Despite significant progress, it remains challenging to connect processes occurring at very small scales—such as molecular exchanges or microbial activity around root hairs—with larger-scale outcomes at the level of root systems or soil profiles. Overcoming this gap is essential for understanding how plant–microbial interactions contribute to soil carbon stabilization, nutrient availability, plant health, and ecosystem resilience.
We welcome experimental and modelling studies that investigate:
- Spatial and temporal gradients in microbial diversity and functions along root systems and soil interfaces.
- The influence of root exudates, decomposition products, and soil structure on microbial activity and nutrient cycling.
- Feedbacks between plant growth, microbial processes, and soil physical properties.
- Methodological advances such as high-resolution imaging, isotopic tracing, multi-omics, and microfluidic systems for studying soil microhabitats.
- Modelling approaches that integrate micro-scale processes with field-scale or ecosystem-scale dynamics.
By integrating knowledge from plant physiology, soil microbiology, biogeochemistry, and soil physics, this session aims to advance a mechanistic understanding of how plant–microbial–soil interactions shape ecosystem functioning under changing environmental conditions.
Acidic soils, covering ~40% of the world’s arable land, pose severe constraints on crop productivity due to aluminum (Al) toxicity. Traditional approaches to studying microbial contributions to plant Al tolerance have been limited by the inability to efficiently isolate and characterize functional microorganisms from complex environmental samples. To address this, we developed an Artificial Intelligence-Assisted Raman-Activated Cell Sorting (AI-RACS) system, which integrates single-cell Raman spectroscopy, optical tweezers, and AI-driven automation to enable high-throughput, label-free sorting of microbial cells based on their metabolic activity under stress conditions. Applied to acidic red soils, AI-RACS successfully isolated Al-tolerant strains by quantifying metabolic activity via deuterium oxide (D₂O) probing, outperforming conventional cultivation methods. These isolates were used to construct synthetic microbial communities (SynComs) that enhanced rice resilience in acidic soils. In field trials, SynCom inoculation increased rice yield by 26.36%, reduced root Al accumulation by 26.5%, and improved phosphorus availability by solubilizing legacy soil phosphorus. Mechanistic studies revealed that microbial cooperation underpins SynCom efficacy: for instance, Pseudomonas sp. and Rhodococcus sp. exhibited enhanced Al tolerance via quinolone-mediated cross-feeding, where degradation of the signaling molecule HHQ reinforced cell walls and optimized metabolic activity under Al stress. Further research demonstrated that SynComs activate host plant adaptations by remodeling root cell walls. Specifically, microbes upregulated xyloglucan endotransglucosylase (XET) activity and brassinosteroid biosynthesis, reducing Al binding sites in roots and decreasing Al accumulation by 47.5%. This synergy between microbial metabolic support and host cell wall modification highlights a novel pathway for mitigating Al toxicity. Our work establishes a scalable framework from AI-RACS-driven functional strain identification to SynCom application, that bridges microbiome ecology and crop resilience. These advances offer practical strategies for sustainable agriculture in acidic soils, leveraging microbial tools to enhance food security without relying on chemical amendments.
How to cite: Liang, Y., Jiang, M., Ma, Z., Zhang, L., Zhou, J., Xu, J., and Zhang, J.: Advancing sustainable agriculture in acidic soils through artificial intelligence-driven functional microbiome mining and microbial-mediated crop resilience, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2740, https://doi.org/10.5194/egusphere-egu26-2740, 2026.
Biological Nitrification Inhibitors (BNIs) are compounds naturally produced by plants to block the nitrification process in the soils. BNIs have been proposed as a potentially safe and effective strategy to increase the nitrogen use efficiency of crops while mitigating the environmental damage derived from overfertilization, namely nitrous oxide emissions and nitrate leaching.
In this study, we investigate the influence of a BNI-enabled winter wheat line on the rhizosphere microbiome compared to its isogenic non-BNI counterpart. We conducted a longitudinal field trial during which rhizosphere samples were collected at different timepoints throughout the vegetative growth phase of the crops, to capture potential shifts in the BNI production, as well as changes in the climatic conditions and the temporal dynamics of the microbial community. Given that ammonia oxidation represents the first and often rate-limiting step of nitrification, we focused on ammonia-oxidizing microorganisms by quantifying the abundance and transcriptional activity of the amoA gene using qPCR and RT-qPCR, to assess the impact of the BNI-wheat on nitrifying microorganisms. To evaluate broader microbial responses and ensure no adverse effects on non-nitrifying key microbial groups, we also characterized the overall microbial community with amplicon sequencing, using specific marker genes to target the prokaryotic, total fungal, arbuscular mycorrhizal and protist communities. This work aims to evaluate the efficacy and safety of a BNI-enabled wheat under similar conditions to a modern intensified agricultural setting.
How to cite: Montserrat Diez, M., Yoshihashi, T., Subbarao Ventaka, G., Bachtsevani, E., Karpouzas, D., Hazard, C., Kerou, M., and Schleper, C.: Exploring the Effects of Biological Nitrification Inhibition on the Rhizosphere Microbiome of a BNI-enabled Winter Wheat, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21640, https://doi.org/10.5194/egusphere-egu26-21640, 2026.
Against the dual pressures of global food security and climate change, sustainable management of intensive agricultural ecosystems has emerged as a core issue in balancing crop production and ecological stability. Tillage practices and straw returning, as key agronomic measures for regulating soil health and crop productivity, are widely recognized as critical approaches to enhance soil organic carbon sequestration, improve soil structure, and strengthen nutrient cycling. However, most existing studies focus on the macro-scale effects of single practices, and there remains a significant knowledge gap in understanding how tillage and straw returning drive ecosystem productivity by modulating micro-scale processes at the root-soil-microbe interface.
To address this knowledge gap, we conducted a long-term field experiment in the Huang-Huai-Hai Plain, with three tillage regimes (plow tillage, subsoiling, rotary tillage) crossed with two straw management strategies (straw returning and no straw returning). We systematically analyzed soil physicochemical properties, root morphological and metabolic characteristics, and annual crop yields (wheat and maize) to unravel the regulatory mechanisms of tillage and straw returning on root-soil-microbe interactions and their linkage to ecosystem productivity.
Results showed that subsoiling and rotary tillage significantly improved soil water storage compared to plow tillage, with subsoiling enhancing water availability more effectively. Straw returning combined with subsoiling increased soil organic carbon (SOC) and total nitrogen (TN) storage in the 0-40 cm layer, with SOC increasing by 41.7% and TN by 23.6% compared to baseline measurements in 2002. Tillage practices reshaped soil aggregate stability: subsoiling and rotary tillage increased the proportion of water-stable aggregates (>0.25 mm) in the 0-20 cm layer, providing favorable habitats for microbial communities. Root metabolic analysis revealed that plow tillage promoted root elongation and smooth surface morphology, while rotary tillage resulted in thicker roots with fewer root hairs. Differential enrichment of key metabolic pathways, including ATP-binding cassette transporters, salicylic acid signaling, and purine metabolism, indicated that tillage practices reprogrammed root-microbe communication at the rhizosphere interface.
