Soil Biology & Biochemistry最新文献

{"title":"Spatial-temporal patterns of foliar and bulk soil 15N isotopic signatures across a heterogeneous landscape: Linkages to soil N status, nitrate leaching, and N2O fluxes","authors":"Elizabeth Gachibu Wangari ,&nbsp;Ricky Mwangada Mwanake ,&nbsp;Tobias Houska ,&nbsp;David Kraus ,&nbsp;Hanna-Marie Kikowatz ,&nbsp;Benjamin Wolf ,&nbsp;Gretchen M. Gettel ,&nbsp;Lutz Breuer ,&nbsp;Per Ambus ,&nbsp;Ralf Kiese ,&nbsp;Klaus Butterbach-Bahl","doi":"10.1016/j.soilbio.2024.109609","DOIUrl":"10.1016/j.soilbio.2024.109609","url":null,"abstract":"<div><div>The natural abundance of plant and bulk soil ¹⁵N isotopic signatures provides valuable insights into the magnitude of nitrogen cycling and loss processes within terrestrial ecosystems. However, ¹⁵N isotopic signatures are highly variable in space due to natural and anthropogenic factors affecting N cycling processes and losses. To date, most studies on foliar and bulk soil ¹⁵N isotopic signatures have focused on N-limited forest ecosystems at relatively large spatial scales, while similar studies in N-enriched ecosystems at finer spatial scales are lacking. To address this gap and evaluate links between soil ¹⁵N isotopic signatures and ecosystem N cycling and loss processes (plant N uptake, N leaching, and gaseous loss), this study quantified foliar and bulk soil ¹⁵N isotopic signatures, soil physicochemical parameters, gaseous (N₂O), and hydrological (NO₃) N losses at 80 sites distributed across a heterogeneous landscape (∼5.8 km²). To account for the spatial-temporal heterogeneity, the measurements were performed in four campaigns (March, June, September 2022, and March 2023) at sites that considered different land uses, soil types, and topography. Results indicated that foliar and bulk soil ¹⁵N isotopic signatures were significantly (P &lt; 0.05) more enriched in arable and grassland ecosystems than forests, suggesting a more open N cycle with significant N cycling and losses due to higher N inputs from fertilizers. Similar to soil inorganic N, N₂O fluxes, and NO₃ leaching rates, landscape-scale foliar and soil ¹⁵N isotopic signatures varied widely spatially, particularly at grassland and arable land (−3 to 9.0‰), with bivariate and multivariate analyses also showing significant relationships between landscape-scale soil ¹⁵N isotopic signatures and the aforementioned parameters (r²: 0.29 to 0.82). Based on these relationships, our findings suggested that foliar and bulk ¹⁵N isotopic signatures may capture fine-scale areas with persistently high and low environmental N losses (N₂O fluxes and NO₃ leaching) within a heterogeneous landscape.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109609"},"PeriodicalIF":9.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369626","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":"The effects of earthworm species on organic matter transformations and soil microbial communities are only partially related to their bioturbation activity","authors":"Luna Vion-Guibert ,&nbsp;Yvan Capowiez ,&nbsp;Gonzague Alavoine ,&nbsp;Ludovic Besaury ,&nbsp;Olivier Delfosse ,&nbsp;Mickaël Hedde ,&nbsp;Claire Marsden ,&nbsp;Gwenaëlle Lashermes","doi":"10.1016/j.soilbio.2024.109606","DOIUrl":"10.1016/j.soilbio.2024.109606","url":null,"abstract":"<div><div>Earthworms are pivotal in shaping soil ecological processes through their bioturbation activity and organic matter consumption. Earthworm species are known to have different impacts on soil structure, but only a small number of species have been studied so far, and few studies have examined how earthworms simultaneously affect soil functions. Here, we measured the impact of different earthworm species on soil structure (bioturbation function), carbon (C) and nitrogen (N) dynamics and the microbial community (organic matter transformation function), while exploring the links between these functions, across distinct soil compartments (surface casts, below-ground drilosphere, and bulk soil). Six earthworm species <em>(Lumbricus terrestris</em>, <em>Allolobophora chlorotica</em>, <em>Octolasion cyaneum, Octodrilus complanatus</em>, <em>Aporrectodea caliginosa meridionalis</em> and <em>Microscolex dubius</em>) of different ecological categories and functional groups were incubated in soil cores with soil and alfalfa litter for 6 weeks. Our results on the bioturbation function illustrated a great diversity of behaviors and confirmed the relevance of a functional classification based on bioturbation metrics. The main microbial hotspots were surface casts, whose characteristics allowed to distinguish two groups of species. <em>Octod. complanatus, L. terrestris</em> and <em>M. dubius</em> induced high humidity (respectively, +57, +48, +74%), high C (respectively, 19.9, 24.8, 33.2 g kg⁻¹ dry soil) and N (respectively, 2, 2.3, 3.2 g kg⁻¹ dry soil) content and microbial community selection, promoting C and N mineralization. The three other species had a lower impact. The below-ground drilosphere only showed specific characteristics in the case of <em>L. terrestris</em>. The effects of the studied species on the organic matter transformation function did not align with their bioturbation activities nor with their ecological category. These findings show that the contribution of earthworms to C and N turnover is only partially dependent on their bioturbation effects and suggest the usefulness of developing distinct functional groups based on the specific soil functions under consideration.