We invite contributions from field, laboratory and modeling studies focused on biological soil health descriptors or indicators, such as microbial respiration, enzyme activities, diversity and functions of soil (micro)organisms and other parameters affected by global change and human activities. This session welcomes contributions on soil health assessment methods, with a focus on biological soil fertility and the ecosystem services provided by soils. We particularly encourage abstracts that explore soil health across temporal and spatial scales, from micro-level to global perspectives.
In Europe soil health is facing emerging challenges that require innovative solutions and policy interventions. We acknowledge that 62% of the European Union (EU) soils are not in healthy condition, while we face serious challenges such as climate change, food security, biodiversity loss, and socio-economic pressures. The severity of these issues is evident in the fact that soil erosion is unsustainable for around ¼ of the EU territory, carbon stocks in soils are declining, nutrients are depleting, and emerging contaminants can pose a serious threat to soil and human health. The costs of soil degradation in the EU may reach up to €70 billion per year, highlighting the urgent need for action.
To address these challenges, the EU has put in place many policies for agro-environmental protection since 2000, including soil protection. The European Green Deal, launched in 2020, has set an ambitious roadmap to make the EU the first carbon-neutral continent with a modern, competitive, and resource-efficient economy. As part of the Green Deal, the European Commission (EC) has put soil protection in a high position on the EU policy agenda, recognizing that healthy soils are essential to achieve climate neutrality, zero pollution, sustainable food provision, and a resilient environment. This increased focus on soil health has led to the development of new policies and initiatives, such as the Soil Monitoring and Resilience Directive, which aims to establish a common framework for monitoring and assessing soil health in the EU.
The Soil Monitoring and Resilience Directive, in place since December 2025, lays down measures for monitoring and assessing soil health, managing soils sustainably, and restoring contaminated sites. Furthermore, the Mission Soil, which aims to set up 100 Living Labs to promote sustainable land and soil management in urban and rural areas, will play a crucial role in achieving the objective of healthy soils by 2050. With an estimated investment of nearly €800 million until 2028, funded research projects under the Mission Soil are expected to reverse soil degradation through action on the ground, underpinned by the development and monitoring of a set of indicators.
In addition to these initiatives, the Carbon Removals and Carbon Farming (CRCF) regulation is the first EU volunteer framework for certifying carbon removals and carbon farming. This regulation will monitor, report, and verify carbon removals, soil emission reduction, and biodiversity benefits, providing a new opportunity for farmers and other stakeholders to contribute to climate change mitigation. The carbon farming framework can also serve as an interesting business model for additional income to farmers, while involving diverse actors such as certification bodies, auditors, tech industry, and creating new jobs. By promoting sustainable land use practices, the CRCF regulation can help sequester carbon, reduce greenhouse gas emissions, and improve soil health.
This presentation will discuss these EU soil policies in detail, with a specific focus on the role and activities of the EU Soil Observatory (EUSO). Overall, the presentation will show how the EU soil policies and the EUSO are advancing the data, knowledge and tools on soils and leading the transition towards healthy soils in the EU.
How to cite: Vieira, D., Panagos, P., Broothaerts, N., and Sánchez-García, C.: Soil Health in Europe: Policy perspectives , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12384, https://doi.org/10.5194/egusphere-egu26-12384, 2026.
Under global change and land-use intensification, changes in soil physical and chemical properties propagate to soil biota, with cascading effects on ecosystem functioning and ecosystem service provision. In turn, soil organisms regulate key soil properties such as aggregation, nutrient cycling, and organic matter stabilization, creating a tightly coupled biophysical feedback loop that underpins soil health and ecosystem resilience. However, across Europe, strong environmental heterogeneity and fragmented datasets have made it difficult to identify biological soil health indicators that are robust across land-use systems and pedoclimatic regions.
We used datasets on soil biotic and abiotic properties generated within the SOB4ES project, land-use information and Earth observation-derived climatic (ERA-5), vegetation (Sentinel-2 NDVI) and topographic (NASA SRTM DEM 30m) variables across European sites. Our aim was to investigate scalable, data-driven approaches for soil health assessment under global change and human pressures. State-of-the-art machine-learning models were used to identify the relative importance of natural environmental drivers, soil state variables and human-induced pressures, shaping soil organism abundance and diversity across spatial scales.
Diversity metrics across multiple taxa consistently showed stronger relationships with environmental gradients than population densities, highlighting diversity as a more sensitive indicator of environmental change than density. Among the most dominant cross-taxa drivers of species richness was soil pH and organic carbon, with highest biodiversity associated with alkaline, carbon-rich soils under moderate moisture conditions. In contrast, high soil moisture and high relative humidity, reflecting both climatic forcing and land-use effects, reduced abundance and diversity across multiple groups, indicating broad sensitivity of soil biota to excess moisture stress under global change. Microbial biomass and nematode density showed particularly strong and accurately captured responses to soil carbon availability, soil texture and elevation, highlighting their value as integrative indicators of soil resource status and ecosystem functioning. Overall, our results demonstrate that biological indicators respond consistently to large-scale gradients in climate, soil chemistry and land-use, supporting their application in spatially explicit soil health assessments and in evaluating the impacts of environmental change and land management across Europe. By integrating microbial, soil faunal indicators across multiple European countries and contrasting pedoclimatic regions, our analysis shows that soil communities are governed by broadly shared environmental controls under global change and land-use pressures, rather than by idiosyncratic, site-specific effects.
The strong contribution of specific soil properties and Earth-observation-derived variables, combined with the ability of machine-learning models to integrate heterogeneous datasets, demonstrates a powerful and scalable approach for identifying robust biological soil health indicators across regions and land-use systems.
Acknowledgments: The work and all the authors were supported by the Horizon Europe project SOB4ES (“Integrating Soil Biodiversity to Ecosystem Services”) under Grant Agreement No. 101112831. We acknowledge all participating investigators from the SOB4ES consortium who contributed to the existing sample collection and the field sampling for the generation of the spatial database used in the current analysis. Partners from KNAW, UVIGO, NUID UCD, UNICT, KU Leuven, CU, ARO, IBB, UL, UoC, SLU, EFWSL, Airfield, MFO, and INRAe provided these contributions.
How to cite: Christou, M. M., Mourouzidou, S., Kavakiotis, Y., Monokrousos, N., Papakostas, S., Karyotis, K., Tsiafouli, M., Koidou, V., Chantzi, P., and Zalidis, G.: Predicting soil biological indicators of soil health and identifying environmental constraints on soil biodiversity across European landscapes using earth observation data and machine learning, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19160, https://doi.org/10.5194/egusphere-egu26-19160, 2026.
