Yet, nutrient management also represents a powerful entry point for change. When carefully designed and context-specific, nutrient strategies can enhance soil fertility, stabilize agricultural landscapes, and reduce diffuse pollution. Advances such as precision fertilization, the recycling of organic amendments, integrated crop–soil–water systems, and the use of digital decision-support tools are opening new pathways to improve nutrient efficiency. These innovations have the potential to transform agriculture into a driver of soil conservation, water protection, and climate resilience, ensuring that productivity gains are achieved without sacrificing ecological health.
We particularly welcome contributions on (but not limited to):
• Precision nutrient application and decision-support tools to minimize losses
• Conservation agriculture practices (e.g., cover crops, crop rotations, no-till) and their impact on soil fertility and hydrological cycles
• Interactions between nutrient management, soil organic carbon dynamics, and erosion control
• Monitoring and modelling of nutrient fluxes in soil–water systems at plot, farm, and watershed scales
• Nature-based and agroecological solutions, and Biostimulants for nutrient retention and water conservation
• Policy, socio-economic, and farmer-engagement perspectives on sustainable nutrient management
By bringing together soil scientists, agronomists, hydrologists, ecologists, and modelers, this session seeks to foster interdisciplinary dialogue and promote actionable solutions for sustainable land and water management. Contributions from early-career scientists, as well as examples from Mediterranean, arid, and semi-arid regions, are especially encouraged.
Efficient management of crop residues is crucial for soil conservation and efficient nutrient dynamics in semi-arid agroecosystems. This study aims to evaluate decomposition dynamics and release of carbon (C) and nitrogen (N) from cover-crop residues in barley (Hordeum vulgare L.) cropping systems in Mediterranean semi-arid conditions. During one year a litterbag experiment is being conducted to examine cover crops decomposition dynamics.
The field experiment consists in two cover crop termination management strategies: chopped (residues left on soil surface) and tilled (incorporated into soil) and three cover crops species: cereal (oat - Avena sativa L.), legume (vetch - Vicia sativa L.) and mix (70:30) of both species. The experiment started at May 2025 and will be monitored 10 samplings times during 48 weeks of litter decomposition simultaneously with the following soil quality parameters: residue decomposition rate, soil mineral nitrogen (NO₃⁻ and NH₄⁺), soil permanganate oxidizable carbon (POxC), soil basal respiration, microbial biomass, and soil enzymatic activities (β-glucosaminidase and dehydrogenase).
Here we present results from the litter decomposition across the first 16 weeks. Plots under chopped termination showed 30% of residue decomposition while plots under tilled termination showed 70% of residue decomposition. In tilled termination, the mixed species had lower decomposition rate compared to cereal and legume, while in chopped termination there were no differences among species in residue decomposition. Most of the decomposition (50 to 70% of total decomposition; in chopped and tilled managements respectively) occurred during the first four weeks. During these weeks, legume residue decomposed more rapidly than cereal and mix species under both terminations, which related with higher soil microbial biomass levels, soil enzymatic activities (dehydrogenase, β-glucosaminidase) and soil nitrates. From the fourth week, there was a decrease in soil microbial biomass and activity for both terminations, which was associated with the summer period (low soil moisture and high temperature).
In our study, the first four weeks after residue incorporation were critical for decomposition, accounting for more than 50% of total decomposition and coinciding with highest soil enzymatic and microbial activity. Whether residues were left on the surface or incorporated into soil, the release of C and N contributed to the stimulation of biological activity and, consequently, to soil health. By week 16, decomposition trends converged across practices, yet legumes consistently accelerated litter decomposition and enhanced nitrogen availability. Cover crops are a key sustainable management practice in semi-arid Mediterranean regions, and understanding their decomposition dynamics is essential to ensure more sustainable agroecosystems in semi-arid Mediterranean regions.
ACKNOWLEDGEMENTS: This research was supported by the Spanish State Agency for Research (AEI) (Grant PID2021–126343OB-C31).
How to cite: Aladrén, A., Álvaro-Fuentes, J., and Martínez, L.: Residue decomposition dynamics under different cropping systems in dryland cereal systems., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9791, https://doi.org/10.5194/egusphere-egu26-9791, 2026.
