Pub Date : 2026-01-14DOI: 10.1016/j.geoderma.2026.117681
Tianli Lan , Yuanming Lai , Xiaoxiao Luo , Fan Yu , Qinguo Ma
Permafrost degradation on the Tibetan Plateau (TP) poses serious risks to the environment and infrastructure. Permafrost changes are controlled by both climate changes and local factors, including climate warming, wetting, and aeolian desertification, but the heat transfer process and hydrothermal mechanism under aeolian sand cover (ASC) remain poorly understood. Using a model test and a coupling numerical model, this study analyzes the effects and mechanisms of warming and wetting on permafrost under ASC. The results indicate that: Under thin ASC, infiltration is tiny and heat conduction dominates heat transfer, and climate warming increases surface heat flux and accelerates permafrost degradation by enhancing the net radiation and reducing the sensible heat. Under thick ASC, infiltration and heat convection become significant, and climate warming increases the annual infiltration by extending the thawing period, drives the decrease in latent heat of evaporation, and further promotes permafrost degradation. As precipitation increases, thin ASC cools the permafrost by enhancing evaporation and reducing surface heat flux. In contrast, thick ASC warms the permafrost by suppressing evaporation increment and enhancing both surface heat flux and subsurface heat convection.
{"title":"Multiple thermophysical effects of aeolian sand cover on permafrost under climate warming and wetting","authors":"Tianli Lan , Yuanming Lai , Xiaoxiao Luo , Fan Yu , Qinguo Ma","doi":"10.1016/j.geoderma.2026.117681","DOIUrl":"10.1016/j.geoderma.2026.117681","url":null,"abstract":"<div><div>Permafrost degradation on the Tibetan Plateau (TP) poses serious risks to the environment and infrastructure. Permafrost changes are controlled by both climate changes and local factors, including climate warming, wetting, and aeolian desertification, but the heat transfer process and hydrothermal mechanism under aeolian sand cover (ASC) remain poorly understood. Using a model test and a coupling numerical model, this study analyzes the effects and mechanisms of warming and wetting on permafrost under ASC. The results indicate that: Under thin ASC, infiltration is tiny and heat conduction dominates heat transfer, and climate warming increases surface heat flux and accelerates permafrost degradation by enhancing the net radiation and reducing the sensible heat. Under thick ASC, infiltration and heat convection become significant, and climate warming increases the annual infiltration by extending the thawing period, drives the decrease in latent heat of evaporation, and further promotes permafrost degradation. As precipitation increases, thin ASC cools the permafrost by enhancing evaporation and reducing surface heat flux. In contrast, thick ASC warms the permafrost by suppressing evaporation increment and enhancing both surface heat flux and subsurface heat convection.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117681"},"PeriodicalIF":6.6,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962588","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}
Pub Date : 2026-01-14DOI: 10.1016/j.geoderma.2026.117674
William Osterholz , Kevin King , Margaret Kalcic , Vinayak Shedekar
Soil health is an objective of management practices including reduced tillage intensity, manure application, crop rotation, and cover crops. However, the relative effectiveness of these practices for promoting healthier soil remains uncertain. We assessed the responses of six soil health indicators (soil organic matter, soil respiration, permanganate oxidizable C (POX-C), soil protein, mean weight diameter of water stable aggregates, and bulk density) to four management practices (manure application, reduced tillage, living cover in fall and spring, and crop diversity) across 50 commercial crop fields in Ohio and Indiana, USA. Simple linear regression, multiple linear regression and random forest analyses largely identified similar relationships between soil health and management practices. Manure application rate was consistently and positively associated with greater soil health values, although the relationship with bulk density was weak. Reduced tillage intensity was associated with greater protein and respiration, but decreased POX-C. Living cover and crop diversity each had limited relationships with the soil health indicators. Soil texture was an important factor driving variability in most soil health indicators. Reducing the management period from 5 yr to 3 yr tended to reduce the predictive ability of the models, but with limited exceptions similar relationships between management and soil health were identifiable. The depth of measurement of soil health indicators changed the interpretation of management-soil health relationships in only one instance (POX-C vs. reduced tillage intensity). Overall, manure application was the most effective practice for improving soil health, with reduced tillage intensity also effective for improving several soil health indicators.
