Geoderma Regional最新文献

{"title":"Maintaining favourable carbon balance in boreal clay soil is challenging even under no-till and crop diversification","authors":"Henri Honkanen,&nbsp;Visa Nuutinen,&nbsp;Jaakko Heikkinen,&nbsp;Riitta Lemola,&nbsp;Eila Turtola,&nbsp;Janne Kaseva,&nbsp;Kristiina Lång","doi":"10.1016/j.geodrs.2024.e00818","DOIUrl":"10.1016/j.geodrs.2024.e00818","url":null,"abstract":"<div><p>We explored the carbon balance, including both gaseous and waterborne carbon, of a long-term experimental site in 2019 and 2020. Additionally, we assessed earthworm abundance and soil aggregation, aiming to uncover potential factors influencing the decomposition and stabilization capacity of organic carbon in the soil. The heavy clay soil site in southern Finland was under long-term cereal monocropping with conventional tillage (CT) and no-till (NT) treatments. Short-term diversification with cover crop and winter rapeseed as a break crop were applied on parts of the site, and the effects of climate, carbon input and soil conditions on the carbon balance were assessed. Net ecosystem exchange (NEE) ranged from −0.32 to 1.91 Mg CO₂-C ha⁻¹ yr⁻¹ in CT and from 0.22 to 2.40 Mg CO₂-C ha⁻¹ yr⁻¹ in NT. Net ecosystem carbon balance ranged from 1.49 to 3.27 Mg C ha⁻¹ yr⁻¹ and 1.51 to 3.67 Mg C ha⁻¹ yr⁻¹ in CT and NT, respectively, indicating carbon loss from soil. The differences in NEE or carbon balance between CT and NT were not statistically discernible. Earthworm abundance was higher in NT than in CT and increased vastly in the NT management after diversification of the rotation with winter rapeseed. Soil erosion measurements showed remarkably lower carbon loss (44%) for NT compared to CT, however, the role of erosion in the carbon balance was minor, ranging from 50 to 120 kg C ha⁻¹ yr⁻¹. The mean size of soil aggregates decreased during the study period, and soil aggregates tended to enlarge in the summer and diminish in the winter. The results highlight the difficulty of maintaining a positive carbon balance in boreal agricultural soils with limited productivity. Furthermore, future climatic conditions may worsen the situation by promoting decomposition and restricting carbon protection in soil aggregates.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00818"},"PeriodicalIF":4.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352009424000658/pdfft?md5=6290558f3379b1754a9da7a1faaed5de&pid=1-s2.0-S2352009424000658-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141133195","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":"Mineral and particle-size chemometric classification using handheld near-infrared instruments for soil in Northeast Brazil","authors":"Pedro G.C. Lucena ,&nbsp;Ramon V.S. Aquino ,&nbsp;Juliet E.S. Sousa ,&nbsp;Valdomiro S. Souza Júnior ,&nbsp;José G.A. Pacheco Filho ,&nbsp;Claudete F. Pereira","doi":"10.1016/j.geodrs.2024.e00819","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00819","url":null,"abstract":"<div><p>The characterization of soil variations crucial for agriculture is challenging due to soil having different mineral composition and particle-size distribution. Traditional methods are costly and time-consuming for large-sized areas. Spectroscopic techniques coupled with chemometrics are alternative ways to overcome these drawbacks. Miniaturized near-infrared (NIR) spectrophotometers provide fast, cost-effective spectra acquisition for assessing soil chemistry and distribution despite challenges like overlapped bands and reduced spectral range. This study presents a pattern recognition strategy to address these limitations, enhancing the use of handheld NIR instruments for soil analysis. The study analyzed 176 soil samples from 15 soil groups in the Northeast region of Brazil. First, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and energy-dispersive X-ray fluorescence spectrometry (EDXRF) were employed to characterize the samples, providing complementary vibrational and elemental information, respectively. Common Dimension Analysis (ComDim) identified links between ATR-FTIR and EDXRF data, aiding soil characterization. The Common Components (CCs) from ComDim were used in Partitioning Around Medoids (PAM) clustering, resulting in five distinct classes based on their mineral composition. These classes showed significant differences in clay and sand contents. With the use of ComDim-PAM, samples were labeled for classification via Partial-least Squares-Discriminant Analysis (PLS-DA) and Support Vector Machine (SVM) using NIR spectra (spectral range: 908–1676 nm) from two handheld instruments (Hand 1 and Hand 2). The SVM models outperformed the PLS-DA models, especially by including variable selection for Hand 1, with test accuracy exceeding 90%. These findings highlight the method's advantages for fast and cost-effective assessment, classification, and soil mapping based on their mineral and particle-size distribution.