Improving nitrogen and phosphorus fertilizer use efficiency is a key priority to reduce nutrient losses and mitigate the environmental impact of intensive agricultural systems. Excessive fertilizer inputs are a major driver of nutrient leaching and emissions, highlighting the need for alternative fertilization strategies capable of increasing nutrient retention and crop uptake. In this context, slow-release fertilizers derived from agricultural wastes represent a promising option for more sustainable crop nutrition management, particularly in high-input horticultural systems.
This study presents the results of a pot experiment conducted on Lactuca sativa L. grown in a controlled soilless substrate. The experiment aimed to compare crop performance and nutrient use efficiency between innovative slow-release fertilizers and conventional synthetic fertilizers. Specifically, natural zeolites loaded with NH₄⁺ and struvite were tested as alternative nutrient sources and compared with ammonium-based synthetic fertilizers. Both recycled materials were isotopically enriched with 15N (~5 atom%), allowing a precise tracing of fertilizer-derived nitrogen within the plant–substrate system. Nitrogen-Fertilizer Use Efficiency (NFUE) was quantified using isotopic mass balance, while Phosphorus Use Efficiency (PUE) was assessed through a conventional mass balance approach under balanced nutrient application rates.
The results indicate that slow-release fertilizers ensured lettuce yields comparable to or higher than those obtained with synthetic fertilizers, while achieving higher NFUE. In particular, the lettuce grows on NH₄⁺-loaded zeolite exhibited higher N derived from fertilizer. Struvite proved to be an effective combined source of nitrogen and phosphorus, supporting plant growth while providing a sustained nutrient supply throughout the cultivation cycle.
Overall, this study confirms the potential of struvite and zeolites as sustainable alternatives to mineral fertilizers, demonstrating their capacity to improve nutrient use efficiency and reduce nutrient losses in intensive horticultural production systems.
How to cite: Degan, A., Ferretti, G., Alberghini, M., Ben-Hassine, M., Aquilano, A., Radicetti, E., Faccini, B., and Coltorti, M.: Use of slow-release fertilizers labeled with 15N (tuff rich in zeolite and struvite) to evaluate nitrogen and phosphorus use efficiency in the cultivation of Lactuca sativa L., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10188, https://doi.org/10.5194/egusphere-egu26-10188, 2026.
Pianosa is a unique island in the Tuscan Archipelago (Italy), characterized by low annual rainfall, and predominantly shallow calcareous soils. Due to the presence of an agricultural colony on Pianosa land, decades of agricultural use profoundly altered soil structure and function. After agricultural activities related to the penal colony were ceased, a long-term natural recovery processes under has initiated, under the main driver of increasing climatic stress. The National Research Council (CNR) has monitored the ecosystem since the early 2000s, and in 2020 launched a new campaign to assess soil health and vegetation recovery after 40 years of abandonment. Preliminary findings indicate that vegetation resilience under climate change is strongly influenced by soil chemical, physical, and biological properties, highlighting the central role of soil microbial communities in driving ecosystem functioning. In this context, biological soil crust components, particularly cyanobacteria, are expected to play a key role in nutrient cycling, organic matter dynamics, and soil water regulation in resource-limited environments. Within this framework, we isolated and characterized native cyanobacterial strains from Pianosa soils to assess their functional traits and evaluate their potential as biostimulants for enhancing organic matter mineralization and nutrient availability in resource-limited calcareous soils. The selected strains were investigated for their ecological relevance and their capacity to influence key soil processes related to carbon and nutrient cycling. Laboratory microcosm experiments, designed to simulate early-stage soil recovery conditions, demonstrated that cyanobacterial inoculation can positively affect soil fertility indicators, including nutrient dynamics and organic matter turnover, while also improving soil water retention capacity. These findings highlight the ability of native cyanobacterial communities to modulate soil physical and biogeochemical properties. Overall, our results support the use of site-adapted cyanobacteria as a nature-based bioaugmentation strategy to restore soil functionality and enhance ecosystem resilience in Mediterranean insular systems increasingly exposed to climate change.
