Pub Date : 2026-02-09DOI: 10.1016/j.still.2026.107104
Shending Chen , Ahmed S. Elrys , Qiaodong Chi , Wenyan Yang , Lei Meng , Zucong Cai , Jinbo Zhang , Baojing Gu , Christoph Müller
Rice generally exhibits lower nitrogen use efficiency (NUE) than other crops, yet the nitrogen (N) process-level mechanisms underlying regional variation remain unclear. Here, we conducted a multi-scale investigation combining laboratory soil incubations, pot experiments with 15N tracings, and field trials across 50 soil samples from China’s rice fields. We quantified soil N transformation rates, evaluated pot-based NUE, and tested N management strategies in two paddy sites with contrasting soils. Results revealed substantial regional differences in gross N transformations, including mineralization, nitrification, and ammonium immobilization, with northern soils exhibiting longer mean retention times of ammonium (average 19.5 days) than southern soils (average 5.4 days). Ammonium retention time was more closely associated with NUE than temperature, precipitation, or nitrification rates. Field trials confirmed that ammonium-stabilizing treatments, particularly combined nitrification and urease inhibitors, improved both yield and NUE in alkaline soils. These findings provide a mechanistic basis for region-specific N management to enhance rice productivity while reducing environmental losses.
{"title":"Unraveling mechanistic insights into soil nitrogen transformation processes for improving NUE in paddy rice systems","authors":"Shending Chen , Ahmed S. Elrys , Qiaodong Chi , Wenyan Yang , Lei Meng , Zucong Cai , Jinbo Zhang , Baojing Gu , Christoph Müller","doi":"10.1016/j.still.2026.107104","DOIUrl":"10.1016/j.still.2026.107104","url":null,"abstract":"<div><div>Rice generally exhibits lower nitrogen use efficiency (NUE) than other crops, yet the nitrogen (N) process-level mechanisms underlying regional variation remain unclear. Here, we conducted a multi-scale investigation combining laboratory soil incubations, pot experiments with <sup>15</sup>N tracings, and field trials across 50 soil samples from China’s rice fields. We quantified soil N transformation rates, evaluated pot-based NUE, and tested N management strategies in two paddy sites with contrasting soils. Results revealed substantial regional differences in gross N transformations, including mineralization, nitrification, and ammonium immobilization, with northern soils exhibiting longer mean retention times of ammonium (average 19.5 days) than southern soils (average 5.4 days). Ammonium retention time was more closely associated with NUE than temperature, precipitation, or nitrification rates. Field trials confirmed that ammonium-stabilizing treatments, particularly combined nitrification and urease inhibitors, improved both yield and NUE in alkaline soils. These findings provide a mechanistic basis for region-specific N management to enhance rice productivity while reducing environmental losses.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"260 ","pages":"Article 107104"},"PeriodicalIF":6.8,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146673","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 : 2026-02-09DOI: 10.1016/j.still.2026.107112
Sihan Zhao , Guang Yang , Yuewei Yang , Xin Yu , Jialu Sun , Xiaolin Zhang , Pinpin Yang , Xiaodong Zhao , Xiaojing Li
Farmland soil is a complex system involving the conversion of multiple biogenic elements, which plays a key role in maintaining soil ecological balance. Extracellular electron transfer (EET) is an essential driving force for material circulation and energy exchange. Thus, it affects the biogeochemical processes and cycles of soil elements, including mineral formation and evolution, nutrient cycling and even the removal of pollutants and the improvement of cultivated land quality. This review summarizes the progress of research on electron transfer in farmland soil. It provides an overview of electroactive microorganisms, electron transfer modes, and their coupled conversion with carbon, nitrogen, sulfur, and iron elements. Afterwards, future research directions are expected, including an in-depth exploration of electron transfer mechanisms, optimization of electron transfer pathways, and improvement of biogenic element conversion. This review puts forward a new way to regulate the biotransformation of elements and provides support for improving the fertility of farmland soil and promoting the sustainable development of agriculture.
