Geoderma最新文献

{"title":"Interactions of silicon and arbuscular mycorrhizal fungi on phosphorus uptake during rice vegetative growth","authors":"Li-Xue Qiu ,&nbsp;Dong-Xing Guan ,&nbsp;Yi-Wen Liu ,&nbsp;Yu Luo ,&nbsp;H. Henry Teng ,&nbsp;Yakov Kuzyakov ,&nbsp;Lena Q. Ma","doi":"10.1016/j.geoderma.2025.117184","DOIUrl":"10.1016/j.geoderma.2025.117184","url":null,"abstract":"<div><div>Silicon (Si) and arbuscular mycorrhizal fungi (AMF) improve phosphorus (P) nutrition in crops, but the mechanisms underlying their interactive effects on P uptake by roots remain elusive. This study investigated the impact of Si and AMF (<em>Rhizophagus irregularis</em> DAOM) on P uptake at rice (<em>Oryza sativa</em> L.) late jointing stage grown in soils with low and high P availability (18.2 vs 62.1 mg P kg⁻¹) under greenhouse conditions. Under low P availability, AMF increased P content in rice leaves and stems by 16.1 % and 11.8 %, respectively. However, simultaneous Si application with AMF inoculation counteracted this positive effect, reducing the P content in leaves and stems by 15.9 % and 8.28 %, respectively, compared to AMF alone, due to a 20.8 % decrease in AMF colonization rate. This reduction may be associated with Si deposition on root cell walls and increased competition between AMF and P-solubilizing bacteria (PSB). In contrast, under high P availability, the combination of Si and AMF increased stem P content by 8.42 % compared to AMF alone, linked to Si-induced raise in PSB abundance. This could strengthen cooperation between AMF and PSB, as AMF mycelial secretions provide<!--> <!-->easily available carbon sources for PSB, and PSB dissolved<!--> <!-->insoluble P forms for AMF uptake. These findings highlight the crucial role of soil P availability in modulating the efficacy of Si and AMF co-application to increase P uptake during rice vegetative growth. Under low P availability, Si reduces AMF functioning by decreasing colonization rates, while under high P availability, Si reinforces the P-promoting effects of AMF by stimulating PSB abundance. This study emphasizes the importance of considering soil P status when developing strategies that employ Si and AMF to optimize P utilization in agroecosystems.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117184"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055225","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":"Gross soil N transformations and microbial communities in Luxembourg beech forest (Fagus sylvatica L.) soils along a pH gradient","authors":"Mengru Jia ,&nbsp;Annemieke Kooijman ,&nbsp;Roland Bol ,&nbsp;Wim W. Wessel ,&nbsp;Kathrin Hassler ,&nbsp;Albert Tietema","doi":"10.1016/j.geoderma.2025.117194","DOIUrl":"10.1016/j.geoderma.2025.117194","url":null,"abstract":"<div><div>Acidic and calcareous soils differ in nitrogen (N) cycling, yet the underlying gross N transformations remain unclear in temperate forests. To address this gap, we quantified gross N transformations and microbial abundances in the organic layer and mineral topsoil (0–5 cm) of four closely situated beech forests along a natural pH gradient. Gross N turnover accelerated from acidic to calcareous soils, with gross mineralization rates increasing 6-fold in the organic layer and 10-fold in the mineral topsoil. However, net N release did not increase accordingly due to concurrent increases in gross immobilization. Enhanced immobilization at higher pH reflected greater microbial N demand under bacterial dominance, evidenced by higher microbial N, lower microbial C:N ratios and reduced fungi-to-bacteria (F:B) ratios. Autotrophic nitrification also increased with pH, corresponding to elevated ammonium supply from gross mineralization and higher abundances of ammonia-oxidizers. Heterotrophic nitrification was much lower than autotrophic nitrification in calcareous soils but equally important in acidic soils. Net N release was restricted to the mineral topsoil, shifting from low ammonium and nitrate release in acidic soils, to substantial nitrate release in calcareous soils, potentially supporting greater plant species richness at high pH. Our results demonstrate that soil N supply mechanisms differ markedly along the pH gradient, from low immobilization at low pH to high nitrification at high pH, driven by shifts in fungal versus bacterial dominance and their distinct N demands. This improved understanding of microbial regulation of acidity-related soil N fertility is crucial for predicting forest responses to global climate disturbances.