How to cite: Maienza, A., Faraloni, C., Chini Zittelli, G., Gallese, F., Balestra, F., Sabatini, F., Vaccari, F., and Lorenzetti, R.: Nature based solution to soil and vegetation recovery in Pianosa Island: Cyanobacteria as Biostimulants for Sustainable Bioaugmentation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17650, https://doi.org/10.5194/egusphere-egu26-17650, 2026.
ABSTRACT
Climate change poses a serious threat to global food security, primarily through rising temperatures, erratic rainfall, and soil degradation. Soil, as the largest terrestrial carbon pool, plays a pivotal role in mitigating climate change through carbon sequestration. This study aims to evaluate the potential of various soil and crop management practices to enhance soil organic carbon (SOC) storage and reduce greenhouse gas emissions in agricultural systems. Field experiments will be conducted in selected agro-ecological zones, employing practices such as conservation tillage, crop residue retention, organic amendments, and biochar application. Soil samples will be analyzed for organic carbon content, bulk density, and nutrient availability, while gas flux measurements will assess CO₂, CH₄, and N₂O emissions. Data were statistically analyzed to determine the relationship between management practices, SOC accumulation, and crop productivity. The study outcomes include identification of sustainable soil management techniques that significantly increase SOC while maintaining or improving yield performance. These findings will contribute to formulating effective strategies for climate-smart agriculture, with implications for carbon credit programs and environmental policy development. This research emphasizes the dual benefits of soil carbon sequestration: enhancing soil fertility and mitigating climate change. It highlights a pathway toward resilient and sustainable agricultural systems, particularly relevant for developing countries like Pakistan, where agriculture is highly vulnerable to climate variability.
Keywords: Soil carbon sequestration, climate change mitigation, sustainable agriculture,
Conservation tillage, soil health
How to cite: Gondal, I. A.: Soil Carbon Sequestration and Climate Change Mitigation: Pathways for Sustainable Agriculture, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-225, https://doi.org/10.5194/egusphere-egu26-225, 2026.
Nitrate leaching is one of the major challenges in agricultural soils in variable climate conditions, causing changes in rainfall patterns influence soil water behavior and nutrient losses. Soil amendments such as biochar and silica have been introduced as an effective strategy to mitigate nitrate leaching by modifying soil water dynamics. However, their combined effects on water percolation and nitrate transport under repeated natural rainfall events are still not well understood. Therefore, in this study, we evaluated the hydrological behavior and nitrate leaching of soils amended with biochar and silica using a soil box experiment (60cm×30cm×20cm) conducted under natural conditions. Four treatments were selected for this project: a control, biochar (2% w/w), silica (1% w/w), and a combined biochar–silica (Si-char) treatment with three replications for each treatment. After preparing the soil, amendments, and soil boxes, the experiment started with an initial saturation phase to establish the same soil moisture conditions in different treatments. Five natural rainfall events were recorded in this phase. Percolation volumes and nitrate concentrations were measured after each rainfall event.
The results showed that across all five rainfall events, biochar and silica treatments reduced nitrate leaching compared to the control. However, the Si-char treatment consistently showed the lowest nitrate leaching, which is the most effective mitigation of nutrient losses. These results highlight the synergistic effects of amendments compared to single application of amendments. Statistical analysis using one-way ANOVA confirmed that nitrate leaching differed significantly among treatments during all rainfall events (p<0.05). In addition, ANOVA results for individual treatments across the events revealed contrasting response patterns. In the control treatment, the difference in nitrate leaching between rainfall events was significant, indicating high sensitivity to rainfall variability. On the other hand, the Si-char treatment showed fewer statistical groups between rainfall events, which indicates that it was more stable and has more predictable behavior in the face of changing rainfall conditions. The better performance of Si-char suggests that biochar and silica acted as a complement. Biochar likely increased soil nitrate retention, while silica contributed to more stable soil water retention and reduced sensitivity to rainfall variability. Together, these processes increased the residence time of water in the soil and limited nitrate transport beyond the root zone. Overall, the results showed that Si-char is the most effective treatment compared to others for reducing nitrate leaching under repeated rainfall events. This approach may be considered by land managers for sustainable nitrogen management in dry farming systems.