{"title":"Soil health indicators respond to management practices on commercial farms","authors":"William Osterholz , Kevin King , Margaret Kalcic , Vinayak Shedekar","doi":"10.1016/j.geoderma.2026.117674","DOIUrl":"10.1016/j.geoderma.2026.117674","url":null,"abstract":"<div><div>Soil health is an objective of management practices including reduced tillage intensity, manure application, crop rotation, and cover crops. However, the relative effectiveness of these practices for promoting healthier soil remains uncertain. We assessed the responses of six soil health indicators (soil organic matter, soil respiration, permanganate oxidizable C (POX-C), soil protein, mean weight diameter of water stable aggregates, and bulk density) to four management practices (manure application, reduced tillage, living cover in fall and spring, and crop diversity) across 50 commercial crop fields in Ohio and Indiana, USA. Simple linear regression, multiple linear regression and random forest analyses largely identified similar relationships between soil health and management practices. Manure application rate was consistently and positively associated with greater soil health values, although the relationship with bulk density was weak. Reduced tillage intensity was associated with greater protein and respiration, but decreased POX-C. Living cover and crop diversity each had limited relationships with the soil health indicators. Soil texture was an important factor driving variability in most soil health indicators. Reducing the management period from 5 yr to 3 yr tended to reduce the predictive ability of the models, but with limited exceptions similar relationships between management and soil health were identifiable. The depth of measurement of soil health indicators changed the interpretation of management-soil health relationships in only one instance (POX-C vs. reduced tillage intensity). Overall, manure application was the most effective practice for improving soil health, with reduced tillage intensity also effective for improving several soil health indicators.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117674"},"PeriodicalIF":6.6,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974842","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}
Pub Date : 2026-01-12DOI: 10.1016/j.geoderma.2025.117669
Shijie He , Beilei Wei , Hao Guo , Huarong Lin , Ruixuan Zhu , Xiaoqi Zhang , Shunting He , Yongfeng Sun , Shengsen Zhou , Andong Cai , Ziting Wang , Zhigang Huang
Agricultural soil acidification affects 40–70% of croplands worldwide and is intensifying with increasing nitrogen fertilization. Although nitrogen fertilizer-induced acidification is well-documented, the quantitative relationships and thresholds between base cations and exchangeable acids across different soil pH levels remain poorly understood. This study conducted a meta-analysis of 2,348 field trials from 157 sites worldwide, quantifying the dynamics of base cations (K+, Ca2+, Mg2+) and exchangeable acids in acidic and neutral soils under long-term nitrogen fertilization. It aims to: (1) quantify nitrogen effects on base cations and exchangeable acids; (2) evaluate the relationship between base cation loss and pH decline in soils with different pH values; and (3) explore how organic matter alleviates exchangeable acids increase. The results showed that under nitrogen fertilization, the exchangeable K+, Ca2+, and Mg2+ decreased significantly in acidic soils by 20.3%, 48.6%, and 43.3%, respectively, but showed relative lower decreases in neutral soils by 17.9%, 14.5%, and 6.3%, respectively. In addition, the exchangeable acid content in acidic soils increased significantly by 116.5%, which was much higher than that in neutral soils (35.7%). Subgroup analyses revealed that the accumulation of exchangeable acids could be effectively inhibited when the soil organic matter content exceeded 25.0 g/kg; moreover, the addition of calcium was of great significance for the retention of soil organic matter. This study emphasizes that acidic soils are more sensitive to nitrogen fertilization than neutral soils and more susceptible to soil acidification. These findings are crucial for understanding the acidification threshold of nitrogen fertilizer application, accumulative effects of fertilization time, and dynamic equilibrium between base cations and exchangeable acids in soils with different pH values. They also provide scientific evidence for quantifying the threshold of organic matter content for acidification relief and mitigating soil acidification caused by nitrogen fertilization.
