Soil Health is defined as the capacity of a soil to function within ecosystem and land-use boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health (FAO, 2015). This soil functionality is mainly defined by processes and fluxes – the dynamic parameters, and not on their total amounts. Most studies, however, use pools of nutrients or static properties, which are hardly to connect with functions.
The main aims of this presentation is to raise the difference between commonly used pools (not reflecting the soil health) and fluxes – defining the soil health, but measured very seldom. Further, the question of the scale size by evaluation of soil health will be discussed.
Numerous soil quality indices (SQI) have been suggested to evaluate specific groups of soil functions, but the comparison of such SQI is impossible because they are based on a combination of properties specific for each soil. To avoid this problem, we suggest an SQI-area approach based on comparison of the areas on a radar diagram of a combination of chemical, biological and physical properties. The new approach is independent of the SQI principle and allows simple comparison of parameter groups and soils of various degradation or recovery stages.
Another approach analyzing the resistance and sensitivity of properties to degradation is suggested to evaluate soil health. The resistance and sensitivity of soil properties are determined through comparison with the decrease of soil organic carbon (SOC) as a universal parameter responsible for many functions. The SQI-area and resistance/sensitivity approaches were tested based on the degradation of Alisols and on recovery of Phaeozems and Chernozems chronosequences after the abandonment of cropland soils. Both the SQI-area and the resistance/sensitivity approaches provide very good visualistion of the results, are useful for basic and applied research, and help decisionmakers to evaluate land-use practices and measure the degree of soil degradation.
References
Guillaume T, Maranguit D, Murtilaksono K, Kuzyakov Y. 2016. Sensitivity and resistance of soil fertility indicators to land-use changes: New concept and examples from conversion of Indonesian rainforest to plantations. Ecological Indicators 67, 49-57.
Kuzyakov Y, Gunina A, Zamanian K, Tian J, Luo Y, Xu X, Yudina A, Aponte H, Alharbi H, Ovsepyan L, Kurganova L, Ge T, Guillaume T. 2020. New approaches for evaluation of soil health, sensitivity and resistance to degradation. Frontiers of Agricultural Science and Engineering 7 (3), 282-288.
How to cite: Kuzyakov, Y.: Soil health: Critical evaluation and approaches, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4581, https://doi.org/10.5194/egusphere-egu25-4581, 2025.
Soil biological health plays a central role in sustainable agriculture, driving critical processes such as nutrient cycling, organic matter formation, water infiltration, and plant disease suppression. Yet, much like human health research – where multifaceted interactions of genetics, lifestyle, and environment make single-factor experiments insufficient – understanding what drives soil biological health requires us to look beyond controlled settings and embrace the complexity of real-world conditions.
In this presentation, I will illustrate how observational studies in agricultural landscapes provide valuable insights into the interplay of management practices, soil organisms, and ecosystem functions. By examining diverse farms across varying climates, soil types, and management intensities, we can better discern which practices bolster soil communities and thereby strengthen ecosystem functioning. Although inherent variability and confounding factors pose challenges, these very complications underscore the need for carefully designed observational work – balancing representativity versus extremes, documenting potential biases, and using robust analytical frameworks to handle complexity.
Drawing on results from recent studies that highlight how different on-farm practices influence soil communities and functioning 1–4, I will also discuss statistical methods for interpreting observational data in these intricate settings. Concluding with a brief outlook, I will touch on how management indicators, guiding principles of sustainable crop management, and soil biological and functional metrics can further advance our understanding of soil biological health – ultimately guiding more resilient and sustainable agricultural systems.
(1) Garland, G. et al. Crop cover is more important than rotational diversity for soil multifunctionality and cereal yields in European cropping systems. Nat Food 2, (2021).
(2) Edlinger, A. et al. Agricultural management and pesticide use reduce the functioning of beneficial plant symbionts. Nat Ecol Evol 6, (2022).
(3) Edlinger, A. et al. The impact of agricultural management on soil aggregation and carbon storage is regulated by climatic thresholds across a 3000 km European gradient. Glob Chang Biol 29, (2023).
(4) Edlinger, A. & Herzog, C. et al. Compost Application Enhances Soil Health and Maintains Crop Yield: Insights From 56 Farmer‐Managed Arable Fields. Journal of Sustainable Agriculture and Environment 4, (2025).
How to cite: Edlinger, A.: Embracing complexity: Observational insights into soil biological health and sustainable agriculture, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19227, https://doi.org/10.5194/egusphere-egu25-19227, 2025.
Healthy soils are essential in achieving climate neutrality, reversing biodiversity loss, providing nutritious food, and safeguarding human health. Despite decades of soil research, soil remains a highly threatened non-renewable resource, with an estimated 62% of EU soils already degraded. This is attributed to the complexity of soil as a material and ecosystem, the diversity of soil types and land uses and to a large extent, the global focus on soil as an agricultural resource rather than as an essential part of environmental protection. The EPA funded project Microbial and Metabolite-based indicators for Soil Health (MMeSH) aims to address the need for biological soil health indicators and environmental protection of soils by using a combined lipidomics, metabolomics, and genomics approach. Advanced mass spectrometry- and nuclear magnetic resonance-based techniques will be used to profile the soil lipidomes from soil organisms. Soils (n=219) were sampled from September 2023 to April 2024 from existing Geological Survey Ireland (GSI) Tellus sites. Sample sites represented key land uses and soil types in Ireland: 51% corresponded to pastures, 13% to agricultural land with natural vegetation, and 12% to peat bogs (based on CORINE Land Cover categories). Peat soils (21%) were the major soil type, followed by luvisols (18%), brown Earths (17%) and surface-water gleys (12%) (based on the Irish Soil Information System database). Lipid extraction and analysis by both gas and liquid chromatography mass spectrometry is ongoing. Phospholipid fatty acids as well as intact polar lipids will be used to identify taxonomic and phenotype changes within the soil microbiome. This coupled with untargeted metabolomics and the identification of other secondary metabolites will aid in the understanding and the development of novel soil health indicators for each unique soil system.