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109606"},"PeriodicalIF":9.8,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369627","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":"Transformed biosolids promote ryegrass growth and microbial carbon cycling at the ‘cost’ of soil carbon","authors":"George D. Mercer ,&nbsp;Bede S. Mickan ,&nbsp;Deirdre B. Gleeson ,&nbsp;Megan H. Ryan","doi":"10.1016/j.soilbio.2024.109603","DOIUrl":"10.1016/j.soilbio.2024.109603","url":null,"abstract":"<div><div>Soil carbon supports desirable ecosystem functions for global agricultural productivity and climate resilience objectives. Wastewater biosolids can be transformed into soil amendments that return carbon and nutrients to agricultural systems in stoichiometric ratios that support carbon stabilisation. However, practicable delivery that enhances stable soil carbon and plant yield remains challenging. Soil carbon stability and nutrient availability are mediated partly by microbial community composition and function, which are poorly understood in soils amended with transformed biosolids. We conducted a 56-day study in a temperature-controlled glasshouse, growing perennial ryegrass (<em>Lolium perenne</em>) in pasture soil amended with straw, straw supplemented with nutrients, or transformed biosolids (composted biosolids, dried biosolids or biosolids biochar), all with equal added carbon (3500 kg ha⁻¹). Control soils, with and without supplementary nutrients, were also included. Plant dry mass, soil chemical characteristics, and soil carbon fractions were measured at harvest. 16S rRNA sequencing was used to infer the composition and putative function of rhizosphere bacterial communities. Shoot dry mass increased for composted biosolids (236%) and dried biosolids (559%), but total carbon in rhizosphere soil decreased for composted biosolids (16.3%), dried biosolids (13.3%) and biosolids biochar (12.7%) when compared to unamended soils. Fine-fraction carbon in rhizosphere soil decreased for straw with supplementary nutrients (6.8%), dried biosolids (6.3%) and biosolids biochar (4.6%). Rhizosphere bacterial communities clustered by treatment, with populations correlated with fine-fraction carbon distinct from those populations correlated with shoot and root dry mass. Path analysis linked fine-fraction carbon loss with increased putative carbon cycling genes, driven by available nutrients and plant growth. Transformed biosolids can trigger a microbial response that reallocates nutrients from organic matter to plants, disrupting soil carbon-nutrient stoichiometry and facilitating carbon loss. Understanding the carbon cost of this ecosystem service is fundamental when translating benefits of transformed biosolids to end users.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109603"},"PeriodicalIF":9.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precipitation and diameter affect wood decomposition both directly and indirectly via deadwood traits and position","authors":"Wanying Yu ,&nbsp;Congwen Wang ,&nbsp;Johannes H.C. Cornelissen ,&nbsp;Xuehua Ye ,&nbsp;Xuejun Yang ,&nbsp;Qingguo Cui ,&nbsp;Zhenying Huang ,&nbsp;Deli Wang ,&nbsp;Guofang Liu","doi":"10.1016/j.soilbio.2024.109604","DOIUrl":"10.1016/j.soilbio.2024.109604","url":null,"abstract":"<div><div>Woody plants are important components of dryland ecosystems. Our understanding of wood decomposition in drylands, an important component of biogeochemical cycling, is poor compared to that in mesic ecosystems. To uncovering the complex interactive effects of the different key drivers, we studied the effects of precipitation, position (aboveground and belowground), wood size and litter quality of plant species (four to five local species and one widespread woody species) on woody litter decomposition rates along a precipitation gradient from 37 to 369 mm, spanning five dryland sites. Wood dry matter content (DMC) was a critical negative predictor of wood decomposition in water-limited ecosystems. Thicker woody litter had lower decomposition rates (<em>k</em> values) directly because of smaller relative surface exposure, and indirectly through higher wood DMC or lower bark mass ratio (bark mass