{"title":"Electron transfer coupling with biogenic elements conversion in farmland soil: A review","authors":"Sihan Zhao , Guang Yang , Yuewei Yang , Xin Yu , Jialu Sun , Xiaolin Zhang , Pinpin Yang , Xiaodong Zhao , Xiaojing Li","doi":"10.1016/j.still.2026.107112","DOIUrl":"10.1016/j.still.2026.107112","url":null,"abstract":"<div><div>Farmland soil is a complex system involving the conversion of multiple biogenic elements, which plays a key role in maintaining soil ecological balance. Extracellular electron transfer (EET) is an essential driving force for material circulation and energy exchange. Thus, it affects the biogeochemical processes and cycles of soil elements, including mineral formation and evolution, nutrient cycling and even the removal of pollutants and the improvement of cultivated land quality. This review summarizes the progress of research on electron transfer in farmland soil. It provides an overview of electroactive microorganisms, electron transfer modes, and their coupled conversion with carbon, nitrogen, sulfur, and iron elements. Afterwards, future research directions are expected, including an in-depth exploration of electron transfer mechanisms, optimization of electron transfer pathways, and improvement of biogenic element conversion. This review puts forward a new way to regulate the biotransformation of elements and provides support for improving the fertility of farmland soil and promoting the sustainable development of agriculture.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"260 ","pages":"Article 107112"},"PeriodicalIF":6.8,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146687","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 : 2026-02-07DOI: 10.1016/j.still.2026.107103
Miyanda Chilipamushi , Claudia von Brömssen , Tino Colombi , Thomas Kätterer , Mats Larsbo
Roots are a major pathway for carbon (C) input into agricultural soils, yet field-scale measurements of belowground C inputs and associated root traits remain limited. Consequently, many soil carbon models rely on fixed root-to-shoot ratios, and root trait variability is rarely considered. In this study, we quantified within-field variation in root-to-shoot ratios and root traits (root diameter, root length density and root tissue density) in spring barley (Hordeum vulgare L.) grown in southwestern Sweden in soil classified as Stagnic Eutric Cambisol, Eutric Stagnosol or Haplic Phaeozem according to the World Reference Base system. Roots (0–40 cm) and shoots were sampled during early to mid-reproductive stage, i.e. milking/early dough development stage, in a 50 × 50 cm grid at 11 sampling locations in the same field in two consecutive years. Shoot and root biomass were not correlated, resulting in variable root-to-shoot ratios (quartile coefficients of variation 7–18 %) and no consistent spatial pattern between years. Root traits displayed clear between year and depth variation, with coarser roots in the topsoil and root tissue densities and root length densities shifting across the profile, reflecting the highly plastic nature of root systems. The spatial variation in root properties in the field could not be explained by basic soil properties. Our findings call for a more mechanistic understanding of the drivers for root-to-shoot ratios and the plastic response of root traits to improve field-scale estimates of root-derived C inputs and SOC modelling accuracy.
{"title":"Within-field variation in root-to-shoot ratios and root traits in spring barley: Implications for estimating carbon inputs","authors":"Miyanda Chilipamushi , Claudia von Brömssen , Tino Colombi , Thomas Kätterer , Mats Larsbo","doi":"10.1016/j.still.2026.107103","DOIUrl":"10.1016/j.still.2026.107103","url":null,"abstract":"<div><div>Roots are a major pathway for carbon (C) input into agricultural soils, yet field-scale measurements of belowground C inputs and associated root traits remain limited. Consequently, many soil carbon models rely on fixed root-to-shoot ratios, and root trait variability is rarely considered. In this study, we quantified within-field variation in root-to-shoot ratios and root traits (root diameter, root length density and root tissue density) in spring barley (<em>Hordeum vulgare</em> L.) grown in southwestern Sweden in soil classified as Stagnic Eutric Cambisol, Eutric Stagnosol or Haplic Phaeozem according to the World Reference Base system. Roots (0–40 cm) and shoots were sampled during early to mid-reproductive stage, i.e. milking/early dough development stage, in a 50 × 50 cm grid at 11 sampling locations in the same field in two consecutive years. Shoot and root biomass were not correlated, resulting in variable root-to-shoot ratios (quartile coefficients of variation 7–18 %) and no consistent spatial pattern between years. Root traits displayed clear between year and depth variation, with coarser roots in the topsoil and root tissue densities and root length densities shifting across the profile, reflecting the highly plastic nature of root systems. The spatial variation in root properties in the field could not be explained by basic soil properties. Our findings call for a more mechanistic understanding of the drivers for root-to-shoot ratios and the plastic response of root traits to improve field-scale estimates of root-derived C inputs and SOC modelling accuracy.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"260 ","pages":"Article 107103"},"PeriodicalIF":6.8,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134153","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 exudates mobilize soil nutrients and create an important pathway for plants to obtain resources. Understanding nutrient-acquisition strategies based on root exudation by coexisting grassland species is crucial for vegetation regrowth and productivity after grazing. We analyzed the nutrient-acquisition strategies and productivity maintenance mechanisms of Leymus chinensis, Stipa grandis and Cleistogenes squarrosa over two consecutive years in a long-term grazing experimental plot in a typical grassland in Inner Mongolia. Grazing significantly promoted the root exudation rates of carbon (C), nitrogen (N), and organic acids. Grazing increased the maximum quantum efficiency of photosystem II, root salicylic acid, and total soluble sugars (TSS), which increased root exudation by improving competitive traits such as root nitrogen (RN) and specific root area (SRA), while reducing tissue-construction traits such as root tissue density (RTD). This shift led L. chinensis to adopt a competitive strategy. Stipa grandis exhibited a higher net photosynthetic rate and non-photochemical quenching, which promoted C and organic acid exudation, thereby increasing specific root length (SRL). Nitrogen exudation further increased RTD, resulting in a conservative strategy. Cleistogenes squarrosa demonstrated a higher carboxylation efficiency, electron transport rate, and TSS, which promoted N and organic acid exudation, and increased SRA and RTD, whereas C exudation increased RN, forming a facultative nutrient-acquisition strategy. These processes mobilized rhizosphere soil nutrients, especially ammonium nitrogen (NH4+-N), and thereby improved aboveground productivity. Our results highlight the importance of plant metabolite in regulating changes in root exudation rates. Furthermore, the trade-offs between plant root exudation and root morphology determined the strategy of belowground resource acquisition, and the mobilization of soil nitrogen and other nutrients. Our results have important theoretical and practical implications for understanding the coexistence of grassland species under grazing pressure and for developing restoration strategies for degraded grasslands.