How to cite: Bartley, M., Buttimer, H., Mupamhadzi, T. L., Jordan, S. F., Kelleher, B., Moffat, A., Schmidt, O., and O'Reilly, S.: Developing novel soil health indicators using lipidomic and metabolomic analyses across key land use types , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19446, https://doi.org/10.5194/egusphere-egu25-19446, 2025.
Soil Health BENCHMARKS, a Horizon Europe-funded initiative, seeks to establish a transparent, harmonized, and cost-effective framework for assessing soil health across Europe. This project leverages 29 European landscape case studies to co-develop a monitoring system that operates at multiple scales and engages diverse users. Collaborating with stakeholders such as land managers, policymakers, legislators, value chain businesses, and NGOs, BENCHMARKS aims to design a system tailored to specific assessment objectives, adaptable to diverse land uses, and practical for implementation.
Key deliverables include a harmonized monitoring framework, an evaluation of soil health indicators proposed by the EU Soil Mission and BENCHMARKS, an integrated soil health assessment tool, and scientific foundations for incentivization schemes targeting value-chain stakeholders. This presentation will highlight the project's monitoring approaches and provide an overview of preliminary findings, with a focus on how these efforts can contribute to soil health monitoring strategies across Europe.
How to cite: Di Lonardo, P.: Soil Health BENCHMARKS: Monitoring approaches for evaluating soil health through indicator measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1834, https://doi.org/10.5194/egusphere-egu25-1834, 2025.
Mining operations are critical to economic growth by supplying essential building materials and minerals. However, they significantly impact ecological systems, particularly in arid regions where soil recovery is slow. Biological soil crusts (biocrusts) and their functional importance and vulnerability are crucial for restoring disturbed arid soils. Biocrusts enhance soil health by improving stability, increasing water retention, and reducing erosion. Consequently, biocrust abundance and development provide a valuable indication of soil rehabilitation and mining restoration success in arid environments. This study aims to evaluate the restoration success of phosphate mining in hyper-arid quarried lands by assessing biocrust development and spatial distribution over time across different restoration stages. The research focuses on the Zin phosphate mines in the Negev Desert, southeastern Israel, which have been operational since 1970. Since 2007, a new ecological restoration method using topsoil application has been implemented in the area. We employed imaging spectroscopy (IS) within the visible, near-infrared, and shortwave infrared regions (VIS-NIR-SWIR, 400–2500 nm) to identify biocrusts, create a biocrust-specific index, and link these findings to soil properties indicative of restoration success. Restored plots of varying ages were compared to adjacent natural plots (as a reference). A partial least-squares regression (PLS-R) model was utilized to predict the spatial distribution of key soil indicators from IS, including soil organic matter, polysaccharides, and proteins, and to identify ecologically oriented biocrust development. Moreover, several spectral indices for biocrust identification were examined, where the brightness index (BI) proved effective in distinguishing restored plots from natural plots, showing significant differences (P<0.01). A novel Biocrust Cellulose Absorption Index (BCAI) was developed using the shortwave infrared region, optimally identified biocrust abundance, and displayed significant differences between natural and restored plots (P<0.01). Natural plots exhibited significantly higher polysaccharide content than restored plots (P<0.01). A triangular model incorporating three indicators - polysaccharide content, BI, and BCAI - was further developed to evaluate restoration success. This model assessed biocrust abundance and development, mapping the spatial distribution of biocrusts as a function of time across various restoration stages. The findings demonstrate the utility of IS and novel indices in assessing biocrust abundance and restoration success. This approach provides insights into restoration dynamics and offers a framework for improving restoration strategies in hyper-arid mining as well as other degraded environments.
Keywords: Phosphate Mines, Biological Soil Crusts, Imaging Spectroscopy, Spectral Indices, Partial Least Square Regression.
How to cite: Collier, T., Ziv, Y., and Paz-Kagan, T.: Biocrust Abundance and Development Determine Soil Restoration Success of Hyper-Arid Phosphate Mines Using Imaging Spectroscopy, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2450, https://doi.org/10.5194/egusphere-egu25-2450, 2025.
Ecological Enzyme Stoichiometry Reveals Seasonal and Treatment-Induced Constraints on C, N, and P Dynamics in Olive Orchard Soils
Olive orchards in semi-arid Mediterranean regions face critical challenges including soil degradation, drought, and erosion, threatening their long-term sustainability. Seasonal monitoring can provide critical insights into soil health dynamics and assess the effect of nature-based solutions (NBSs) on seasonal soil functioning. Extracellular enzymes are the primary drivers of soil organic matter breakdown and assessing their activity and ecological stoichiometry can serve as an indicator of microbial nutrient demand and status. The primary goal of this study was to assess the nutrient status of the soil microbial biomass in olive orchards as affected by non-tillage (NT), the addition of pruning residues (PR), the combination of pruning residues and legumes (PL), the addition of pruning residues with no-tillage (PNT), and biochar (BI) relative to conventional tillage (TI). For this, we measured microbial C, N, and P acquisition through activities of key extracellular enzymes, 1,4-b-glucosidase (BG), 1,4-ß-N-acetylglucosaminidase (NAG), and acid/alkaline phosphatases (AP) in olive orchards. Soil samples were taken in four comparable olive orchards in Crete, Greece, over six seasons (autumn 2022 to spring 2024). The proportional activity of C vs. N acquiring enzymes (BG/ [BG + NAG]) was analyzed relative to C and P acquiring enzyme activity (BG/[BG + AP]). We then calculated the vector length (quantifying the relative C vs. nutrient limitation) and angle (quantifying the relative P vs. N limitation).
