, where isolated single raster cell polygons dominated the plot in each classification: 96 % in WRB, 73 % in HU and 70 % in ST, compared to the total number of polygons. Landscape metrics proved that ST exhibited the best north–south orientation (the orientation of highs/lows), length, perimeter, area, aggregation and interspersion/juxtaposition of polygons. HU showed an intermediate performance, while WRB had the least satisfactory alignment with the north–south orientation, length, perimeter and area, as well as patch cohesion and aggregation of polygons. After analyzing the scatterplot of elevation versus mean NDVI, and also elevation versus long-term NDVI range, we noted a cutpoint of 95.47 m, which separated the more productive and less variable zone from the lower lying less productive less certain zone, given its periodical precipitation-related waterlogging.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00927"},"PeriodicalIF":3.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Soil organic carbon dynamics (2008–2020) across different cultivated land use types in a subtropical region","authors":"Jianming Li ,&nbsp;Siqi Li ,&nbsp;Rui Zhao ,&nbsp;Shihe Xing ,&nbsp;Hanyue Chen ,&nbsp;Yan Huang ,&nbsp;Liming Zhang ,&nbsp;Jing Li","doi":"10.1016/j.geodrs.2025.e00926","DOIUrl":"10.1016/j.geodrs.2025.e00926","url":null,"abstract":"<div><div>Soil organic carbon (SOC) improves soil structure, retains water, and increases nutrient availability, which enhances crop productivity and serves as a significant carbon sink for climate mitigation. While it has been proposed that alterations in land use can significantly influence SOC sequestration, limited research has delved into the distinct impacts of various types of cultivated land use. The main objective of this study was to compare differences in SOC dynamics across diverse cultivated land use types in 84 counties (cities and districts) within Fujian Province, a typical subtropical area of China. This study utilizes 230,445 measured soil samples and a high-resolution 1:50,000 soil map—the most detailed database of its kind applied at the provincial scale—to simulate SOC dynamics under different cultivated land use types from 2008 to 2020. By integrating this comprehensive dataset with the DNDC (Denitrification and Decomposition) model, our approach offers greater spatial precision and more robust simulations. The results indicated that the average annual soil carbon sequestration rate (<em>d</em>_<em>SOC</em>) for all cultivated land, paddy fields, dry land, and irrigated land, was 13.16, 30.98, −12.31, and −5.52 kg·ha⁻¹, respectively. The total change of SOC (<em>T</em>_{<em>ΔSOC</em>}) values were 171.06 Gg and 402.80 Gg for all cultivated land and paddy fields, while they were −160.20 Gg and −71.72 Gg for dry land and irrigated land, respectively. Over the past 13 years, the interannual variations of <em>T</em>_{<em>ΔSOC</em>} reveal a range of −263.66 to 254.71 Gg across all cultivated land in the province. Positive <em>T</em>_{<em>ΔSOC</em>} for all cultivated land dominated from 2008 to 2016, while a shift to negative values is apparent after 2017. In general, the cultivated land throughout the province displayed a modest carbon-sink behavior. More specifically, paddy fields functioned as effective carbon sinks, while both dry land and irrigated land behaved as carbon sources. The high initial SOC content is the main direct factor negatively correlated with <em>d</em>_<em>SOC</em>. Rainfall indirectly reduces <em>d</em>_<em>SOC</em> by promoting an increase in clay content in both dry land and irrigated land. To improve future agricultural management, we should increase the amount of organic fertilizer applied to paddy field while maintaining economic efficiency and crop growth, and apply biochar and implement wet season drainage for both dry and irrigated land.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00926"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A coupled model of greenhouse gas emissions from erosion and accretion prone zones of mangrove ecosystem, Sundarban, India","authors":"Nilanjan Das ,&nbsp;Debarati Pal ,&nbsp;Rabin Chakrabortty ,&nbsp;Subodh Chandra Pal ,&nbsp;Sudipto Mandal","doi":"10.1016/j.geodrs.2025.e00928","DOIUrl":"10.1016/j.geodrs.2025.e00928","url":null,"abstract":"<div><div>Soil erosion (SE) and accretion process resulting from anthropogenic and natural causes has a substantial impact on soil quality and functionality, thereby influencing greenhouse gas (GHG) emissions. Here, the determination of the extent of SE, resultant accretion and emissions of GHGs like CO₂, CH₄, and N₂O was quantified from the Sundarban mangrove ecosystem (SME). A Random Forest (RF) spatial model was proposed to predict the geographical distribution of