Soil health is essential for crop production and plays a crucial role in agricultural sustainability by supporting vital ecosystem and societal services. The manipulation of beneficial microbes is an emerging strategy for improving soil quality in agroecosystems. However, little is known about whether microbes enriched through organic fertilization can promote plant growth and soil health. This study employed amplicon sequencing and shotgun metagenomics to characterize the fertilizer-induced shifts in soil microbial communities and metabolism-related genes, and their correlations with soil health index. Core organic fertilizer-induced microbial taxa were then isolated and their growth-promoting and soil health-improving effects were experimentally verified. Our results demonstrated that the continuous application of organic fertilizer with higher nitrogen input enhanced soil health index by 119%. Random forest analyses revealed that the abundances of functional genes involved in nitrogen assimilation, especially nasB, gdh, and nirA were important predictors of soil health index. More importantly, functional genes involved in nitrogen cycling explained more variance (63.78%) in soil health index than phosphorus (38.73%) and carbon (32.33%) cycling. Furthermore, inoculation with synthetic communities (SynCom) derived from organic fertilization, which consisted of five Pseudomonas spp. and one Microbacterium sp., enhanced the soil health index by 36.1% compared to the non-inoculated control and significantly improved plant growth, including height, shoot dry weight, and root dry weight. These findings show that organic fertilization-induced core species enhance soil health and plant performance, laying the foundation for leveraging the beneficial microbes for sustainable agricultural practices.
How to cite: Shu, D., Sun, X., and Wei, G.: Core soil microbiota mediated by long-term organic fertilization enhance soil health and plant productivity, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10418, https://doi.org/10.5194/egusphere-egu26-10418, 2026.
Cover crops are increasingly promoted as a management strategy to enhance soil carbon (C) stocks and soil health, but their effects on greenhouse gas (GHG) emissions remain uncertain, particularly in flooded rice systems where anaerobic conditions prevail. In these systems, organic inputs such as green manures have been widely reported to stimulate methane (CH₄) emissions, raising concerns about their net climate impact.
Here, we evaluated the impacts of contrasting rice rotational strategies, i.e., winter fallow, hairy vetch (Vicia villosa Roth), and Italian ryegrass (Lolium multiflorum Lam.), on soil health, C dynamics, and GHG emissions in a Mediterranean rice system located in the Ebro Delta (NE Spain). The field experiment was established in 2021, and the results presented here cover the period from February 2024 to October 2025.
Soil biological health was assessed by integrating weekly measurements of CH₄ and nitrous oxide (N₂O) emissions with microbial biomass C and nitrogen (N) and litter decomposition of cover crop shoots and roots assessed at key stages of the rice growing cycle. These indicators were complemented by measurements of soil organic carbon (SOC) stocks and soil aggregation to evaluate links between biological activity, soil structure, and C storage. Ongoing analyses of microbial necromass and SOC fractionation into particulate and mineral-associated pools will provide further mechanistic insight into C stabilization processes under different cover crop strategies.
Cover crop identity strongly influenced biogeochemical dynamics. CH₄ emissions peaked under vetch during the flooded cultivation phase, whereas no significant treatment effects were detected for N₂O emissions, despite a tendency towards lower emissions under vetch. Consequently, no net differences in global warming potential were observed among treatments. Shoot litter decomposition was significantly slower for vetch than for ryegrass, a pattern not mirrored in roots, and consistent with differences in residue lignin content. However, rapid mass loss occurred for both residue types under anaerobic conditions, suggesting an important role of solubilization processes. SOC stocks did not differ among treatments in the most superficial soil layer, but ryegrass was associated with significantly lower stocks in the 10–30 cm soil layer. Cover cropping tended to promote macroaggregate formation, suggesting potential improvements in soil structure and physical protection of organic matter. Microbial biomass C and N were marginally higher under vetch in autumn, indicating enhanced soil biological activity. At the agronomic level, rice grain yield showed a marginal increase under vetch.
Overall, our results suggest that vetch represents a promising cover crop option in Mediterranean rice paddies, enhancing soil biological functioning and rice productivity while not leading to clear increases in total GHG emissions.
Acknowledgements
This study was funded by The Government of Catalonia through the projects AgriCarboniCat and Carboni al Sòl.
How to cite: Llovet Martín, A., Pérez-Méndez, N., Catala-Forner, M., Borrull, J., Jornet, L., Matamoros, L., and Martínez-Eixarch, M.: Vetch cover cropping enhances soil biological functioning and rice productivity without increasing greenhouse gas emissions in a Mediterranean rice system, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19422, https://doi.org/10.5194/egusphere-egu26-19422, 2026.
Despite being a highly popular topic in agroecological research, the impact of wildflower strips (WFSs) on soil biota and related ecosystem services remains poorly understood. To achieve a more comprehensive understanding, we need long-term studies that combine biodiversity and decomposition data while accounting for the additive effects of management. In this study, we analysed earthworm abundance, species richness and biomass, soil arthropod abundance, and litter decomposition rates in WFSs and adjacent crops across three years, controlling for sowing term and seed mixture effects. Furthermore, we evaluated how contrasting WFS tillage managements (tillage vs. no-till) affect epigeic and soil arthropod communities.
Earthworm abundance, species richness, biomass, and soil arthropod abundance were consistently higher in wildflower strips than in cropped margins. Moreover, the effects strengthen over time, suggesting cumulative benefits from reduced disturbance and the establishment of permanent vegetation. Tillage effects showed taxon-specific responses to disturbances, with carabids, isopods, and other soil-dwelling arthropods being negatively affected. In contrast, taxa less bound to soil stability, such as spiders, exhibited transient rebound dynamics. Undisturbed WFSs showed a lower long-term decomposition rate, suggesting a trade-off between biodiversity gains and decomposition under less disturbed soil conditions.
These results underscore the importance of WFSs for soil biota in agricultural contexts, suggesting that disturbance-sensitive management strategies should be implemented to enhance soil biodiversity. However, the potential trade-offs with ecosystem services, such as decomposition, require further investigation to optimise agricultural practices. Building on these findings, we plan to explore further how changes in vegetation structure influence epigeic arthropods, hypothesising that denser, more structurally complex vegetation promotes higher abundance and diversity.
How to cite: Venturo, A., Štrobl, M., Hlava, J., Brandová, E., Tajovský, K., Pařízek, V., Pecníková, N., and Knapp, M.: Wildflower strips and soil fauna: multi-taxa responses to management and consequences for decomposition, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21942, https://doi.org/10.5194/egusphere-egu26-21942, 2026.
Soils are crucial for biogeochemical elemental cycles and, on a more anthropocentric note, for agriculture. The ongoing degradation of agricultural soils, including horticultural substrates, has large scale implications for crops, humans and the surrounding ecosystems (OneHealth). One critical aspect of soil degradation is the subsequent loss of functional microbial diversity, which is essential for soil and plant health. Thus, the maintenance and manipulation of those microbial players is a key interest of sustainable farming and the European Union (The Mission 'A Soil Deal for Europe'; SPIN-FERT: Grant agreement ID: 101157265, DOI: https://doi.org/10.3030/101157265).
To understand the role of artificial humic substances on plant health, plant performance and soil microbiomes we grew tomato seedlings along a soil disturbance gradient. Each substrate was treated with artificial humic substance and/or Rhizoctonia solani AG-4, a fungal soilborne plant pathogen, to infer potential mechanisms of plant growth enhancement and disease resistance. We hypothesize that humic substances increase soil microbial diversity and disease resistance of tomato seedlings.
Plant height and microbial diversity were observed to be highest in undisturbed soil and were further increased by the addition of humic substance and decreased by the presence of R. solani. Disease incidence was noticeably lower under humic substance amendment except for the most disturbed soil. Both treatments caused the microbial communities of the soil and rhizosphere to shift, with β-diversity clustering the most complete and distinct after the disturbance recovery and revealing several plant and soil health associated taxa to be enriched through humic substance addition.