Subsoiling with straw returning achieved the highest grain yield (8.28 t hm⁻² for wheat and 11.83 t hm⁻² for maize), which was attributed to improved soil structure, enhanced nutrient cycling, and synergistic root-soil-microbe interactions. This study demonstrates that tillage and straw returning regulate soil interface processes, effectively bridging micro-scale root metabolism and aggregate dynamics to macro-scale ecosystem productivity. These findings provide a robust scientific basis for sustainable farming management in the Huang-Huai-Hai region and highlight the critical role of rhizosphere plant-microbial interactions in scaling ecological processes from soil habitats to ecosystem functions.
How to cite: Ning, T., Liu, Z., Zhao, H., and Li, G.: Tillage and Straw Returning Modulate Aggregate Stability, Root Metabolism, and Soil Biotic Interactions for Ecosystem Productivity, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6133, https://doi.org/10.5194/egusphere-egu26-6133, 2026.
Cover crops in farming systems are traditionally integrated into crop rotations to enhance root access to resources in top- and subsoils, particularly nutrients and water. Living mulch systems, functioning as cover crop, also referred to as strip-tillage systems, involve low-growing, often perennial, ground cover (like clover) beneath or between cash crop rows, creating a living soil cover during the growing season – a strategy to diversify crop management to agricultural polycultures. Living mulch systems not only improve soil structure at the physical level, but also create opportunities for diverse rhizosphere microbial interactions. However, current research provides only limited insight into the role of soil microorganisms in living mulch systems, particularly under field conditions where system complexity is substantially higher. Besides the implications of direct root-root or root-bacteria-root interactions, plants can also interact belowground via their mycorrhizal partners. As one of the most effective endosymbiotic fungi, arbuscular mycorrhizal fungi (AMF) are obligate symbionts that rely on carbon supply provided by their plant host in exchange to nutrients. As this symbiosis is often not species-specific, plant-plant interactions can occur via a shared hyphal network.
We evaluated how living mulch system with white clover affects AMF colonization in maize and hyphal network formation. We hypothesize that a living ground cover of white clover would enhance AMF abundance, diversity, and maize root colonization. To investigate the potential role of AMF in nitrogen exchange between white clover and the maize plants, we designed a sandwich-structured mesh tube system that allows control of AMF hyphae as the only way for isotopic nitrogen transport under field conditions. This setup enables testing whether 15N-labeled in the white clover can be transferred via the hyphal network of AMF to maize roots. By EA-IRMS we could quantify the one-directional 15N transfer from white clover to the maize via the hyphal pathway, an observation that was supported by using a combination of PLFA analysis, MBC and MBN measurements, and high-throughput Illumina sequencing. This provides clear evidence that AMF hyphae function as a bridging network facilitating connectivity and N transport between the two plant species of the living mulch system.
In conclusion, our study specifically investigated the role of AMF in living mulch systems, aiming to provide guidance for optimizing plant partner selection for this sustainable agricultural practice.
How to cite: Pu, Y., Füllgrabe, H., Zimmermann, I. M., Wang, J., Ai, J., Shi, Y., Spielvogel, S., and Dippold, M. A.: The Role of AMF in Living Mulch Systems: The Potential for AMF as a Bridge in Root-Hyphae-Root Nitrogen Exchange, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14662, https://doi.org/10.5194/egusphere-egu26-14662, 2026.
Low phosphorus (P) fertilizer utilization efficiency remains a major constraint in calcareous and semi-arid soils due to rapid sorption and precipitation of orthophosphate (orthoP). Polyphosphate (polyP) fertilizers have been proposed as an alternative P source, yet their interactions with rhizosphere microorganisms and the implications for plant P acquisition are still insufficiently understood.
Here, we investigated how P fertilizer type (orthoP vs. polyP) influence rhizosphere microbial activity, enzymatic processes, and plant P uptake. Field and pot experiments were conducted under low initial soil P conditions (Olsen P ≈ 8 mg kg⁻¹), combining crop performance measurements with analyses of arbuscular mycorrhizal fungi (AMF), phosphate-solubilizing and polyphosphate-hydrolyzing bacteria, and rhizosphere phosphatase activity.
PolyP fertilization consistently altered rhizosphere biological activity compared with orthoP. PolyP treatments increased the abundance and activity of phosphate-solubilizing and polyphosphate-hydrolyzing bacteria, which were able to utilize polyP as a sole P source. PolyP hydrolysis by bacteria was not directly associated with bulk pH changes, indicating enzymatic rather than purely chemical control. In parallel, polyP enhanced AMF colonization in both field-grown wheat and pot-grown tomato, suggesting improved biological P acquisition pathways. Acid and alkaline phosphatase activities in the rhizosphere were generally higher under polyP fertilization, reflecting enhanced microbial and plant-driven P mobilization.
These results demonstrate that P fertilizer type strongly regulates rhizosphere microbial communities and enzymatic activity, with polyP promoting biologically mediated P transformation and uptake. Our findings highlight the importance of considering soil–plant–microbe interactions when evaluating alternative P fertilizers and developing strategies to improve P use efficiency in calcareous soils.
How to cite: Erel, R., Shabtai, D., Kushmaro Biera, A., Nahari, I., Mutakale, I., and Toren, N.: Effects of phosphorus fertilizer type on rhizosphere microbial activity and plant phosphorus acquisition, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21453, https://doi.org/10.5194/egusphere-egu26-21453, 2026.
Classical theory posits that late-successional plants develop symbiotic mycorrhizal networks to improve plant nutrient use efficiency and soil nutrient conservation, particularly of nutrients like phosphorus (P), which become depleted during plant community development. However, experimental test of these hypothesized functions are lacking. Here, we conducted a experiment of trenches lined with mesh screens of varying sizes across subtropical succession and a regional survey of 14 subtropical forest sites to explore mycorrhizal hyphal effects on soil nitrogen (N) and P cycling and plant use efficiency. Results revealed that later successional plants had greater P use efficiency, showing lower leaf P concentration and a higher N:P ratio than early successional ones. Ectomycorrhizal (EcM) fungal abundance increase with succession and largely explain the variation in plant PUE and leaf N: P ratio. At late successional stage, these fungi promote soil P conservation through enhancing soil P adsorption and microbial biomass P: N ratio, while simultaneously stimulating nitrogen (N) cycling through the greater release of N-related relative to P-related enzymes. Regionally, EcM abundance was positively correlated with soil N: P enzyme ratio, and nonlinearly correlated to leaf N:P ratio after controlling for soil nutrients, confirming its role in enhancing soil N cycling and P conservation. Our findings highlight EcM fungal critical role in balancing forest N and P cycling, underscoring the need to integrate mycorrhizal effects into nutrient management strategies for subtropical forests.