{"title":"Nitrogen fertilization induces greater loss of base cations and accumulation of exchangeable acids in acidic soils than in neutral soils","authors":"Shijie He , Beilei Wei , Hao Guo , Huarong Lin , Ruixuan Zhu , Xiaoqi Zhang , Shunting He , Yongfeng Sun , Shengsen Zhou , Andong Cai , Ziting Wang , Zhigang Huang","doi":"10.1016/j.geoderma.2025.117669","DOIUrl":"10.1016/j.geoderma.2025.117669","url":null,"abstract":"<div><div>Agricultural soil acidification affects 40–70% of croplands worldwide and is intensifying with increasing nitrogen fertilization. Although nitrogen fertilizer-induced acidification is well-documented, the quantitative relationships and thresholds between base cations and exchangeable acids across different soil pH levels remain poorly understood. This study conducted a meta-analysis of 2,348 field trials from 157 sites worldwide, quantifying the dynamics of base cations (K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>) and exchangeable acids in acidic and neutral soils under long-term nitrogen fertilization. It aims to: (1) quantify nitrogen effects on base cations and exchangeable acids; (2) evaluate the relationship between base cation loss and pH decline in soils with different pH values; and (3) explore how organic matter alleviates exchangeable acids increase. The results showed that under nitrogen fertilization, the exchangeable K<sup>+</sup>, Ca<sup>2+</sup>, and Mg<sup>2+</sup> decreased significantly in acidic soils by 20.3%, 48.6%, and 43.3%, respectively, but showed relative lower decreases in neutral soils by 17.9%, 14.5%, and 6.3%, respectively. In addition, the exchangeable acid content in acidic soils increased significantly by 116.5%, which was much higher than that in neutral soils (35.7%). Subgroup analyses revealed that the accumulation of exchangeable acids could be effectively inhibited when the soil organic matter content exceeded 25.0 g/kg; moreover, the addition of calcium was of great significance for the retention of soil organic matter. This study emphasizes that acidic soils are more sensitive to nitrogen fertilization than neutral soils and more susceptible to soil acidification. These findings are crucial for understanding the acidification threshold of nitrogen fertilizer application, accumulative effects of fertilization time, and dynamic equilibrium between base cations and exchangeable acids in soils with different pH values. They also provide scientific evidence for quantifying the threshold of organic matter content for acidification relief and mitigating soil acidification caused by nitrogen fertilization.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117669"},"PeriodicalIF":6.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956994","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}
Pub Date : 2026-01-12DOI: 10.1016/j.geoderma.2026.117680
Wei Peng , Lin Liu , Meng Tian , Xiaomeng Yao
The growing demand for studying coupled hydrothermal transport processes in layered soils comes with a need for accurate estimations of thermal properties using the heat pulse (HP) sensor. In the case where a HP sensor is installed vertically in a double-layered soil with the sensor crossing a soil horizon interface, its measurements are affected by different upper and lower layered properties. This study combined laboratory and numerical experiments to quantify the effect of the soil horizon interface on HP measurements, and to develop a parameterized cylindrical perfect conductor (PCPC) model that accounts for the interface position and layered properties. Results indicated that the effect of the layered soil properties on HP measurements depended on the soil horizon interface position, specifically when the soil horizon interface was within 15 mm vertically above or below the thermocouples in the HP sensor. A sigmoid function was used to quantify the effects of soil layer properties and soil horizon interface position on HP measurements. The developed PCPC model, based on the sigmoid function, exhibited strong agreement with the numerical simulations, yielding soil thermal property estimates all within a maximum relative error of −3.1%. The PCPC model effectively captured the combined effects of soil horizon interface and thermal properties of soil layers on the HP measurements in a double-layered soil system. This model provides a theoretical basis for the inversion of soil thermal property in such a double-layered soil environments with a HP sensor vertically crossing a soil horizon interface.