Our preliminary analyses reveal significant seasonal and treatment-specific variations in microbial nutrient status and cycling. During Autumn 2022 and Winter 2023, a strong positive correlation between the C:N ratio and vector length indicates that microbes prioritize C-mineralizing enzymes (BG), likely due to slower decomposition rates and limited organic C availability under cooler conditions. This supports the idea that microbial communities focus on C acquisition under C-limiting conditions during the off-season. In Spring 2023, the highest BG/(BG+AP) ratios were observed indicating a shift toward P acquisition, likely driven by increased plant P demand during active plant and microbial growth. BI-treated soils showed higher BG/(BG+NAG) and BG/(BG+AP) ratios, lower AP activity (compared to TI), and larger vector angles, indicating increased P acquisition, and suggesting that biochar alleviates P limitation, especially in spring. Increased BG/(BG+AP) ratios in the presence of legumes (PL), particularly in spring, suggest that organic N from legumes helped the microbes to prioritize P during plant growth peaks. Larger vector angles in spring further indicated that PL enhanced microbial P acquisition during high-demand periods.
Seasonal shifts in microbial nutrient stoichiometry (biomass C:N:P), shifting enzyme activities, and changes in soil chemistry illustrate that nature-based solution (NBS) treatments such as BI and RP can alleviate microbial nutrient constraints and promote balanced nutrient cycling, thus providing viable tools for restoration of degraded orchard soils.
Keywords: Ecological stoichiometry, soil enzyme activity, soil organic matter, b-1,4-glucosidase, b-1,4-N-acetylglucosaminidase, phosphatase.
How to cite: Tul, S., Frantzeskou, M., and Paranychianakis, N.: Ecological Enzyme Stoichiometry Reveals Seasonal and Treatment-Induced Constraints on C, N, and P Dynamics in Olive Orchard Soils, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-854, https://doi.org/10.5194/egusphere-egu25-854, 2025.
A critical asset of healthy soils is a rich and functionally diverse microbiota, yet many agricultural practices - including frequent pesticide use and insufficient organic amendments - risk compromising this biological foundation. In this contribution, we present results from two complementary studies conducted on more than 100 farms in Switzerland to investigate how pesticide application and compost use affect the diversity, composition and structure of soil microbial communities. Using a combination of molecular analyses (16S/ITS rRNA amplicon sequencing, quantitative PCR of functional genes), soil physicochemical properties and indicators for soil functions, we found that pesticide residues are associated with shifts in microbial community composition and, in some cases, reduced bacterial diversity. Conversely, farms that regularly apply compost show increased fungal richness and more complex microbial networks than reference farms. By linking these changes in microbial community traits to soil functional indicators - such as soil respiration and aggregate stability - we could shed light on the interrelationships of soil biodiversity, physicochemical properties, and soil functions, as well as the influence of agricultural management.
How to cite: Walder, F. and van der Heijden, M.: From pesticides to compost: How agricultural management practices shape soil microbial communities and soil functions across Swiss farms, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11594, https://doi.org/10.5194/egusphere-egu25-11594, 2025.
Earthworms play a vital role in soil agroecosystems, representing a major part of the total soil fauna. Through their activities they provide essential ecosystem services, including improving soil structure, increasing nutrient availability for plants and ultimately supporting plant growth and boosting crop production. In a nutshell, they make a major contribution to maintaining soil health. However, while earthworms are generally regarded positively in agricultural settings, they are also threatened, e.g. by intensifying land use, certain agricultural practices and climate change. A British study has already found that earthworm abundances have declined significantly in recent decades, suggesting that earthworms are indeed under pressure. In addition, different earthworm species play different roles in the soil and maintaining their diversity is key to promoting soil health. Here we present the results of a recent field study in which 400 sites in Austria were sampled for earthworms in order to investigate the total earthworm biodiversity in arable land, grassland and field margins. The goal was (i) to describe the current state of earthworm biodiversity on agricultural land in Austria, (ii) to determine the most important factors driving earthworm biodiversity, and (iii) to investigate the geographic distribution of earthworms in the country and whether this is linked with future threats and opportunities. Preliminary results suggest that about 30 different species inhabit these agriculturally used fields, representing around half of the known earthworm biodiversity in Austria. While earthworm communities differed little between land uses, higher intensity farming was associated with lower earthworm abundance and biodiversity. This is likely due to a combination of management factors and environmental conditions. Further research will provide a more detailed understanding of these effects and their interactions and allow us to take steps to promote earthworm biodiversity and thus soil health in the future.
How to cite: Mittmannsgruber, M., Monoshyn, D., Gruber, E., Wiedenegger, E., and Zaller, J. G.: From alpine pastures to cropland – initial results from a country-wide earthworm monitoring initiative in Austria , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8660, https://doi.org/10.5194/egusphere-egu25-8660, 2025.