How to cite: Liu, R., He, Y., and Zhou, X.: Linking mycorrhizal status to plant nutrient strategy across subtropical forest succession, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8904, https://doi.org/10.5194/egusphere-egu26-8904, 2026.
Forest biodiversity is widely assumed to enhance soil ecosystem functioning, yet empirical evidence remains inconsistent, partly due to the strong spatial heterogeneity and multiple interaction pathways linking plants and soil microorganisms. Ecosystem multifunctionality offers a useful framework to integrate these complex responses, but biodiversity effects may depend on scale as well as abiotic and biotic context. Here, we compare two forest biodiversity experiments conducted in contrasting biomes to assess how tree diversity, vegetation structure, and local fine-scale interactions shape soil microbial multifunctionality.
In a temperate forest biodiversity experiment (MyDiv), we investigated how tree species richness and mycorrhizal type (arbuscular vs. ectomycorrhizal) influence soil microbial functioning at the scale of individual trees and tree–tree interaction zones. Soil multifunctionality, derived from microbial biomass, respiration, enzyme activities, and aggregate stability, increased with tree species richness, particularly in ectomycorrhizal-associated plots. Importantly, positive biodiversity effects were spatially constrained to soils close to target trees and did not extend into interaction zones, highlighting the importance of localized root–microbe and mycorrhizal-mediated processes.
In contrast, a subtropical forest biodiversity experiment (BEF-China) examined the combined influence of tree species richness (up to 24 species), understory shrub presence, and shrub–tree interactions on soil microbial multifunctionality. Preliminary analyses indicate that soil multifunctionality and individual microbial functions are comparatively stable across gradients of tree species richness, suggesting a weaker or more buffered biodiversity effect under higher structural complexity and environmental heterogeneity.
Together, these experiments reveal that biodiversity–multifunctionality relationships are strongly context-dependent, varying across biomes, vegetation layers, and spatial scales. Our comparison suggests that localized plant–microbe interactions and mycorrhizal strategies may be key drivers of soil multifunctionality in simpler systems, whereas increasing community complexity may dampen detectable biodiversity effects. These findings underscore the need to integrate spatial scale and environmental context when assessing biodiversity–ecosystem functioning relationships.
How to cite: Christel, H., Beugnon, R., Huang, Y., Delory, B., Ferlian, O., Ul Haq, H., Wubet, T., Eisenhauer, N., and Cesarz, S.: Tree diversity effects on soil multifunctionality differ across biomes and spatial scales, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14698, https://doi.org/10.5194/egusphere-egu26-14698, 2026.
Biochar has been widely promoted as a carbon sequestration strategy in agricultural soils. However, comparatively less attention has been paid to how biochar alters the physical, chemical, and biological properties of soils, particularly within the rhizosphere where plant–microbe interactions are most active.
In this study, we investigated rhizosphere responses of soybean (Glycine max (L.)) to two contrasting biochar type (woody biochar and poultry biochar) applied at different placement strategies (surface vs. mix application). We quantified changes in the forms and amounts of rhizosphere carbon and nitrogen, assessed nodulation as a proxy for nitrogen-fixing bacterial activity, and evaluated rhizosphere enzyme activity.
Our results demonstrate that soybean root morphology responded strongly to biochar type. Poultry biochar, which contains substantial essential nutrients (N and P), promoted a root system characterized by a greater proportion of vertical root components. In contrast, woody biochar induced a wider and more laterally developed root architecture, as confirmed by quantitative root trait analysis.
Enzyme activities in the rhizosphere (β-glucosidase, N-acetylglucosaminidase, and phosphatase) are currently being analyzed, and preliminary observations indicate consistently higher enzyme activities and greater microbial biomass in the woody biochar compared with the poultry biochar treatment. This pattern is likely associated with enhanced nodule formation under woody biochar, suggesting intensified rhizosphere microbial activity coupled with biological N fixation.
By contrast, biochar placement showed minimal effects on soil biochemical indicators, implying that the primary influence of biochar in this system is mediated through chemical and biological pathways rather than physical modification. It indicates that biochar type, rather than placement, primarily governs soybean rhizosphere responses by reshaping root architecture and associated microbial activity.
How to cite: Kim, K.: Biochar type shapes root architecture and rhizosphere enzyme hotspots, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6170, https://doi.org/10.5194/egusphere-egu26-6170, 2026.
In peatlands, as predominantly waterlogged and thus anoxic ecosystems, incomplete and limited decomposition of organic matter leads to accumulation of peat, while ongoing, albeit slow decomposition releases greenhouse gases (CO2, CH4, and N2O) into the atmosphere. Thus, peatlands function simultaneously as major global carbon sinks and reservoirs and as active sources of greenhouse gases. Diverse microbial communities, characterized by a wide range of metabolic capabilities, regulate organic matter decomposition under both oxic and anoxic conditions, along with thermodynamic and transport related constraints. Decomposition under anoxic conditions is a process that often represents the main bottleneck in carbon mineralization in peatlands. However, the functional role of percolation fen microbiomes in organic matter decomposition and carbon mineralization under varying environmental conditions remains poorly understood.
We investigated the effects of ten key organic model substrates with different molecular complexity and three aeration regimes (oxic, anoxic, and oxic–anoxic shift) on microbial CO2 and CH4 production as an indicator of potential carbon mineralization over a 56-day incubation time series. We also evaluated inorganic and organic terminal electron acceptor availability by measuring electron-accepting (EAC) and electron-donating capacities (EDC) and other geochemical parameters (e.g., pH, DOC, trace metals, major ions, and NH4+) in relation to microbial respiration.
Our results showed that CO2 and CH4 production were highly substrate-specific. Each complex substrate, including plant tissues (e.g., Carex spp., Typha spp., Alnus spp.), lignin, cellulose, and chitin exhibited a distinct temporal pattern of CO2 and CH4 production throughout the incubation period. In contrast, simple substrates (e.g., artificial root exudate, acetate, tannic acid, and cyanin) showed similar patterns as observed in the non-amended control sample. Similar substrate-specific trends were observed for EAC and EDC. The oxic–anoxic shift condition resulted in the highest CO2 production while CH4 production remained suppressed as compared to continuously anoxic conditions. Despite this, EAC did not increase under the oxic–anoxic shift; rather, its pattern closely resembled the permanently anoxic treatment, indicating that the brief oxygen exposure was insufficient to recharge EAC and that microbes consumed the O2 faster than regeneration of organic matter EAC by O2 could occur. Furthermore, our multivariate analysis of aeration conditions and substrates using PERMANOVA showed a significant effect of O2 availability throughout the incubation period (p = 0.001, R2 = 0.62). While microbial responses and geochemical parameters did not differ among aeration conditions at early stage of incubation, but clear separation emerged in the second half of the incubation period, driven primarily by divergence in the oxic condition, while the anoxic and oxic–anoxic conditions remained similar to each other.