By altering the soil microbiome composition, the plant is offered a wider selection of microorganisms to recruit from while the fungal pathogen is met with a more diverse battery of potential antagonists. Our findings may contribute to more effective manipulation of the microbial aspects of agriculture to promote and improve healthy produce.
How to cite: Streblow, M., Bickel, S., Lamprecht, A., Wicaksono, W. A., Filoneko, S., Antonietti, M., and Berg, G.: Degree of soil disturbance affects success of microbiome restoration by artificial humic substances: a plant health perspective, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9634, https://doi.org/10.5194/egusphere-egu26-9634, 2026.
The soil eco-enzymatic stoichiometry approach has been widely used in terrestrial ecosystems for decades to assess microbial carbon (C), nitrogen (N), and phosphorus (P) limitation based on the ratios of five arbitrary-selected enzyme activities. As numerous enzymes are involved in soil C, N, and P cycling, it remains uncertain whether the stoichiometric approach will be valid if it is based on different set of eco-enzymes.
To address this issue, soils were collected from six long-term field experiments (12–123 years in duration) at Bad Lauchstädt, central Germany. These experiments encompass a wide range of soil organic matter contents (1.4–6.9%) and include contrasting field treatments such as fertilization regimes, land-use intensity, and fallow periods. In addition to the five basic enzymes (β-glucosidase, cellobiohydrolase, N-acetyl-glucoseaminidase, leucine aminopeptidase, and acid phosphatase), lipase activity was measured and incorporated into the stoichiometric analysis.
The additional C-cycling enzyme (lipase) increased vector length by 12–90% across all experiments and treatments, in numerous cases increasing a threshold value 0.6 and indicating microbial C limitation, which was not evident by basic set of enzymes. Vector angles showed variable responses to lipase addition. For example, vector angles increased by 13–41% under natural succession and excessive manure application, suggesting reduced N limitation, whereas no effect of lipase addition was observed on vector angles under poor soil conditions (no fertilization and 36 years fallow). However, soil microbial biomass C:N ratios ranged from 20 to 45 under poor soil conditions, indicating strong microbial N limitation, which contradicts the stoichiometry results.
Overall, our findings highlight the considerable uncertainty and potential biases of the enzyme stoichiometry approach and emphasize the need to identify more reliable ecological indicators of microbial nutrient limitation.
How to cite: Wang, S. and Blagodatskaya, E.: Validity of eco-enzymatic stoichiometry to reveal microbial C and nutrients limitation: Evidence from six long-term field experiments, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5884, https://doi.org/10.5194/egusphere-egu26-5884, 2026.
Climate models predict that the frequency, magnitude, spatial extent and duration of extreme climate events such as drought will further increase throughout Europe in the 21st century. Drought not only affects water availability but also alters the rhizosphere microbiome and its functions, consequently hampering soil nutrient cycling and crop nutrition. One measure to circumvent drought conditions in soil, at least during short to intermediate dry periods, is the application of additives to enhance P availability by improving diffusion conditions in the rhizosphere. However, studies focusing on the effect of soil additives on crop nutrition and functional capabilities of the rhizosphere microbiome during drought are scarce. We conducted a rhizotron experiment planted with spring wheat and induced 11 days of drought to investigate the effect of novel soil additives such as pelleted biochar-lignocellulose hydrogels including activators and nutrient loadings versus pyrolyzed biochar on wheat´s phosphorus (P) nutrition. Besides analyses of macro- and micro-nutrients in root and shoot as well as wheat’s active gene transporters (PM ATPase, ALMT, MATE, PHT, PHO1, SWEET), we determined the co-localization of enzymatic properties (Vmax, Km), pH, and microbial functional gene abundance in rhizosphere hotspots.
The area of rhizosphere phosphomonoesterases hotspots reduced to 1% during drought without additives (non-drought condition 4%). Biochar-hydrogel pellets amended to soil shifted microbial community composition, increased their diversity, and enhanced functional gene abundances of the microbiome in rhizosphere hotspots under drought conditions. The P content in roots was up to 3-fold higher with pellets than without. Higher P mobilization was determined in soil amended with pellets rather than solely biochar or control which was in line with a doubling in abundance of phosphomonoesterase genes. Consequently, the addition of the pellets increased P availability in the rhizosphere, potentially based on improved diffusion processes. Wheat´s PHT1.6 transporter in the shoots, which are crucial for P uptake and remobilization, was 9-fold higher in pellet amended soil than in control. Moreover, there was a 3-fold increase in the abundance of the PHO1 transporter in roots, which facilitates P transport from roots to shoots. The root: shoot ratio was 3-fold lower when the pellets were added implying less investment in root development across the wheat growth period. Wheat´s active PM ATPase and SWEET gene expression in shoots was 2-fold higher with added pellets than in control during drought, highlighting the potential of H+-ATPase gene regulation in shoots as a strategy to increase the proton motive force and thus co-transport with phosphate.
The results suggest an ameliorated functional redundancy of the microbiome mitigating drought stress and improving soil health compared to single biochar application. Next the application of ecologically uncritical soil additives such as pelleted biodegradable lignocellulose hydrogels with pyrolyzed biochar to mitigate drought stress in crop production is going to be investigated in field trails.
How to cite: Islam, M. A., Lorenzen, C., Kashi, H., Shi, Y., Sagervanshi, A., Mühling, K.-H., Spielvogel, S., and Loeppmann, S.: Soil additives ameliorate crop´s phosphorus nutrition and the rhizosphere microbiome during drought , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13697, https://doi.org/10.5194/egusphere-egu26-13697, 2026.
Drying and rewetting (D/W) causes substantial stress to soil microbial communities, with important consequences for soil carbon (C) and nitrogen (N) dynamics. The impacts of biochar addition on these effects are underexplored. Fine biochar increases soil pH and enhances adsorption of labile ammonium (NH4+) released during repeated D/W cycles due to large surface area. We therefore hypothesised that application of fine biochar would decrease D/W-induced soil N2O emissions. Arable soils were prepared as (i) unamended controls, (ii) soils limed to replicate biochar pH effects, and (iii) soils amended at 1% of the dry soil weight with two particle-size fractions of biochar (<1.4mm “fine” and >3mm “coarse” pellets) produced from wheat straw and anaerobic digestate feedstocks. These soils were subjected to different frequencies of D/W cycles; 0, 1 or 4 cycles during a 58-day period. Ammonium nitrate fertilizer was applied at the start and after 45 days of incubation.
In the early stages of the incubation, lime and biochar addition both increased soil N2O emissions relative to the controls. However, fine digestate biochar reduced cumulative N2O emissions by 12.9% in the soil subjected to 0-cycles of D/W compared with non-amended control soils. Addition of lime to induce the same pH change as the biochar additions tended to decrease N2O emissions, suggesting that the reduction in N2O was partly mediated by a pH increase. Increasing D/W frequency elevated N2O emissions across the treatments except for both particle size wheat straw biochar amended soils, where N2O emissions were not altered by D/W frequency. Nonetheless, comparing N2O emissions at highest D/W frequency across treatments, the N2O released from soil amended with fine wheat straw biochar was the lowest. Lime and biochar addition decreased NH4+ concentration in soil by 19 – 55.5% compared to control soils. This reduction in NH4+ concentration suggest a pH-induced stimulation of nitrification with minimal N2O release. Overall, application of fine biochar mitigates soil N2O emissions, even during extreme D/W scenarios that may become increasingly frequent with climate change, and should therefore be considered a promising management practice for N2O emissions reduction in arable soils.