Following the cessation of active hostilities in the Kyiv and Chernihiv regions in 2022, research was initiated to investigate the effects of military soil degradation. By 2024, approximately 150 hectares of agricultural land affected by active hostilities were identified and surveyed. These areas showed evidence of degradation due to aerial bombing, burning of military equipment, and artillery shelling.
Subsequently, a comprehensive series of laboratory tests were conducted on the collected soil samples to determine agrophysical and agrochemical parameters, as well as the presence of heavy metals and radionuclides. The results revealed that the density of 137Cs contamination in these areas ranged from 2.07 to 8.20 kBq/m², and for 90Sr – from 0.62 to 3.49 kBq/m², respectively. These values don`t fall within the limits established for radioactive contamination zones under the Law 'On the Legal Regime of the Territory Affected by Radioactive Contamination as a Result of the Chornobyl Disaster' (137Cs: higher 185 kBq/m², 90Sr: higher 5.55 kBq/m²). Based on the observed levels of radioactive soil contamination and the transfer coefficients to agricultural plants, as well as measurements conducted during the study (e.g., the 137Cs content in wheat grain was below 3 Bq/kg), it is not expected that permissible levels of 137Cs contamination for agricultural products will be exceeded.
The analysis of soil agrochemical parameters in the Chernihiv region revealed a slight increase in the pH levels of water and salt extracts at explosion sites (craters). This rise in pH may be attributed to the infiltration of pollutants into the soil or the surfacing of deeper soil layers with naturally higher pH values. The concentration of mobile phosphorus forms in soil samples collected from explosion sites and areas of burned military equipment was found to be lower than in the control samples, with a maximum decrease of up to 40%. In terms of trace element content, an increase in the concentrations of mobile Cu forms by up to sixfold, as well as a decrease by up to thirteenfold compared to the control (military-undisturbed areas), were recorded. Conversely, a decrease in the concentration of mobile Zn forms was noted, with a maximum reduction of up to eightfold relative to the control. For mobile Fe forms, a significant increase in concentration was detected in explosion areas, with levels rising up to fivefold higher than the control. This increase in trace element concentrations is preliminarily attributed to the disruption of the soil structure, the mixing of soil horizons, and the physical and chemical weathering of element compounds within the soil.
In certain locations, an increase in the concentration of mobile forms of heavy metals was recorded compared to undisturbed areas, particularly for Cd, Mn, Ni, Pb, Co, and Cr. Nevertheless, no exceedance of the maximum permissible concentrations of these chemical elements, as stipulated in the current regulatory documents in Ukraine, was detected in the studied soils. The samples taken from the Kyiv region are still at the measurement stage.
We acknowledge the Ministry of Education and Science of Ukraine for the financial support of this research (Project 0124U001049).
How to cite: Illienko, V., Salnikova, A., Klepko, A., and Lazarev, M.: Military soil degradation in the northern part of Ukraine, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8455, https://doi.org/10.5194/egusphere-egu25-8455, 2025.
Soil microbial basal respiration is a proposed biological indicator of soil health and a key parameter in studying microbial carbon cycling. It is commonly quantified in closed-chamber incubations by measuring the increase in CO2 concentration in the vial headspace over time compared to a known background. Assuming a linear CO2 increase solely caused by microbial activity, respiration rate estimates derived between 1 and 24 hours should compare, but differences have been observed previously.
To investigate how and why estimates of microbial respiration rate vary with incubation duration and amount of soil, gas samples were collected at 12 time points over a 24-hour period for ten soils covering two texture categories and a gradient of organic carbon content.
Microbial respiration rate was on average 3.4-fold higher after 1 hour than after 24 hours. The apparent decline in microbial respiration over time was related to a violation of the assumption that the sample CO2 concentration at the beginning of the incubation equals the assumed background in soil-free blanks. Follow-up experiments indicated that the dissolution of CO2 in the soil solution during the pre-incubation can cause an initial peak in emissions at the start of the incubation (i.e. CO2 artefact) through shifts in chemical equilibria caused by the method itself, which can be misinterpreted as high initial respiration rates.
Over time, the contribution of the method’s artefact decreases. Factors like soil moisture, amount of soil incubated, microbial activity rate, and chamber closure timing affect the artefact's magnitude. Optimising incubation duration and headspace-to-soil ratio (e.g. 24-hour incubation at 22 mL vial : 1 g soil) can mitigate the effect of the CO2 artefact and produce unbiased estimates of microbial respiration rates.
How to cite: Schroeder, J.: CO2 artefact can distort estimate of microbial basal respiration rate in closed chambers , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8038, https://doi.org/10.5194/egusphere-egu25-8038, 2025.
Introduction
Soil respiration is an important part of the carbon cycle and is a significant terrestrial carbon source. There is currently very limited research focused on characterising soil respiration in Singapore, and even among studies conducted in Southeast Asia, most of the research focuses on primary forests rather than urbanized soils. The objectives of this study were to assess the variation of soil respiration with land use, characterise the daily cycles of soil respiration and identify the factors which drive soil respiration in an urban catchment.
Methods
Soil Respiration was measured at 7 forests sites and 12 urban park sites in Singapore, using a portable Li Cor Soil Respiration Smart Chamber. Soil samples were also collected from each of the sites and their nutrient concentrations were quantified. Additionally, at one park and one forest, the daily cycle of soil respiration was measured from 7 am to 7pm, where half hourly measurements were taken, along with corresponding measurements of soil temperature and moisture.