Our study demonstrates that aeration regimes and substrate quality strongly influence microbiome-driven biomass turnover in fen peatlands. Notably, microbial communities exhibit a more rapid response to O2 availability than terminal electron acceptors, even following brief oxygen exposure. Furthermore, microbial organic matter decomposition patterns shift over time in accordance with the complexity of each substrate. We are currently performing metagenomic and proteomic analyses to elucidate the fen peatland microbial community functional structures involved in these diverging responses.
How to cite: Khosrozadeh, S., Knorr, K.-H., and Hinzke, T.: Dynamic responses of percolation fen microbiome activity to organic matter and oxygen availability, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5260, https://doi.org/10.5194/egusphere-egu26-5260, 2026.
Since the Bronze Age, heavy metals have been accumulating in soils at non-ferrous metal production sites, allowing these accumulations to be used in modern geoarchaeological research as evidence of metallurgical production and metalworking at archaeological settlements. Soils in cities where modern metallurgical plants are located have been actively studied to assess the accumulation and transformation of heavy metal compounds, evaluate soil health, and determine the impact on urban and surrounding native ecosystems. Based on the example of Bronze Age archaeological sites, where metallurgical enterprises were small and had been inactive for several thousand years, especially if the settlement ceased to exist after that, it can be assumed that concentrations decrease, especially when this is facilitated by hydromorphic conditions with acidic pH, when many heavy metals remain mobile. However, the duration of heavy metal persistence in soils and their chemical forms remains unclear. Scanning electron microscopy (SEM) allows, in some cases, to identify individual areas of heavy metal accumulation (Cu, Zn, Ni, Pb, Co) at the submicron level. In the case of soils exposed to the influence of a modern large copper-nickel metallurgical plant in the city of Monchegorsk (Murmansk region, Russia, Kola Arctic), individual metal and slag particles ranging in size from 1 to several tens of micrometers of mono- and poly-element composition were identified at the submicron level. Raman spectroscopy has revealed a variety of chemical compounds that contain nickel, copper, and zinc. High concentrations of copper and zinc, similar to those found in medieval cultural layers with archaeological traces of metallurgical production in the nearest large city of Rostov Veliky, were found in the soils of a Bronze Age settlement (Pesochnoe-1 settlement, Textile ceramic archaeological culture, 14C age – 2100–1800 cal BC, Yaroslavl’ region, central part of European Russia). Using SEM, it was possible to identify anomalous zones of Cu and Zn accumulation in burnt, finely dispersed animal bones (within the first micrometers) used as fuel for metalworking. Even in humid conditions, high concentrations were preserved in these soils with cultural layers due to the abundance of calcium phosphate (small fragments of animal bones, including burnt ones, more than 10% of the total mass).
How to cite: Dolgikh, A., Shishkov, V., Konoplianikova, Y., Chuburina, A., Mergelov, N., and Zazovskaya, E.: Using scanning electron microscopy and Raman spectroscopy to characterize heavy metal-containing compounds in soils around metal facilities from the Bronze Age to the present day, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16739, https://doi.org/10.5194/egusphere-egu26-16739, 2026.
Fungi are among the most important degraders of dead plant materials and hence fuel the global carbon cycle. Production of the enzymes required for plant cell wall degradation is tightly regulated in fungi by environmental conditions including nutrient quality and quantity, temperature, pH and light. This sophisticated regulation indicates that the energy intensive production of enzymes is optimized to fulfil the needs of the fungus but to minimize excess and avoid feeding of so-called “exploiter-“ or “cheater-“microbes.
We therefore asked how fungi sense degradable material and discriminate to root exudates or living tissue of plants to balance enzyme production with available resources. With the filamentous saprophyte Trichoderma reesei we identified two cell-surface receptors (CSG1 and CSG2), which are distinct from previously identified glucose sensors. T. reesei uses detection of a precise amount of glucose, but not other sugars released from plant materials, by these receptors as a proxy for cellulosic material to initiate translation of cellulases. Also special attachment structures formed by T. reesei on natural plant material are missing in the absence of CSG1 or CSG2. Moreover, CSG1 and CSG2 are required for colonization of plant roots and hence these receptors – as well as glucose - play an important role for fungus-plant interaction.
As pheromone receptors were shown in Fusarium as important for plant sensing, we were interested in a potential crosstalk between glucose- and pheromone- sensing. Although CSG1 and CSG2 are dispensible for sexual development, fruiting body formation of T. reesei is accelerated in the presence of plant roots.
We conclude that T. reesei senses extracellular glucose concentrations to discriminate between degradable plant material (liberated glucose amount correlating with enzymes secreted) and the presence of a plant (secreted glucose not correlating with enzymes secreted). Upon interaction of plant roots with T. reesei fruiting bodies, the fungus recognized also the living plant as carbon source, but did not harm growth. Hence the benefit of detecting a plant can be interpreted as one reason for accelerated sexual development by the fungus to improve its interaction with the nourishing plant.
How to cite: Schmoll, M., Hinterdobler, W., Li, G., Turra, D., Schalamun, M., Kindel, S., Sauer, U., Beier, S., Rodriguez-Iglesias, A., Compant, S., Vitale, S., and Di Pietro, A.: A beneficial fungus uses glucose concentrations to balance cellulase production and to recognize living plants, which accelerate fungal development, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17339, https://doi.org/10.5194/egusphere-egu26-17339, 2026.
Soil microorganisms play a central role in terrestrial carbon (C) cycling, yet our mechanistic understanding of how environmental change alters their functioning remains limited. In a world increasingly affected by climate variability, drought and subsequent rewetting events, and the resistance and resilience of microbial functions to them, are particularly important. Rewetting of dry soils triggers a strong biogeochemical response, characterized by a large pulse of microbial CO2 emissions (the Birch effect) and a progressive recovery of microbial growth. The magnitude and temporal dynamics of these responses provide valuable information on microbial community functioning and have important implications for soil C dynamics. Recent studies indicate that climatic history shapes microbial resistance and resilience through ecological memory: communities frequently exposed to drying-rewetting cycles tend to recover growth more rapidly and exhibit sharper respiration peaks, whereas less adapted communities show delayed growth recovery and prolonged and more complex respiration responses. However, how plants modulate microbial perception of drought-rewetting events and provide the resources that enable microbial adaptation and response remains poorly understood.