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117194"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143125053","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":"Direct evidence for the mineralization of inositol phosphates in soil as revealed by 31P NMR analysis of soil suspensions treated with phytases and organic anions","authors":"Alan E. Richardson ,&nbsp;Timothy I. McLaren ,&nbsp;Timothy S. George","doi":"10.1016/j.geoderma.2025.117187","DOIUrl":"10.1016/j.geoderma.2025.117187","url":null,"abstract":"<div><div>Soil suspension assays were used to demonstrate synergistic interaction between citrate and phytase for mobilization and <em>in situ</em> mineralization of organic P. This synergy was evident in both unfertilized and fertilized soil where P mobilization by citrate was increased by 3.7 to 7.0-fold across both inorganic and organic pools. In the presence of citrate, phytase from different fungal sources further increased the proportion of P mineralization by an average of 47% from the total extracted P. Specific analysis by ³¹P NMR of the monoester-P extracted from the fertilized soil showed that the P released was associated with both direct hydrolysis of identifiable biomolecules of inositol hexa<em>kis</em>phosphate (IHP, identified as the <em>myo</em> and <em>scyllo</em> isomers) and via a significant reduction of the broad-peak of monoester P. Functionality of endogenous soil phosphatase and phytase activities were also evident in the mineralization assays. The specific hydrolysis of IHP was further enhanced when phytase was added, where the total concentration of the extracted IHP was reduced by 92%. The addition of phytase in the absence of citrate (i.e., water suspensions only) by contrast had no measurable effect on the mineralization of soil organic P. Our results further our understanding of the biochemical nature and speciation of organic P in soils and the potential contribution that mineralization of organic P makes to the soil P cycle. This is particularly relevant to the rhizosphere where functional interaction of citrate and phytase and utilization of specific organic P substrates may offer opportunity for improved P-use efficiency.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117187"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143125295","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":"Shrub encroachment accelerates the processes of moisture redistribution in alpine meadows on the Qinghai-Tibetan Plateau","authors":"Lirong Zhao ,&nbsp;Kexin Li ,&nbsp;Ni Zhu ,&nbsp;Junmei Gao ,&nbsp;Jing Zhang ,&nbsp;Di Wang ,&nbsp;Xiaoli Wang ,&nbsp;Yanlong Wang ,&nbsp;Yushou Ma ,&nbsp;Yu Liu","doi":"10.1016/j.geoderma.2025.117196","DOIUrl":"10.1016/j.geoderma.2025.117196","url":null,"abstract":"<div><div>Shrub encroachment in alpine meadows is rapidly occurring under global warming, significantly impacting the regulation of runoff, soil water retention and groundwater conservation. However, the dynamics of soil moisture redistribution following shrub encroachment are poorly understood. Here, the groundwater recharge and water uptake strategies of vegetation were explored through stable water isotope analysis to determine the mechanism of moisture redistribution on the Qinghai-Tibetan Plateau following shrub encroachment. The results indicated that the soil moisture content (SMC) of alpine shrublands (AS) increased significantly compared with that of alpine meadows (AM) and bare lands (BL), which resulted from a decrease in root biomass and an increase in capillary porosity. Furthermore, groundwater recharge from BL and AS was 4.17 and 3.30 times greater than that from AM (12 %), respectively, which was attributed to changes in soil porosity induced by the disappearance of mattic epipedons. In AS, <em>Salix cupularis</em> took up 57 % of the soil moisture from soil depth of 0–10 cm due to high root biomass, and this uptake level was significantly greater than that of <em>Kobresia pygmaea</em> (12 %). Overall, the soil moisture redistribution processes were markedly affected by changes in vegetation and soil parameters under shrub encroachment. These findings suggest that rapid shrub encroachment can accelerate rainfall infiltration and soil moisture dynamics, which can significantly influence hydrological processes on the Qinghai-Tibetan Plateau.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117196"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143125352","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":"Effects of wildlife conservation and land use intensification on heterotrophic soil respiration and temperature sensitivity (Q10) in semiarid savannas","authors":"A. Sandhage-Hofmann ,&nbsp;J. Lenzen ,&nbsp;K. Frindte ,&nbsp;A. Angombe ,&nbsp;W. Amelung","doi":"10.1016/j.geoderma.2025.117171","DOIUrl":"10.1016/j.geoderma.2025.117171","url":null,"abstract":"<div><div>Increasing global temperatures promote heterotrophic soil respiration (Rh) and subsequent carbon losses. In addition, greater variability in precipitation leads to more frequent rainfall following