GHG emissions throughout the Sundarban. Gas samples were gathered from the mangrove bed in 2022 using the enclosed box technique. Next, the <em>Shuttle Radar Topographic Mission Digital Elevation Model (</em>SRTM DEM), and Landsat 8 data were used to produce thematic inputs for the RUSLE model in a GIS platform. Both models were coupled to observe the match between erosion and GHG emission. The result showed that coastal most western part of Sundarban is prominent for CO₂ (28.29–31.29 mmol m⁻² d⁻¹) and CH₄ (0.281–0.329 mmol m⁻² d⁻¹) emission while N₂O fluctuated more (0.137–0.169 mmol m⁻² d⁻¹) at central eastern part due to high deforested agriculture and aquaculture practices. The study revealed that the islands of Sundarban, located at the edge of the Bay of Bengal (BoB) have an increased risk of SE (&gt;12 t ha⁻¹ yr⁻¹) as these islands encounter high oceanic water surges and cyclones yearly. The accuracy of the models were adjudged by the estimation of SE and GHG emission. The measured precision and area under the curve of receiver operating characteristics was 0.796 for RUSLE and 0.784 for RF models, respectively. An “Automated Linear Regression (ALR) model” showed that N₂O was the most sensitive (Normalized Importance: 0.55) to erosion. Regression results showed association between GHGs and erosion were weakly correlated (R² for CO₂, CH₄, and N₂O were 54.79 %, 43.51 %, and 55.08 %). According to the “Artificial Neural Network (ANN) model, rainfall and runoff erosivity factor (R)” was the prime governing factor (normalized importance 100 %) for SE. The “RUSLE model” with “Coupled Model Intercomparison Project-6 (CMIP6)” “rainfall data”, a “Global Circulation Model (GCM)” and the historical climatic data from 1960 to 1989 revealed the CO₂, CH₄ and N₂O emissions would be 7.13 %, 39.25 %, and 38.18 % respectively by 2100. Accretion phenomena was more on the upstream regions of the Sundarban estuary. The work will help the environmental managers in identifying the erosion-prone zones, thereby reducing the land cover changes for anthropogenic benefits that promoted SE.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00928"},"PeriodicalIF":3.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen mineralization potential depletion in pampas (Argentina) croplands following conversion from native grasslands","authors":"Nicolas Wyngaard ,&nbsp;Cecilia Crespo ,&nbsp;Gisela Vanesa García ,&nbsp;Nahuel Ignacio Reussi Calvo ,&nbsp;Camila Rivero ,&nbsp;Walter Daniel Carciochi ,&nbsp;Mercedes Eyherabide ,&nbsp;Gastón Larrea ,&nbsp;Hernán Angelini ,&nbsp;Pablo Barbieri ,&nbsp;Hernán Rene Sainz Rozas","doi":"10.1016/j.geodrs.2025.e00925","DOIUrl":"10.1016/j.geodrs.2025.e00925","url":null,"abstract":"<div><div>In the Argentinean Pampas, where Phaeozems soils are predominant, the conversion of native grasslands into croplands has negatively affected soil fertility and health. Nitrogen (N) mineralized during an anaerobic incubation (N_an), an estimator of N potential mineralization, is frequently used to evaluate soil health. The objectives of our study were to determine the magnitude of the N_an depletion caused by agriculture (dN_an), and to assess the relative contribution of land use, climate, and soil properties on dN_an in the Argentinean Pampas. We conducted a soil survey at 409 sites distributed throughout the Argentinean Pampas region. At each site, pairwise samples (0–20 cm) were collected from uncultivated and agricultural soils. At each site, different edaphic, climatic, and productive variables were evaluated. The direct and indirect effect of different variables over dN_an was evaluated through a path analysis. The conversion of native grasslands from the Argentinean Pampas into croplands generally decreased N_an values, with N_an reductions ranging from 0 to 216 mg kg⁻¹ (representing 0 to 79 % of the N_an value at uncultivated soils). The magnitude of the N_an depletion was influenced by edaphic variables [i.e. original N_an value (N_an at uncropped soils), soil organic matter depletion, clay content] and climatic variables (i.e. precipitation). These four variables explained 85 % of the dN_an variability. From the path analysis, it was determined that soils with greater original N_an values (<em>r</em> = 0.89) and greater soil organic matter depletion (<em>r</em> = 0.65) presented larger dN_an, while increases in clay content (<em>r</em> = 0.30) or mean annual precipitation (<em>r</em> = 0.25) resulted in lower dN_an values. The identification of the drivers of N_an depletion can aid in the classification of areas with greater vulnerability to soil degradation and in the development of models to predict N_an depletion in soils. Such models would hold significant potential as tools for policymakers and program developers engaged in the formulation and implementation of targeted interventions aimed at halting or reversing this degradation process.