Results & Discussion
When comparing soil respiration rates between parks and forests, we found that, on average, respiration rates in the forests were slightly higher than those in the parks (Forests – 3.62, Parks – 3.46 umol CO2.m-2s-1) (Fig 1), but the difference was not statistically significant (Wilcox test p value > 0.05).
Next, the daily variation of soil respiration was characterised and our results revealed that the magnitude of variation in soil respiration throughout the day was small (Forest: 2.34-2.52, Park: 3.80-4.26 umol CO2/m2.s) (Fig 2). This lack of variation can be explained by relatively minor changes in soil temperature and moisture. Soil temperatures in Singapore did not vary much throughout the day (Forest: 26.2 – 28.00C, Park: 27.1 – 30.30C), and as previous research shows, more significant changes in temperature are required to see significant changes in soil respiration.
Finally, in order to determine what factors affected soil respiration, the relationship between soil nutrients and soil respiration was assessed. Results revealed that only NO3- was strongly positively correlated with soil respiration and a linear regression analysis revealed that soil nitrate concentrations explained about 50% of the variation of soil respiration (Adjusted R2 = 0.503, p<0.05). Other nutrients like phosphate, ammonium and dissolved organic carbon has no significant relationship with soil respiration.
Fig 1: Variation of Soil Respiration by Land use
Fig 2: Daily cycle of Soil respiration in a park and forest
In terms of future work, we also plan on conducting soil respiration measurements on managed land use types like agriculture and golf courses. Additionally, we plan on further characterising temporal variations of soil respiration, including diurnal and seasonal variations, across land use types. Finally, we will collect additional data on soil parameters like total organic carbon, microbial populations and community diversity and use these to develop models for soil respiration as well.
Acknowledgements
This research grant is funded by the Singapore National Research Foundation under its Competitive Funding for Water Research (CWR) initiative and administered by PUB, Singapore’s National Water Agency.
How to cite: Senaratna, K. Y. K., Te, S. H., Fatichi, S., and Gin, K. Y.-H.: Characterising Soil Respiration rates across different land uses in a Tropical Urban Catchment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13880, https://doi.org/10.5194/egusphere-egu25-13880, 2025.
Recent climatic changes have increased the unpredictability of rainfall events with a heightened probability of droughts, thus influencing the belowground carbon sequestration. Soil structure is shaped by physical, chemical, and biological processes and their interactions. Droughts are linked to the loss of soil structural stability, reduced pore-water connectivity, and organic carbon transport, therefore affecting soil microbial activity. The protection of carbon within the soil matrix is majorly driven by its accessibility to microbial decomposers and is also determined by the abundance of soil pores of a specific size range. In this study, we investigated the effects of drought on soil pore characteristics like pore size distribution, porosity, distances to pores, and biochemical properties such as microbial biomass carbon, ergosterol content, and soil organic carbon. The study site was a Long-term Ecological Research experiment of a short grass steppe ecosystem with treatments of 66% rain exclusion (regarded as drought) and control plots in a randomized complete block design. Dominant plant species include C4 grasses, blue grama (Bouteloua gracilis), buffalo grass (Buchloe dactyloides), and C3 plains prickly pear cactus (Opuntia polyacantha). This study aims to understand the importance of soil structure in interaction with organic matter and microbial activity. Intact soil cores of 5 cm in height by 5 cm in diameter were collected from 5-10 cm of soil depth to derive the soil pore characteristics using the X-ray computed microtomography technique (X-ray µCT, resolution of 18 µm). Bulk and intact soil samples were collected during the fifth year of the treatments in place.
The results demonstrated that drought differentially affected pores of different size ranges, substantially increasing volumes of > 60 µm diameter pores, and decreasing the volumes of 36-60 µm pores, while not affecting <18 µm pores. Drought decreased total volume, number of fragments, and fragment size of soil POM, and markedly decreased microbial biomass, and enzyme activities. Furthermore, the bulk soil samples were analyzed for base chemical properties such as pH, cation exchange capacity, available phosphorus, exchangeable potassium, magnesium, and calcium We surmise that a 5-year drought in SGS prairie soils, despite increasing the volume of medium-sized pores and pore connectivity, the lower microbial quotient (qMic), along with higher metabolic quotient (qCO2) contributes to greater loss of C as CO2 and slower C accumulation in the soil.
How to cite: Thotakuri, G., Dor, M., Guber, A., Kravchenko, A., and Smith, M.: Long-term drought alters pore structure and biochemical characteristics in soils of short-grass steppe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4470, https://doi.org/10.5194/egusphere-egu25-4470, 2025.
Agricultural soils contribute as major polluters of nitrous oxide (N2O) emissions in Europe, which are a result of microbial nitrification and denitrification processes. Nitrification inhibitors (NI) have gained attention by decreasing N2O emissions and nitrate leaching, thereby promoting the uptake of nitrogen (N) by plants. However, concerns have been raised about the long-term efficiency of NI at the scale of microbial communities, for example if taxa develop resistance. This work hypothesises that target and non-target microbial taxa develop resistance to NIs over time after showing initial sensitivity to 3,4-Dimethylpyrazole phosphate (DMPP) application. More in depth, specific nitrifying organisms will be less resilient against DMPP in an agricultural field with a high clay/sand ratio. Lastly, different types of fertilizations interact differently with DMPP, creating a change in the response of Ammonia oxidizing bacteria and archaea gene abundance.