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"38 ","pages":"Article e00819"},"PeriodicalIF":4.1,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141286284","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":"Lithotype composition and micro-topographic features: Drivers of soil variability on semiarid limestone plateaus","authors":"Daniel Pontes de Oliveira ,&nbsp;Renata Cristina Bovi ,&nbsp;Yuri Fernando Parra Castilho ,&nbsp;Valdomiro Severino de Souza Júnior ,&nbsp;Miguel Cooper ,&nbsp;Hermano Melo Queiroz ,&nbsp;Marcelo Metri Corrêa ,&nbsp;Ricardo Espíndola Romero ,&nbsp;Tiago Osório Ferreira","doi":"10.1016/j.geodrs.2024.e00814","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00814","url":null,"abstract":"<div><p>Different soil classes indicate that pedoenvironments undergo varied formation conditions. Among the soil formation factors, relief is predominantly employed in predicting soil distribution at a landscape, guided by the <em>catena</em> concept, where soils are genetically linked from the summit to a footslope. The relationship between soil classes and relief emphasizes the importance of understanding the landscape's topography in driving distribution and characteristics of different soils. This study aims to unravel the combined role of limestone composition and microrelief in soils pedogenesis through morphological, chemical, physical, mineralogical, and micromorphological attributes of a six soil profiles sequence. The topography of the study area on the Apodi Plateau was examined, exposing variations in surface relief classified as convex, flat, and concave. Furthermore, two limestone samples were collected at different points on the concave and convex surfaces for chemical characterization. The chemical and morphological results indicate that the soils on the concave surface are more weathered and developed, evidenced by the depth, a low ki index (mean ± s.d.: 1.8 ± 0.5), low clay activity values (54.62), and lower contents of crystalline iron (mean ± s.d.: 3.7 ± 0.6 g kg⁻¹) and CaCO₃ (mean ± s.d.: 20.7 ± 17.8 g kg⁻¹). Micromorphological analyses revealed that the pedality and accommodation degree of the aggregates increase towards the concave surface, indicating more active pedogenesis. The variation in the related distribution pattern from convex to concave surfaces can be an indication of distinct pedogenesis. Observations on convex and flat surfaces revealed carbonate nodules and CaCO₃ depletion, suggesting a favorable environment for carbonate precipitation due to lower water action. The concave surface exhibited higher weathering rates on a local scale, influenced by microrelief and predominant water flow. The weathering-susceptible limestone with increased insoluble residues in this area conditions the development of a more advanced soil in the concave surface.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00814"},"PeriodicalIF":4.1,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141090563","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":"Soil carbon stabilization of mining-degraded, reforested lands in southern Ontario","authors":"Joseph B. Yavitt ,&nbsp;Madeline Czymmek ,&nbsp;Gwendolyn T. Pipes ,&nbsp;Patrick Levasseur ,&nbsp;Nathan Basiliko","doi":"10.1016/j.geodrs.2024.e00809","DOIUrl":"10.1016/j.geodrs.2024.e00809","url":null,"abstract":"<div><p>We took advantage of the northern forest near Sudbury, Ontario, Canada where logging and metal-mining pollution had degraded the landscape prior to it being restored and reforested to investigate how soil organic matter is stabilized with stand age in highly ‘eroded’ sites with minimal residual soil and in ‘stable’ sites with residual soil. Soil organic matter in sandy, acidic soils of the northern forest is thought to be stabilized in organo-mineral particles (&lt;20 μm in size); however, forest disturbance and soil erosion might help to promote less-decomposed