dry periods, resulting in a ’pulse’ of microbial activity and carbon release known as the Birch effect, especially in dry regions. But the effect of wildlife conservation and landuse intensification on Rh and Q10 in savanna systems is almost unknown. We hypothesized that i) the Rh pulse after rewetting (“Birch” effect) contributes notably to carbon losses in semi-arid regions, ii) conservation with increasing elephant numbers leads to higher Rh and lower Q10 values compared to rangeland and cropland, iii) modulated locally by habitat type (subcanopy, grass, bare patch), and iv) explained by microbial community composition. We sampled topsoils (0–10 cm) from different habitat types in high and low elephant density plots, croplands, and rangelands in savanna woodlands of the Zambezi region, Namibia. The samples were incubated at different temperatures (20-40° C) using a Respicond® apparatus. Microbial biomass and associated community composition were analyzed by DNA analysis. Immediately after rewetting, carbon losses were substantial and amounted to 200 g CO₂-C day^-1ha⁻¹. High elephant densities had the highest Rh at 25° C (1.21 µg CO₂ g^-1h⁻¹) relative to other land uses (mean 0.75 µg CO₂ g^-1h⁻¹) and significantly higher qPCR copy numbers. Rh was similar under different habitat types. The mean Q10 value during the growing season was comparable under cultivation and high elephant density (∼2.3), exceeding fixed values of land surface models. Warming increased Rh from 0.6 µg CO₂ g^-1h⁻¹ at 20° C by a mean factor of 2.6 at 40° C, with the highest increase at high elephant densities (factor 3.4). Generalized linear mixed models identified contents of nitrogen, silt, pH, and land use type as main predictor variables, explaining 57 % of Rh variability. We conclude that savanna soil’s vulnerability to climate warming is comparable between conservation and intensification but that carbon losses due to warming will be highest under wildlife conservation with high elephant densities.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117171"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020009","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":"Response of root- and soil-associated AM fungi to nitrogen addition and simulated drought in a Chinese fir plantation","authors":"Jiamian Shi ,&nbsp;Xiaojie Li ,&nbsp;Ge Song ,&nbsp;Shengsheng Jin ,&nbsp;Luhong Zhou ,&nbsp;Maokui Lyu ,&nbsp;Jinsheng Xie ,&nbsp;Yalin Hu ,&nbsp;Hang-Wei Hu ,&nbsp;Ji-Zheng He ,&nbsp;Yong Zheng","doi":"10.1016/j.geoderma.2025.117176","DOIUrl":"10.1016/j.geoderma.2025.117176","url":null,"abstract":"<div><div>Global change factors like atmospheric nitrogen (N) deposition and drought pose threats to forest ecosystem including soil microbial diversity. However, how arbuscular mycorrhizal (AM) fungi associated with tree respond to N deposition and drought remains largely unknown. Here root- and soil-inhabiting AM fungi were examined in a field experiment involving N addition and simulated drought (precipitation exclusion) in a Chinese fir (<em>Cunninghamia lanceolata</em>) plantation. The results showed that precipitation exclusion significantly reduced AM fungal intraradical colonization rate in summer, while N addition had no significant effect on AM fungal morphological traits of intraradical colonization rate, hyphal and spore densities. However, seasonal changes significantly affected AM fungal morphological traits, with higher values were observed in summer than in winter. Neither N addition nor drought significantly affected AM fungal diversity or community composition, but AM fungal communities exhibited pronounced seasonal differences. In winter, both root- and soil-associated AM fungal community composition significantly correlated with the ratio of microbial biomass carbon and phosphorus (MBC/MBP), while in summer AM fungal communities were primarily associated with MBP and DOC. These findings highlight the importance of accounting for interaction of N addition and drought, and seasonal response difference on AM fungi in subtropical forest ecosystems.