We analysed how plant diversity and root length influence microbial growth, respiration, and carbon-use efficiency during drought-rewetting events across the soil vertical profile (at different depths). We used complementary experimental settings including gradients of plant species richness (1-60 species and different plant functional groups) and a comparison between wheat and kernza; a conventional annual crop versus a deep-rooted perennial capable of reaching depths of up to 2.5 m. Our results highlight the importance of plants in modulating microbial responses to drought, with the potential to enhance microbial performance and to strengthen soil C sequestration. Higher plant diversity positively affected microbial resistance and resilience, likely by increasing the availability of high-quality C that supports microbial stress tolerance strategies. Longer root systems promoted greater microbial biomass and C cycling at depth, with a tendency towards increased resistance and resilience. The effects on long-term soil C storage remained uncertain as enhanced microbial activity at deep layers may increase the accumulation of persistent organic matter through microbial necromass formation, but also stimulate soil organic matter decomposition via priming.
How to cite: C. Brangarí, A.: Plant diversity and root depth modulate microbial resistance and resilience to drought, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22053, https://doi.org/10.5194/egusphere-egu26-22053, 2026.
Xylella fastidiosa (Xf) represents one of the most severe threats to olive cultivation in the Mediterranean basin, causing extensive tree decline and major economic and ecological losses. Although olive cultivars showing tolerance or resistance to Xf have been identified, the biological mechanisms underlying these traits remain poorly understood. In this context, the Italian Ministry of Agriculture, Food Sovereignty and Forests (MASAF) funded, among other initiatives, the NOVIXGEN project, aimed at developing a coordinated strategy to combat Xf through a multidisciplinary approach. One of the main objectives of the project is the monitoring, selection, and characterization of olive genetic material with potential resistance or tolerance traits to Xf, together with the investigation of host–pathogen interaction mechanisms in infected areas of the Apulia region. In addition, plants, like other organisms, are now regarded as one with their associated microbiota, forming holobionts rather than isolated genomic entities. Accordingly, the study of soil microbiota may shed light on the mechanisms underlying the acquisition of resistance or tolerance traits to Xf in olive trees. This study aimed to characterize the functional activity and taxonomic composition of soil microbial communities associated with tolerant and non-tolerant olive cultivars.
Soil samples were collected from the root zones of tolerant and non-tolerant olive trees belonging to different cultivars (i.e. Leccino, Frantoio, Cellina di Nardò, Ogliarola, Pendolino, Nociara, and Cima di Melfi) across infected areas of the Apulia region. The activity of soil microbiota was assessed by community-level physiological profiling (CLPP) using ECOPLATE (BIOLOG), while the community diversity and composition was assessed using a targeted metagenomic sequencing for the bacteria (V3-V4 of 16S) and fungi (ITS2) communities using MiSeq sequencing (ILLUMINA).
By combining functional and taxonomic aspects of soil microbial communities, we aim to identify microbial features potentially associated with olive tolerance to Xylella fastidiosa, providing a framework for future investigations on plant–microbiome interactions in Xf-infected agroecosystems.
How to cite: Vitali, F., Valboa, G., Del Duca, S., Esposito, A., Mocali, S., and Fabiani, A.: Functional and taxonomic characterization of soil microbial communities associated with tolerance to Xylella fastidiosa in olive trees, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21009, https://doi.org/10.5194/egusphere-egu26-21009, 2026.
Eucalypt tree plantations have been identified as important drivers of land use change and biodiversity loss. In the Mediterranean basin, the abandonment of these forest stands is leading to a natural decay of the plantations, triggering a process of secondary succession. Despite the apparent recovery of these stands, there is not enough evidence to claim that passive restoration alone is sufficient to restore ecosystem functioning, particularly regarding the interactions between plants and soil microorganisms, which are fundamental for forest processes. This study evaluates the compositional and functional recovery of woody plant communities and the recovery of soil microbial activity and function along an abandonment gradient of eucalypt plantations including managed plantations, recently abandoned plantations, long-abandoned plantations, and native Quercus suber forests as reference ecosystems. We analyzed shrub and tree taxonomic and functional diversity based on resource acquisition traits and symbiotic associations (e.g. mycorrhizal type), alongside soil microbial activity and microbial functional diversity to evaluate biodiversity and ecosystem function recovery. We further assessed the relationship between these parameters. Results indicate that tree taxonomic diversity peaked in long-abandoned plantations, shrub taxonomic diversity remained constant along the gradient, and shrub functional diversity decreased in long-abandoned plantations. Soil microbial activity was suppressed in managed plantations, and soil microbial diversity was highest in long-abandoned stands. A negative correlation between shrub and microbial functional diversity was observed, which was mitigated when the relative abundance of ectomycorrhizal host shrubs was high. Our findings suggest that in this nutrient-limited and highly disturbed Mediterranean context, the coexistence of high shrub and soil microbial functional diversity is constrained by resource competition, unless nitrogen dynamics are mediated by ectomycorrhizal fungi. Furthermore, the results indicate that shrub community assembly shows high variability in the traits driving microbial functional diversity, and consequently microbial functional recovery is not guaranteed through passive restoration alone. Therefore, restoration actions should focus on steering shrub communities towards compositions that support high microbial functional diversity, specifically targeting ectomycorrhizal hosts and nitrogen fixers, to re-establish top-down and bottom-up plant-soil feedbacks.
How to cite: Viniegra Villanueva, J. P., Merino Martín, L., and Granda Fernández, E.: Effects of eucalypt plantation abandonment on functional diversity of vegetation and soil microbiota in a mediterranean region, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20876, https://doi.org/10.5194/egusphere-egu26-20876, 2026.
Chlorella sorokiniana is a protein-rich microalga whose extracellular exudates are increasingly recognized for their potential as natural surface-active compounds. Although dissolved organic matter (DOM) and microbial exudates are known to affect soil wettability and heavy metal mobility, the specific interfacial behavior of C. sorokiniana exudates has not yet been quantitatively studied. In this research, we examined the combined physicochemical properties of these exudates and investigated how their molecular composition influences surface activity. The algae's growth was monitored daily through optical density at 750 nm (OD₇₅₀), chlorophyll levels, and biomass measurements. After three weeks, during the late exponential to early stationary phase, exudate production was quantified via Non-Purgeable Organic Carbon (NPOC) and Total Nitrogen (TN), which reached 12 mg/L and 430 mg/L respectively, indicating active organic matter release. Surface tension measurements using pendant drop techniques showed a reduction from 72 mN/m to 53 mN/m, confirming biosurfactant activity. Contact angles on hydrophobic polystyrene measured by the Wilhelmy plate method were advancing at 71.5° and receding at 60°, reflecting increased wettability caused by the exudates. The amphiphilic nature and effects on interfacial interactions were characterized through surface free energy components based on the Owens-Wendt-Rabel-Kaelbel (OWRK) model. Fluorescence analysis with Excitation–Emission Matrix (EEM) and PARAFAC identified two main protein-like fluorophores—tyrosine-like (Ex/Em ≈ 275/305 nm) and tryptophan-like (Ex/Em ≈ 275/340 nm)—confirming their protein origin. Overall, this study highlights C. sorokiniana exudates as natural biosurfactants, directly connecting their molecular makeup to their surface activity.
