Geoderma Regional最新文献

{"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":"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}

{"title":"Organic carbon stocks across various land use systems in Sandy Ultisols and Oxisols in Brazil","authors":"Maria Cecília Vieira Totti ,&nbsp;Yuri Lopes Zinn ,&nbsp;Sérgio Henrique Godinho Silva ,&nbsp;Bruno Montoani Silva ,&nbsp;Fernanda Almeida Bócoli ,&nbsp;Vanêssa Lopes de Faria ,&nbsp;Andrés Olaya Montes ,&nbsp;Salvador Francisco Acuña-Guzman ,&nbsp;Alexandre Uezu ,&nbsp;Laury Cullen Junior ,&nbsp;Vinícius Ferreira Fernandes ,&nbsp;Junior Cesar Avanzi","doi":"10.1016/j.geodrs.2025.e00924","DOIUrl":"10.1016/j.geodrs.2025.e00924","url":null,"abstract":"<div><div>Soil organic carbon (SOC) is a major carbon pool that can be easily affected by land use change, especially in tropical humid sandy soils, where organic decomposition is fast and SOC stabilization is weak. Here, we assessed SOC stocks in coarse-textured Oxisols and Ultisols under six contrasting land uses in western São Paulo, Brazil, an area marked by warm temperatures, within the Atlantic Rainforest biome. Soils were sampled for bulk density and SOC content to a 1-m depth in areas under a) primary native forest, b) native forest restoration, c) pastures, d) sugarcane, e) cassava, and f) annual crops. Even under primary forests, SOC stocks were low relatively to other Brazilian soils under cooler climates and with finer textures, and the effect of land use changes varied with soil type. In both soil types, the lowest SOC stocks occurred under cassava cultivation, a traditional indigenous crop with low soil coverage and which requires intensive soil disturbance for harvesting. In Ultisols, forest restoration and sugarcane presented the highest SOC stocks, whereas in Oxisols, the highest stocks occurred under primary forests and pastures, suggesting that gramineous perennial crops with little soil disturbance are effective in preserving or even sequestering SOC in these areas. When only primary forests are compared, SOC stocks in Oxisols were higher than in Ultisols, probably due the effect of higher soil bulk densities on the Ultisols, rendering root development and thus SOC accrual in subsoil more difficult.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00924"},"PeriodicalIF":3.1,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144470","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":"Eutrophic soils and weathering levels influence the distribution of seasonally dry forests in Brazil","authors":"Sara Ramos dos Santos ,&nbsp;Carolina Malala Martins Souza ,&nbsp;David Lukas de Arruda ,&nbsp;Danilo de Lima Camêlo ,&nbsp;Jairo Tronto ,&nbsp;Greice Leal Pereira ,&nbsp;Danilo Cesar de Mello ,&nbsp;Wilson Tadeu Lopes da Silva ,&nbsp;Liovando Marciano da Costa ,&nbsp;Carlos Ernesto Gonçalves Reynaud Schaefer","doi":"10.1016/j.geodrs.2025.e00921","DOIUrl":"10.1016/j.geodrs.2025.e00921","url":null,"abstract":"<div><div>Seasonally Dry Forests, or ‘Dry Forests,’ are characterized by deciduous vegetation that sheds leaf during the dry season due to strong soil moisture stress. Despite their ecological significance, as part of the Atlantic Forest realm, research on the diversity, genesis, and soil-vegetation interactions in these ecosystems remains limited. This study investigated the soil attributes of Dry Forests of an ecotonal zone, comparing with the neighboring biomes, the Caatinga (Steppe Savanna) and Cerrado (Brazilian Savanna). We analyzed 16 soil profiles, evaluating their physical, chemical, and mineralogical properties using Principal Component Analysis (PCA). Dry Forest soils (DFS) showed higher amounts of exchangeable cations such as Ca²⁺, Mg²⁺, and K⁺ (Sum of Bases: 2.84–14.79 cmol_c dm⁻³ in the surface horizons) and no detectable Al³⁺. The clay fraction of DFS is mainly illite and kaolinite. The PCA results (PC1: 29.4 %) revealed that Dry Forest soils, particularly on limestone, are more fertile than adjacent Caatinga and Cerrado soils. In contrast, according to the interpretation of PC2 (19.5 %) Cerrado soils are much more weathered and nutrient-depleted (Sum of Bases: 0.37–1.29 cmol_c dm⁻³ in the surface horizons), while Caatinga soils exhibit an intermediate fertility (Sum of Bases: 1.48–21.81 cmol_c dm⁻³ in the surface horizons), and less weathered. The lithologies under DFS at northern Minas Gerais are limestones of the Bambuí Group, resistant sedimentary rocks of the Macaúbas Group, and Granite/gneisses of the Crystalline Basement, which strongly influence soil fertility, mineralogy, and weathering degree. The higher nutrient levels and organic matter contents (2.05–12.03 % in the surface horizons) in DFS support greater productivity and biomass accumulation. These findings highlight the ecological significance of DFS on diverse geological substrates, offering insights for conservation, sustainable management, and ecological restoration in the face of increasing deforestation and land degradation threats.