Geoderma最新文献

{"title":"Heavy metal contamination threats carbon sequestration of paddy soils with an attenuated microbial anabolism","authors":"Li Xiong ,&nbsp;Marios Drosos ,&nbsp;Min Jiao ,&nbsp;Jianfei Sun ,&nbsp;Guilong Li ,&nbsp;Longxin He ,&nbsp;Fan Li ,&nbsp;Cheng Liu ,&nbsp;Antonio Scopa ,&nbsp;Wenjian Xia ,&nbsp;Caihong Shao ,&nbsp;Zengbing Liu","doi":"10.1016/j.geoderma.2025.117486","DOIUrl":"10.1016/j.geoderma.2025.117486","url":null,"abstract":"<div><div>As a global environmental concern, heavy metal pollution significantly impacts soil organic carbon (SOC) dynamics. Nevertheless,<!--> <!-->the<!--> <!-->microbial mechanisms governing SOC persistence under heavy metal contamination remain unclear,<!--> <!-->as<!--> <!-->previous research primarily focused on microbial catabolism. This study elucidated SOC variation induced by heavy metal contamination from the perspective of microbial anabolism,<!--> <!-->a key contributor to SOC sequestration according to recent theory.<!--> <!-->Herein a field survey was conducted at 13 sampling sites in polluted rice paddies, determining both SOC content and key microbial parameters. Nemerow index (a comprehensive index of pollution level) ranged from 0.48 to 2.93, with cadmium and copper as the primary contaminants. SOC content ranged between 14.56 and 23.97g kg⁻¹ <!-->across<!--> <!-->sampling sites and showed a negative relationship with nemerow index (R² = 0.46,<!--> <em>P</em> &lt; 0.001). Variation partitioning and random forest analyses indicated that SOC reduction was primarily driven by the<!--> <!-->combined<!--> <!-->effects of microbial factors and heavy metal pollution, with dominant role of microbial factors. Nemerow index negatively correlated with microbial C use efficiency (CUE) (R² = 0.42,<!--> <em>P</em> &lt; 0.001) and microbial biomass turnover (R² = 0.12,<!--> <em>P</em> = 0.017). Structural equation modeling further suggested that heavy metal pollution reduced SOC<!--> <!-->by<!--> <!-->decreasing microbial biomass carbon (MBC) formation and microbial residue accumulation through negative effects on microbial CUE and soil nitrogen availability. Collectively, our research<!--> <!-->provided robust evidences<!--> <!-->that heavy metal pollution could threat C sequestration of paddy soils by attenuating microbial anabolism with reduced accumulation of microbial-derived carbon.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117486"},"PeriodicalIF":6.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing digital soil mapping with multi-year crop cover data: Impacts on model accuracy and soil interpretation","authors":"Babak Kasraei ,&nbsp;Margaret G. Schmidt ,&nbsp;Daniel D. Saurette ,&nbsp;Chuck E. Bulmer ,&nbsp;Jin Zhang ,&nbsp;Travis Pennell ,&nbsp;Kingsley John ,&nbsp;Brandon Heung","doi":"10.1016/j.geoderma.2025.117481","DOIUrl":"10.1016/j.geoderma.2025.117481","url":null,"abstract":"<div><div>Vegetation cover has a significant influence on soil properties and is commonly used as a covariate in digital soil mapping (DSM). Crop frequency (CrFr) covariates, representing the frequency with which a certain crop or class of crops are grown over multiple years, can be derived from multi-year vegetation data. Such data have the potential to provide promising insights into soil conditions and can enhance predictions of soil properties. Predictive modelling within a DSM framework can improve our understanding of the relationship between crop cover and different soil properties. This study had two main objectives: (1) to develop DSM models for six soil properties—bulk density (BD), organic carbon (OC), A horizon thickness (AT), total nitrogen (TN), pH, and cation exchange capacity (CEC)—both with and without CrFr covariates, and to compare their accuracy metrics; each soil property was modelled independently as a separate response variable; and (2) to investigate the relationships between covariates such as crop types, precipitation, and temperature and soil properties. The study was conducted in the Ottawa, Canada, region, an area with diverse crop cover. From 13 years of Annual Crop Inventory (ACI) raster data, five CrFr covariates were generated and added to other covariates commonly used in DSM, resulting in a total of 54 covariates for model training. Twelve models were developed for the six soil properties, both with and without CrFr covariates. Validation results showed that including CrFr covariates improved the accuracy of models for BD, OC, AT, and TN. However, the impact on models for pH and CEC was minimal, indicating that intrinsic soil factors likely influence these properties more than CrFr. Partial dependence plots indicated that the models captured expected patterns, such as the negative association of forest cover with BD and its positive relationship with OC and TN. In contrast, crops such as legumes and corn exhibit the opposite effects. Forests exhibited a negative relationship with AT, whereas croplands showed a positive association, indicating a likely difference between the Ap horizon and Ah. Uncertainty analysis revealed lower uncertainty in agricultural cropland areas and those with lower elevations. This study highlights the potential of DSM in assessing the impact of crop type on soils and suggesting what crops may be more beneficial for soil.