How to cite: Bore, E. K., Child, H. T., Friggens, N. L., Hook, C., Cressey, E. L., Wierzbicki, L., Dowdle, J., Richard K. Tennant, R. K., van Groenigen, K. J., and Hartley, I. P.: Size matters: Fine biochar application mitigates N2O emissions during extreme drying and rewetting events in arable soils, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20980, https://doi.org/10.5194/egusphere-egu26-20980, 2026.
Rapid urbanization has substantially changed the soil environment, causing changes in the composition and distribution of soil pathogens. However, critical knowledge gaps persist regarding soil human pathogens in urban regions which are characterized by intensive human-environment interactions. This issue has become urgent amid growing public attention on environmental health and public health events. Utilizing field monitoring, high-throughput sequencing, and geospatial analysis, this study provides the first systematic assessment of human-associated soil pathogens distribution across a typical urban agglomeration in north China. There were 16 major human-pathogenic species identified in soils, with Stenotrophomonas predominating (detected in 57.00% of samples). Significant differences were observed in both abundance and species of soil human pathogens as well as network structure from urban to rural areas, and peri-urban areas can be identified as contamination hotspots. Results of showed that socioeconomic factors accounted for 34.5% of soil human pathogens distribution variability, particularly facility agriculture distribution and cropland fragmentation. Furthermore, we developed an innovation risk assessment framework with considering 12 indicators encompassing abundance and species number of soil human pathogens, network structure, and human exposure parameters to quantify urban-rural exposure risks of human pathogens. The evaluated results demonstrated elevated risks in peri-urban areas, with children being more susceptible than adults to threats posed by soil human pathogens in urban areas. This study provides an innovative approach for quantifying risk of soil human pathogens and scientific guidance for preventing soil human pathogens contamination and enhancing soil health in rapid urbanization areas.
How to cite: Li, M.: Soil human pathogens in rapid urbanization areas: occurrence, distribution, and potential risk, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6026, https://doi.org/10.5194/egusphere-egu26-6026, 2026.
Soil biodiversity is crucial for our functional biosphere and 95% of our food relies on healthy soil. Yet over 70% of earth’s soil is degraded, highlighting the urgency to restore soil health, a goal emphasized by the recent European Soil Monitoring directive. Soil-born nematodes exist within all trophic levels of the soil food web and represent a universal bioindicator of soil biodiversity, even in degraded soils. However, this indicator is not widely used and requires nematologist and soil ecology experts as well as significant labor-intensive manual analyses. With the support of EIC and EIT, we developed an automated end-to-end diagnosis tool, comprised of an automated soil sample imaging system (NEMASCOPE TM) and a multi-level, taxonomy-guided computer vision AI for nematode species identification. Our technology provides quantitative soil biodiversity parameters based on the existing scientific framework of Nematode-based Indices (NBIs), assessing soil health, immunity, fertility, soil-based plant parasites, carbon cycling, pollution, and organic degradation pathway, among other NBIs for soil assessment. Validated by research phytopathogenic laboratories, the tool demonstrated to be in average more accurate (>90%) and over 20-times faster (<15 min) in end-to-end biodiversity analysis compared to manual analysis. The system’s nematode identification performance we evaluated on Root-knot nematode (RKN) species level identification accuracy across Meloidogyne species that are among the most economically damaging plant-parasitic nematodes, using naturally infested field samples containing M. chitwoodi, which are challenging to distinguish from other Meloidogyne species due to their morphological similarities. Compared with manual identification, the AI-based approach achieved an accuracy of ~95% in identifying RKN genera with species-level prediction accuracy for M. chitwoodi with ~96%, essentially matching manual expert performance. Our platform demonstrates expert-level accuracy for nematode identification down to the species level particularly necessary for plant-parasite index (PPI) assessment. The technology allows scalable, industry-ready diagnostics addressing the global shortage of nematologist expertise with the potential to become a new standard in commercial and research sectors, aiding in the global efforts to manage and restore soil health.
How to cite: Kurfurst, V., Janissen, R., Matar, Z., Verheijen, G., Cervenka, A., Wigman, A., Tanahashi, K., Kolarik, M., and Issa, H.: Automated imaging and taxonomy-guided AI for accurate and scalable soil biodiversity diagnosis, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21429, https://doi.org/10.5194/egusphere-egu26-21429, 2026.
Changes to the structure or functioning of the soil microbial community could alter the way it metabolises aboveground organic inputs, with significant potential implications for plant nutrient availability, the carbon cycle, and other aspects of soil health. Human activities have been shown to alter microbial diversity and activity in various study sites. However, different ecosystems respond differently to the same disturbance, so we need to identify the globally common patterns.
We perform a meta-analysis of the effects of five human activities – land use change, ecosystem restoration, pollution, pesticide use and fertiliser addition – on microbial diversity (measured as Shannon index of the catabolic diversity) and activity (measured as soil basal respiration). From an initial 693 records from Web of Science, we short-list 177 studies covering 924 datapoints across all six inhabited continents. For each of the five human activities, we identify treatment-control pairs from this dataset, and calculate their log response ratios (‘lRR’, the logarithm of the ratio of the treatment diversity or activity to the control value). From these lRRs, we calculate an overall effect size and confidence interval under a robust variance estimation meta-regression model. We also check for publication bias and any changes in reported effect size over time.
Our dataset did not significantly differ from a random sampling of land points on the earth along various climatic and edaphic axes. Median catabolic diversity in our dataset was 2.57 (with 95% of readings in the range 0.90 - 4.43) and median respiration activity was 1.63 μg CO2 g−1 h−1 (with 95% of readings between 0.12 and 150). Among human activities, fertiliser addition and ecosystem restoration increased diversity (by +12.9% and +8.4% respectively) and activity (+38.9% and +73.5%), while land use change reduced diversity (by 1.5%) and activity (by 21.0%). The effects of pollution and pesticide use were not statistically significant. We found no significant effect of publication bias, and no consistent trends in reported effect size over time.
Greater diversity generally improves ecosystem efficiency, so we expected an increase in diversity to lead to greater carbon assimilation by microbes and a decrease in respiration activity. However, we found human activities to cause changes in the same direction for both diversity and activity. Also, the increase in respiration activity in response to ecosystem restoration is almost three times the reduction in activity due to land use change, even after accounting for the different baselines. This suggests that restored ecosystems might use carbon less efficiently compared to intact ones.
Our results show that land use intensity has a negative impact on soil microbial diversity and activity, whereas nutrient addition has a positive effect. Soil microbes mediate how much carbon and other nutrients remain in soil and how much is lost to the atmosphere or other pools. Therefore, learning how humans alter their community structure and functioning will help in better understanding current global problems like soil nutrient deficiencies and climate change.