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00925"},"PeriodicalIF":3.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing soil texture spatial prediction in the Brazilian Cerrado: Insights from random forest and spectral data","authors":"Marcelo Henrique Procópio Pelegrino ,&nbsp;Luiz Roberto Guimarães Guilherme ,&nbsp;Geraldo de Oliveira Lima ,&nbsp;Raul Poppiel ,&nbsp;Kabindra Adhikari ,&nbsp;José Melo Demattê ,&nbsp;Nilton Curi ,&nbsp;Michele Duarte de Menezes","doi":"10.1016/j.geodrs.2025.e00922","DOIUrl":"10.1016/j.geodrs.2025.e00922","url":null,"abstract":"<div><div>Soil texture is crucial for assessing soil quality, crop suitability, and land management. However, precise large-scale soil texture mapping remains challenging. This study integrated a Synthetic Soil Image (SySI) with standard environmental covariates in a digital soil mapping framework to map soil particle size distribution in Brazil's Cerrado biome. Four random forest model arrangements were explored for soil texture modeling. Using an extensive legacy dataset of Cerrado topsoil (0–20 cm), the most accurate model explained approximately 83 % of clay, 86 % of sand, and 74 % of silt variance, with RMSE values of 89 g kg⁻¹ (clay), 102 g kg⁻¹ (sand), and 53 g kg⁻¹ (silt). The findings revealed that elevation and bioclimate have strong predictive capacities, especially when bare soil spectra data are available. Elevation was the only relevant terrain derivative for predicting soil texture. This approach improved model interpretability and provided high-resolution, accurate soil texture maps, aiding users and public policies. Since 65 % of Cerrado soil classes (Ferralsols and Arenosols) do not significantly increase clay content with depth, this work adds value to agricultural soil mapping.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00922"},"PeriodicalIF":3.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic matter fractions and stabilization potential in some Andosols of Iran","authors":"Mohammad Ali Monajjem ,&nbsp;Eleonora Bonifacio ,&nbsp;Ahmad Heidari","doi":"10.1016/j.geodrs.2025.e00923","DOIUrl":"10.1016/j.geodrs.2025.e00923","url":null,"abstract":"<div><div>Soils play a vital role in the carbon cycle of terrestrial ecosystems, serving as both a source and a sink for carbon. However, the carbon storage capacity of soils is not yet fully understood. This study was conducted to investigate the actual and potential carbon stabilization in 12 selected soil samples from four out of 17 pedons of Andosols studied in the Alborz Mountain range of central Iran. To evaluate the present stabilization of OM, organic carbon (OC) fractionation was performed through chemical oxidation a followed by mineral dissolution. Various OC fractions were extracted and analyzed for their total organic carbon (TOC), nitrogen (N), and C/N ratios. The fractions include water-extractable organic carbon (WEOC), labile OC released by NaOCl, mineral-associated OC released by HF, and the recalcitrant OC fraction. Furthermore, the samples were incubated for 180 days to evaluate CO₂ emissions. The relationships between various forms of Fe, Al, Si, plus allophane, and sub-fractions of OC in the topsoil and subsoil samples were investigated. The high amounts of WEOC suggest poor stabilization of the organic compounds particularly for small and aromatic moieties. The negative correlation between clay and NaOCl-labile fraction (<em>r</em> = −0.696, <em>p</em> &lt; 0.01) implies a role of the mineral fraction in protecting C from oxidation. The organic matter (OM) released by the HF treatment accounted for small portion of OM with a very low C/N ratio suggesting that mineral-associated OM is mainly composed N-rich organic molecules. The recalcitrant fraction, instead, showed a higher C/N ratio. The amounts of OC released as CO₂ after 180 days incubation of the control samples represent an 8 to 18 % loss of the total OM. The stabilization potential was evaluated by adding Humic Acid (HA) to the samples and evaluating the CO₂ emissions upon incubation. Upon HA additions, CO₂ emission increased sharply until 30 days of incubation and then increased more smoothly. Interactions with minerals were found to be an important mechanism acting in the preservation of palatable, N-rich organic moieties, but this OM-pool did not dominate among OM fractions. Surprisingly, intrinsic recalcitrance seemed an important mechanism in the stabilization of organic matter, also thanks to the migration of small aromatic molecules in the subsoil horizons.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00923"},"PeriodicalIF":3.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}