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117176"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020010","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":"Using near-infrared spectroscopy to estimate soil water retention curves with the van Genuchten model","authors":"Youssef Fouad,&nbsp;Inès Soltani,&nbsp;Christophe Cudennec,&nbsp;Didier Michot","doi":"10.1016/j.geoderma.2025.117175","DOIUrl":"10.1016/j.geoderma.2025.117175","url":null,"abstract":"<div><div>Hydraulic properties of unsaturated soils are essential for understanding hydric functioning and solving flow and mass-transfer problems in the vadose zone. One of the best-known models for representing the experimental soil–water retention curve, which describes the matric potential (h) as a function of the water content (θ) of a soil horizon, is the van Genuchten (VG) model. It requires four parameters whose values vary by soil type: residual water content (θ_r), saturated water content (θ_s), the inverse of the air-entry pressure (α) and a shape parameter (n). The main objective of this study was to show the relevance of using near-infrared (NIR) spectroscopy to estimate the parameters of the VG model, based on the relation established between the soil water spectral index (SWSI) and θ (Soltani et al., 2019a). Based on this approach, the effective saturation of VG equals the effective SWSI. We applied the approach to 25 soil samples collected from topsoil and subsoil horizons in Brittany (western France), which exhibited high variability in texture and soil organic carbon content ranging from 0.07 % to 6.23 %. The results showed that i) the NIR-spectroscopy approach was relevant for estimating hydraulic parameters θ_s, α and n of the VG model and ii) the parameters obtained from a VG-like equation based on the relation between h and SWSI predicted values of θ of the soil–water retention curve that were similar to observed values, with a root-mean-square error of 0.031 and 0.045 cm³cm⁻³ for topsoil and subsoil horizons, respectively. The method was thus more accurate for topsoil horizons.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117175"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020011","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":"Freeze-thaw carry-over effect promotes decomposition of recalcitrant carbon in peatlands by nitrogen limitation","authors":"Jiawen Yan ,&nbsp;Lianxi Sheng ,&nbsp;Xiaofei Yu ,&nbsp;Shanshan Ding ,&nbsp;Yongen Min ,&nbsp;Hongyan Shen ,&nbsp;Yuanchun Zou","doi":"10.1016/j.geoderma.2025.117182","DOIUrl":"10.1016/j.geoderma.2025.117182","url":null,"abstract":"<div><div>Peatlands are pivotal in global carbon sequestration initiatives. However, studies of winter ecological factors and their subsequent effects on soil carbon–nitrogen (C-N) coupling processes remain limited, particularly amidst altering snowpack conditions due to climate change. Here, an in situ field experiment focusing on snowpack manipulation (presence and absence) was conducted within a northern peatland, China. The N functional groups and availability, bacterial community’s structure, succession and metabolic function, and carbohydrate-active enzymes (CAZymes) were determined at 0–30 cm (topsoil) and 30–60 cm (subsoil) employing synchrotron radiation X-ray absorption near-edge structure (XANES) and metagenomic sequencing technologies. The findings revealed that snowpack absence augmented the number of freeze–thaw cycles by 9 times, causing the subsoil that initially did not experience freeze–thaw cycles to undergo 17 cycles. This amplification of freeze–thaw cycles significantly influenced soil N processes during the freeze–thaw period and subsequent seasons. Specifically, it resulted in a 40.2 % and 1.8 % increase in the metabolic potential of denitrification in the topsoil and subsoil, respectively. Concurrently, there was a reduction in inorganic N content by 4.1 % and 4.4 % in the topsoil and subsoil, respectively. Furthermore, the diminished N availability (ammonium and inorganic N) intensifying soil N limitation subsequently altered microbial assembly processes. This shift led to a significant increase in the abundance of CAZymes encoding the decomposition of lignin (19.2 % and 4.8 %), chitin (4.8 % and 1.4 %), and murein (9.0 % and 0.8 %) in the topsoil and subsoil. Additionally, the content of pyridine, primarily derived from the decomposition of lignin and microbial cell walls, increased by 2.2 % and 1.9 % at two studied depths under snowpack absence conditions. These results uncover a cascading relationship between snowpack conditions, N availability, and the decomposition of recalcitrant carbon in peatland soils, highlighting the need for further comprehensive studies in this domain.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117182"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020251","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":"Low-severity wildfire prevents catastrophic impacts on fungal communities and soil carbon stability in a fire-affected Douglas-fir ecosystem","authors":"Timothy J. Philpott ,&nbsp;Gabriel Danyagri ,&nbsp;Brian Wallace ,&nbsp;Mae Frank","doi":"10.1016/j.geoderma.2025.117189","DOIUrl":"10.1016/j.geoderma.2025.117189","url":null,"abstract":"<div><div>The growing frequency, extent and severity of wildfire is destabilizing carbon sinks in western North America, underscoring an urgent need to better understand fire impacts on soil carbon stocks, carbon stability, and fungi that regulate soil carbon