How to cite: Mathew, J., Roy, S., and Bagchi, S.: A Global Meta-analysis on the Impact of Human Activities on Soil Microbial Diversity and Carbon Cycling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3355, https://doi.org/10.5194/egusphere-egu26-3355, 2026.
Soil organic carbon (SOC) plays a central role in regulating soil fertility, water retention, and quantifying risks of soil degradation (Afshar et al., 2025). While climate variability is increasingly recognized as a major pressure on SOC, large-scale assessments of drought impacts on forest soils remain limited. Recent studies emphasize that drought effects on SOC are highly context dependent, shaped by soil carbon status, climate regime, and interacting environmental controls, calling for flexible modeling frameworks that can capture nonlinear responses (Hassani et al., 2024; Shokri et al., 2025).
In this study, we analyze SOC change between 2009 and 2018 across European forest soils using generalized additive models (GAMs) applied to harmonized LUCAS topsoil observations. SOC change is modelled as a nonlinear function of initial SOC, drought characteristics derived from the Standardized Precipitation Evapotranspiration Index (SPEI), climate, and soil properties.
GAM results show that drought severity exerts a significant, nonlinear impact on SOC change (p < 0.001), strongly modulated by initial SOC and climatic parameters. On average, under severe drought conditions, SOC declines by ~32% relative to mild drought conditions. Overall, the results demonstrate that drought impacts on forest SOC are state-dependent and spatially heterogeneous, governed by the combined influence of drought severity, initial carbon stocks, and regional climate conditions.
References:
- Afshar, M. H., Hassani, A., Aminzadeh, M., Borrelli, P., Panagos, P., Robinson, D. A., Or, D., & Shokri, N. (2025). Spatial and temporal assessment of soil degradation risk in Europe. Scientific reports, 15, 44636. https://doi.org/10.1038/s41598-025-33318-7
- Hassani, A., Smith, P., & Shokri, N. (2024). Negative correlation between soil salinity and soil organic carbon variability. Proceedings of the National Academy of Sciences, 121(18), e2317332121. https://doi.org/10.1073/pnas.2317332121
- Shokri, N., Robinson, D. A., Afshar, et al. (2025). Rethinking global soil degradation: Drivers, impacts, and solutions. Reviews of geophysics, 63(4), e2025RG000883. https://doi.org/10.1029/2025RG000883
How to cite: H. Afshar, M., Robinson, D. A., Panagos, P., and Shokri, N.: How Drought Influences Forest Soil Organic Carbon, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13105, https://doi.org/10.5194/egusphere-egu26-13105, 2026.
The Rural Development Administration (RDA) of South Korea periodically conducts the "Survey on the Status of Agricultural Resources and Environment" to conserve agricultural resources and improve the agro-environment. This program monitors changes in soil fertility, heavy metals, pesticide residues, and microbial communities, as well as agricultural water quality, input usage, and the public functions of agriculture. The results serve as fundamental data for establishing national agricultural policies. Among these factors, soil chemical properties are critical indicators linked to both crop productivity and environmental pollution. This study analyzes the results of soil chemical property surveys conducted over the past four years (2021–2024) and evaluates trends since 1999. From 2021 to 2024, annual topsoil (0–15 cm) samples were collected from uplands (1,760), orchards (1,470), paddy fields (2,110), and greenhouse cultivation sites (1,374). The samples were analyzed for pH (1:5), EC, organic matter (OM), available phosphate (Avail. P), exchangeable cations (K, Ca, Mg), and available silicate (for paddies). Analytical accuracy was strictly managed using reference materials provided by the National Institute of Agricultural Sciences (NAS). The results showed that the mean soil pH was 6.1 for paddies and 6.5 for uplands, while the mean OM content was 27 g kg⁻¹ for both land use types, maintaining levels within the optimal range. These values indicate an increasing trend compared to 1999, reflecting the positive effects of long-term government support programs for soil amendments (since 1957) and organic fertilizers (since 1999). Nutrient contents, including Avail. P, K, and Ca, showed a gradual increasing trend over time. Notably, greenhouse cultivation sites exhibited more severe nutrient accumulation compared to other land use types, largely due to the closed environment of rain-sheltered facilities preventing leaching. These findings suggest that national policies should encourage the use of appropriate fertilizer amounts on agricultural land. Furthermore, integrating these soil monitoring results with fertilizer input data would enable the identification of nutrient sources, facilitating more efficient and sustainable nutrient management strategies.
How to cite: Chough, N., Lee, E., Kim, M.-S., Lee, T.-G., and Jung, H.: Evaluation of Soil Chemical Characteristics by Agricultural Land Use Type in South Korea over the Recent Four Years, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16629, https://doi.org/10.5194/egusphere-egu26-16629, 2026.
Soil biota plays a key role in pedogenesis, influencing nutrient cycling, organic matter transformation, and soil structure, while its composition depends on edaphic properties and pedological origin. In Mediterranean ecosystems, semi-arid conditions and historical land use have altered soil and vegetation dynamics, making natural recovery after land abandonment slow and uncertain. We assessed soil quality more than three decades after agricultural and pastoral abandonment on Pianosa Island a very representative territory of Mediterranean environment, characterized to be a limestone plateau of about 10km2, approximately 20-25 m above sea level. The island has been a penal agricultural colony for more than one century, intensively exploiting almost the entire surface. The agricultural fields have been abandoned at the beginning of the 90's and the natural vegetation is now expanding, with different degree along the island. For its peculiar history and nature, Pianosa represents an extrapordinary on-field natural laboratory. An integrated approach was used to assess soil quality, combining vegetation surveys and chemical, physical, and biological soil analyses. Five environmental groups were identified, reflecting different regeneration stages: ex-managed areas with low Mediterranean shrub recovery degree, consistent with a higher contribution of pioneer and sub-mature shrub species; ex-managed areas with high Mediterranean shrub recovery, with a greater presence of mature shrub species and a more developed shrub structure; Mediterranean shrublands; coniferous forests; and coniferous forests largely colonized by Mediterranean shrubs. Results indicate that, even without human disturbance, recovery of soil biological attributes is extremely slow. Intrinsic soil properties and historical vegetation legacies strongly influence biotic reassembly and ecosystem functioning. These findings underscore the need to integrate pedological constraints and biological indicators in restoration strategies to sustain ecosystem services in Mediterranean landscapes.
How to cite: Lorenzetti, R., Maienza, A., Biancofiore, G., Gallese, F., Sabatini, F., Massetti, L., Renella, G., and Vaccari, F. P.: Climate-driven soil dynamics over 30 years: insights from biological indicators across mediterranean shrubland recovery following agricultural abandonment, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18328, https://doi.org/10.5194/egusphere-egu26-18328, 2026.