How to cite: Adhena, G. K. and Gilboa, A.: Surface activity of Chlorella exudates, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5165, https://doi.org/10.5194/egusphere-egu26-5165, 2026.
Soil aggregates are central to soil ecological functioning, regulating both carbon sequestration and nutrient retention. The rice–crayfish (RC) farming system has been widely promoted as a diversification strategy for rice monoculture, yet its capacity to stabilize soil organic carbon (SOC) has largely been inferred from bulk soil measurements, leaving underlying aggregate-scale mechanisms unresolved. Here, using an eight-year field experiment on the Jianghan Plain, China, we provide the first long-term, depth-resolved evidence that RC enhances SOC sequestration through aggregate-mediated carbon protection rather than changes in aggregate size distribution alone. Across surface (0–20 cm) and subsurface (20–40 cm) soils, SOC stocks were strongly and negatively coupled to aggregate-level carbon mineralization. Large macroaggregates—comprising more than 60% of total aggregate mass—exhibited the lowest mineralization quotients, revealing a previously unquantified stabilization efficiency within RC systems. RC farming increased SOC concentrations within large macroaggregates by 45% in surface soils and 38% in subsurface soils, resulting in an 8% increase in SOC stocks across the 0–40 cm profile. Crucially, this increase occurred despite elevated absolute mineralization potential, demonstrating a decoupling between carbon input and decomposition intensity that has not previously been documented in rice–aquaculture systems. In parallel, RC enhanced soil ecosystem multifunctionality by 18-fold in surface soils, linking aggregate-scale carbon persistence to broader gains in nutrient cycling and soil function. By explicitly connecting soil structural hierarchy, mineralization efficiency, and multifunctionality, this study identifies a mechanistic pathway through which integrated rice–aquaculture systems can simultaneously enhance carbon sequestration and agroecosystem performance—advancing RC farming from a productivity-based practice to a quantifiable, process-driven climate mitigation strategy.
How to cite: yang, W., Wang, S., Xu, Y., Tom Harrison, M., Zhou, Y., Liu, K., Zhou, D., Dong, H., Nie, J., Liu, Z., and Zhu, B.: Rice-crayfish farming systems improve soil carbon stocks and ecosystems services, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2172, https://doi.org/10.5194/egusphere-egu26-2172, 2026.
The sensitivity of biodiversity and ecosystem functions to climate and land-use changes needs to be estimated by the set of eco-indicators linking physical and biochemical properties of the soil matrix with microbial functional traits and C transformation processes.
We tested reliability of two basic eco-indicators to capture the complexity of soil processes across scales: i) metabolic quotient (qCO2), i.e. the ratio of respiration-to-microbial biomass and ii) the ratio of microbial biomass-to-soil C content (MBC/SOC). The sensitivity of these eco-indicators was evaluated across different experimental treatments of long-term field experiments within the same geographical site at agricultural station in Bad Lauchstädt, Germany. Both qCO2 and MBC/SOC provided complementary information and were sensitive to land use, fertilization and climate at the field scale. Among the land-use tested, an extensive meadow demonstrated most promising response to the future climate conditions. We will also discuss an ability of the set of these coupled indexes (qCO2 and MBC/SOC) to mirror the carbon sequestration potential in agricultural soils.
How to cite: Blagodatskaya, E., Wang, S., and Merbach, I.: Carbon sequestration-related eco-indicators in long-term field trials, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20464, https://doi.org/10.5194/egusphere-egu26-20464, 2026.
The organic form of nitrogen (N) is a critical intermediate shaping mutualistic and competitive interactions between plant roots and soil microorganisms in the rhizosphere. Yet, the spatial dynamics of nutrient cycling and microbial community assembly in legacy-affected soils remain poorly understood. In this study, we used visualization approaches to localize hotspots of organic N and associated enzymatic activity in soils influenced by plant legacy effects, and we analyzed the microbial communities associated with these hotspots. Our results showed that plant N content and rhizosphere organic N declined after one generation of plant growth. These reductions were accompanied by increased soil microbial diversity and a community shift from copiotrophic to oligotrophic dominance. The abundance of beneficial microorganisms was higher in the newly-growth roots, while soil-borne plant pathogen increased in the legacy-affect soil. Furthermore, genes abundance of N-related transporter and urease were detected exclusively in the rhizosphere of developed seminal roots in the legacy-affect soil, highlighting functional specialization in response to plant-driven soil modifications. These findings suggest that plant legacy effects can restructure rhizosphere nutrient distribution and microbial communities in ways that influence nutrient availability, root health, and plant-soil feedbacks. Understanding these spatially explicit interactions can improve predictions of plant resilience under nutrient-limited conditions and guide strategies to harness beneficial microorganisms for sustainable nutrient management.
How to cite: Shen, G., Daniel Prada Salcedo, L., Bei, Q., Guber, A., and Blagodatskaya, E.: Plant Legacy Effects Shape Rhizosphere Microbial Diversity, Function, and Organic Nitrogen Dynamics, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19876, https://doi.org/10.5194/egusphere-egu26-19876, 2026.
Winter wheat is one of the most important crops worldwide. Consequently, farmers have increased the proportion of wheat in their crop rotations. However, self-succession of WW leads to significant yield decline, which is attributed to the soil-borne fungus Gaeumannomyces tritici (Gt; take-all). This yield decline is also observed in years without pronounced Gt presence in the soil, suggesting a moderating role of the soil microbial community in plant-soil feedbacks. At the same time, there is growing interest in harnessing the beneficial properties of plant growth-promoting bacteria to enhance plant health and productivity. The potential of using such beneficial rhizobacteria to alleviate biomass reduction in successive wheat rotations is substantial. In this experiment, we explored this management option by seed-inoculating wheat plants with Bacillus pumilus. Wheat was grown in soil after oilseed rape (W1) and soil after one season of wheat (W2). We measured soil mineral N, microbial diversity and community composition, as well as, microbial activity. Special focus was placed on root plastic responses as a function of the microbial inoculant and wheat rotational position. W1 produced more biomass and had a higher yield than W2. Successively grown wheat had a much lower root growth, compared to wheat grown after oilseed rape. Bacillus pumilus inoculation did not mitigate the yield reduction in W2. Differences in catalytic efficiency of β-glucosidase and leucine aminopeptidase were observed between W2 and W1, with higher and lower efficiencies, respectively, in W2; these effects were mainly driven by Bacillus pumilus inoculation. We discuss potential mechanisms that moderate these effects.