{"title":"Analysis of soil thermal property measurements in double-layered soils with the heat pulse sensor vertically crossing a soil horizon interface","authors":"Wei Peng , Lin Liu , Meng Tian , Xiaomeng Yao","doi":"10.1016/j.geoderma.2026.117680","DOIUrl":"10.1016/j.geoderma.2026.117680","url":null,"abstract":"<div><div>The growing demand for studying coupled hydrothermal transport processes in layered soils comes with a need for accurate estimations of thermal properties using the heat pulse (HP) sensor. In the case where a HP sensor is installed vertically in a double-layered soil with the sensor crossing a soil horizon interface, its measurements are affected by different upper and lower layered properties. This study combined laboratory and numerical experiments to quantify the effect of the soil horizon interface on HP measurements, and to develop a parameterized cylindrical perfect conductor (PCPC) model that accounts for the interface position and layered properties. Results indicated that the effect of the layered soil properties on HP measurements depended on the soil horizon interface position, specifically when the soil horizon interface was within 15 mm vertically above or below the thermocouples in the HP sensor. A sigmoid function was used to quantify the effects of soil layer properties and soil horizon interface position on HP measurements. The developed PCPC model, based on the sigmoid function, exhibited strong agreement with the numerical simulations, yielding soil thermal property estimates all within a maximum relative error of −3.1%. The PCPC model effectively captured the combined effects of soil horizon interface and thermal properties of soil layers on the HP measurements in a double-layered soil system. This model provides a theoretical basis for the inversion of soil thermal property in such a double-layered soil environments with a HP sensor vertically crossing a soil horizon interface.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117680"},"PeriodicalIF":6.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956993","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}
Pub Date : 2026-01-10DOI: 10.1016/j.geoderma.2025.117665
Chunyu Hou , Shangwen Xia , Xuan Liu , Jiaojiao Jiao , Yi Xiong , Hong Chen , Changwei Ma , Jianping Wu
Plant-soil interactions in terrestrial ecosystems profoundly shape the structure and function of belowground communities. Soil nematodes play a vital role in facilitating key belowground ecological processes, however, it remains poorly understood how different plant phenological functional types regulate their community composition and function in tropical forest soils. To address this, we selected three tropical deciduous species—Terminalia bellirica, Melia azedarach, and Albizia lucidior—and three tropical evergreen species—Castanopsis indica, Trema orientalis, and Syzygium jambos—for a two-year common garden pot experiment in Xishuangbanna Tropical Botanical Garden. We evaluated soil physicochemical properties, leaf functional traits, the nematode abundance and biomass, and their function (energy flux). Our results showed that evergreen species had higher aboveground biomass, leaf thickness, soil dissolved organic carbon, and soil total phosphorus compared to deciduous species. Furthermore, evergreen species exhibited greater abundance, biomass, and energy flux than deciduous species, with increases of 69.12 %, 93.47 %, and 107.55 % for herbivores, and increases of 46.51 %, 27.72 %, and 68.46 % for the total nematodes. Although herbivores abundance positively contributed to total energy flux, this effect was indirectly modulated by plant aboveground biomass and soil dissolved organic carbon. Our findings demonstrate that phenological functional types regulate herbivores by altering the resource quantity available to the soil food web, consequently shaping the community structure of soil nematodes and influencing the energy flow patterns. Based on this common garden pot experiment, we conclude that evergreen species enhance the abundance of herbivores and total soil nematodes, while simultaneously increasing soil carbon storage potential, relative to deciduous species.