{"title":"Trade-offs between root exudation and root traits induced by coexisting species under a grazing gradient can mobilize available nitrogen to promote grassland productivity","authors":"Guisen Yang, Jirui Gong, Shangpeng Zhang, Ruijing Wang, Tong Wang, Yaohong Yu, Qin Xie","doi":"10.1016/j.still.2026.107108","DOIUrl":"10.1016/j.still.2026.107108","url":null,"abstract":"<div><div>Root exudates mobilize soil nutrients and create an important pathway for plants to obtain resources. Understanding nutrient-acquisition strategies based on root exudation by coexisting grassland species is crucial for vegetation regrowth and productivity after grazing. We analyzed the nutrient-acquisition strategies and productivity maintenance mechanisms of <em>Leymus chinensis</em>, <em>Stipa grandis</em> and <em>Cleistogenes squarrosa</em> over two consecutive years in a long-term grazing experimental plot in a typical grassland in Inner Mongolia. Grazing significantly promoted the root exudation rates of carbon (C), nitrogen (N), and organic acids. Grazing increased the maximum quantum efficiency of photosystem II, root salicylic acid, and total soluble sugars (<em>TSS</em>), which increased root exudation by improving competitive traits such as root nitrogen (<em>RN</em>) and specific root area (<em>SRA</em>), while reducing tissue-construction traits such as root tissue density (<em>RTD</em>). This shift led <em>L. chinensis</em> to adopt a competitive strategy. <em>Stipa grandis</em> exhibited a higher net photosynthetic rate and non-photochemical quenching, which promoted C and organic acid exudation, thereby increasing specific root length (<em>SRL</em>). Nitrogen exudation further increased <em>RTD</em>, resulting in a conservative strategy. <em>Cleistogenes squarrosa</em> demonstrated a higher carboxylation efficiency, electron transport rate, and <em>TSS</em>, which promoted N and organic acid exudation, and increased <em>SRA</em> and <em>RTD</em>, whereas C exudation increased <em>RN</em>, forming a facultative nutrient-acquisition strategy. These processes mobilized rhizosphere soil nutrients, especially ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N), and thereby improved aboveground productivity. Our results highlight the importance of plant metabolite in regulating changes in root exudation rates. Furthermore, the trade-offs between plant root exudation and root morphology determined the strategy of belowground resource acquisition, and the mobilization of soil nitrogen and other nutrients. Our results have important theoretical and practical implications for understanding the coexistence of grassland species under grazing pressure and for developing restoration strategies for degraded grasslands.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"260 ","pages":"Article 107108"},"PeriodicalIF":6.8,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134154","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 : 2026-02-05DOI: 10.1016/j.still.2026.107102
Lucas Raimundo Rauber , Leonardo Khaoê Giovanetti , Carolina Oliveira De Alcântara , Pedro de Mello Holme , Cledimar Rogério Lourenzi , Claudinei Kurtz , Jucinei José Comin , Arcângelo Loss
Conservation Agriculture for vegetable production, which is designated as No-Tillage Vegetable System (NTVS) in southern Brazil, sustainably improves food production through the strategic arrangement of cover crops (CCs) in crop rotation. However, the functional differentiation of CCs arrangements needs further understanding in NTVS. This study investigated the functional differentiation of CCs combinations in an NTVS in southern Brazil. The experiment was conducted on a Humic Dystrudept soil in southern Brazil. Treatments included: T1 — fallow in fall/winter (weeds, mainly Galinsoga parviflora) followed by onion (Allium cepa L.) and then corn (Zea mays) (F/Oni/C); T2 — turnip forage (Raphanus sativus L.) in fall/winter followed by onion and then millet (Pennisetum glaucum) (T/Oni/M); T3 — mix of oats (Avena strigosa) and turnip forage in fall/winter, followed by onion and then beans (Phaseolus vulgaris) (O+T/Oni/B); and T4 — oats in fall/winter followed by onion and then soybean (Glycine max) (O/Oni/S). From 2024–2025, after 16 years of long-term experiment that has been carrying out, the following traits were evaluated: soil penetration resistance (PR) (0–50 cm); aggregate stability (0–10 cm); water infiltration into the soil (using concentric double ring); carbon (C) and nitrogen (N) contents (0–10 cm); β-glucosidase enzyme activity and glomalin fractions (0–10 cm); qualitative indices of soil structure and health; and biomass production by CCs. The onion yield data from 2019 to 2024 was also added to the database. The system with the greatest diversity of CCs (O+T/Oni/B) showed the highest water infiltration. The T/Oni/M treatment promoted greater enzymatic activity and lower PR (0–15 cm). Treatments with summer grasses (T/Oni/M; F/Oni/C) resulted in higher biomass production and improved qualitative indexes of soil health, while those with summer legumes (O+T/Oni/B; O/Oni/S) increased onion yield. Aggregate stability, C and N content, and glomalin levels in the soil were high across treatments but had no significant differences. In conclusion, each CC system provides specific benefits to the soil. These findings demonstrate the high degree of functional differentiation of CCs in organic NTVS, allowing management to be tailored to goals (e.g., biomass production, biological activity, water infiltration, or crop yield). The diversity of species, the quantity and type of biomass, and seasonality influence the physical and biological properties of the soil and the functional differentiation between CCs in a long-term organic NTVS. Qualitative indicators of soil health complement quantitative indicators and broaden the functional differentiation of CC arrangements, guiding the regenerative management of soil health.