Afforestation can enhance carbon sequestration in global drylands but may impair ecosystem functioning via deep-soil water depletion. However, it remains unclear how afforestation-driven turnover in soil biota influences aboveground vegetation status and soil multifunctionality, particularly in deep soil. Here, we conducted a ~500-km transect survey across four precipitation regions on the Loess Plateau, China, comparing 25-year-old plantations with adjacent croplands. We characterized soil biota (bacteria, fungi, protists, and invertebrates) using amplicon sequencing and quantified soil multifunctionality in topsoil (0–20 cm) and deep soil (160–200 cm). We found that afforestation was linked to stronger effects in deep versus topsoil, and the magnitude of these effects varied across the precipitation gradient. Afforestation consistently reduced deep-soil water and multifunctionality, whereas topsoil responses became increasingly negative at the drier range of the precipitation gradient. Soil biotic change was driven primarily by community turnover rather than diversity, and turnover responses across all biotic groups weakened with reduced precipitation. Turnover patterns further supported a trade-off between aboveground greening and belowground functioning. Soil biota that established after afforestation were positively associated with canopy greenness but negatively associated with soil multifunctionality, whereas those that disappeared showed the opposite linkages. Biota that persisted before and after afforestation were positively associated with both canopy greenness and multifunctionality. Overall, our results show that gains in aboveground greenness can mask persistent deep-soil functional losses in dryland afforestation, emphasizing that restoration success should be evaluated with explicit deep-soil indicators.
How to cite: Xu, Z., Anthony, M., Qiu, T., and Hu, Z.: Deep soil biota drive trade-offs between above and belowground functioning during dryland restoration, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20319, https://doi.org/10.5194/egusphere-egu26-20319, 2026.
Microbial life-history strategies determine how microbial communities prioritize resource allocation toward growth, resource acquisition, or stress tolerance. However, how soil microbial communities adjust their life-history strategies in response to distinct soil fertility remains poorly understood. In this study, metatranscriptomic sequencing was performed to investigate shifts in microbial life-history strategies in soils with different fertility, developed by 37 year diverse fertilization regimes: no fertilization, mineral fertilization, manure fertilization, and combined mineral/manure fertilization. Organic amendments increased the transcript abundance of genes (normalized by transcripts per million [TPM]) related to biogeochemical cycles by 13 %–246 % relative to unfertilized soils. We quantified the relative transcript abundance of each functional pathway within individual biogeochemical cycles to compare transcriptional allocation across treatments. Within each cycle, organic amendments increased the relative transcript abundance of genes involved in organic matter degradation by 9 %–12 % and dissimilatory nitrate reduction by 24 %–37 % relative to unfertilized soils. Although TPM-normalized transcript abundance of growth-associated genes increased 1.8- to 2.2-fold in fertilized soils, their relative abundance among all life-history transcripts remained stable at approximately 77 %. Organic inputs altered microbial resource allocation by favoring resource acquisition over stress tolerance. This shift was associated with increased nutrient availability and soil pH neutralization. Taxonomic analysis revealed growth yield as the dominant strategy across most phyla. Within each strategy, Desulfobacterota showed a strong association with growth yield, Verrucomicrobiota with resource acquisition, and Pseudomonadota and Actinomycetota with stress tolerance. Notably, while strategy preferences were broadly conserved across phyla, fertilization modulated the intensity of strategy-specific gene expression, indicating functional plasticity of microbial communities in response to environmental change. Collectively, our findings suggest that differences in soil fertility resulting from long-term fertilization alter microbial resource allocation among life-history strategies by changing the functional expression of transcripts assigned to different taxa, reflecting the functional plasticity of soil microbial communities under intensified agriculture.
How to cite: Li, L., Xue, C., Wang, Y., Liu, M., Guo, J., Liu, M., and Ling, N.: Microbial lifestyles adapted to distinct soil fertility , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6628, https://doi.org/10.5194/egusphere-egu26-6628, 2026.
Soil salinization-alkalization severely undermines soil multifunctionality (SMF) by disrupting essential biogeochemical and ecological processes. Remediating saline-alkali soils is therefore critical for enhancing SMF, safeguarding food security, and improving carbon storage. Although previous studies have applied meta-analysis to evaluate soil remediation strategies, the design of location-specific agricultural practices for rehabilitating saline-alkali lands and optimizing their carbon sequestration potential remains underexplored, largely due to China’s pronounced spatial heterogeneity. To address these gaps, this study presents the first integration of nationwide meta-analysis with machine learning-driven spatial predictive modeling to assess the effects of different remediation measures (i.e., physical, chemical, and biological) on soil organic carbon (SOC) content and SMF in saline-alkali lands. We produced spatial maps of effect sizes for SMF and SOC and categorized them into four regions (i.e., northwestern, northeastern, northern, and coastal) based on distinct climatic and hydrological conditions. The results indicate that the topsoil SOC stock in China’s saline-alkali lands is estimated at 126.05 Tg, which could be increased by up to 30% under biological remediation measures. A strong positive relationship was observed between SOC and SMF, with SOC enhancement indirectly boosting crop productivity in saline-alkali soils. On a national scale, chemical remediation proved to be the optimal management strategy for simultaneously promoting SMF and SOC sequestration. Biological measures showed comparable benefits, particularly in the northwestern, northeastern, and coastal regions. However, future changes in temperature and precipitation are projected to undermine SMF improvements while accelerating SOC accumulation under remediation, potentially weakening the SOC–SMF linkage in saline-alkali soils. These insights are vital for guiding future efforts to ensure food security and mitigate climate change.
How to cite: Han, Z.: Location-optimized remediation measures for soil multifunctionality and carbon sequestration of saline-alkali land in China, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16219, https://doi.org/10.5194/egusphere-egu26-16219, 2026.
Plant root exudates dynamically shape rhizosphere microbiomes, yet how they drive the succession of active microbial communities across development remains unclear. Through a novel integration of quantitative stable isotope probing (qSIP), metagenomics and metabolomics, we established a direct link between dynamic root exudate profiles and the succession of active rhizosphere microbiota in watermelon rhizosphere. The results showed that microbial activity in the rhizosphere increased progressively from the seedling to the flowering stage. The microbial codon usage bias increased, with genomes becoming progressively streamlined, suggesting rhizosphere selection toward a microbial community with enhanced growth potential but lower functional redundancy. From seedling to flowering, the metabolic network of rhizosphere microbes utilising root exudates became simpler. Dominant active taxa provided persistent core functions for the plant (e.g., root development and pathogen suppression), and specifically produced siderophores during flowering, thus stabilising rhizosphere ecosystem functioning. Overall, these results reveal how plants orchestrate microbial succession through exudate chemistry, optimising rhizosphere function across development.
How to cite: Zhang, H., Xu, Q., Ruan, Y., Huang, Q., Guo, S., Kuzyakov, Y., Shen, Q., and Ling, N.: Active microbiome succession in the rhizosphere of growing plants, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6480, https://doi.org/10.5194/egusphere-egu26-6480, 2026.
Conservation tillage is a pivotal agricultural strategy for climate change mitigation, primarily credited for enhancing soil organic carbon (SOC) sequestration. However, a comprehensive understanding of its effects on the underlying biological drivers, i.e., the soil microbial community and its metabolic functions, remains fragmented at the global scale. We synthesized global evidence on the effects of conservation tillage on soil microbial community structure, enzyme activities, and metabolic indicators (CUE, Q10, qCO₂, MQ, and CUE). Conservation tillage significantly increases microbial biomass and activities of carbon-, nitrogen-, and phosphorus-acquiring enzymes. Across studies, microbial CUE and MQ increase while qCO₂ decreases, indicating enhanced microbial growth efficiency and reduced carbon loss through respiration. Conservation tillage also moderates the temperature sensitivity of soil respiration, suggesting improved stability of soil carbon under climate warming. These effects are context-dependent and regulated by climate, soil properties, and management duration. Our synthesis demonstrates that conservation tillage promotes a microbial metabolic strategy favoring soil carbon retention and provides a mechanistic basis for evaluating management-induced changes in soil carbon sequestration potential.