The study was conducted on agricultural fields located in Köningslutter, Lower Saxony (Silt loam) and Hohenhiem, Baden-Wuerttemberg (Silty clay loam). One of three distinct fertilizers was applied to each field, specifically ammonium sulphate nitrate, slurry or urea ammonium nitrate solution, in combination with or without DMPP. Samples were taken at four different time points over the growing season of winter wheat. Additional physicochemical parameters including N mineralisation rates, pH, carbon and N content, and respiration rates of CO2, N2O and CH4 were measured simultaneously. Microbial communities were analysed with qPCR targeting functional genes related to nitrification and denitrification (amoA and nosZ1/2, respectively). Amplicon sequencing of universal prokaryote taxonomic markers and amoA was performed to investigate the response of target and non-target taxa to DMPP addition over time. Statistical analyses are being conducted.
How to cite: Groven, A.-C., Wonneberger, A., Binder, I., Russer, R., Pacholski, A., Finn, D., and Tebbe, C.: The impact of the nitrification inhibitor DMPP on agricultural soil microbial communities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19893, https://doi.org/10.5194/egusphere-egu25-19893, 2025.
Conventional petroleum-based plastics are non-degradable materials that are difficult to degrade during disposal and landfill after use; therefore, they have an adverse environmental impact over a long period of time. An example is the problem of soil landfill of agricultural mulching films, which are discarded after agricultural activities. Plastic particles alter the physicochemical properties of the soil, resulting in reduced crop yields and disruption of nutrient cycling within the soil ecosystem, while also impacting groundwater contamination. Furthermore, they serve as carriers for organic pollutants such as heavy metals, pesticides, and herbicides, causing greater environmental contamination. To solve this problem, there has been a growing interest in bioplastics as alternatives to conventional fossil-based plastics, particularly in the agricultural field. In order to reduce the pollution load in the soil through the utilization of bioplastics, it is essential to thoroughly understand the microorganisms involved in biodegradation and their corresponding biodegradation characteristics within soil and compost environments. Therefore, in this study, microbial communities were characterized during the degradation of two bioplastics (Polylactic acid (PLA) and Polybutylene adipate terephthalate (PBAT)), under mesophilic (35℃) and thermophilic (58℃) composting conditions. PLA and PBAT films and granules were buried in chicken manure compost, and the biodegradability was assessed based on the weight loss over time. PLA film was degraded rapidly, by 41.5% in 5 days and by 91.15% in 10 days under thermophilic composting conditions, and completely degraded in 15 days. Under mesophilic composting conditions, PLA film showed a degradation rate of 17.9% in 20 days. To characterize microbial communities during the bioplastics degradation, compost samples near the bioplastics were collected, followed by DNA extraction. The 16S rRNA gene region was amplified using the 515F/806R primer set to investigate the bacterial community, as well as the ITS2 gene region using the ITS3/ITS4 primer set to analyze the fungal community. Subsequently, the sequences were analyzed using Illumina Miseq. The information obtained in this study can be used to secure promising bioresources to enhance bioplastics degradation.
How to cite: Cho, K.-S., Cho, I., and Kim, G.: Characterization of Microbial Communities during Bioplastics Degradation in Mesophilic and Thermophilic Composting Conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3918, https://doi.org/10.5194/egusphere-egu25-3918, 2025.
The use of biochemicals in agriculture has become crucial to meeting the global demand for food production. Agrochemicals, such as fertilizers and pesticides, are widely applied to enhance crop efficiency. Additionally, other chemicals like nitrification inhibitors offer the potential to mitigate the environmental impact caused by the excessive use of fertilizers. While their effects on targeted microbial taxa are known, their broader environmental risk to the entire microbial community remains poorly understood.
Considering the urgency of assessing these risks, extraction and deep sequencing of total RNA offers a powerful approach to unveil non-target effects without favoring specific taxa or introducing bias from dead or dormant biomass. By simultanously analysing rRNA and mRNA, it is possible to investigate negative effects not only on the activity of specific taxa but also on critical ecosystem functions providing the potential to discover previously unknown effects.
Here, we demonstrate how total RNA analysis can enhance our understanding of non-target effects of agrochemicals on microbial soil communities. In the GENEPEASE II project, the impact of the commercial fungicide Prosaro was examined using soil microcosms over a 6 months period. Besides the expected decline in fungal taxa, significant effects on the overall microbial community were observed, as indicated by shifts in the rRNA and the gene expression profiles (all ANOVAs p < 0.05). Ongoing in-depth analyses will identify individual taxa affected by the fungicide. By linking these taxa to their ecological roles in natural settings and identifying up- and downregulated genes, we aim to pinpoint ecosystem functions that are potentially affected by the use of the fungicide.
Moving forward, this method will be applied to a field trial investigating the non-target effects of nitrification inhibitors nitrapyrin and DMPP. Both compounds have the potential to reduce emissions of the greenhouse gas N2O. In this context, the analysis of mRNA provides an opportunity to investigate potential impacts on enzymes closely related to ammonia monooxygenase, the primary target of nitrification inhibition. Such effects could potentially impact greenhouse gas-regulating processes, such as methane oxidation, and therefore counteract the positive environmental benefits of nitrification inhibition.
Ultimately, refining this method for the presented experiments will help to develop a robust approach for utilizing total RNA in various agrochemical applications. Thus, total RNA analysis can serve as a crucial tool for incorporating microbial community data into environmental risk assessments, therefore contributing to a more sustainable future in agriculture.