divided by wood mass for a given branch length). Mean annual precipitation (MAP) increased the <em>k</em> values both directly, and indirectly by decreasing the wood DMC and increasing the bark mass ratio due to species turnover. The <em>k</em> values of buried woody litter were mostly two to three times higher than litter on the soil surface, but not different at the extremely arid site. A steeper slope of the relationship between overall woody litter quality (particularly wood DMC) or annual precipitation and <em>k</em> values was observed belowground than aboveground, as related to the higher moisture belowground than aboveground. These findings highlight the complex interactions among climate (precipitation), litter position, size and quality on wood decomposition in drylands, thereby helping to improve our mechanistic understanding of dryland woody litter decomposition. We conclude that wood decomposition at the regional and local scales will influence biogeochemical cycling in drylands under future climate change through both direct effects of moisture and indirect effects of litter quality characteristics.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109604"},"PeriodicalIF":9.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Litter mixture effects on nitrogen dynamics during decomposition predominantly vary among biomes but little with litter identity, diversity and soil fauna","authors":"Shixing Zhou ,&nbsp;Olaf Butenschoen ,&nbsp;I. Tanya Handa ,&nbsp;Matty P. Berg ,&nbsp;Brendan McKie ,&nbsp;Congde Huang ,&nbsp;Stephan Hättenschwiler ,&nbsp;Stefan Scheu","doi":"10.1016/j.soilbio.2024.109602","DOIUrl":"10.1016/j.soilbio.2024.109602","url":null,"abstract":"<div><div>Nitrogen (N) is essential for net primary production, with much of the required N in terrestrial ecosystems derived from recycling via litter decomposition. The diversity and identity of plant species and decomposer organisms affect N cycling during litter decomposition, yet the generality and magnitude of these effects remain uncertain. To fill this gap, a decomposition experiment with four leaf litter species that differed widely in initial litter quality was conducted including single species and all possible multispecies mixtures, with and without microarthropods access across a broad latitudinal gradient covering four major forest biomes of the Northern Hemisphere. The results showed that leaf litter N dynamics (both N loss and N immobilization) in single species treatments depended primarily on litter species identity and the local environmental context. We found strong mixture effects, that overall tended to increase N loss and to reduce ¹⁵N transfer. The relative mixture effects on N dynamics differed among forest biomes, but were little affected by the other factors we manipulated. The N loss of individual litter species in mixtures not only depended on litter identity and soil microarthropod access, but also on forest biomes; while ¹⁵N transfer depended strongly on litter mixing, independently of litter species richness or composition of the mixtures. Litter N dynamics were mainly driven by a small subset of litter traits, regardless of species richness and microarthropod access. Overall, our results highlight that litter mixture strongly affects N dynamics during decomposition, with the mixture effects predominantly varying among forest biomes but little with litter identity, diversity and microarthropod access. To improve predictions on how changes in tree species composition and diversity may impact nutrient dynamics in forest ecosystems in face of increasing N deposition, interactions between litter and soil but also within litter mixtures need closer attention.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109602"},"PeriodicalIF":9.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358748","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":"Investigating drivers of free-living diazotroph activity in paddy soils across China","authors":"Xiaomin Wang ,&nbsp;Min Wu ,&nbsp;Zhijun Wei ,&nbsp;Christina Hazard ,&nbsp;Graeme W. Nicol ,&nbsp;Huicheng Zhao ,&nbsp;Binbin Liu ,&nbsp;Jinbo Zhang ,&nbsp;Jun Shan ,&nbsp;Xiaoyuan Yan","doi":"10.1016/j.soilbio.2024.109601","DOIUrl":"10.1016/j.soilbio.2024.109601","url":null,"abstract":"<div><div>Microbially mediated N fixation is widespread in rice paddy ecosystems and crucial in maintaining soil fertility. However, our understanding of the factors determining the distribution of free-living diazotrophic microorganisms that perform this process in paddy fields is limited. This study investigated the spatial distribution and factors influencing presence and potential activity of free-living microorganisms capable of N₂ fixation in addition to dissimilatory nitrate reduction to ammonium (DNRA), anaerobic ammonium oxidation (anammox), and denitrification in 