plant detritus being stabilized within aggregate structures (53 μm in size). We use a combination of physical fractionation (size) and chemical analysis (carbon to nitrogen ratio, natural abundance of stable isotopes of carbon and nitrogen) of the fractions. The composition of bulk soils with young trees (15-yr old) was 25% microaggregates (53 to 250 μm in size) and 47% in a smaller silt + clay fraction (&lt;53-μm in size). Bulk soil with older trees (28- and 30- to 32-yr old) had equal proportions of macroaggregates (&gt;250 μm in size), microaggregates, and silt + clay fraction. The C density was much greater and less decomposed for macroaggregates than for the silt + clay fraction. Untreated sites, with trees but not restored with added lime, had a smaller proportion of macroaggregates in bulk soil. Even though aggregate structures typically are not associated with sandy, acidic forest soils, the results for these Regosols in the northern forest of the Greater Sudbury region show that stabilized soil C involves formation of macroaggregates along with microaggregates, both of which help to stabilize particulate organic matter.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00809"},"PeriodicalIF":4.1,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141045626","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":"Upper limit of mineral-associated organic carbon in temperate and sub-tropical soils: How far is it?","authors":"Francisco J. Matus ,&nbsp;Fernando Paz-Pellat ,&nbsp;Sara Covaleda ,&nbsp;Jorge D. Etchevers ,&nbsp;Claudia Hidalgo ,&nbsp;Aurelio Báez","doi":"10.1016/j.geodrs.2024.e00811","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00811","url":null,"abstract":"<div><p>Soil organic carbon (SOC) is the main terrestrial C pool and is roughly divided into stable mineral-associated organic carbon (MAOC) and particulate organic matter carbon (POC). However, the sequestration capacity of MAOC remains unquantified. Currently, soils are considered to have a limited capacity to accumulate MAOC, primarily due to the presence of fine fractions, i.e. silt and clay particles. However, it is unlikely that saturation will occur in all soils due to land use. Therefore it is necessary to investigate whether soils from different latitudes and their silt and clay fractions that comprise MAOC are saturated. We selected 71 soil samples that were physically fractionated from a Mexican inventory of vegetation with a wide range of SOC (4–186 g kg⁻¹ soil) and clay (126–777 g kg⁻¹ soil) contents. Soils were grouped into non-volcanic soils and allophanic Andosols. In the first group, we found a positive and highly significant linear relationship between SOC and MAOC contents, but no upper limit was detected. We found a common slope of 0.86 (R² = 0.97, <em>p</em> &lt; 0.01), i.e. 86% of the SOC was contained in MAOC irrespective of soil types and management, a value very similar to that in other studies. Conversely, for allophanic Andosols, which had SOC content twice that of non-volcanic soils, a second-order polynomial function (R² = 0.98, <em>p</em> &lt; 0.01) was established, the upper limit of which exceeded 186 g SOC kg⁻¹ for a MAOC of 134 g kg⁻¹. This was also supported by an increasing polynomial function of particulate organic carbon (POC) as the SOC increased. In both types of soils, maximum MAOCs were found between 700 and 800 g kg⁻¹ of silt and clay in medium-textured soils. The amount of silt and clay particles was limited by SOC accumulation in the silt fraction as clay became saturated. These results are influenced by the mass proportion of silt and clay that follows a unique pattern in allophanic Andosols and non-volcanic soils. An investigation of a comprehensive database comprising 21,315 soil profiles sampled 0–30 cm across Mexico showed that most soils are below 186 g SOC kg⁻¹ the bending point above which the upper limit does exist.