How to cite: Katebikord, A., Funk, R., Mohammed, M. J., and Maerker, M.: Silica-Biochar (Si-char) control of nitrate leaching in a soil box experiment, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20640, https://doi.org/10.5194/egusphere-egu26-20640, 2026.
Intercropping strategies represent a promising agronomic approach to improve nitrogen (N) use efficiency and reduce fertilizer inputs in intensive horticultural systems. This study evaluated the capacity of intercropping systems to maintain crop productivity under reduced nitrogen fertilization in Mediterranean conditions.
Field experiments were conducted during the 2025 growing season using broccoli (Brassica oleracea var. italica) and watermelon (Citrullus lanatus) as model crops. Optimal nitrogen fertilization rates were established for each crop and subsequently reduced by 30% to assess crop performance under lower N inputs. Different intercropping combinations were implemented and compared with monocropping systems under both optimal and reduced nitrogen supply. Agronomic parameters, including yield and biomass production, were evaluated together with plant nitrogen status and nitrate accumulation in plant tissues and soil.
The results showed that intercropping systems enhanced nitrogen use efficiency and mitigated the negative effects of a 30% reduction in nitrogen fertilization. In several intercropping combinations, crop yield was maintained or only slightly reduced compared to monocropping under optimal nitrogen supply. In addition, intercropping significantly reduced nitrate accumulation in leaves and soil, indicating improved nitrogen uptake and utilization.
These findings demonstrate that intercropping strategies can effectively reduce nitrogen inputs while maintaining crop productivity in Mediterranean horticultural systems.
How to cite: Fernández-Martínez, É., Martínez-Nicolás, J. J., Gimeno-Nieves, V., Yabor, L., and García-Sánchez, F.: Intercropping Strategies to Maintain Crop Productivity under Reduced Nitrogen Fertilization in Mediterranean Horticultural Systems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3059, https://doi.org/10.5194/egusphere-egu26-3059, 2026.
Accurate monitoring of crop nitrogen status is essential to optimize fertilization management and reduce nitrate losses in intensive horticultural systems. This study aimed to calibrate crop monitoring tools based on ion-selective electrodes and remote sensing indices for nitrogen status assessment in horticultural crops.
Field experiments were conducted during the 2025 growing season on broccoli and watermelon grown under Mediterranean conditions and subjected to different nitrogen fertilization levels. Crop nitrogen status was assessed using complementary approaches. Multispectral satellite imagery and UAV-based hyperspectral data were used to calculate vegetation indices related to chlorophyll and nitrogen status, including NDRE, GNDVI, TCARI and OSAVI. These indices were calibrated against leaf nitrogen concentration and nitrate content determined by conventional laboratory analyses. In parallel, xylem sap was extracted from leaves and analyzed using ion-selective electrodes to determine nitrate concentration.
Strong relationships were observed between nitrogen supply, spectral indices and nitrate concentration in xylem sap, enabling the development of calibration models for real-time crop nitrogen monitoring. The integration of proximal sensing with remote sensing improved the robustness of nitrogen diagnostics across crops and growth stages.
These results highlight the potential of combining ion-selective electrodes and remote sensing tools as decision-support systems for optimized nitrogen management.
How to cite: Garcia Sanchez, F., Yabor, L., Fernandez Martinez, E., Brotons Martinez, J. M., Gimeno Nieves, V., and Carmara Zapata, J. M.: Calibration of Crop Nitrogen Monitoring Using Ion-Selective Electrodes and Remote Sensing Indices in Horticultural Crops, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1862, https://doi.org/10.5194/egusphere-egu26-1862, 2026.
Enhancing nitrogen fertilization management contributes to the sustainability of agricultural production. A multi-criteria analysis applied to nitrogen fertilization in broccoli crops enables producers to make informed decisions. In 2023, broccoli production was analyzed under different nitrogen fertilization rates using economic, social, agronomic, and environmental criteria to determine the most suitable alternative from a sustainability perspective. Based on expert opinions, the importance of each criterion was quantified using the Analytic Hierarchy Process (AHP). The ranking of the alternatives was established using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Economic and agronomic criteria exhibited a higher weighting than the others. The results established that a rate of 150 units of nitrogen fertilizer is the most suitable under the experimental conditions studied. In conclusion, multi-criteria analysis using a combination of AHP and TOPSIS can support growers' decision-making in broccoli production under Mediterranean conditions.