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00921"},"PeriodicalIF":3.1,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144467","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":"Transformation of Chernozem by increasing land use intensity in suburban Hajdúság, Eastern Hungary","authors":"Tibor József Novák,&nbsp;Áron Béni,&nbsp;Rita Kremper,&nbsp;Evelin Juhász,&nbsp;Ida Kincses,&nbsp;Zsolt Sándor,&nbsp;Magdolna Tállai,&nbsp;Andrea B. Kovács","doi":"10.1016/j.geodrs.2025.e00920","DOIUrl":"10.1016/j.geodrs.2025.e00920","url":null,"abstract":"<div><div>Chernozem under different agricultural land use were compared in a suburban area: three on cropland with different land use histories; one in an area of complex cultivation; one fallow; and one under grassland, considered to be in close to natural state, as a control. Soil profiles at each site were described and classified, and chemical characteristics analyzed in detail. Topsoil (0-40 cm) bulk density (BD), total organic carbon (TOC), total nitrogen (TN), ammonium lactate-extractable P, K, Ca and Mg were measured, and microbiological communities were characterized by phospholipid-fatty acid (PLFA) markers. We found significantly increased BD but decreased TOC and TN in the cultivated sites compared to the control. Values of ammonium lactate-extractable P (P-AL) were higher at the natural site, but Ca-AL, Mg-AL and K-AL content of the cultivated and mineral-fertilized agricultural sites were higher than or equal to the grassland site. Total microbiological activity correlates significantly positively with TOC and TN and negatively with the BD. Sites with perennial vegetation cover and higher biodiversity showed greater microbiological activity and, in case of the arbuscular mycorrhizal fungi, actinobacteria and anaerobe bacteria, the differences are significant. Despite the nutrient depletion and lesser microbiological activity, cropland sites preserved their taxonomic status as Chernozem. Sites that have undergone more extreme human impacts before the recent land use had lost their diagnostic features (aggregation, color, secondary carbonate accumulation) and now key out as Kastanozem, Phaeozem or Regosol.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00920"},"PeriodicalIF":3.1,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144466","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":"Estimation and mapping of soil pH in urban landscapes","authors":"Azamat Suleymanov ,&nbsp;Evgeny Abakumov ,&nbsp;Vyacheslav Polyakov ,&nbsp;Alexander Kozlov ,&nbsp;Nicolas P.A. Saby ,&nbsp;Petr Kuzmenko ,&nbsp;Salavat Telyagissov ,&nbsp;João Augusto Coblinski","doi":"10.1016/j.geodrs.2025.e00919","DOIUrl":"10.1016/j.geodrs.2025.e00919","url":null,"abstract":"<div><div>Despite their significance in understanding soil ecology and health, there is a scarcity of studies on soil modelling in urbanized landscapes. In this study, we evaluated the performance of machine learning (ML) and hybrid techniques in predicting topsoil pH (0–20 cm) in the city of St. Petersburg (Russia). We used a dataset of 84 soil pH measurements and environmental covariates, including remote sensing data, relief and anthropogenic maps. We applied Random Forest (RF) and RF plus Residual Kriging (RFRK) approaches for digital mapping of pH values. The predictive performance of the models was assessed using several metrics, mean absolute error (MAE), including root mean squared error (RMSE), coefficient of determination (R²) and Nash–Sutcliffe model efficiency coefficient (NSE). We also evaluated the prediction uncertainty with the prediction interval coverage probability (PICP) and “Area of applicability” (AOA) approach. Our results showed the pH levels varied between 4.4 and 8.6 and were characterized by moderate spatial dependence. Both models demonstrated similar performance, whereas the RFRK model slightly outperformed the RF approach with prediction performance MAE = 0.50, RMSE = 0.58, R² = 0.63 and NSE = 0.47. The PICP suggested that the uncertainty associated with pH was underestimated, whereas almost all predicted areas were within the AOA. We found that remote sensing covariates (vegetation indices) were the most important predictors of soil pH. According to the generated maps, alkaline soils were mostly located in urbanized areas with dense buildings, whereas low pH values were observed in parks and open relatively undisturbed areas. Our findings highlight the potential of remote sensing data for digital mapping of soil pH in urban environments, typically characterized by higher complexity and heterogeneity.