Geoderma Regional最新文献

{"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}

{"title":"Land use effect on soil quality and its implication to soil carbon storage in Aleta Chuko, Ethiopia","authors":"Zenebe Shuite ,&nbsp;Ambachew Demessie ,&nbsp;Tesfaye Abebe","doi":"10.1016/j.geodrs.2025.e00917","DOIUrl":"10.1016/j.geodrs.2025.e00917","url":null,"abstract":"<div><div>Soil quality index (SQI) is a useful tool to identify soil productivity status and design management strategies. Land use (LU) and management conditions can affect the physico-chemical qualities of the soil which in turn influences the carbon storage ability of the soil. However, the effects of LU on soil quality and associated carbon storage are not well understood in the Aleta Chuko. Three transect lines were drawn based on spatial analogue design covering three LU types, 4 plots for each land use from individual transect, 12 plots per LU, a total of 36 plots, and then 108 soil samples (0–30 cm depth) were taken in three diagonal pits within 20 × 20 m. 19 soil physico-chemical and biological properties were evaluated for SQI, and 12 soil quality indicators were selected using principal component analysis. The results showed that soil physico-chemical and biological characteristics were better under Coffee-enset based agroforestry (CEA) than Chat mono-cropping (CM) and Eucalyptus woodlot (EW). CEA showed significantly higher macro aggregate ≥ 5 mm, steady infiltration rate, Av. P, Av. K, Ex. K, total N, CEC and MBC, but no significant difference was observed between CM and EW in these variables (p &lt; 0.05). SQI of CEA, CM and EW were 0.61, 0.53 and 0.50, respectively. The higher SQI in CEA was due to high MBC(586.3 μg g⁻¹ soil), litterfall, SOM (4.7 %) and low bulk density (BD, 0.87 g cm⁻³). Total soil organic carbon was significantly higher in CEA (35.2) &gt; CM (24.2) &gt; EW (19.4) g kg⁻¹ soil and the same is true for Mg²⁺ CEA (4.9), CM (3.9) and EW (2.7) meq 100 g⁻¹ (p &lt; 0.05). Multiple regression analysis on five (BD, CEC, MBC, Ex. Ca and macro aggregates) soil quality determinant variables predicting SOC showed that these variables have a significant effect on SOC (p &lt; 0.001). Specifically, BD and MBC were significant negatively and positively predicting variables of SOC, respectively (p &lt; 0.001). This study suggests that LU practice and management variances over similar biophysical environments resulted in variations in soil physico-chemical, biological properties and the subsequent difference in SQI which in turn determine SOC storage capacity of the soil. Long-term effects of Eucalyptus and CM on soils should be a concern for degradation, although their short-term economic benefits are attractive.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00917"},"PeriodicalIF":3.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144465","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":"Physically protected carbon stocks in a Brazilian Oxisol under homogeneous forest systems","authors":"Maicon dos Santos da Silva ,&nbsp;Patrícia Anjos Bittencourt Barreto-Garcia ,&nbsp;Paulo Henrique Marques Monroe ,&nbsp;Marcos Gervasio Pereira ,&nbsp;Luiz Alberto da Silva Rodrigues Pinto ,&nbsp;Marcio Renato Nunes","doi":"10.1016/j.geodrs.2024.e00915","DOIUrl":"10.1016/j.geodrs.2024.e00915","url":null,"abstract":"<div><div>The soil organic carbon (SOC) stock and its occlusion within aggregates is at the center of discussions regarding climate change and global warming, as it is one of the mechanisms capable of mitigating the effects of these phenomena. Despite this, studies on the topic in tropical soils under native forest species plantations are still scarce. Therefore, we developed this study asking how SOC and occluded carbon stocks in aggregates respond to homogeneous <em>Pterogyne nitens</em> (N-fixing species) and <em>Eucalyptus urophylla</em> plantations when compared to a native forest? The study was conducted in Oxisol under three forest systems: two homogeneous plantations (<em>P. nitens</em> and <em>E. urophylla</em>) and a native forest (NF), located in the State of Bahia, Brazil. Litter and soil samples were collected up to a meter deep. The soil samples were subjected to physical fractionation by wet sieving, obtaining three size classes of water-stable aggregates: macroaggegates (2000–250 μm), microaggregates (250–53 μm) silt+clay (&lt; 53 μm). The macroaggegates and microaggegates were sonicated to separate free and occluded particulate carbon. The carbon in whole soil and occluded in the aggregates were determined by the wet acidified oxidation method. The SOC stock (depth 100 cm) showed a reduction in the <em>P. nitens</em> plantation (123.1 Mg ha⁻¹) and maintenance in the <em>E. urophylla</em> plantation (194.4 Mg ha⁻¹) when compared to the NF (240.9 Mg ha⁻¹). Occluded carbon showed a lower value in plantations compared to NF, representing an average of 5.8 % of the SOC. The <em>P. nitens</em> plantation negatively impacted SOC stock as a result of lower litter amounts and higher litter decomposition rates. In contrast, the <em>E. urophylla</em> plantation maintained SOC stocks close to those found in the NF due to the large amounts of litter and its high recalcitrance. Both forest plantations affect carbon occlusion in the aggregates, and therefore the SOC is poorly protected physically.</div></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"40 ","pages":"Article e00915"},"PeriodicalIF":3.1,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144970","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}