How to cite: Horstmann, L., Gözdereliler, E., Zervas, T., Donhauser, J., Nielsen, C. S., Kjøller, R., Ekelund, F., Priemé, A., Jacobsen, C. S., and Ellegaard-Jensen, L.: Environmental risk assessment at the microbial level: utilizing total RNA sequencing to evaluate the non-target impact of biochemicals in agriculture, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21642, https://doi.org/10.5194/egusphere-egu25-21642, 2025.
Soil organic carbon (SOC) is a key indicator of healthy soils. Among the sources contributing to the SOC pool, the role of microbial biomass and especially necromass is often overlooked. Microbial necromass sometimes reaches 40 times of the microbial biomass, emphasizing the role of soil microorganisms in carbon sequestration. However, overall, determining necromass in soils is not common. In this study, we aimed to examine (i) the microbial biomass and necromass in agriculturally used soils across Austria, Central Europe, and (ii) the effect of environmental factors and soil parameters on biomass-necromass contributions in arable and grassland ecosystems.
We sampled soils (soil corer with 2.5 cm diameter and 10 cm depth, 3 samples per site) from 400 sites across Austria, from 150 m a.s.l. up to 2500 m a.s.l. including croplands, grasslands, and grass strips. The cooled samples were analysed for microbial biomass using Chloroform Fumigation Extraction (CFE) and for microbial necromass using amino sugars extraction. Moreover, composite soil samples (2.5 cm diameter, 10 cm depth; 3 samples per site) were used to determine pH (CaCl2), SOC, texture, potassium, phosphorus, nitrogen, humus content. The climate data (mean annual air temperature and annual precipitation) was obtained from Geosphere Austria, the Austrian Federal Agency for Geology, Geophysics, Climatology and Meteorology, Vienna. Soil management data was obtained through questionnaires directly from the land owners or operators. Data were statistically analysed using CatBoost models.
Average microbial carbon (MC) across sites was 401 ± 256 mg g-1 and microbial nitrogen (MN) 65.0 ± 48.9 mg g-1. Both MC and MN significantly increased in the order croplands < grass strips < grasslands (HSD, p<0.001). Preliminary analyses showed specific effects of soil and environmental parameters on the proportion of microbial biomass and necromass in the soils.
Our results indicate that land use significantly impacts microbial biomass distribution, potentially affecting nutrient cycling and soil health. Understanding these dynamics could inform land management practices aimed at improving soil fertility and mitigating climate change through enhanced carbon sequestration.
How to cite: Monoshyn, D., Mittmannsgruber, M., Wiedenegger, E., Gruber, E., Murugan, R., Inselsbacher, E., and Zaller, J. G.: Microbial Biomass and Necromass in Austrian Soils, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3553, https://doi.org/10.5194/egusphere-egu25-3553, 2025.
Ukraine is prosperous in agricultural activities. Agricultural land covers 68.5% of the total land area. Additionally, Ukraine exports around 10% of the global cereals abroad and thus plays an important role in global food security. Crop production in Ukraine is dominated by grains (wheat, barley, corn), technical crops (sunflowers, sugar beets), potatoes1. Livestock production is dominated by poultry, pigs, cows1. However, agricultural activities have been under threat over the past two decades. An important reason is climate change. Climate drivers such as temperature and precipitation have changed their patterns in space and time in Ukraine since 2000. The implications of those changes on agriculture are poorly studied, namely on crop yield, synthetic fertilizers, and animal manure. Furthermore, the potential implications of agriculture and climate on future water scarcity are unknown considering the ongoing Russian-Ukrainian war.
In this study, we aim to assess the relationship between climate drivers and agriculture in Ukraine over the past two decades (2000-2020) and discuss the potential implications of these drivers on future water scarcity considering the Russian-Ukrainian war as an additional (unexpected) threat. We do this in a spatially explicit way. We collect the following data for agriculture: crop yield, crop area, fertilizers, irrigation2. Data for climate drivers include air temperature and precipitation3. For agriculture, data is based on one-year time steps, and data for climate drivers is seasonal every year between 2000 and 2020. We map the data for 24 provinces in Ukraine. We also show the historical changes over the studied period. From a historical perspective, we identify the main relationship between the climate drivers and agricultural aspects by province in Ukraine. We take these insights and discuss how water scarcity would change in the future if climate change and food production continue following the historical pattern, and consider the war as an additional threat. One of the results shows that water quantity is influenced by climate change; examples are droughts (less precipitation over time). Water quality is influenced by agricultural runoff and war activities; examples are too many nutrients from agriculture in rivers and too many emerging pollutants from destroyed treatment facilities.
Keywords: agriculture, climate parameters, water scarcity, drivers, implications
Acknowledgments: European Union HORIZON-MISS-2023-OCEAN-SOIL-01 Grant Agreement No. 101156867 (Path4Med).
1: European Parliamentary Research Service: Ukrainian agriculture, PE 760.432 – April 2024
2: The online platform AgroStats: Agricultural statistical data in Ukraine (1980-2023)
3: Climate Change Viewer platform: air temperature and precipitation in Ukraine (1981-2020)
How to cite: Strokal, V., Labenko, O., Ladyka, M., Palamarchuk, S., Naumovska, O., Vagaliuk, L., and Voitenko, L.: Relationship between climate drivers and agriculture in Ukraine: changes over the past two decades and potential implications on water scarcity in the future, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6172, https://doi.org/10.5194/egusphere-egu25-6172, 2025.