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00919"},"PeriodicalIF":3.1,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144993","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":"Investigating soil properties influencing the depth and degree of lessivage in Florida soils using a random forest modeling approach","authors":"Daniel J. Colopietro ,&nbsp;Julio Pachon ,&nbsp;Allan Bacon","doi":"10.1016/j.geodrs.2025.e00916","DOIUrl":"10.1016/j.geodrs.2025.e00916","url":null,"abstract":"<div><div>The translocation of clay sized particles is an extensive soil process that occurs in over half of the total surface area covered by soil globally. However, investigations into lessivage are usually limited in extent and scale, and results from experimental data do not reflect natural conditions since control is exerted on various soil properties, such as particle size distributions, and clay mineralogy. Using the NCSS Soil Characterization Database and the USDA Soil Taxonomy definition for an argillic horizon, a random forest machine learning approach was used to investigate lessivage in Florida soils. Within the database, 395 soil profiles observed and described in Florida were identified to have an argillic horizon and lack the presence of a lithologic discontinuity. The coefficient of determination (<em>R</em>^<em>2</em>), and the root mean square error (RMSE) were used to estimate the performance of the random forest model. The validation results showed that the model for the depth of lessivage achieved an <em>R</em>^<em>2</em> of 0.59 ± 0.07 and an RMSE of 27.86 ± 2.62 cm and the model for the degree of lessivage achieved an <em>R</em>^<em>2</em> of 0.68 ± 0.14 and an RMSE of 5.91 ± 3.25. A variable importance analysis indicated that the concentration of OC, the CEC, and the total extractable bases in the eluvial zone were the dominant soil properties in predicting the depth of the argillic horizon. The response in the predicted depth to the argillic horizon was similar with each of the aforementioned correlated variables and indicative of the flocculating mechanism, whereby polyvalent cations anchor OM to particle surfaces which then enables particle bridging. Whereas, extractable acidity in the eluvial zone and sand concentration in the illuvial zone were the dominant soil properties in predicting the degree of lessivage. As extractable acidity in the eluvial zone increased, the degree of lessivage decreased which could be indicative of coagulation due to an increase in the activity of Al³⁺ and H⁺ ions. Another mechanism identified in clay immobilization in this study is the cessation of the wetting front as a result of the loss of energy. As the depth to gleying increased, the predicted depth to the argillic horizon increased and the degree of lessivage increased. However, based on the variable importance analysis, this mechanism was not determined to be dominant in Florida soils.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00916"},"PeriodicalIF":3.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144464","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":"Tracking pedogenic carbonate formation and alkalinity migration in agricultural soils amended with crushed wollastonite ore – Evidence from field trials in Southwestern Ontario","authors":"Reza Khalidy,&nbsp;Fatima Haque,&nbsp;Yi Wai Chiang,&nbsp;Rafael M. Santos","doi":"10.1016/j.geodrs.2025.e00918","DOIUrl":"10.1016/j.geodrs.2025.e00918","url":null,"abstract":"<div><div>Considered a well-known carbon sequestration method, terrestrial enhanced rock weathering (ERW) involves the application of crushed silicate-bearing minerals to urban and agricultural soils. Once dissolved in a soil–water system, alkaline minerals adjust the pH in a range favorable for pedogenic carbonate formation and, hence, atmospheric carbon drawdown. As a fast-weathering Ca-rich mineral, wollastonite is recognized as a primary candidate for this process. Although previous studies have demonstrated the potential of wollastonite to sequester carbon in croplands, no study has investigated the fate of wollastonite over the vertical profile of soil. Furthermore, no studies have investigated changes in the elemental composition of soils due to wollastonite amendment at the field scale. The present study presents the results of multiyear sample collection from different layers (0–15, 15–30, and 30–60 cm) of agricultural soil amended with wollastonite in Woodstock, Ontario, Canada. The impact of initial soil pH on pedogenic carbonate formation was also investigated through the inclusion of two more field trials (Thorndale and Dawn-Euphemia, Ontario). The results indicated that wollastonite addition increased the inorganic carbon pool of the soil at a rate as fast as 0.55 t CO₂/(ha·month) at higher (20 t/ha) wollastonite dosages, and with efficiencies reaching up to 0.42 t CO₂/t wollastonite (as CO₃^2-). Elemental composition analyses (WDXRF) revealed increases in the Ca (0.05–0.32 %) and Mg (0.01–0.02 %) contents in the amended soils that either were inferior to the theoretical amendment change, suggesting migration of weathering products to deeper layers, or in some cases similar and thus correlating with pedogenic carbonate retention in surficial layers. The implications of composite sampling and year-over-year comparisons on the estimated uncertainty from statistical analysis (hierarchical permutation test of the Wilcoxon signed-rank test) is discussed. This study concludes that carbonate formation is not limited to surficial layers and that deeper layers also need to be taken into account when estimating carbon capture due to ERW practices.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00918"},"PeriodicalIF":3.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144992","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}