How to cite: Kaloterakis, N., Braun-Kiewnick, A., Babin, D., Rashtbari, M., dos Anjos Leal, O., Zhao, K., Razavi, B. S., Smalla, K., and Brüggemann, N.: Exploring the potential of plant-growth promoting rhizobacteria to mitigate yield decline in wheat rotations, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9024, https://doi.org/10.5194/egusphere-egu26-9024, 2026.
Peatlands are ecosystems that comprise the largest terrestrial carbon store on Earth. They play a critical role in climate change mitigation, while also supporting unique biodiversity, regulating water flow and serving as paleoecological archives. Understanding the history of peatland formation and present subsurface conditions is essential for effective conservation and restoration efforts. Past glacial processes have had a first-order impact on peatland development in both mountain environments and lowlands. Although the role of climate in peat initiation is well explored, the influence of glaciations on postglacial peat-forming processes remains poorly investigated.
Glaciers can provide suitable conditions for peatland formation by the ability to i) form local depressions and ii) deliver abundant fine sediments to induce ponding. However, the efficiency of glacial erosion strongly depends on geological factors like rock erodibility or basal topography. Other factors may in turn impede postglacial peat accumulation despite apparently suitable geological and climatic conditions. These include e.g. a high flood frequency, fluvial erosion in alluvial valleys, or, in mountainous environments, high landslide frequency.
To investigate peatland substrata, we apply a combination of geophysical methods, including ground penetrating radar and electrical resistivity tomography, and core drilling. We present characteristic peatland environments in central and perialpine settings and discuss how i) glacial depositional and ii) glacial erosional processes control their formation. In addition, we examine the onset of peat growth and rates of peat accumulation in formerly glaciated regions of the Eastern Alps.
These insights contribute to the understanding of present-day peatland ecosystem functioning, as subsurface stratigraphy often controls hydrological characteristics and vegetation patterns. Such knowledge is essential for peatland conservation and restoration strategies aimed at maintaining their role as important habitats and long-term carbon stores.
How to cite: Mattiazzi, M., Hopfinger, M., Salcher, B., Otto, J.-C., Orozco, A. F., Tribsch, A., Wimmer, X., and Watson-Cook, E.: Glacial Preconditioning of Alpine Peatland Formation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9684, https://doi.org/10.5194/egusphere-egu26-9684, 2026.
Mine tailings represent a large-scale issue requiring the development of a sustainable remediation management plan with a multifactorial approach. In the Iglesiente region, past mining activities left severe contamination of Zn, Pb and Cd. Among bioremediation technologies, phytoremediation appears to be a promising strategy owing to the use of autochthonous plant species and their associated microorganisms naturally adapted to these harsh conditions. Among phytoremediation strategies, phytostabilization takes place at the root-substrate interface, where excluder-type metallophytes and their root-associated microorganisms reduce metal mobility and bioavailability. The effectiveness of this process largely depends on the structure and function of the rhizospheric microbiome. Therefore, the study of microbiome in rhizosphere and roots of native plants is crucial for the development of a successful remediation strategy. In this study, we investigated the rhizosphere and root microbiomes of Pistacia lentiscus, a metallophyte autochthonous plant species of Sardinian mining areas. Furthermore, the environmental context was analysed with a multifactorial approach to understand the most suitable application of phytoremediation in real field conditions. Sampling was conducted in three zones based on proximity to a mine tailing deposit: outside, at the border, and inside the dump. A comprehensive insight into soil communities was achieved by using diverse techniques. In this study we analysed: i) physico-chemical properties of mine substrates, ii) microbial activity by the dehydrogenase assay, iii) functional diversity patterns of microbial community with the BIOLOG system, iv) bacterial and fungal communities by high-throughput sequencing of ribosomal genes. Metals levels in the tailings showed a certain degree of spatial heterogeneity. Dehydrogenase activity showed a marked and statistically significant differences in the functional diversity of the rhizospheric microbial communities from the three different investigated areas. Analysis of microbial community by high-throughput sequencing allow us to understand how microbial communities were affected by environmental conditions and metals. Our results highlight the importance of plant-associated microbiomes in metal-contaminated environments and support their relevance for site-specific remediation strategies. This work has been developed within the framework of the project e.INS www.einsardinia.eu (Next Generation EU- PNRR-M4 C2 I1.5 CUP F53C22000430001).
How to cite: Mandaresu, M., Vitali, F., Mocali, S., Carucci, A., Cappai, G., and Tamburini, E.: Study of microbial diversity associated to Pistacia lentiscus, a metallophyte of Sardinian mining areas, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20148, https://doi.org/10.5194/egusphere-egu26-20148, 2026.
Tree species differ in how they acquire nutrients through arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) symbioses, yet how these contrasting mycorrhizal strategies regulate soil microbial nutrient mobilization and its coupling to tree nutrient status remains poorly resolved. Here, using a 10-year temperate tree diversity experiment, we quantified soil microbial community structure, phospholipid fatty acid (PLFA)-derived carbon (C) sources tracing, ecoenzymatic stoichiometry, and foliar nutrient pools to test how tree diversity and mycorrhizal type control the linkage between soil microbial nutrient acquisition and foliar nutrient pools. We found that the tree mycorrhizal type exerted a dominant control on microbial community structure. AMF-associated tree mixtures (plots dominated by AMF tree species) were characterized by saprotrophic Ascomycota, which exhibited a higher contribution of root-derived C to fungal biomass, whereas EMF-associated mixtures were dominated by symbiotrophic Basidiomycota that relied more strongly on detritus-derived C. Ecoenzymatic strategies diverged consistently with these contrasting C acquisition pathways. AMF-associated soils exhibited higher C-acquiring enzyme activity and a greater vector length (an index of microbial C acquisition investment), indicating stronger microbial investment in C acquisition from soil organic matter. In contrast, EMF-associated soils exhibited lower vector angles (indicating relative microbial investment in nitrogen versus phosphorus acquisition) and significantly higher nitrogen (N)-acquiring enzyme activity, reflecting enhanced microbial N acquisition. Across all tree mixtures, fungal community composition was tightly linked to ecoenzymatic stoichiometry, and both were significantly associated with foliar N pools. Partial least squares path modelling revealed that mycorrhizal type influenced foliar N pools primarily through indirect pathways contributed by fungal community structure and microbial N-acquisition strategy. Together, these results demonstrate that mycorrhizal type governs how soil microbes channel C from the tree into N mobilization pathways, thereby regulating the strength of belowground–aboveground N coupling. Our findings reveal a mechanism by which mycorrhizal associations, rather than tree diversity alone, shape soil microbe–tree interactions in temperate forest ecosystems.