{"title":"Functional differentiation of cover crops in the long-term no-tillage vegetable system","authors":"Lucas Raimundo Rauber , Leonardo Khaoê Giovanetti , Carolina Oliveira De Alcântara , Pedro de Mello Holme , Cledimar Rogério Lourenzi , Claudinei Kurtz , Jucinei José Comin , Arcângelo Loss","doi":"10.1016/j.still.2026.107102","DOIUrl":"10.1016/j.still.2026.107102","url":null,"abstract":"<div><div>Conservation Agriculture for vegetable production, which is designated as No-Tillage Vegetable System (NTVS) in southern Brazil, sustainably improves food production through the strategic arrangement of cover crops (CCs) in crop rotation. However, the functional differentiation of CCs arrangements needs further understanding in NTVS. This study investigated the functional differentiation of CCs combinations in an NTVS in southern Brazil. The experiment was conducted on a Humic Dystrudept soil in southern Brazil. Treatments included: T1 — fallow in fall/winter (weeds, mainly <em>Galinsoga parviflora</em>) followed by onion (<em>Allium cepa</em> L.) and then corn (<em>Zea mays</em>) (F/Oni/C); T2 — turnip forage (<em>Raphanus sativus</em> L.) in fall/winter followed by onion and then millet (<em>Pennisetum glaucum</em>) (T/Oni/M); T3 — mix of oats (<em>Avena strigosa</em>) and turnip forage in fall/winter, followed by onion and then beans (<em>Phaseolus vulgaris</em>) (O+T/Oni/B); and T4 — oats in fall/winter followed by onion and then soybean (<em>Glycine max</em>) (O/Oni/S). From 2024–2025, after 16 years of long-term experiment that has been carrying out, the following traits were evaluated: soil penetration resistance (PR) (0–50 cm); aggregate stability (0–10 cm); water infiltration into the soil (using concentric double ring); carbon (C) and nitrogen (N) contents (0–10 cm); β-glucosidase enzyme activity and glomalin fractions (0–10 cm); qualitative indices of soil structure and health; and biomass production by CCs. The onion yield data from 2019 to 2024 was also added to the database. The system with the greatest diversity of CCs (O+T/Oni/B) showed the highest water infiltration. The T/Oni/M treatment promoted greater enzymatic activity and lower PR (0–15 cm). Treatments with summer grasses (T/Oni/M; F/Oni/C) resulted in higher biomass production and improved qualitative indexes of soil health, while those with summer legumes (O+T/Oni/B; O/Oni/S) increased onion yield. Aggregate stability, C and N content, and glomalin levels in the soil were high across treatments but had no significant differences. In conclusion, each CC system provides specific benefits to the soil. These findings demonstrate the high degree of functional differentiation of CCs in organic NTVS, allowing management to be tailored to goals (e.g., biomass production, biological activity, water infiltration, or crop yield). The diversity of species, the quantity and type of biomass, and seasonality influence the physical and biological properties of the soil and the functional differentiation between CCs in a long-term organic NTVS. Qualitative indicators of soil health complement quantitative indicators and broaden the functional differentiation of CC arrangements, guiding the regenerative management of soil health.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"260 ","pages":"Article 107102"},"PeriodicalIF":6.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134160","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 : 2026-02-04DOI: 10.1016/j.still.2026.107097
Nannan Yue , Zhongbao Xin
Microplastics (MPs) have emerged as widespread and persistent pollutants in terrestrial ecosystems, yet their distribution and influencing factors in terraced landscapes remain underexplored. Large-scale soil and water conservation projects have been established in the hilly regions of the Loess Plateau, China. However, limited research has addressed how different terraced land use types influence the occurrence and characteristics of soil MPs in this erosion-prone area. The objective of this study was to investigate differences in MPs abundance, color, shape, polymer composition, and vertical distribution among terraced farmland, terraced forestland, terraced orchard, and abandoned cropland in the Qiaozigou watershed. The spatial distribution of MPs within the watershed was examined to assess the effects of land use and soil and water conservation measures on MPs. The results indicated that MPs abundance was high in the terraced watersheds. The MPs abundance in the surface soil (0–10 cm) of terraced farmland was 1300 ± 108.78 items/kg, whereas the MPs content in abandoned cropland was significantly lower, i.e., one-third lower. However, in the reforested areas, no significant difference in MPs content was found compared with that in the terraced farmlands. With increasing soil depth, the MPs abundance in terraced farmland decreased by approximately 50 % relative to the surface layer (0–10 cm), while that in abandoned cropland decreased by about 33 %. Transparent MPs accounted for 77.81 % of all samples, and polyethylene terephthalate (PET) was found to be a prevalent MPs polymer. Densely populated areas with higher levels of human activity typically produce greater amounts of transparent fiber MPs. This study demonstrated the impact of different land use types on MPs in the Qiaozigou watershed, providing new insights into the likely sources of soil MPs under various terrace management strategies.