{"title":"Plant phenological functional types shape soil nematode abundance and function by regulating aboveground biomass and soil dissolved organic carbon in tropical Xishuangbanna","authors":"Chunyu Hou , Shangwen Xia , Xuan Liu , Jiaojiao Jiao , Yi Xiong , Hong Chen , Changwei Ma , Jianping Wu","doi":"10.1016/j.geoderma.2025.117665","DOIUrl":"10.1016/j.geoderma.2025.117665","url":null,"abstract":"<div><div>Plant-soil interactions in terrestrial ecosystems profoundly shape the structure and function of belowground communities. Soil nematodes play a vital role in facilitating key belowground ecological processes, however, it remains poorly understood how different plant phenological functional types regulate their community composition and function in tropical forest soils. To address this, we selected three tropical deciduous species—<em>Terminalia bellirica</em>, <em>Melia azedarach</em>, and <em>Albizia lucidior</em>—and three tropical evergreen species—<em>Castanopsis indica</em>, <em>Trema orientalis</em>, and <em>Syzygium jambos</em>—for a two-year common garden pot experiment in Xishuangbanna Tropical Botanical Garden. We evaluated soil physicochemical properties, leaf functional traits, the nematode abundance and biomass, and their function (energy flux). Our results showed that evergreen species had higher aboveground biomass, leaf thickness, soil dissolved organic carbon, and soil total phosphorus compared to deciduous species. Furthermore, evergreen species exhibited greater abundance, biomass, and energy flux than deciduous species, with increases of 69.12 %, 93.47 %, and 107.55 % for herbivores, and increases of 46.51 %, 27.72 %, and 68.46 % for the total nematodes. Although herbivores abundance positively contributed to total energy flux, this effect was indirectly modulated by plant aboveground biomass and soil dissolved organic carbon. Our findings demonstrate that phenological functional types regulate herbivores by altering the resource quantity available to the soil food web, consequently shaping the community structure of soil nematodes and influencing the energy flow patterns. Based on this common garden pot experiment, we conclude that evergreen species enhance the abundance of herbivores and total soil nematodes, while simultaneously increasing soil carbon storage potential, relative to deciduous species.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117665"},"PeriodicalIF":6.6,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941327","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}
Pub Date : 2026-01-10DOI: 10.1016/j.geoderma.2026.117675
Rouyun Zhou , Bolang Luo , Ming Ao , Taicong Liu , Ruichun Meng , Loua-Augustin Bonaventure , Xiaoli Qian , Jean-Louis Morel , Pan Wu , Shizhong Wang , Rongliang Qiu
Natural oxidation of geogenic Cr(III) to carcinogenic Cr(VI) is a major source of Cr contamination in soil and water. However, the mechanisms of Cr(VI) generation and occurrence under anoxic conditions remain unclear. Although Mn(III/IV) oxides are considered key oxidants, their interactions with stable Cr(III) minerals and the subsequent fate of Cr(VI) represent critical knowledge gaps. This study combines field profile analysis of serpentinite weathering in southwest China with laboratory experiments to clarify these processes. We introduce a new mechanism termed “in situ oxidation-surface adsorption” mechanism: the stability of secondary Cr(III) minerals governs oxidation sensitivity, Mn(III/IV) oxides drive Cr(VI) generation via direct surface contact, while Fe(III)/Mn(III/IV) oxides act as effective adsorbents retaining Cr(VI) in the solid-phase. Experimental results indicate that sub-stable Cr(OH)3 formed during serpentinite weathering is the primary contributor to Cr(VI) generation, while Cr2O3 is negligible. In conditions with low reductants, more than 99.8% of the Cr(VI) generated is adsorbed onto the surfaces of Fe(III)/Mn(III/IV) oxides, creating a stable “Cr(VI) reservoir” with limited release into the aqueous phase. These findings challenge conventional dissolution-migration-oxidation models and enhance our understanding of Cr(VI) generation and accumulation in anoxic soils, providing crucial insights for assessing and managing geological Cr risks.
{"title":"Mechanisms of generation and accumulation of geogenic Cr(VI) in serpentinite-weathered soils","authors":"Rouyun Zhou , Bolang Luo , Ming Ao , Taicong Liu , Ruichun Meng , Loua-Augustin Bonaventure , Xiaoli Qian , Jean-Louis Morel , Pan Wu , Shizhong Wang , Rongliang Qiu","doi":"10.1016/j.geoderma.2026.117675","DOIUrl":"10.1016/j.geoderma.2026.117675","url":null,"abstract":"<div><div>Natural oxidation of geogenic Cr(III) to carcinogenic Cr(VI) is a major source of Cr contamination in soil and water. However, the mechanisms of Cr(VI) generation and occurrence under anoxic conditions remain unclear. Although Mn(III/IV) oxides are considered key oxidants, their interactions with stable Cr(III) minerals and the subsequent fate of Cr(VI) represent critical knowledge gaps. This study combines