50 paddy soils across China. Using ¹⁵N isotope tracing in laboratory incubations and microbial community analysis via metagenomics, we demonstrate that paddy soils may represent a previously underappreciated hotspot for N₂ fixation with mean potential rates of 24.4 ± 17.8 nmol N g⁻¹ h⁻¹, 10-fold higher than DNRA (2.55 ± 0.4 nmol N g⁻¹ h⁻¹), and could counterbalance a portion of N₂ losses through anammox and denitrification (9.24 ± 1.1 nmol N g⁻¹ h⁻¹). Site longitude and organic carbon (C) concentrations, as well as the diazotrophic community composition, were the dominant abiotic and biotic factors accounting for regional variations in potential N₂ fixation rates. The N₂ metabolic pathways predicted from the metagenome-assembled genomes (MAGs) revealed significant co-occurrence of the diazotroph marker gene <em>nifH</em> with denitrification-associated genes (<em>nirS/K</em> and <em>nosZ</em>) and organic C oxidation-related genes (<em>yiaY</em> and <em>galM</em>). Furthermore, enzymes involved in organic C oxidation, particularly glycoside hydrolases and glycosyltransferases, were not only phenotypically correlated with free-living N₂ fixation rates but were also identified in <em>nifH</em>-containing MAGs, indicating the heterotrophic capabilities of diazotrophs in paddy soils. Collectively, our results underscore the substantial contribution of free-living N₂ fixation to soil N fertility in paddy fields, and highlight the importance of coupling organic C oxidation with nitrate reduction to enhance N₂ fixation.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109601"},"PeriodicalIF":9.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322082","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":"Reindeer shape soil methanogenic and methanotrophic communities in subarctic fen peatlands, with a minor impact on methane emissions — A field study","authors":"Raija Laiho ,&nbsp;Petri Salovaara ,&nbsp;Päivi Mäkiranta ,&nbsp;Krista Peltoniemi ,&nbsp;Timo Penttilä ,&nbsp;Tuomas Rajala ,&nbsp;Jenni Hultman ,&nbsp;Mika Korkiakoski ,&nbsp;Hannu Fritze","doi":"10.1016/j.soilbio.2024.109590","DOIUrl":"10.1016/j.soilbio.2024.109590","url":null,"abstract":"<div><div>Laboratory and field studies with other grazer species suggest that reindeer (<em>Rangifer tarandus</em> L.) grazing on northern peatlands could shape the peat soil microbial communities and lead to higher ecosystem methane (CH₄) emissions. We investigated this at two sedge fens in northern Finland, Lompolojänkkä and Halssiaapa, in experiments where reindeer grazing presence or absence was achieved with exclosure fences, and the effects of reindeer droppings were evaluated comparing dropping additions either on peat surface or trampled into the peat to controls with no droppings. Active soil methanogen and methanotroph communities were analyzed by metatranscriptomics. Soil CH₄ fluxes were quantified with manual chambers and portable gas analyzer. Reindeer presence and dropping additions were both connected to differences in the soil communities as compared to controls (no presence or no droppings). The responses differed between the two fens. Activity of rumen microbes in peat could not be detected. Structural equation models indicated that the ecosystem CH₄ flux in both fens depended on measurement year and sedge leaf area. At Halssiaapa trampled droppings, and at Lompolojänkkä both surface and trampled droppings reduced the sedge leaf area. While at Halssiaapa the dropping effect was not altogether statistically significant, in Lompolojänkkä surface droppings reduced the CH₄ flux both directly and through the reduced leaf area. In conclusion, while both reindeer presence and dropping addition were diversely reflected in the active soil communities, reindeer effects on the CH₄ flux were indirect and mediated via vegetation. The results contrast our earlier laboratory findings, and i) caution against liberal generalizations from lab studies to field conditions in peatlands, as well as ii) point to a need for rigorous multivariate analyses for deciphering the complex interactions governing the functions of these ecosystems.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109590"},"PeriodicalIF":9.8,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species-specific impact of protists in controlling litter decomposition","authors":"Yuxin Wang ,&nbsp;Thomas Edison E. dela Cruz ,&nbsp;James Kennard S. Jacob ,&nbsp;Stefan Geisen","doi":"10.1016/j.soilbio.2024.109598","DOIUrl":"10.1016/j.soilbio.2024.109598","url":null,"abstract":"<div><div>Protists affect soil microbiome composition and functioning, potentially increasing litter decomposition and plant growth. Yet, the role of different protist species, individually or in combinations, in regulating microbial-mediated litter decomposition remains unknown, as well as if these interactions feedback to plant growth. Using a full-factorial design of three protist species combinations with bacterial and fungal communities, we found that only one protist species reduced litter decomposition by 19%, with other species and combinations not affecting litter decomposition. Despite a positive correlation between plant growth and litter decomposition, we did not observe protist-induced changes in plant growth. Overall, our results highlight that protists affect litter decomposition in a species-specific manner, including reducing litter decomposition.