{"title":"Microplastics in terraced topsoil under diverse land uses on the Chinese Loess Plateau","authors":"Nannan Yue , Zhongbao Xin","doi":"10.1016/j.still.2026.107097","DOIUrl":"10.1016/j.still.2026.107097","url":null,"abstract":"<div><div>Microplastics (MPs) have emerged as widespread and persistent pollutants in terrestrial ecosystems, yet their distribution and influencing factors in terraced landscapes remain underexplored. Large-scale soil and water conservation projects have been established in the hilly regions of the Loess Plateau, China. However, limited research has addressed how different terraced land use types influence the occurrence and characteristics of soil MPs in this erosion-prone area. The objective of this study was to investigate differences in MPs abundance, color, shape, polymer composition, and vertical distribution among terraced farmland, terraced forestland, terraced orchard, and abandoned cropland in the Qiaozigou watershed. The spatial distribution of MPs within the watershed was examined to assess the effects of land use and soil and water conservation measures on MPs. The results indicated that MPs abundance was high in the terraced watersheds. The MPs abundance in the surface soil (0–10 cm) of terraced farmland was 1300 ± 108.78 items/kg, whereas the MPs content in abandoned cropland was significantly lower, i.e., one-third lower. However, in the reforested areas, no significant difference in MPs content was found compared with that in the terraced farmlands. With increasing soil depth, the MPs abundance in terraced farmland decreased by approximately 50 % relative to the surface layer (0–10 cm), while that in abandoned cropland decreased by about 33 %. Transparent MPs accounted for 77.81 % of all samples, and polyethylene terephthalate (PET) was found to be a prevalent MPs polymer. Densely populated areas with higher levels of human activity typically produce greater amounts of transparent fiber MPs. This study demonstrated the impact of different land use types on MPs in the Qiaozigou watershed, providing new insights into the likely sources of soil MPs under various terrace management strategies.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"259 ","pages":"Article 107097"},"PeriodicalIF":6.8,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134162","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 : 2026-02-03DOI: 10.1016/j.still.2026.107100
Xinxin You , Wenyi Xu , Linna Du , Sheng Wang , Yan Zhou , Xiaomin Ma , Hua Qin , Junhui Chen
Organic substitution for chemical fertilizer and inoculation of phosphate-solubilizing bacteria (PSB) benefit sustainable agriculture, yet their individual or combined effects on soil stoichiometry and phosphorus (P) fractions accumulation remains poorly understood. Here, a 6-year field experiment was set up with four fertilization regimes, including no fertilizer (CK), chemical fertilizer (CF), partial organic substitution (POS) of chemical fertilizer with compost manure, and POS together with PSB inoculants (MOF). Compared with the CF, both POS and MOF increased rice yield and P uptake but had weak effects on soil total carbon (C), nitrogen (N) and P contents after six years. The MOF significantly increased dissolved organic C and decreased microbial biomass C:P ratio, resulting in an increased C:P imbalance between microorganisms and their resources compared with POS. Though both POS and MOF increased the accumulation of soil recalcitrant P fraction compared with the CK, MOF significantly decreased the accumulation of residual P and NaHCO3-Pi in comparison with the POS treatment. Solution 31P NMR spectra analysis revealed that MOF remarkably increased phosphate monoesters accumulation and their proportion compared to the CF. POS increased the relative abundances of the functional genes and enzyme activities involved in cellulose and hemicellulose degradation, while MOF increased those of organic P mineralization. Partial least squares path modeling suggested that changes in C:P imbalance play a key role in affecting P accumulation by affecting microbial composition, the organic C and P related degradation genes and enzymes activities. Our study suggests that partial organic substitution and its inoculation with PSB induced divergent effects on P fractions accumulation by changing C and P related function, providing insight into the potential mechanisms of organic management on P mobilization in future agriculture production.