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117481"},"PeriodicalIF":6.6,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additive effects dominate phosphorus offsetting positive effects of nitrogen to terrestrial ecosystem N2O emissions","authors":"Xueyan Lu ,&nbsp;Weijia Cao ,&nbsp;Guoxiu Jia ,&nbsp;Lixin Wang ,&nbsp;Huamin Liu ,&nbsp;Xiaoye Cao ,&nbsp;Frank Yonghong Li ,&nbsp;Lu Wen","doi":"10.1016/j.geoderma.2025.117483","DOIUrl":"10.1016/j.geoderma.2025.117483","url":null,"abstract":"<div><div>Nitrous oxide (N₂O) emissions from terrestrial ecosystem significantly contribute to global warming and are substantially influenced by nitrogen (N) and phosphorus (P) additions. Yet, the precise interactive effects of N and P addition on N₂O emissions remain poorly understood. We synthesized 714 observations from 198 publications to evaluate the response of N₂O emission rates to N and P addition across terrestrial ecosystems. Our results revealed that N and nitrogen + phosphorus (NP) additions increased N₂O emissions by 122.5 % and 64.5 %, respectively. In contrast, P addition alone reduced N₂O emissions by 16.3 %. Akaike mixed model weights identified ecosystem type as a factor commonly influencing N₂O emissions under added N, P, and NP. Predominantly additive interactions between N and P additions drove N₂O emission responses, rather than synergistic or antagonistic interactions. Antagonistic effects were exclusively observed in cropland ecosystems. Collectively, these findings demonstrate that N and P addition exhibit independent and additive effects on N₂O emissions in terrestrial ecosystems. This implies that the stimulatory effect of N and the inhibitory effect of P can be quantitatively combined to improve predictions of N₂O emissions under nutrient enrichment scenarios.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117483"},"PeriodicalIF":6.6,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144866427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term migration of 137Cs in Swedish grassland soil profiles following the Chornobyl accident","authors":"Klas Rosén ,&nbsp;Ingrid Öborn ,&nbsp;Mykhailo Vinichuk","doi":"10.1016/j.geoderma.2025.117479","DOIUrl":"10.1016/j.geoderma.2025.117479","url":null,"abstract":"<div><div>This study presents long-term findings (1987–2008) on the vertical migration of ¹³⁷Cs from the Chornobyl accident in undisturbed grassland soils in central and northern Sweden. We examined five mineral and three organic soils, with ¹³⁷Cs deposition in 1986 ranging from 16 to 190 kBq m². ¹³⁷Cs activities were measured in 1 cm slices at depths of 0–10 cm and in 2.5 cm slices at 10–50 cm. Distribution (kBq m²) was calculated for different soil horizons, and migration rates were determined based on observed depths. During the initial period after the fallout (1987–1992), ¹³⁷Cs was primarily located in the upper 0–2 cm layers of both mineral and organic soils, comprising 77 % to 94 % of the radionuclide. During the intermediate period (1994–2003), the average migration depth was 4.0 cm in mineral soils and 5.5 cm in the organic soils while during the later period (2004–2008) it was 4.4 and 7.0 cm, respectively. After about 20 years, approximately 80 % of the ¹³⁷Cs activity was found in the upper 0–6 cm at five out of eight sites, and 75–78 % within 0–9 cm at two sites regardless of soil type. The average radionuclide migration rate of ¹³⁷Cs in the period 1987 to 2008 across various sites was 0.31 cm yr−¹. In mineral soils, the average migration rate was 0.28 cm yr−¹ (range 0.13–0.47) and in organic soils it was 0.3 cm yr−¹ (range 0.17–0.76). There was no significant relationship between soil clay content in mineral soils and the average migration depth of the radionuclide during the study period (P = 0.423).</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117479"},"PeriodicalIF":6.