How to cite: Carmara-Zapata, J. M., Garcia-Sanchez, F., and Brotons-Martínez, J. M.: Multi-Criteria Analysis for Decision-Making in Broccoli Nitrogen Fertilization, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16959, https://doi.org/10.5194/egusphere-egu26-16959, 2026.
Nitrogen fertilization management has a significant impact on the sustainability of agricultural production. To facilitate decision-making for watermelon producers—a key crop in Mediterranean countries—a multi-criteria analysis was employed. This study determines the optimal nitrogen fertilization rate by integrating economic, social, agronomic, and environmental factors. The Analytic Hierarchy Process (AHP) was used to aggregate expert opinions on the importance of each criterion, revealing that economic and agronomic factors were the most critical. Subsequently, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) identified a rate of 200 nitrogen units as the optimal choice. Ultimately, this methodology promotes the sustainability of watermelon production in Mediterranean environments by optimizing nitrogen management.
How to cite: Camara-Zapata, J. M., García Sánchez, F., and Brotons Martínez, J. M.: An AHP-TOPSIS Multi-Criteria Decision-Making Approach for NitrogenFertilization Management in Watermelon Cultivation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21172, https://doi.org/10.5194/egusphere-egu26-21172, 2026.
Production of litter from standing trees, shrubs, and other herbaceous species in agroforestry (AF) systems contributes significantly to maintaining and enhancing soil fertility. The contribution of litterfall to nutrient cycling in AF systems at the stand level in Ethiopia remains understudied. The study aimed to compare litterfall production and investigate associated macro and micro-nutrients in enset based, enset-coffee based and coffee-fruit tree-enset based AF systems. Five farms were selected randomly from each AF system and each farm had three replications. Litterfall traps were randomly assigned in a 10×10 meter farm plot and litterfall collection was carried out for one year. A multiple linear regression model was developed to examine the effect of climatic factors (temperature, rainfall, wind speed, and relative air humidity) on litterfall production. The annual litterfall production of the AF system as stand level per unit area of land was the highest for the coffee-fruit tree-enset based AF system (average 9.8 tone ha-1), followed by the coffee-enset based (4.1 tone ha-1), and the Enset based (3.7 tone ha-1). The associated annual fluxes Ca, K, Mg, Mn, Na, P, and S (kg ha-1) in the AF system with the highest litterfall sepcifically, coffee-fruit tree-enset basedAF were 186, 99, 23, 6, 1, 8 and 10 respectively. The corresponding C and N fluxes (kg ha-1) were 4692 and 192 respectively. The result of one-way ANOVA followed by post-hoc testing (Fisher’s LSD test) (n=12) showed that the coffee-fruit tree-enset based AF system was significantly different(P<0.05) for the nutrients Ca, K, Mg, Mn, Na and P. The annual nutrientflux of nutrients in the current study was considerably higher than ones reported for some forests and AF systems of tropical regions. The results of multiple regression analysis using stepwise backward model fit method revealed that, out of the four climatic factors, temperature was the only predictor which has a significant effect on litterfall production and included in the model. In general, the implication of good nutrient flux is the sustainable production of crops, fruits, vegetables, and other spices as aresult of efficient nutrient cycling of different elements within the system.
How to cite: Tesfay, H., Sandén, H., Bauer, A., and Melcher, A.: Litterfall Production and Associated Macro and Micro- nutrient Fluxes in Indigenous Agroforestry Systems of the Southeastern Rift Valley Landscapes, Ethiopia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18515, https://doi.org/10.5194/egusphere-egu26-18515, 2026.
Nitrogen (N) and phosphorus (P) are essential nutrients for crop production; however, excessive nutrient inputs beyond crop demand remain a major driver of nutrient losses to soil–water systems, resulting in eutrophication, greenhouse gas emissions, and declining nutrient use efficiency. Nutrient balance, defined as the difference between nutrient inputs from fertilizers and livestock manure and nutrient outputs via crop uptake, provides an integrative indicator for assessing nutrient surpluses and associated environmental risks in agricultural land.