{"title":"Contrasting effects of partial organic substitution and its inoculation with phosphate-solubilizing bacteria on stoichiometric imbalances and phosphorus fractions accumulation after six-year application in a rice paddy","authors":"Xinxin You , Wenyi Xu , Linna Du , Sheng Wang , Yan Zhou , Xiaomin Ma , Hua Qin , Junhui Chen","doi":"10.1016/j.still.2026.107100","DOIUrl":"10.1016/j.still.2026.107100","url":null,"abstract":"<div><div>Organic substitution for chemical fertilizer and inoculation of phosphate-solubilizing bacteria (PSB) benefit sustainable agriculture, yet their individual or combined effects on soil stoichiometry and phosphorus (P) fractions accumulation remains poorly understood. Here, a 6-year field experiment was set up with four fertilization regimes, including no fertilizer (CK), chemical fertilizer (CF), partial organic substitution (POS) of chemical fertilizer with compost manure, and POS together with PSB inoculants (MOF). Compared with the CF, both POS and MOF increased rice yield and P uptake but had weak effects on soil total carbon (C), nitrogen (N) and P contents after six years. The MOF significantly increased dissolved organic C and decreased microbial biomass C:P ratio, resulting in an increased C:P imbalance between microorganisms and their resources compared with POS. Though both POS and MOF increased the accumulation of soil recalcitrant P fraction compared with the CK, MOF significantly decreased the accumulation of residual P and NaHCO<sub>3</sub>-Pi in comparison with the POS treatment. Solution <sup>31</sup>P NMR spectra analysis revealed that MOF remarkably increased phosphate monoesters accumulation and their proportion compared to the CF. POS increased the relative abundances of the functional genes and enzyme activities involved in cellulose and hemicellulose degradation, while MOF increased those of organic P mineralization. Partial least squares path modeling suggested that changes in C:P imbalance play a key role in affecting P accumulation by affecting microbial composition, the organic C and P related degradation genes and enzymes activities. Our study suggests that partial organic substitution and its inoculation with PSB induced divergent effects on P fractions accumulation by changing C and P related function, providing insight into the potential mechanisms of organic management on P mobilization in future agriculture production.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"259 ","pages":"Article 107100"},"PeriodicalIF":6.8,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110820","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 : 2026-02-02DOI: 10.1016/j.still.2026.107098
Zhicai Xiao , Mingming Guo , Xin Liu , Zhuoxin Chen , Xingyi Zhang , Jinzhong Xu , Shaoliang Zhang , Jielin Liu , Xing Han , Ruifeng Xie
Grassland ecosystems, particularly in cold and high-altitude regions, are highly vulnerable to gully erosion owing to their simple structure and environmental sensitivity, making it a severe form of grassland degradation. However, most previous studies have focused on agricultural systems, leaving limited understanding of the long-term evolution and drivers of permanent gullies in grasslands. To address this issue, we analyzed gully erosion dynamics and its determinants in a 103 km² area of the Hulunbuir grassland using remote sensing image from 1973, 1983, 2011, and 2020. Results showed that gully quantity, gully density and ground lacerative degree increased by 54.13 times, 286.66 times, and 591.01 times, respectively from 1973 to 2020, with the annual soil loss thickness of 0.023 mm. From 1973–2020, the average gully erosion rates in length, width, area, and volume were 4.64 m yr⁻¹ , 0.06 m yr⁻¹ , 17.17 m² yr⁻¹ , and 20.44 m³ yr⁻¹ , respectively. The merge of gullies (MG) showed greater linear gully erosion rate and areal gully erosion rate than newly formed gully (NFG) and continuously developing gully (CDG), while NFG showed the highest gully widening rates. Gully erosion rates in length, area and volume peaked at 4–5° slopes, with sunny and semi‑sunny aspects being more conducive to development, and linearly increased with gully drainage area. Cumulative gully growth length (ΔL), area (ΔA), and volume (ΔV) increased as a power relationship of cumulative climate indicators (Pre, R, R10, R95p, RX5day, SDII, Tem) and human activity intensity (grazing intensity, built up area, road density). The coupled effects of human activity with topography and climate exert the greatest influence on gully erosion, with the relative contribution of 37.13 % and 35.75 %, respectively. Overall, during 1973–2020, permanent gullies in the Hulunbuir grassland remained in the early lifecycle stage of development. However, intensifying anthropogenic pressures coupled with amplified climate variability progressively elevated erosion risks. This trajectory necessitates implementation of scientific gully control strategies to curb accelerated soil loss and establish sustainable human-land synergies.