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00811"},"PeriodicalIF":4.1,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140951321","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":"Vegetation degradation alters soil physicochemical properties and potentially affects ecosystem services in green spaces of a tropical megacity (Lubumbashi, DR Congo)","authors":"Grace Queen Mashagiro ,&nbsp;Bazirake Basile Mujinya ,&nbsp;Gilles Colinet ,&nbsp;Grégory Mahy","doi":"10.1016/j.geodrs.2024.e00810","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00810","url":null,"abstract":"<div><p>Urban soils are degraded by various human pressures, including vegetation degradation, leading to changes in physical and chemical characteristics and affecting important ecosystem services. Soil physical properties are an important fertility control parameter, providing the basis for sustainable soil use in urban conditions; however, they do not receive sufficient attention in work on tropical cities. We assessed the impact of vegetation degradation in six urban green spaces (bare soils versus vegetated soils) on the physical (texture, soil bulk density and structure) and chemical (pH, cation exchange capacity (CEC), organic carbon (OC), nitrogen (N), phosphorus (P), potassium (K), copper (Cu) and manganese (Mn)) qualities of soils in a tropical megacity (Lubumbashi, DR Congo). Vegetated soils presented better physical and chemical qualities than bare soils. Vegetated soils were characterized by a high clay and silt content and a good consistency (soil structure), while bare soils were characterized by a high sand content and high bulk density. Vegetated soils were characterized by higher pH, OC, N, C/N ratio, CEC, P, and K. There was no significant difference in Mn or Cu between bare and vegetated soils. Cu was highly variable between sites (from 99 ± 61 mg.kg⁻¹ in VS to 8559 ± 151 mg.kg⁻¹ in BS). Our results demonstrate that the destruction of vegetation, leading to bare soil, negatively affects soil properties and may interfere with ecosystem services provided by urban soils in tropical climates. The physical properties observed in bare soils in this study, including silt, clay, and sand content, soil structure, and soil bulk density, along with chemical properties such as soil pH, cation exchange capacity, and soil organic carbon, can influence the ecosystem services provided by urban soils. These services include regulating water flow and nutrient cycling, enhancing nutrient availability, and supporting ecosystem functions through the cycling of water and nutrients.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00810"},"PeriodicalIF":4.1,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352009424000579/pdfft?md5=2d747f3a323ab5558f3e44a0eb163b84&pid=1-s2.0-S2352009424000579-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141068603","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":"Multivariate regional deep learning prediction of soil properties from near-infrared, mid-infrared and their combined spectra","authors":"Rumbidzai W. Nyawasha ,&nbsp;Alexandre M.J.-C. Wadoux ,&nbsp;Pierre Todoroff ,&nbsp;Regis Chikowo ,&nbsp;Gatien N. Falconnier ,&nbsp;Maeva Lagorsse ,&nbsp;Marc Corbeels ,&nbsp;Rémi Cardinael","doi":"10.1016/j.geodrs.2024.e00805","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00805","url":null,"abstract":"<div><p>Artificial neural network (ANN) models have been successfully used in infrared spectroscopy research for the prediction of soil properties. They often show better performance than conventional methods such as partial least squares regression (PLSR). In this paper we develop and evaluate a multivariate extension of ANN for predicting correlated soil properties: total carbon (C), total nitrogen (N), clay, silt, and sand contents, using visible near-infrared (vis-NIR), mid-infrared (MIR) or combined spectra (vis-NIR + MIR). We hypothesize that accounting for the correlation through joint modelling of soil properties with a single model can eliminate “pedological chimera”: unrealistic values that may arise when properties are predicted independently such as when calculating ratio or soil texture values. We tested two types of ANN models, a univariate (ANN-UV) and a multivariate model (ANN-MV), using a dataset of 228 soil samples collected from Murehwa district in Zimbabwe at two soil depth intervals (0–20 and 20–40 cm). The models were compared with results from a univariate PLSR (PLSR-UV) model. We found that the multivariate ANN model was better at conserving the observed correlations between properties and consequently gave realistic soil C:N and C:Clay ratios, but that there was no improvement in prediction accuracy over using a univariate model (ANN or PLSR). The use of combined spectra (vis-NIR + MIR) did not make any significant improvements in prediction accuracy of the multivariate ANN model compared to using the vis-NIR or MIR only. We conclude that the multivariate ANN model is better suited for the prediction of multiple correlated soil properties and that it is flexible and can account for compositional constrains. The multivariate ANN model helps to keep realistic ratio values – with strong implications for assessment studies that make use of such predicted soil values.