cycling. Here, we examined the effects of wildfire two years post-burn on soil carbon and fungal communities across a fire severity gradient in Douglas-fir forests in central British Columbia, Canada. We observed no significant differences in soil carbon or fungal community composition between low-severity and unburned stands. In contrast, high-severity wildfire resulted in a 49 % reduction in belowground carbon stocks (20.7 Mg C·ha⁻¹), a 91 % decline in ectomycorrhizal fungi, 5- to 27-fold increases in pathogenic fungi, and a proliferation of pyrophilous taxa compared to unburned stands. Carbon was lost primarily as light particulate organic matter, whereas impacts to mineral-associated carbon were muted. Pyrogenic carbon preferentially associated with the mineral fraction, modestly increasing (∼0.15 Mg C·ha⁻¹) the proportion of carbon resistant to decay in this stable fraction. Select helotialean (e.g. <em>Phialocephala fortinii</em>) and other pyrophilous taxa were well-correlated with pyrogenic carbon, suggesting this consortium is well-adapted to decompose persistent carbon and will likely continue to mineralize soil carbon even after high severity wildfire. The markedly higher abundance of pathogenic fungi and reduced ectomycorrhizal abundance in stands affected by high-severity fires pose risks to post-fire recovery, particularly if pathogen proliferation reduces conifer fitness. These results highlight that low-severity wildfires have comparatively muted impacts on soil carbon and fungal communities relative to high-severity wildfires, underscoring the importance of management strategies such as thinning and prescribed burns to mitigate the catastrophic effects of high-severity wildfires.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117189"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055179","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":"Thermogravimetric data suggest synergy between different organic fractions and clay in soil structure formation","authors":"Ivan Šimkovic,&nbsp;Andrej Hrabovský,&nbsp;Adela Joanna Hamerníková,&nbsp;Silvia Ihnačáková,&nbsp;Pavel Dlapa","doi":"10.1016/j.geoderma.2025.117166","DOIUrl":"10.1016/j.geoderma.2025.117166","url":null,"abstract":"<div><div>Although it has been recognized that soil structure formation affects soil organic carbon (SOC) sequestration, experimental data elucidating the relation between mechanical properties of soil structure and soil organic matter (SOM) stability are lacking. This study assesses the link between aggregate stability and SOM stability in lowland and hilly land soils of Central Europe. Overall, 39 topsoil samples were taken. Besides determining basic properties and nutrient availability, stability of soil aggregates was quantified using wet sieving (WS) and rainfall simulation (RS) procedures. The samples were analyzed by thermogravimetry and differential scanning calorimetry (TG-DSC). Besides significant correlations with basic soil properties and contents of selected nutrients, the aggregate stability data were linked to thermal processes, such as water desorption and SOM degradation. The RS values were significantly correlated (r &gt; 0.7, p &lt; 0.001) with the rate of water desorption (T &lt; 200 °C) and SOM degradation (200 – 570 °C). Observed correlation pattern, with multiple maxima, suggests that aggregate stability is supported by clay and several SOM fractions, each showing different thermal stability. Significant correlations observed bellow 200 °C indicate that properties controlling soil specific surface area (SOM and clay) are important also for the aggregate stability. The 78 % of the variance observed in aggregate stability testing was explained by multilinear regression using weight loss rates recorded at selected temperatures (80, 130, 248, 401 and 455 °C) as predictors. We observed different relations between exothermic energy values, soil aggregate stability and thermal stability of SOM (SOC). Exothermic heat flux normalized with respect to SOC mass (energy density) indicates presence of stable organic fraction, as it showed correlation also with clay, which has positive effect on SOC stabilization. This is in line with the positive correlation between SOC energy density and aggregate stability. On contrary, normalizing the heat with respect to SOM mass indicates the content of labile organic components, as the correlations with clay or aggregate stability were insignificant. The TG-DSC data revealed that hilly land soils are depleted in fresh organic material, which is due to their genesis and the erosion intensified by tillage.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"454 ","pages":"Article 117166"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055181","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}