{"title":"Temporal trajectory and determinants of permanent gully erosion in the grassland: A long-term analysis spanning 1973–2020","authors":"Zhicai Xiao , Mingming Guo , Xin Liu , Zhuoxin Chen , Xingyi Zhang , Jinzhong Xu , Shaoliang Zhang , Jielin Liu , Xing Han , Ruifeng Xie","doi":"10.1016/j.still.2026.107098","DOIUrl":"10.1016/j.still.2026.107098","url":null,"abstract":"<div><div>Grassland ecosystems, particularly in cold and high-altitude regions, are highly vulnerable to gully erosion owing to their simple structure and environmental sensitivity, making it a severe form of grassland degradation. However, most previous studies have focused on agricultural systems, leaving limited understanding of the long-term evolution and drivers of permanent gullies in grasslands. To address this issue, we analyzed gully erosion dynamics and its determinants in a 103 km² area of the Hulunbuir grassland using remote sensing image from 1973, 1983, 2011, and 2020. Results showed that gully quantity, gully density and ground lacerative degree increased by 54.13 times, 286.66 times, and 591.01 times, respectively from 1973 to 2020, with the annual soil loss thickness of 0.023 mm. From 1973–2020, the average gully erosion rates in length, width, area, and volume were 4.64 m yr⁻¹ , 0.06 m yr⁻¹ , 17.17 m² yr⁻¹ , and 20.44 m³ yr⁻¹ , respectively. The merge of gullies (MG) showed greater linear gully erosion rate and areal gully erosion rate than newly formed gully (NFG) and continuously developing gully (CDG), while NFG showed the highest gully widening rates. Gully erosion rates in length, area and volume peaked at 4–5° slopes, with sunny and semi‑sunny aspects being more conducive to development, and linearly increased with gully drainage area. Cumulative gully growth length (ΔL), area (ΔA), and volume (ΔV) increased as a power relationship of cumulative climate indicators (Pre, R, R10, R95p, RX5day, SDII, Tem) and human activity intensity (grazing intensity, built up area, road density). The coupled effects of human activity with topography and climate exert the greatest influence on gully erosion, with the relative contribution of 37.13 % and 35.75 %, respectively. Overall, during 1973–2020, permanent gullies in the Hulunbuir grassland remained in the early lifecycle stage of development. However, intensifying anthropogenic pressures coupled with amplified climate variability progressively elevated erosion risks. This trajectory necessitates implementation of scientific gully control strategies to curb accelerated soil loss and establish sustainable human-land synergies.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"259 ","pages":"Article 107098"},"PeriodicalIF":6.8,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110571","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}
Soil degradation (SD), primarily driven by erosion, poses a significant threat to agricultural productivity, ecosystem resilience, and long-term food security in semi-arid regions. This study develops an integrated framework to assess the intensity, spatial distribution, and erosion susceptibility of SD across northwestern Iran. A total of 592 soil samples were collected from 393 farmlands and 199 grasslands. The Soil Health Index (SHI) was calculated using a Minimum Data Set (MDS) approach to select the most representative physicochemical indicators of soil functionality. The 90th percentile of SHI values from grasslands was used as a reference for near-natural soil conditions, enabling quantification of degradation severity in agricultural lands. Machine learning models, including Random Forest (RF), Artificial Neural Network (ANN), and Support Vector Machine (SVM), were employed to predict spatial patterns of SD. Results showed that Inceptisols exhibited the highest degradation (mean SD = 0.353 ± 0.040), whereas Mollisols were the least degraded (mean SD = 0.199 ± 0.018), reflecting variations in soil organic carbon (SOC), bulk density (BD), and erosion susceptibility. RF outperformed other models (R² = 0.81, RMSE = 0.064), and feature importance analysis identified vegetation indices (NDVI, SAVI) and topographic factors (slope, LS-factor, TWI) as the key determinants of SD. Cold spots with relatively stable soil conditions were observed in northern and northeastern regions. This integrated approach provides a robust basis for mapping erosion-sensitive soils and designing evidence-based conservation strategies, supporting sustainable management of semi-arid agricultural lands.