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00805"},"PeriodicalIF":4.1,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140906835","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":"Soil health indicators in oil palm agroforestry systems in the eastern Amazon, Brazil","authors":"Mila Façanha Gomes ,&nbsp;Raimundo Leonardo Lima de Oliveira ,&nbsp;Lucélia Rosa de Jesus Costa ,&nbsp;Wilian Victor da Silva Campos ,&nbsp;Osvaldo Ryohei Kato ,&nbsp;Debora Cristina Castellani ,&nbsp;Steel Silva Vasconcelos","doi":"10.1016/j.geodrs.2024.e00806","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00806","url":null,"abstract":"<div><p>Agroforestry systems (AFSs) are generally recognized for improving soil health and increasing soil carbon (C) stock. In the Amazon region, oil palm AFSs have been promoted as a productive strategy and may offer an additional benefit of recovering degraded areas. Our objective was to evaluate whether the management practices adopted in oil palm AFSs affect soil health indicators and C stock. We carried out a study in Tomé-Açu, state of Pará, eastern Amazon, through which we evaluated two oil palm AFSs that differed in species diversity: higher diversity (AFShigh) and lower diversity (AFSlow). We used a regenerating forest (FOR) to compare with the oil palm AFSs, as regenerating forests are also a model of environmental recovery in the eastern Amazon. In the 0–10, 10–20 and 20–30 cm soil layers, we evaluated chemical indicators (active acidity (pH), calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P), and aluminum (Al)), (b) physical indicators (density (SD) and stability of aggregates (AGGRE)), and (c) biological indicators (permanganate oxidizable carbon (POXC), particulate organic carbon (POC), total soil carbon (SOC content) and root stock (ROOT)). We also evaluated the total soil carbon stock (SOC stock). The values of the biological indicators in the most superficial layer, especially the C indicators, were higher in the AFSlow (C content: 1.63 ± 0.13%, POXC: 568 ± 17 mg kg⁻¹, POC: 0.63 ± 0.10 g kg⁻¹) and the AFShigh (C content: 1.84 ± 0.04%, POXC: 656 ± 24 mg kg⁻¹, POC: 0.83 ± 0.06 g kg⁻¹) than in FOR (C content: 1.35 ± 0.09%, POXC: 336 ± 10 mg kg⁻¹, POC: 0.44 ± 0.03 g kg⁻¹). In general, the values of chemical indicators were higher in the AFSs than in FOR, except for the Al content, which was higher in FOR than in the AFSs. The physical indicators did not show a specific pattern of variation between the AFSs and FOR; aggregate stability was higher in FOR (range throughout the soil profile: 5.57 ± 0.09 to 5.38 ± 0.24 mm) than in the AFSlow (5.41 ± 0.03 to 3.79 ± 0.07 mm) and the AFShigh (5.07 ± 0.01 to 3.79 ± 0.11 mm) in all the soil layers, and soil density was higher in the AFShigh and FOR than in the AFSlow in most subsurface layers. Therefore, oil palm AFSs improve the chemical and biological health of the soil, especially in the more superficial layers, but it does not improve the physical health of the soil when compared to the forest.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00806"},"PeriodicalIF":4.1,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140947720","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":"Variability of soil organic carbon and nutrient content across land uses and agriculturally induced land use changes in the forest-savanna transition zone of Cameroon","authors":"Viviane Pauline Mandah ,&nbsp;Paul Tematio ,&nbsp;Adalbert A. Onana ,&nbsp;Komi K.M. Fiaboe ,&nbsp;Emmanuel Arthur ,&nbsp;Mekonnen H. Giweta ,&nbsp;Rose Ndango ,&nbsp;Francis B.T. Silatsa ,&nbsp;Duchel D.I. Voulemo ,&nbsp;Jean Baptiste Biloa ,&nbsp;Cedrick Nguemezi ,&nbsp;Cargele Masso","doi":"10.1016/j.geodrs.2024.e00808","DOIUrl":"https://doi.org/10.1016/j.geodrs.2024.e00808","url":null,"abstract":"<div><p>Data expressing the effects of land use change on soil attributes is still very scarce in Cameroon as in most of Africa. In this regard, this study aimed to assess soil organic carbon (OC), nitrogen (N), phosphorus (P), and potassium (K) content across