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydro-physical and carbon properties of peat across peatland types and climate zones","authors":"Ji Qi ,&nbsp;Sophia Weigt ,&nbsp;Miaorun Wang ,&nbsp;Fereidoun Rezanezhad ,&nbsp;William Quinton ,&nbsp;Dominik Zak ,&nbsp;Sate Ahmad ,&nbsp;Lingxiao Wang ,&nbsp;Ying Zhao ,&nbsp;Bernd Lennartz ,&nbsp;Haojie Liu","doi":"10.1016/j.geoderma.2025.117480","DOIUrl":"10.1016/j.geoderma.2025.117480","url":null,"abstract":"<div><div>The hydro-physical properties of peat play a pivotal role in regulating the water, nutrient, and carbon cycles of peatland ecosystems. However, our understanding of peat hydraulic properties remains limited, especially at a global perspective. In this study, we compiled a comprehensive global database of the peat physical, hydraulic, and chemical properties, including bulk density (BD), porosity, macroporosity, saturated hydraulic conductivity (<em>K</em>_s), carbon content, and carbon density, encompassing tropical peatlands, boreal and temperate fens and bogs, and permafrost regions. Our primary objective was to examine how these properties varied along a BD gradient across peatland types and climate zones. The results revealed a robust linear relationship between carbon density and BD for various peatland types with carbon content exceeding 35 % (<em>R</em>² &gt; 0.93, <em>p</em> &lt; 0.001). The carbon density of tropical peatlands was more sensitive to changes in BD than that of boreal and temperate peatlands. Total porosity was found to decrease linearly as BD increased, while macroporosity followed a power-law relationship with BD. These trends were consistent across all peatland types, underscoring a strong and reliable association between BD and both total porosity and macroporosity. Additionally, <em>K</em>_s exhibited a general decline with increasing BD, with the relationship characterized by log–log functions that varied among peatland types and climate zones. These findings indicated that hydraulic functions of peat (e.g., carbon density, <em>K</em>_s) were significantly influenced by the peat-forming vegetation such as woody plants, <em>Sphagnum</em>, sedges, and the prevailing climatic conditions of the peatland. This study demonstrated that the key peat hydro-physical–chemical parameters—including carbon density, porosity, macroporosity, and <em>K</em>_s could be reliably estimated using the BD, with relatively high coefficients of determination (<em>R</em>² &gt; 0.4), highlighting the critical importance of determining BD as a proxy for estimating other hydro-physical properties of peat when direct measurements are unavailable and potentially serving as reliable tools for estimating the carbon stock of peatlands across peatland types and climate zones.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117480"},"PeriodicalIF":6.6,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-resolution electrical resistivity tomography for quantitative interpretation of sub-surface karst structures: A case study in Southwest China","authors":"Weiwei Jiang ,&nbsp;Tao Peng ,&nbsp;Xingbao Zhang ,&nbsp;Shijie Wang ,&nbsp;Zargham Mohammadi ,&nbsp;Zhanyu Tang","doi":"10.1016/j.geoderma.2025.117460","DOIUrl":"10.1016/j.geoderma.2025.117460","url":null,"abstract":"<div><div>Soil-epikarst thickness and near surface characteristics are important components in understanding surface and groundwater interactions in karst environments. However, the complex lithological conditions, non-transparent rock and soil structures, and strong spatial heterogeneity limit the accurate quantification of soil thickness (ST) and epikarst thickness (EkT). In this study, we investigated the soil-epikarst structures and their spatial distribution at key topographic locations including different hillslope position, ridge, saddle, and valley using Electrical Resistance Tomography (5268 sampling points) in a peak cluster-valley catchment in Southwest China. The application of revised inflexion points in 1D resistivity vertical profiles for improving ST and EkT characterization accuracy was assessed, with interpretations validated against borehole data. The results show that compared with the interpretation accuracy of using a specific resistivity threshold at interfaces, the revised inflexion point of the 1D resistivity vertical profile significantly improved the interpretation accuracy of ST and EkT. The average ST in the valley (3.23 m) is much greater than that in hillslopes (0.49 m), while the average EkT in the valley (3.77 m) is smaller than that in hillslopes (3.93 m). The ST and EkT demonstrated a synchronous zonality variation pattern at different hillslope positions and valley. Plan and profile curvature, flow length up/down, aspect, and elevation are key topographic characteristics affecting EkT’s spatial heterogeneity. The key findings of this study contribute to advancing the accurate interpretation of soil-epikarst structures under complex lithological conditions in karst areas, and support underground structural parameters for hydrological simulation at catchment scale.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117460"},"PeriodicalIF":6.