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109598"},"PeriodicalIF":9.8,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase transformation of schwertmannite changes microbial iron and sulfate-reducing processes in flooded paddy soil and decreases arsenic accumulation in rice (Oryza sativa L.)","authors":"Ru Wang ,&nbsp;Xinxin Wang ,&nbsp;Hua Li ,&nbsp;Xiaomeng Wang ,&nbsp;Zengping Ning ,&nbsp;Chengshuai Liu ,&nbsp;Lixiang Zhou ,&nbsp;Guanyu Zheng","doi":"10.1016/j.soilbio.2024.109600","DOIUrl":"10.1016/j.soilbio.2024.109600","url":null,"abstract":"<div><div>Rice (<em>Oryza sativa</em> L.) is known to accumulate inorganic arsenic (iAs) and dimethylarsenate (DMA) in its grains, which threatens both human health and rice yield. Although schwertmannite, a metastable Fe (Ⅲ)-oxyhydroxysulfate mineral with extremely high adsorption capacity for iAs, has been proposed to remediate paddy soil to decrease As accumulation in rice, it remains unclear whether the phase transformation of schwertmannite would occur in flooded paddy soil and how its phase transformation changes the soil microbial processes that impact the accumulation of iAs and DMA in grains. Here, we found that amending As-contaminated paddy soil with 0.5%–1% (w/w) schwertmannite decreased the accumulation of iAs and DMA in grains by 37.41%–43.29% and 50.60%–73.89%, respectively, even though schwertmannite has transformed to goethite and secondary FeS was formed in both rhizosphere and bulk soils. The phase transformation of schwertmannite released a considerable amount of SO₄²⁻ into porewater, thereby increasing the abundances of both sulfate-reducing bacteria and the <em>dsrB</em> gene but decreasing the abundance of iron-reducing bacteria. This result suggested that schwertmannite phase transformation has promoted sulfate-reducing process and weakened iron-reducing process in flooded soil. Such promoted sulfate-reducing process and weakened iron-reducing process in paddy soil can decrease the reductive dissolution of As-bearing (oxyhydr)oxides, increase the formation of secondary FeS mineral for decreasing porewater As concentration, and strengthen the role of Fe plaque as a barrier for As absorption by rice. Additionally, the application of schwertmannite has decreased the abundance of <em>arsM</em> gene and weakened As methylation process in soil. Therefore, the effective decrease of iAs and DMA accumulation in rice grains by schwertmannite can not only be ascribed to the adsorption capacity of schwertmannite for As and the adsorption or incorporation of As by transformation products, but also contributed by the promoted sulfate-reducing process and the weakened iron-reducing process in flooded paddy soil.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109600"},"PeriodicalIF":9.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318665","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":"A rhizosphere effect promotes the persistence of gas oxidization activity in soil","authors":"Anne de la Porte ,&nbsp;Audrey-Anne Durand ,&nbsp;Joann Whalen ,&nbsp;Étienne Yergeau ,&nbsp;Philippe Constant","doi":"10.1016/j.soilbio.2024.109599","DOIUrl":"10.1016/j.soilbio.2024.109599","url":null,"abstract":"<div><div>Labile carbon and nutrients of the rhizosphere promote the activity of trace gas oxidizing bacteria (TGOB), but the capacity of the rhizosphere effect to support their persistence upon activation has received less attention. Here, we hypothesized that the activation response of TGOB in soil before planting is proportional to the persistence of their activity after wheat growth. The TGOB were activated in sandy-loam and peat soils under a static atmosphere containing elevated concentration of hydrogen (H₂), carbon monoxide (CO) or methane (CH₄). Our hypothesis was proven to hold true in sandy-loam soil, whereas higher organic matter in peat soil was less favourable for the persistence of TGOB activity. We conclude that the energy potential of the trace gas oxidation reaction and soil nutrients both intervein in the persistence of TGOB activity.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"199 ","pages":"Article 109599"},"PeriodicalIF":9.8,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314869","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}