How to cite: Zhang, H., Wang, W., Bönisch, E., Yi, H., Ferlian, O., Beugnon, R., Dietrich, P., Proß, T., Seitz, S., Yang, X., Scholten, T., Eisenhauer, N., and Oelmann, Y.: Tree mycorrhizal type couples soil microbial N mobilization to foliar N pools, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11943, https://doi.org/10.5194/egusphere-egu26-11943, 2026.
Diazotrophs are crucial for sustainable agriculture by converting atmospheric N2 into plant-absorbable nitrogen via biological nitrogen fixation. Historically, excessive chemical fertilizer application has been employed to enhance soybean yield; however, this approach poses direct and indirect threats to the sustainable and healthy development of soil organisms. Rhizobial inoculation not only offers an eco-friendly alternative to synthetic nitrogen fertilizers but also contributes to sustainable agricultural practices. Understanding how different agricultural practices affect diazotrophic communities can provide valuable insights for optimizing nitrogen management in crop production.
In the study, we employed the nifH gene as a molecular marker to assess the impact of 10 years of nitrogen fertilization and Bradyrhizobium inoculation on diazotrophic community structure. Treatments included no fertilization (CK), phosphorus plus potassium (PK), PK plus urea (PK + N), and PK plus Bradyrhizobium japonicum 5821 (PK + R). Soil samples were collected 30 cm from the plant as bulk soil and the soil adhering to the root as rhizosphere soil.
The analysis of non-metric multidimensional scaling, neutral community model and the Spearman relationship indicated that at soybeans flowering-podding stage, Bradyrhizobium inoculation increased nifH gene copies but decreased the Shannon index in both bulk and rhizosphere soils compared to nitrogen fertilization. At maturity, Bradyrhizobium inoculation reduced nifH gene copies while increasing the Shannon index in both bulk and rhizosphere soils. Bradyrhizobium inoculation lowered beta diversity in the rhizosphere during the floweringpodding but increased it in mature bulk soil. The dominant diazotrophic genera were Bacillus, Azohydromonas, and Skermanella. Bradyrhizobium inoculation enhanced Bacillus abundance during flowering-podding but reduced it while boosting Azohydromonas and Skermanella during maturity.
Overall, Bradyrhizobium inoculation decreased network complexity but increased diazotrophic dynamics compared to nitrogen fertilization. Long-term Bradyrhizobium inoculation fosters diazotrophic interactions more effectively than nitrogen fertilization.
How to cite: penghui, W., mingchao, M., wanling, W., xin, J., and jun, L.: Influence of Long - term Nitrogen Fertilizer and Bradyrhizobium Inoculation on Diazotrophic Communities at Soil Interface during Soybean Cultivation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6211, https://doi.org/10.5194/egusphere-egu26-6211, 2026.
This study investigated an innovative strip straw returning and tillage system to evaluate its impacts on water-salt transport and winter wheat yield in coastal saline-alkali land. The experimental design implemented strip-wise tillage with deep plowing (2.4 m width) intervals of 4.8 m (DR4.8) or 2.4 m (DR2.4), and rotary tillage in other strips. Combined with two straw returning methods: concentrated (C) and uniform (U) straw return. The concentrated straw treatment specifically transferred straw from rotary-tilled strips into deep-plowed strips. Four experimental treatments of tillage combined with straw returning: CDR4.8, UDR4.8, CDR2.4, UDR2.4, and rotary tillage combined with uniform straw returning were used as the routine treatment (UR). Our results in coastal mild (Chang Yi) to moderate (Wu Di) saline-alkali land demonstrated that deep-plowed strips concentrated straw within the 0-30 cm soil layer, creating localized modifications in water-salt distribution that drove transverse displacement of solute-laden water from rotary-tilled to deep-plowed strips. The lateral migration of water and salt from the rotary-tilled strip to the deep-plowed strip significantly increases with an increase in the straw returned in the deep-plowed strip (Wu Di: water- 73.50%; salt-77.62%, Chang Yi: water- 78.62%; salt-57.67%). It is worth noting that the lateral migration rate of water and salt in each treatment gradually decreased with the advancement of the growth period. The transverse transport efficiency of CDR2.4 and UDR2.4 was significantly higher than that of CDR4.8 and UDR4.8 (Wu Di- 18.68%; Chang Yi- 34.63%), and the transverse transport efficiency of Wu Di was significantly higher than Chang Yi (22.82%). Two years of field trials in both places showed that the highest yield was achieved with the CDR4.8 treatment (Wu Di- 9.52%; Chang Yi- 8.98% increase compared to R). These findings establish that integrated strip tillage with straw redistribution offers a promising approach for sustainable coastal saline-alkali land improvement.
How to cite: Li, G.: Water-salt Displacement in Different Width Strip Tillage by Concentrated Straw Return Increased Wheat Yield in Coastal Saline-alkali Land, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8563, https://doi.org/10.5194/egusphere-egu26-8563, 2026.
Grain production in the Huang-Huai-Hai region of China has long relied on high-intensity nitrogen (N) fertilization, resulting in a decoupling between fertilizer input and yield gains as well as conspicuously low nitrogen use efficiency (NUE). To develop a synergistic optimization regime integrating tillage and nitrogen management for reducing N input while enhancing NUE, a field experiment was conducted based on a long-term positioning trial initiated in 2005. The experiment employed two tillage practices (rotary tillage, RT; subsoiling, ST) and three N application rates (100%, 75% and 0% of the conventional dosage). Results showed that ST significantly increased contents of total nitrogen, nitrate nitrogen and microbial biomass nitrogen in the 0–20 cm (p<0.05), while N application elevated soil nitrogen storage in the 0–40 cm profile (p<0.05). Bacterial community diversity and richness peaked under the 75% N treatment but were minimized under 100% N application. Higher N input promoted nitrogen accumulation in maize across all growth stages and increased the proportion of nitrogen allocated to grains. Compared with 100% N, 75% N application improved partial factor productivity of nitrogen, NUE and agronomic nitrogen efficiency. At the same N rate, ST outperformed RT in grain nitrogen accumulation, partial factor productivity of nitrogen and nitrogen harvest index. The conventional N application (100% N) sustained high yields, it compromised NUE. The combined practice of subsoiling and reduced N application can synchronously improve soil quality, crop yield and NUE, providing a feasible technical solution for sustainable grain production in the Huang-Huai-Hai region.
How to cite: Liu, Z.: Effects of tillage practices and nitrogen application on maize nitrogen utilization and soil bacterial communities, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8518, https://doi.org/10.5194/egusphere-egu26-8518, 2026.