In Korea, national nutrient balances remain among the highest in OECD countries, reaching 240 kg N ha⁻¹ and 44 kg P ha⁻¹ in 2022, largely due to livestock-related nutrient inputs. To explore effective strategies for reducing nutrient surpluses and improving soil and water conservation, this study evaluated three national-scale nutrient management scenarios: (i) optimized fertilizer application based on soil testing, (ii) reduction in livestock numbers, and (iii) improvement of livestock manure treatment rates. Scenario analysis showed that nutrient balances could be reduced by up to 20%, 25%, and 50% under scenarios (i), (ii), and (iii), respectively, indicating that enhanced manure treatment is the most effective leverage for mitigating nutrient overloads at the national scale.
These findings highlight the importance of integrated nutrient management approaches that combine precision fertilizer use with improvements in livestock manure management. Furthermore, the results suggest that improving manure treatment efficiency, together with circular nutrient use and manure-to-energy conversion, can contribute to reducing nutrient losses to water bodies while supporting long-term sustainability and climate mitigation goals. This study provides a policy-relevant framework for advancing nutrient management strategies aimed at soil and water conservation in intensive agricultural systems.
How to cite: Park, H., Lee, Y., and Lee, C.: National-scale Scenario Analysis of Nutrient Management Strategies for Soil and Water Conservation in Korea, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16600, https://doi.org/10.5194/egusphere-egu26-16600, 2026.
Soil fertility depletion, spatially variable nutrient limitations, and increasing climate variability are major constraints to crop productivity and resource conservation in Sub‑Saharan Africa (SSA). Sustainable nutrient management strategies that simultaneously improve crop yields, enhance soil health, and reduce nutrient losses are urgently needed to strengthen agricultural resilience. This study presents an integrated modelling framework for quantifying gaps in nitrogen (N), phosphorus (P), and potassium (K) fertilization under water‑limited conditions. The aim is to support site‑specific nutrient recommendations that improve fertilizer use efficiency while contributing to soil and water conservation.
The framework combines three complementary models. INITIATOR simulates soil nutrient stocks and flows, providing a spatially explicit assessment of nutrient availability and potential depletion risks. WOFOST estimates water‑limited maize yield potential, capturing the influence of rainfall variability and soil moisture dynamics on attainable production. QUEFTS then models nutrient uptake and yield responses, enabling calculation of nutrient requirements that match crop demand without excess application. Together, these components enable a holistic evaluation of nutrient management in soil–crop–water systems on different management levels.
The approach was applied to Uganda, a country characterized by strong agro‑ecological diversity, high interannual rainfall variability, and widespread soil degradation. Using 1 km resolution SoilGrids data and climate records from 2001–2024, spatially explicit water‑limited yield potentials were simulated for maize across the country. Fertilizer requirements were calculated based on median attainable yields for the period . Results reveal substantial geographic variation in nutrient availability, nutrient use efficiency, and fertilizer needs. In many areas, low soil nutrient stocks combined with high potential yield estimates lead to large fertilization gaps, while in other regions the gap is smaller due to relatively higher soil fertility or lower potential yields due to moisture constraints.
These findings demonstrate that uniform fertilizer recommendations are unlikely to be effective under the diverse soil and climatic conditions of SSA. The proposed modelling framework provides a robust decision‑support tool for developing precision nutrient management strategies that align nutrient inputs with both crop demand and water availability. Such targeted approaches can help reduce nutrient losses to the environment, maintain soil fertility, and support sustainable intensification efforts across smallholder farming systems. This work highlights the potential of integrated soil–crop–climate modelling to guide context‑appropriate nutrient management solutions that enhance productivity while promoting soil and water conservation.