How to cite: Huang, Y., Huo, M., Han, Z., Wang, J., Liu, S., and Zou, J.: Global patterns of microbial metabolic regulation under conservation tillage and implications for soil carbon cycling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17619, https://doi.org/10.5194/egusphere-egu26-17619, 2026.
Soil degradation in agricultural systems is a major environmental and production challenge in European agriculture, requiring both technical innovations and participatory approaches that support real-world adoption and lasting impact (Bouma, 2014; Montanarella et al., 2016). The MultiSoil (Horizon Europe, Mission “A Soil Deal for Europe,” G.A. 101218951; https://www.multisoil.eu/) employs a multi-actor approach and a co-creation framework to develop, test, and demonstrate agricultural practices that enhance soil functional biodiversity and crop health (Leclère et al., 2023).
This contribution outlines the MultiSoil project's stakeholder engagement and co-creation strategy, highlighting the role of digital marketing tools in enhancing participation and interaction. Integrating face-to-face participatory activities—such as farmer-led workshops and round-table discussions—with targeted digital outreach can improve inclusiveness, accessibility, and continuity of engagement in sustainability-oriented research (Reed et al., 2018; Ingram et al., 2020).
We describe activities conducted by the Institute of Natural Resources and Agrobiology of Seville (IRNAS-CSIC) in Mediterranean agricultural systems, in which soil management practices, including organic amendments, biochar application, cover crops, and biodiversity-based management, are being implemented. These actions are supported by digital dissemination campaigns, tailored communication materials, perception surveys, and participatory dynamics shared through professional networks and sector-specific digital channels. This combined approach has increased both the number and diversity of participating stakeholders—particularly farmers—enhancing the representativeness of the co-creation process (Eitzinger et al., 2019).
Digital marketing tools are not used as one-way dissemination channels but as active co-creation instruments that support trust-building, mutual learning, and the emergence of communities of practice focused on soil health (Wenger-Trayner & Wenger-Trayner, 2020). The observed increase in stakeholder participation enhances the quality of social feedback, strengthens ownership of proposed practices, and improves the potential for scaling and replication.
Overall, this work demonstrates how integrating digital engagement tools can reinforce Living Lab and multi-actor approaches in soil science, helping bridge the gap between research and society and supporting the transition towards more resilient and sustainable agricultural systems (European Commission, 2021).
Acknowledgements
MultiSoil project (Multifunctional Soil Biodiversity: Unlocking Potential for Healthy Cropping Systems), EU Horizon Europe programme (GA No. 101218951). The local stakeholders involved in the co-creation activities are also acknowledged.
References
Bouma, J. (2014). J Plant Nutr Soil Sci. 177: 111–120.
Eitzinger, A., et al. (2019). Comput. Electron. Agric, 158: 109–121.
European Commission. (2021). EU Mission: A Soil Deal for Europe – Implementation Plan.
Ingram, J., et al. (2020). J. Rural Stud. 78: 65–77.
Leclère, M., et al. (2023). Agron. Sustain. Dev. 43: 13.
Montanarella, L., et al. (2016). The world’s soils are under threat. SOIL, 2: 79–82.
Reed, M. S., et al. (2018). A theory of participation: What makes stakeholder and public engagement in environmental management work? Restor. Ecol. 26: S7–S17.
How to cite: González-Pérez, J. A., González-Peñaloza, F., Cuella-Guerra, D., García-Ruíz, O., de la Rosa, J. M., and Team, T. M.: Co-creation of soil health solutions through digital marketing tools: enhancing stakeholder engagement in the MultiSoil project, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12434, https://doi.org/10.5194/egusphere-egu26-12434, 2026.
Posters virtual: Thu, 7 May, 14:00–18:00 | vPoster spot 1a
EGU26-9411 | Posters virtual | VPS15
Soil microbiome state in militarily impacted soils of UkraineThu, 07 May, 14:18–14:21 (CEST) vPoster spot 1a
Military operations in Ukraine are causing significant changes to the environment, with soil being one of the most vulnerable components. Explosions, the utilisation of heavy machinery, and the pollution emanating from military facilities are collectively responsible for the deterioration of the soil physical properties. This results in a reduction of soil fertility and an alteration in the soil microbiome composition. Microorganisms play a pivotal role in biogeochemical processes that affect soil quality, its regenerative capacity, and the stability of agroecosystems. The rehabilitation and restoration of ecosystems, including soils, in the aftermath of armed conflict is crucial to ensure food security and strongly depends on the soil conditions. Therefore, comprehensive study to investigate the consequences of military interventions on the microorganisms, as well as physico-chemical characteristics of soils, and their consequent influence on the ecological conditions are necessary.
We collected soil samples from a militarily disturbed area in the vicinity of the village Moshchun in the Kyiv region in May 2025. The site presents a crater left by an aerial bomb explosion in the spring of 2022. The agrochemical parameters were determined according to the standard protocols. For microbiological analysis, soil suspension was plated onto selective nutrient media. The directional coefficients microbiological processes in soil (i.e., mineralisation-immobilisation coefficients, oligotrophy, pedotrophy) were calculated according to SSU 3750-98, and microbial transformation of soil organic matter – according to Mukha V.D.
The agrochemical parameters of the soil sampled in the crater and in the area directly adjacent to it indicates degradation of the soil organic matter and a decrease in nitrogen availability. These changes indicate the areas of significant thermal and mechanical destruction. An increase in mineral nitrogen in the centre of the approximately 6 m deep crater may reflect the exposure of inorganic nitrogen from deeper parent material layers. We also observed a decrease in the contents of mobile phosphorus and potassium, as well as soil organic matter (or humus) content. These findings confirm the negative impact of the explosion on soil fertility indicators.
Samples collected from the crater and adjacent undisturbed areas exhibited pronounced shifts in the abundance of different microbial groups. In the immediate vicinity of the explosion epicentre, the abundance of oligotrophs and pedotrophs increased, whereas populations of ammonifiers, phosphate mobilisers and cellulose decomposers decreased. Directionality coefficients of microbiological processes indicate a general shift toward predominance, of mineralisation processes withn the explosion-affected zones, resulting in the loss of organic carbon and a negative humus balance. The elevated proportion of oligotrophic and pedotrophic microorganisms in the crater centre suggest depletion of readily available nutrients for the microbiota, accompanied by active uptake of mobile nutrients from deeper soil or parent materials.
We acknowledge the Ministry of Education and Science of Ukraine for the financial support of this research (Projects 0124U001049 and 0124U000960).
How to cite: Illienko, V., Salnikova, A., Bondar, V., Lazarev, M., and Klepko, A.: Soil microbiome state in militarily impacted soils of Ukraine, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9411, https://doi.org/10.5194/egusphere-egu26-9411, 2026.