field profile analysis of serpentinite weathering in southwest China with laboratory experiments to clarify these processes. We introduce a new mechanism termed “in situ oxidation-surface adsorption” mechanism: the stability of secondary Cr(III) minerals governs oxidation sensitivity, Mn(III/IV) oxides drive Cr(VI) generation via direct surface contact, while Fe(III)/Mn(III/IV) oxides act as effective adsorbents retaining Cr(VI) in the solid-phase. Experimental results indicate that sub-stable Cr(OH)<sub>3</sub> formed during serpentinite weathering is the primary contributor to Cr(VI) generation, while Cr<sub>2</sub>O<sub>3</sub> is negligible. In conditions with low reductants, more than 99.8% of the Cr(VI) generated is adsorbed onto the surfaces of Fe(III)/Mn(III/IV) oxides, creating a stable “Cr(VI) reservoir” with limited release into the aqueous phase. These findings challenge conventional dissolution-migration-oxidation models and enhance our understanding of Cr(VI) generation and accumulation in anoxic soils, providing crucial insights for assessing and managing geological Cr risks.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117675"},"PeriodicalIF":6.6,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956995","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}
Pub Date : 2026-01-09DOI: 10.1016/j.geoderma.2026.117673
V. Daimonakos , A.Van Zinderen , J. Muñoz-Rojas , D. Costa , J.P. Nunes , S.A. Prats
The use of vegetation suppression, such as herbicide application and mechanical plowing in olive orchards can exacerbate soil erosion. Maintaining understory vegetation can mitigate erosion and enhance soil fertility. Although prior research has assessed the soil management impact on erosion, knowledge gaps persist regarding dominant erosion processes across spatial scales and management effects on soil microenvironments (tree canopy, wheel ruts, vegetation strips). This study systematically evaluates how soil management (herbicides, plowing, no intervention) and spatial scales (microplots, hillslope plots) affect erosion dynamics, soil properties and their interactions with rainfall, ground cover, and orchard characteristics in Alentejo, Portugal. Over two years, seven orchards with varying management practices were monitored for erosion rates, ground cover, and soil properties. Soil management strongly influenced erosion, with herbicides inducing the highest hillslope-scale erosion (average 11.3 t ha−1 yr−1) and plowing dominating microplot erosion, while untreated plots exhibited minimal erosion (up to 99 % lower than the herbicide treatments). Wheel rut areas increased hillslope erosion through runoff concentration and bare soil, while vegetation strips suppressed it completely. Tree canopy areas varied: plowing mobilized new sediments, whereas untreated/herbicide microplots showed no erosion due to vegetation cover or stone‑lag armoring. Hillslope erosion stemmed from cumulative runoff, while microplots were influenced by soil properties like roughness or bulk density. Our findings highlight the need to consider scale effects in erosion modelling and policy. Future research should explore longer-term trends, expand underlying conditions (e.g. soil types, climatic zones or management practices), and refine soil erosion models to support sustainable soil conservation.
{"title":"How strongly do management practices and scales influence soil erosion rates in olive orchards? Empirical evidence from Alentejo (Portugal)","authors":"V. Daimonakos , A.Van Zinderen , J. Muñoz-Rojas , D. Costa , J.P. Nunes , S.A. Prats","doi":"10.1016/j.geoderma.2026.117673","DOIUrl":"10.1016/j.geoderma.2026.117673","url":null,"abstract":"<div><div>The use of vegetation suppression, such as herbicide application and mechanical plowing in olive orchards can exacerbate soil erosion. Maintaining understory vegetation can mitigate erosion and enhance soil fertility. Although prior research has assessed the soil management impact on erosion, knowledge gaps persist regarding dominant erosion processes across spatial scales and management effects on soil microenvironments (tree canopy, wheel ruts, vegetation strips). This study systematically evaluates how soil management (herbicides, plowing, no intervention) and spatial scales (microplots, hillslope plots) affect erosion dynamics, soil properties and their interactions with rainfall, ground cover, and orchard characteristics in Alentejo, Portugal. Over two years, seven orchards with varying management practices were monitored for erosion rates, ground cover, and soil properties. Soil management strongly influenced erosion, with herbicides inducing the highest hillslope-scale erosion (average 11.3 t ha<sup>−1</sup> yr<sup>−1</sup>) and plowing dominating microplot erosion, while untreated plots exhibited minimal erosion (up to 99 % lower than the herbicide treatments). Wheel rut areas increased hillslope erosion through runoff concentration and bare soil, while vegetation strips suppressed it completely. Tree canopy areas varied: plowing mobilized new sediments, whereas untreated/herbicide microplots showed no erosion due to vegetation cover or stone‑lag armoring. Hillslope erosion stemmed from cumulative runoff, while microplots were influenced by soil properties like roughness or bulk density. Our findings highlight the need to consider scale effects in erosion modelling and policy. Future research should explore longer-term trends, expand underlying conditions (e.g. soil types, climatic zones or management practices), and refine soil erosion models to support sustainable soil conservation.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117673"},"PeriodicalIF":6.6,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915418","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}