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of absolute unsaturated hydraulic conductivity of soils with Weibull pore size distribution","authors":"Xin Tong ,&nbsp;Zhenlei Yang ,&nbsp;Weili Duan ,&nbsp;Zi Li ,&nbsp;Xuan Yu ,&nbsp;Wenjuan Zheng","doi":"10.1016/j.geoderma.2025.117473","DOIUrl":"10.1016/j.geoderma.2025.117473","url":null,"abstract":"<div><div>Predicting absolute hydraulic conductivity solely from soil water retention is essential when no conductivity data are available. This study developed an approach to reliably predict saturated capillary conductivity <span><math><mrow><msub><mi>K</mi><mrow><mi>sc</mi></mrow></msub></mrow></math></span> only from the Weibull distribution based water retention. Three new <span><math><mrow><msub><mi>K</mi><mrow><mi>sc</mi></mrow></msub></mrow></math></span> functions were derived and then incorporated into the Peters-Durner-Iden (PDI) and Brunswick (BW) model systems. A model-specific saturated tortuosity <span><math><mrow><msub><mi>τ</mi><mi>s</mi></msub></mrow></math></span> value was determined via fitting each of the nine predicted conductivity models to 12 calibration soils. Using the generally effective <span><math><mrow><msub><mi>τ</mi><mi>s</mi></msub></mrow></math></span> obtained from calibration, one then predicted <span><math><mrow><msub><mi>K</mi><mrow><mi>sc</mi></mrow></msub></mrow></math></span> and finally absolute hydraulic conductivity for the 25 test soils only from optimized water retention parameters. Model-data comparison results showed that the PDI-based and BW-based models, accounting for both capillary and noncapillary flow, predict the conductivity data better than the capillary-based Weibull distribution conductivity models, particularly in the dry range where noncapillary flow processes predominate. In addition, the cut-and-random-rejoin model proposed by Mualem performed the best within the PDI and BW model systems, proving the wide application of the Mualem model in soil physics and hydrology.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117473"},"PeriodicalIF":6.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fitting and comparing water retention curves for soils under contrasting experimental treatment: Examples from conservation agriculture trials in southern Africa","authors":"I. Sandram ,&nbsp;W. Namaona ,&nbsp;N. Magwero ,&nbsp;V. Mbanyele ,&nbsp;C. Miti ,&nbsp;M. Moombe ,&nbsp;T. Mtangadura ,&nbsp;P. Lubinga ,&nbsp;C.B. Chisanga ,&nbsp;I. Nyagumbo ,&nbsp;K. Njira ,&nbsp;I.S. Ligowe ,&nbsp;J. Banda ,&nbsp;W.R. Whalley ,&nbsp;G. Sakala ,&nbsp;E. Phiri ,&nbsp;P.C. Nalivata ,&nbsp;H. Nezomba ,&nbsp;P. Mapfumo ,&nbsp;F. Mtambanengwe ,&nbsp;J.G. Chimungu","doi":"10.1016/j.geoderma.2025.117431","DOIUrl":"10.1016/j.geoderma.2025.117431","url":null,"abstract":"<div><div>Conservation Agriculture (CA) is proposed as a ‘climate-smart’ intervention for resilient crop production in dryland areas affected by climate change. Evidence is needed for how these practices affect fundamental properties of the soil. The soil water retention curve (SWRC) is a physical attribute of the soil which provides information on its porous structure and physical quality. It is also critical for modelling processes in the soil such as water movement, water availability for plants and infiltration into the soil during rainfall events. In this paper we estimate parameters of the van Genuchten model of the SWRC from experiments on CA interventions in southern Africa, using a linear mixed modelling framework. The method we use, stochastic approximation maximization, allows for maximum likelihood estimation of the parameters without use of linearizing approximation. We show how sequential fitting of model parameters, with marginal false discovery rate control, allows us to make robust inferences about differences in the SWRC between soils under contrasting experimental management. We also show how the method allows us to draw samples from distribution of SWRC parameters, reflecting the uncertainty which arises from variation within the management treatments. Indices of soil physical quality may be computed from the parameter estimates to compare treatments, and by computing them from the samples, the uncertainty in these indices can also be assessed. We use the estimated model parameters to simulate infiltration of water into the soils under different management during a rainfall event. Again, by using the samples from the joint distributions of the parameters the effects of uncertainty in these parameters as propagated through the model can be computed. We applied these methods to soils collected from experimental plots under CA and conventional tillage (CV) at sites in Zimbabwe, Zambia and Malawi. We observed differences in the SWRC for the CA and CV plots at the Zambian site where a physically vulnerable soil showed greater macroporosity under CA than CV. In contrast, a sandy and organic-poor soil at the site in Zimbabwe showed somewhat greater macroporosity under cultivation rather than CA management. There was no detectable treatment effect of the management system on the SWRC for the soils at the site in Malawi.