land uses and agricultural-induced land use changes in the forest-savanna transition zone of Cameroon. Nine land uses were identified in the study area showing five directions of land use changes namely the change from the native forest to cocoa agroforestry, native savannah to cocoa agroforestry, native savannah to cropland, savannah fallow to cropland, and transition zone fallow to cropland. The soil was sampled at 0–10 cm (upper layer) and 10–30 cm (lower layer) depths in three replicates for each land use and analyzed for physicochemical properties. There were significant differences across the land uses for OC (<em>p &lt; 0.02</em>), N (<em>p &lt; 0.01</em>), C/N (<em>p &lt; 0.01</em>), pH (<em>p &lt; 0.02</em>), soil organic carbon stocks (SOCS) (<em>p &lt; 0.01</em>), and soil nitrogen stocks (SNS) (<em>p &lt; 0.01</em>), with a relatively higher magnitude in the upper soil layer. Higher magnitudes of OC (26.1 to 22.5 g kg⁻¹), N (2.5 to 1.6 g kg⁻¹), SOCS (32.1 to 27.8 Mg ha⁻¹), and SNS (2.9 to1.9 Mg ha⁻¹) were observed in native lands and cocoa agroforestry with the highest in the native forest and the forest-based cocoa agroforestry. Meanwhile, the effect of land use change on soil properties was mainly significant in the change from native savannah to croplands at <em>p &lt; 0.05</em> for OC, N, SOCS, and SNS, and <em>p &lt; 0.02</em> for P. Therefore, agroforestry is an alternative to enhance the ecological resilience of lands affected by land use changes.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00808"},"PeriodicalIF":4.1,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352009424000555/pdfft?md5=571cc3c375fb5a72b2b87fae1c1e7cdf&pid=1-s2.0-S2352009424000555-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140951320","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":"Contrasted effects of shade tree legumes on soil organic carbon stock and carbon balance in 20-year cacao agroforestry, Ivory Coast","authors":"Brahima K. Silue ,&nbsp;Armand W. Koné ,&nbsp;Dominique Masse ,&nbsp;Patricia Moulin-Esmard ,&nbsp;Alain J.A. Kotaix ,&nbsp;Lydie Chapuis-Lardy","doi":"10.1016/j.geodrs.2024.e00807","DOIUrl":"10.1016/j.geodrs.2024.e00807","url":null,"abstract":"<div><p>Cacao–based agroforestry systems are promoted as adaptation and mitigation solutions for cacao production and carbon sequestration. Based on a 20-year experiment, we assessed the impact of associated shade tree legume (ATL), <em>Albizia lebbeck</em> and <em>Acacia mangium</em> on the total carbon stock (in soil at 60 cm depth + tree biomass + litter) of cacao stands. This study included cacao systems shaded with either <em>A. lebbeck</em> (Cacao-Alb) or <em>A. mangium</em> (Cacao-Aca) and full-sun cacao stands (Control). Soil organic carbon (SOC) contents (up to 60 cm deep) were estimated by a calibrated near-infrared spectroscopy model. Total tree biomasses were estimated using allometric equations. Leaf litter was sampled from 1-m² quadrats. Compared to Control, Cacao-Aca had a significant negative impact on the carbon stock in the cacao biomass (−47%) as well and in the soil at depths of 10 cm (−23%), 30 cm (−21%) and 60 cm (−12%). In contrast, Cacao-Alb had a nonsignificant effect on carbon storage in the cacao biomass, whereas it generally had a positive influence on the SOC stock regardless of depth, i.e., +6% at the 0–10 cm depth, +7% at 0–30 cm, +20% at 30–60 cm and + 11% at 0–60 cm. Cacao-Aca had a significant positive impact (+71%) on the total carbon stock per hectare. The increase in Cacao-Alb relative to that in the Control reached +38%, but the difference was not significant. These contrasting results between the two tree legume species could be explained by the high-quality litter, reflected by the lower C/N and C/P ratios produced by <em>A. lebbeck,</em> and the greater negative impact of <em>A. mangium</em> on cacao biomass. The main finding of this study is that the impact of intercropping cacao with shade tree legumes on the stand-level total carbon stock depends on the ATL species.</p></div>","PeriodicalId":56001,"journal":{"name":"Geoderma Regional","volume":"37 ","pages":"Article e00807"},"PeriodicalIF":4.1,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352009424000543/pdfft?md5=c84fe3a9c2c80de3f8c9939315e2cbab&pid=1-s2.0-S2352009424000543-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141041069","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}