{"title":"An integrated soil health and machine learning framework for quantifying soil degradation in semi-arid agricultural lands","authors":"Kamal Khosravi Aqdam , Farrokh Asadzadeh , Salar Rezapour , Amin Nouri , Farzin Shabani","doi":"10.1016/j.still.2026.107099","DOIUrl":"10.1016/j.still.2026.107099","url":null,"abstract":"<div><div>Soil degradation (SD), primarily driven by erosion, poses a significant threat to agricultural productivity, ecosystem resilience, and long-term food security in semi-arid regions. This study develops an integrated framework to assess the intensity, spatial distribution, and erosion susceptibility of SD across northwestern Iran. A total of 592 soil samples were collected from 393 farmlands and 199 grasslands. The Soil Health Index (SHI) was calculated using a Minimum Data Set (MDS) approach to select the most representative physicochemical indicators of soil functionality. The 90th percentile of SHI values from grasslands was used as a reference for near-natural soil conditions, enabling quantification of degradation severity in agricultural lands. Machine learning models, including Random Forest (RF), Artificial Neural Network (ANN), and Support Vector Machine (SVM), were employed to predict spatial patterns of SD. Results showed that Inceptisols exhibited the highest degradation (mean SD = 0.353 ± 0.040), whereas Mollisols were the least degraded (mean SD = 0.199 ± 0.018), reflecting variations in soil organic carbon (SOC), bulk density (BD), and erosion susceptibility. RF outperformed other models (R² = 0.81, RMSE = 0.064), and feature importance analysis identified vegetation indices (NDVI, SAVI) and topographic factors (slope, LS-factor, TWI) as the key determinants of SD. Cold spots with relatively stable soil conditions were observed in northern and northeastern regions. This integrated approach provides a robust basis for mapping erosion-sensitive soils and designing evidence-based conservation strategies, supporting sustainable management of semi-arid agricultural lands.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"259 ","pages":"Article 107099"},"PeriodicalIF":6.8,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110570","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 : 2026-01-30DOI: 10.1016/j.still.2026.107062
Anna Carolina A.R. Zanatta , Eduardo G. Couto , Ana Maria X. dos Santos , Daniella C.S. Assis , Letícia G. Vogel , Matheus C. Cardoso , Bruno A. Bartsch , José A.M. Dematte
Spectroscopy offers a rapid and non-destructive approach for characterizing carbon in fire-affected soils, particularly in the Cerrado biome. Distinguishing total carbon (TC) from pyrogenic carbon (PC) remains challenging because both exhibit similar spectral signatures. This study evaluates the performance of Vis–NIR, MIR, and XRF spectroscopy for estimating TC and PC in soils under prescribed fire (PRF) and no-fire management (NPRF), as well as in associated charred materials.Vis–NIR provided the best estimates of TC in PRF soils, reflecting its sensitivity to fire-induced changes in organic matter. In NPRF soils, MIR showed the highest performance for TC due to its responsiveness to functional groups in more heterogeneous, minimally disturbed matrices. For PC, combining Vis–NIR and MIR improved predictions in both management systems, with higher accuracy in NPRF soils. XRF, although highly sensitive to fire-derived elements such as Fe, Si, and Ca, showed limited performance for PC in soils; however, it achieved the best results for PC estimation in charred residues. Vis–NIR was most effective for TC in the same material.The results indicate clear differences in TC and PC behavior across fire regimes. PRF soils showed lower TC and greater thermal alteration, whereas NPRF soils preserved higher TC with less aromatic enrichment. Although PC prediction remained moderate across models, the complementary information from Vis–NIR, MIR, and XRF improved the interpretation of the physicochemical factors controlling carbon variability. Refining multispectral calibration strategies will strengthen TC and PC discrimination and support carbon monitoring and fire-management planning in tropical ecosystems.
{"title":"Integrated multispectral analysis of pyrogenic and total carbon in fire-managed cerrado soils","authors":"Anna Carolina A.R. Zanatta , Eduardo G. Couto , Ana Maria X. dos Santos , Daniella C.S. Assis , Letícia G. Vogel , Matheus C. Cardoso , Bruno A. Bartsch , José A.M. Dematte","doi":"10.1016/j.still.2026.107062","DOIUrl":"10.1016/j.still.2026.107062","url":null,"abstract":"<div><div>Spectroscopy offers a rapid and non-destructive approach for characterizing carbon in fire-affected soils, particularly in the Cerrado biome. Distinguishing total carbon (TC) from pyrogenic carbon (PC) remains challenging because both exhibit similar spectral signatures. This study evaluates the performance of Vis–NIR, MIR, and XRF spectroscopy for estimating TC and PC in soils under prescribed fire (PRF) and no-fire management (NPRF), as well as in associated charred materials.Vis–NIR provided the best estimates of TC in PRF soils, reflecting its sensitivity to fire-induced changes in organic matter. In NPRF soils, MIR showed the highest performance for TC due to its responsiveness to functional groups in more heterogeneous, minimally disturbed matrices. For PC, combining Vis–NIR and MIR improved predictions in both management systems, with higher accuracy in NPRF soils. XRF, although highly sensitive to fire-derived elements such as Fe, Si, and Ca, showed limited performance for PC in soils; however, it achieved the best results for PC estimation in charred residues. Vis–NIR was most effective for TC in the same material.The results indicate clear differences in TC and PC behavior across fire regimes. PRF soils showed lower TC and greater thermal alteration, whereas NPRF soils preserved higher TC with less aromatic enrichment. Although PC prediction remained moderate across models, the complementary information from Vis–NIR, MIR, and XRF improved the interpretation of the physicochemical factors controlling carbon variability. Refining multispectral calibration strategies will strengthen TC and PC discrimination and support carbon monitoring and fire-management planning in tropical ecosystems.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"259 ","pages":"Article 107062"},"PeriodicalIF":6.8,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079074","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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