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117431"},"PeriodicalIF":6.6,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term nitrogen addition improves soil phosphorus availability by regulating phosphorus-cycling microbial communities in a karst forest","authors":"Yuanshuang Yuan,&nbsp;Xianwang Du,&nbsp;Yicong Yin,&nbsp;Guowei Xia","doi":"10.1016/j.geoderma.2025.117478","DOIUrl":"10.1016/j.geoderma.2025.117478","url":null,"abstract":"<div><div>The widening imbalance between escalating nitrogen (N) deposition and depleting soil phosphorus (P) amplifies the urgency of investigating P cycling processes in terrestrial ecosystems. However, the mechanisms by which P-cycling functional profiles drive soil P mobilization under enhanced N deposition remain to be addressed. After a three-year N-addition experiment at varying rates in a karst forest, we determined the soil P fractions and associated bacterial communities involved in regulating P cycling in rhizosphere and bulk soils. Our results showed that N addition increased plant-available P in both bulk soil (+17 % under low N, +22 % under high N) and rhizosphere soil (+6%, +23 %), while concurrently reducing organic P in bulk soil (−18 %, −24 %) and rhizosphere soil (−8%, –23 %) under corresponding N rates. In addition, N treatment substantially shifted the composition of the P-cycling bacterial community and increased the richness of the community, indicating that N input enhances P availability, potentially through the regulation of the bacterial communities involved in P cycling. Moreover, we found that the functional bacterial genes responsible for P transformation differed between the bulk and rhizosphere soils. Specifically, in the bulk soil, P mineralization genes and P solubilization genes were significantly increased by N treatment. In contrast, in the rhizosphere soil, P mineralization and P regulation genes increased in response to N addition. Together, these results suggest that N addition improves soil P availability by regulating P-cycling functional bacterial communities; however, the specific functional profiles driving P mobilization may differ between bulk and rhizosphere soils. These findings provide novel insight into the regulatory processes of soil P cycling in terrestrial ecosystems under global changes (e.g., N deposition) from a microbial gene perspective.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117478"},"PeriodicalIF":6.6,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144831624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of the Global-Local modelling approach for FT-NIR predictions of SOC and TN in diverse Saskatchewan agricultural soils","authors":"Gbenga Adejumo ,&nbsp;Mervin St. Luce ,&nbsp;David Bulmer ,&nbsp;Preston Sorenson ,&nbsp;Derek Peak","doi":"10.1016/j.geoderma.2025.117477","DOIUrl":"10.1016/j.geoderma.2025.117477","url":null,"abstract":"<div><div>Precision agriculture requires a reliable, cost-effective method to measure soil organic carbon (SOC) and total nitrogen (TN), and Fourier Transform Near Infrared (FT-NIR) spectroscopy offers a promising solution. Here, we applied the <em>Global-Local</em> model to improve FT-NIR SOC and TN predictions in Saskatchewan agricultural soils. Soil samples (SOC: <em>n =</em> 1876; TN: <em>n =</em> 1442) were collected in 2020 and 2021 from six Saskatchewan agricultural regions. Spectral data were acquired, preprocessed using continuous wavelet transform (CWT), and modelled using Cubist regression. The <em>Global-Local</em> model was applied by combining a small subset of site-specific samples (<em>Lab</em>) with their <em>k</em>-nearest neighbours (<em>Neighbour</em>) from Saskatchewan spectral datasets. Its performance was compared with Leave-One-Site-Out (<em>LOSOV</em>), site-specific, <em>Lab</em>, <em>Neighbour</em>, and traditional spiking. Compared to <em>LOSOV</em> (SOC: R² = 0.55 – 0.76, CCC = 0.67 – 0.79, RPD = 1.20 – 1.44), site-specific models gave higher performance (SOC: R² = 0.71 – 0.88, CCC = 0.82 – 0.92; RPD = 1.59 – 2.70). The <em>Global-Local</em> model performed better than <em>LOSOV</em> and performed similarly to the best <em>Lab</em> or <em>Neighbour</em> models. Compared to the <em>Global-Local</em>, traditional spiking either improved or gave similar results due to higher variability in target variable and spectra datasets. The more accurate models using either spiking or <em>Global-Local</em> than <em>LOSOV</em> confirms the importance of incorporating site-specific samples into training datasets. Our results indicate that the application of the <em>Global-Local</em> model should be restricted to an individual field level, which was its original purpose. Future studies on optimization of the <em>Global-Local</em> model is needed to scale-up its application.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"461 ","pages":"Article 117477"},"PeriodicalIF":6.6,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}