Root carbon (C) inputs play a pivotal role in mediating the formation, accumulation, and turnover of soil organic C (SOC). However, how different root functional modules (absorptive roots [ARs] vs. transport roots [TRs]) regulate SOC dynamics under elevated atmospheric nitrogen (N) deposition remains unclear. By separately collecting rhizosphere soils of ARs and TRs and quantifying SOC accumulation therein, we characterized the distinct roles of these two root modules in regulating SOC dynamics in a subtropical karst forest subjected to different rates of N additions. Nitrogen addition promoted SOC accumulation in the rhizosphere of both ARs and TRs, especially at higher N-addition rate. Moreover, the rhizosphere SOC contents of ARs were significantly higher than those of TRs across N-addition treatments. Correlation analysis indicated that under the influence of ARs, SOC content was significantly and positively correlated with both protective mineral-associated SOC poos and microbial carbon pump (MCP) efficacy. By contrast, in the context of TRs, a significantly positive association was observed exclusively between SOC content and protective mineral pools, with no significant correlation of SOC content with MCP efficacy. These findings suggest that ARs outweigh TRs in mediating the effects of N addition on SOC accumulation. Mechanisms driving N-induced SOC accumulation may differ between two root functional modules, with each module governing distinct regulatory pathways. This study highlights the necessity to integrate root functional traits, particularly those distinguishing ARs and TRs, into process-based predictive frameworks of ecosystem C cycling. Such integration is critical for improving the mechanistic understanding and predictive accuracy of soil C dynamics in the context of projected N deposition regimes.
{"title":"Absorptive roots outweigh transport roots in modulating nitrogen-addition effects on soil organic carbon accumulation in a subtropical forest","authors":"Yuanshuang Yuan , Xianwang Du , Yicong Yin , Bartosz Adamczyk , Ziliang Zhang","doi":"10.1016/j.geoderma.2025.117571","DOIUrl":"10.1016/j.geoderma.2025.117571","url":null,"abstract":"<div><div>Root carbon (C) inputs play a pivotal role in mediating the formation, accumulation, and turnover of soil organic C (SOC). However, how different root functional modules (absorptive roots [ARs] vs. transport roots [TRs]) regulate SOC dynamics under elevated atmospheric nitrogen (N) deposition remains unclear. By separately collecting rhizosphere soils of ARs and TRs and quantifying SOC accumulation therein, we characterized the distinct roles of these two root modules in regulating SOC dynamics in a subtropical karst forest subjected to different rates of N additions. Nitrogen addition promoted SOC accumulation in the rhizosphere of both ARs and TRs, especially at higher N-addition rate. Moreover, the rhizosphere SOC contents of ARs were significantly higher than those of TRs across N-addition treatments. Correlation analysis indicated that under the influence of ARs, SOC content was significantly and positively correlated with both protective mineral-associated SOC poos and microbial carbon pump (MCP) efficacy. By contrast, in the context of TRs, a significantly positive association was observed exclusively between SOC content and protective mineral pools, with no significant correlation of SOC content with MCP efficacy. These findings suggest that ARs outweigh TRs in mediating the effects of N addition on SOC accumulation. Mechanisms driving N-induced SOC accumulation may differ between two root functional modules, with each module governing distinct regulatory pathways. This study highlights the necessity to integrate root functional traits, particularly those distinguishing ARs and TRs, into process-based predictive frameworks of ecosystem C cycling. Such integration is critical for improving the mechanistic understanding and predictive accuracy of soil C dynamics in the context of projected N deposition regimes.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"465 ","pages":"Article 117571"},"PeriodicalIF":6.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823031","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}
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