EGU26-1236 | ECS | Posters virtual | VPS15
Soil quality responses to extensive grazing use in subalpine pastures across the Pyrenees.Thu, 07 May, 14:21–14:24 (CEST) vPoster spot 1a
Subalpine pastures in the Pyrenees are part of a long-standing cultural landscape shaped by centuries of extensive free-range grazing and transhumance. Like other European mountain regions, these grasslands are biodiversity-rich socio-ecological systems whose persistence depends on continuous management. Their ecological and cultural value is increasingly threatened by land abandonment, shrub encroachment, and climate warming, which reduce forage quality, alter soil processes, and compromise ecosystem resilience. Understanding how grazing influences soil functioning is therefore essential for sustainable pastoral management. We tested the hypothesis that, within low-stocking extensive systems, areas with moderately higher grazing exhibit enhanced soil quality relative to lightly used areas through effects on vegetation, nutrient inputs, and biogeochemical functioning, while remaining within low-intensity stocking levels.
We assessed soil quality under two relative grazing uses, Higher grazing use (HG) and Lower grazing use (LG), in extensive free-range systems with very low absolute stocking densities. At the Spanish site, the grazing unit comprises ~8,000 ha used by a free-ranging herd of 30 cattle (~0.04 LU·ha⁻¹). GPS tracking of five collared cows revealed strong contrasts in site use: 3,496 minutes in HG areas versus 298 minutes in LG areas during July–September. Parcels were classified based on vegetation structure and field indicators of bovine activity. At each site (Spain, Andorra, France), two areas (HG, LG) were sampled, each with four replicated subplots. Soil cores were collected at 0–6 cm (bulk density, mesofauna) and 0–20 cm (physical, chemical, biological properties), and aboveground biomass was harvested in 40×40 cm quadrats.
Soil Quality Index (SQI) values were calculated using the Minimum Data Set approach (Andrews et al., 2002), normalized on a 0.1–1 scale. Mesofauna was incorporated through the Ecological–Morphological Index (Menta et al., 2018).
The highest-weighted SQI indicators were electrical conductivity (0.560), total glomalin (0.197), pH (0.197), cation exchange capacity (0.197), water saturation content (0.170), coarse fragments (0.170), Olsen-P (0.073), porosity (0.073), bulk density (0.073), and clay (0.073). SQI showed consistent regional patterns, with higher values in HG areas: Spain 0.780 ± 0.005 vs. 0.727 ± 0.017; France 0.624 ± 0.027 vs. 0.606 ± 0.008; Andorra 0.714 ± 0.034 vs. 0.692 ± 0.024.
Several high-weight indicators showed grazing-related changes. Aggregate stability increased under higher grazing in Andorra but decreased in France and Spain. Total glomalin was identical between HG and LG in Andorra and France, but lower under LG in Spain. Cation exchange capacity and pH were consistently higher in HG. Electrical conductivity remained slightly higher in HG, especially in Spain. Coarse fragments varied by site, but their contribution was moderate relative to conductivity and cation exchange capacity.
Overall, moderately higher grazing helps maintain soil structural stability, supports fungal contributions to soil carbon, preserves cation-exchange capacity and pH, and sustains electrical conductivity within functional ranges. Together, these processes enhance soil quality in extensive free-range systems. Our findings highlight intermediate grazing as a key driver of soil functioning and ecosystem resilience in subalpine Pyrenean pastures, emphasizing the integration of soil indicators, biological communities, and grazing patterns for sustainable management of high-mountain rangelands.
How to cite: Quintana, S., Martí, C., Badía, D., and Santolaria, P.: Soil quality responses to extensive grazing use in subalpine pastures across the Pyrenees., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1236, https://doi.org/10.5194/egusphere-egu26-1236, 2026.
EGU26-21989 | ECS | Posters virtual | VPS15
Biological indicators of soil health under soybean cultivation as affected by mycorrhizal application and seed treatment in typical chernozemThu, 07 May, 14:24–14:27 (CEST) vPoster spot 1a
Introduction
Soybean has a strong impact on soil biological processes by interacting with microorganisms. Using arbuscular mycorrhizal fungi (AMF) and bacterial inoculants improves nutrient uptake and soil biological activity. However, the combined effects of these treatments with chemical seed treatment on soil health indicators in chernozem soils under intensive farming have not been studied enough.
Materials and Methods
The research was carried out on typical chernozem after maize for silage and soybeans. All variants of the experiment were created under uniform mineral fertilization (N₆₀P₆₀K₆₀).
The experimental design included the following treatments:
- Control – mineral fertilization only, without seed treatment, arbuscular mycorrhizal fungi, or inoculation;
- Chemical seed treatment – mineral fertilization with seed treatment (Maxim XL, 1.0 l/t);
- Mycorrhizal treatment – MycoApply (4.0 g/ha) combined with seed treatment (Maxim XL, 1.0 l/t) under mineral fertilization;
- Combined biological treatment – MycoApply (4.0 g/ha) + HiStick inoculant (400 g/ha) with seed treatment (Maxim XL, 1.0 l/t) under mineral fertilization
The number of microorganisms capable of ammonification, amylolysis, oligotrophy, pedotrophy, phosphate mobilization, and actinomycetes was assessed. The functional indices of soil health were evaluated using the coefficients of mineralization-immobilization, organic matter transformation, oligotrophy, and pedotrophy.
Results and Discussion
The control samples showed fairly high soil biological activity, which suggested a substantial presence of ammonifying microorganisms. The presence of numerous oligotrophic and pedotrophic microorganisms suggests the stable organic matter pools were frequently used. The limited quantity of actinomycetes present suggests a reduced rate of humification and carbon stabilization.
The application of Maxim XL led to a broader decrease in microbial populations, especially affecting oligotrophic and pedotrophic microorganisms. Lower values for the coefficient of organic matter changes suggest a dampening of microbial actions involved in breaking down organic residues.
Integrating MycoApply with a chemical seed treatment helped recover some microbial populations and improved functional measures when contrasted with seeds that only received the chemical treatment. More phosphate-mobilizing microorganisms showed up, meaning there was more phosphorus available.
The biological treatment, which included MycoApply with HiStick and Maxim XL, showed the best microbial response, as compared to other treatments. The presence of mycorrhizal fungi and bacterial inoculant lessened some of the negative aspects associated with chemical seed treatment. We found that microbial numbers and activity were greater than with just the chemical treatment by itself. Even though the microbial levels did not quite get back to where they started, this treatment did make the microbial community more resilient and stable when a lot of fertilizer was used.
Conclusions
In a common chernozem soil, various seed treatments for soybean farming caused noticeably different reactions in the biological markers for soil health. The application of chemical seed treatments independently led to a reduction in both microbial activity and the processes involved in organic matter transformation. In contrast, applying arbuscular mycorrhizal fungi, especially when paired with bacterial inoculation, somewhat lessened these problems and contributed to more even soil microbial activity. The findings indicate that biological methods can sustain soil health and ecosystem functions in soybean-based agroecosystems under conditions of global change.
How to cite: Pravylov, V.: Biological indicators of soil health under soybean cultivation as affected by mycorrhizal application and seed treatment in typical chernozem, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21989, https://doi.org/10.5194/egusphere-egu26-21989, 2026.