Tropical peat swamp forests are critical components of the global carbon (C) and nitrogen (N) cycles, with microbial decomposers playing a pivotal role in the assimilation of these elements through the activity of extracellular enzymes in the soil. This study examines the impact of C and N decomposition on microbial enzymatic activity in the Padang Alan soil of the Maludam peat swamp forest, Sarawak. To evaluate the role of extracellular enzymes in driving C and N cycling, soil samples were collected at four depths (0–10 cm, 10–50 cm, 50–100 cm, and 100–150 cm) and subjected for enzymatic assays. C-acquiring enzymatic activities were assessed using β-1,4-glucosidase and phenol oxidase, while N-assimilation activity was measured using β-1,4-N-acetylglucosaminidase. The findings revealed that both C- and N-acquiring enzyme activities peaked at the 0–10 cm depth, where organic matter decomposition is most active, and declined with increasing depth. This pattern underscores the dominance of enzymatic activities in the top soil layers, where decomposition processes are most dynamic. Additionally, N decomposition is influenced by the progression of lignin degradation during decomposition process. Although enzymatic responses varied with soil depth, edaphic factors were found to control enzymatic activity predominantly. These results deepen our understanding of microbial-mediated nutrient cycling in tropical peat soils and emphasize the relationship between soil depth, enzyme activity, and nutrient cycling. Nonetheless, enzymatic activity can be varied by forest type, and elucidating the microbial nutrient demand in peat soil provides important insights into nutrient cycling of tropical peatland ecosystems.
How to cite: Lindang, H. U., Lau, S. Y. L., Laing, R. S., Raczka, N. C., and Melling, L.: Soil Enzyme Activity in Tropical Peat Swamp Forest : Insights from Sarawak, Malaysia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15871, https://doi.org/10.5194/egusphere-egu25-15871, 2025.
Arid regions are increasingly impacted by water scarcity and land degradation driven by both anthropogenic pressures and natural factors. In Jordan, a predominantly arid country, strategies have been implemented to mitigate these challenges and adapt to the changing climate. Among these strategies, Marab Water Harvesting Technology (WHT) has been established as a key method for sustainable water management. Traditionally, the cropping system in Marab areas has focused on barley monoculture, which limits the production of ecosystem services. To enhance the production of these positive externalities, vetch (Vicia sativa), a leguminous crop, has been introduced into the cropping system. This diversification aims to improve soil fertility and the quality of fodder available for livestock, and to support sustainable agriculture. Preliminary field data are promising, confirming the effectiveness of Marab WHT in providing sufficient water for vetch cultivation, consistent with existing literature. Additionally, vetch has improved total soil nitrogen and organic matter in the Marab cropping system. To further evaluate the scalability and resilience of this cropping system under varying climatic conditions, the FAO AquaCrop model is being employed to test its application in different regions and its adaptability to climate change.
How to cite: Strohmeier, S., Renzi, N., Castelli, G., Bresci, E., Al Widyan, J., Hilali, M. E.-D., and Haddad, M.: Enhancing Ecosystem Services of Marab Water Harvesting Technology: Integrating Vetch into Traditional Barley-based Cropping Systems for Soil Fertility Restoration, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16522, https://doi.org/10.5194/egusphere-egu25-16522, 2025.
The Geological Survey of India (GSI) conducted an extensive geochemical survey under the National Geochemical Mapping (NGCM) project in Odisha, analysing 28,115 stream sediment samples. This study focused on 10 potentially toxic elements (Co, Cu, Cd, Cr, Zn, W, As, Mn, Ni, and V) from a dataset of 51 elements to evaluate soil contamination across the state. Multivariate statistical techniques revealed significant inter-element relationships, while Geographic Information System (GIS) methods were employed to generate interpolated geochemical distribution maps. The study identified a concentration hierarchy of Cr > Mn > V > Zn > Ni > Cu > Co > Cd > As > W among the elements, with Spearman correlation analysis indicating strong associations among Cd and W. Soil contamination levels were evaluated using pollution indices such as the geo-accumulation index (Igeo), contamination factor (CF), Pollution Load Index (PLI), and Potential Ecological Risk Index (PERI). The results revealed moderate to high pollution levels in Odisha's northern and southwestern regions, primarily driven by Cd, W, Cr, and Ni. Principal Component Analysis (PCA) identifies four significant components in the dataset, with distinct contributions from various elements. PC1, accounting for the largest variance, is primarily influenced by Cd (17%), Cr (16%), and Ni (14%), suggesting a strong association with ultramafic geological sources, sulfide mineralization, or to some extent industrial pollution. In contrast, PC2 is dominated by Co (26%), Mn (23%), Cu (21%), and Zn (18%), which are often linked to metalliferous inputs, soil geochemistry, and anthropogenic activities such as mining and industrial discharge. Health risk assessment showed children were more vulnerable to Co, Cr, V, As and Cd toxicity in the study region. Whereas, Cd, Cr, and Co are major risk contributors for adult males and females. The hazards associated with non-carcinogenic and carcinogenic soil metals exceeded tolerable thresholds. The computed Hazard Index indicates that soil particle ingestion is the primary exposure pathway associated with elevated risk, succeeded by dermal contact. The results endorse the formulation of targeted remediation plans and policies to mitigate health concerns linked to these polluted soils.
How to cite: Dey, P., Tripathy, S., and Pruseth, K. L.: Evaluation of Potentially Toxic Element Contamination and Related Health Risk Assessment in Soil of Odisha, India, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18753, https://doi.org/10.5194/egusphere-egu25-18753, 2025.