How to cite: Vavlas, N.-C., van den Dool, K., Tolomio, M., Schut, A., Berghuijs, H., de Wit, A., Mossa, A., Leenaars, J., Silatsa Tedou, F., Stewart, Z., Nagarajan, L., Kodjovi Ezui, G., Gaihre, Y., de Vries, W., and Ros, G.: Spatially Explicit NPK Fertilization Gaps Under Water‑Limited Conditions: An Integrated Modelling Approach for Sustainable Nutrient Management in Sub‑Saharan Africa, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19889, https://doi.org/10.5194/egusphere-egu26-19889, 2026.
Efficient nitrogen (N) management is a major challenge in Mediterranean agriculture due to high spatial variability, climatic constraints and increasing environmental pressure. To address these challenges, a decision support system (DSS), named TeleNitro DSS, was developed within a PRIMA project involving Spain, Italy, Morocco and Tunisia, targeting horticultural crops such as melon, pepper and broccoli to support real-time, field-specific nitrogen management.
The TeleNitro DSS integrates crop information, soil properties, irrigation water quality, climatic data and remote sensing products. Multispectral satellite imagery is used to derive vegetation indices related to crop vigor and nitrogen status, while field and laboratory measurements, including nitrate determination using ion-selective electrodes, are incorporated to improve diagnostic accuracy. The system architecture includes data acquisition and integration, intelligent analysis modules and a user-oriented interface.
The DSS provides actionable outputs such as nitrogen status diagnostics, fertilization recommendations and climate-informed alerts, enabling dynamic adjustment of nitrogen applications throughout the growing season. It also allows tracking of management decisions and agronomic outcomes, supporting continuous optimization of fertilization strategies.
The TeleNitro DSS is designed to improve nitrogen use efficiency, reduce fertilizer losses and support sustainable crop management through digital decision-making tools.
How to cite: Hernández, P., García-Sánchez, F., Camara Zapata, J. M., and Jorquera, D.: Design and Development of a Decision Support System for Real-Time Nitrogen Management in Mediterranean Cropping Systems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22660, https://doi.org/10.5194/egusphere-egu26-22660, 2026.
Spatial allocation of best management practices (BMPs) is crucial for reducing non-point source pollution at the watershed scale. However, uncertainty in BMP effectiveness caused by varying hydro-meteorological conditions can pose challenges to achieving water quality management goals, emphasizing the need to incorporate these uncertainties into decision-making. Here we develop a credibility-based chance-constrained programming (CCP) framework to explicitly embed uncertainty into BMP planning and to support reliable multiobjective decisions. We model the dependence in BMP effectiveness with vine copulas and assess its implications for outlet loads via a Markov-based surrogate that approximates the relationship between BMP spatial configurations and outlet load responses. We couple this stochastic simulation–optimization workflow with NSGA-II to search Pareto-optimal trade-offs between implementation cost and nutrient-load reduction while explicitly estimating the reliability (credibility) of candidate solutions. To support actionable choices, the resulting solution set is further condensed via clustering and fuzzy-set ranking to identify representative best-compromise solutions. The results show that the system cost increased by up to 3.4 times with the increase of reduction goal (30–60%). Notably, higher credibility levels allow for slight increases in pollution loads (1.48%-5.67%) without significantly raising costs. Overall, the proposed uncertainty-aware CCP framework enables decisionmakers to balance costs and environmental benefits while ensuring robust and reliable decisions. This approach is highly adaptable to BMP planning in complex environmental systems, enhancing its practicality for multiobjective watershed management.
How to cite: Ding, W. and Hu, C.: A copula-based chance-constrained programming framework for BMPs spatial configuration planning, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5498, https://doi.org/10.5194/egusphere-egu26-5498, 2026.
Agricultural soil plays a dual role in the terrestrial carbon cycle, acting both as an important carbon reservoir and a major source of greenhouse gas (GHG) emissions. Organic fertilizer substitution (OFS) is thought to be an effective management strategy to improve soil carbon(C) content and soil health, while at the same time maintaining crop productivity. However, the optimal ratio of OFS that can simultaneously enhance crop yield and reduce soil C losses remains unclear for sustainable agricultural soil management. Therefore, in this study we access the optimized ratio of OFS across China and quantify the responses of crop yield and net C balance to variations in OFS. We compiled a database of crop yield and net C balance—defined as changes in soil organic carbon (SOC) and greenhouse gas (GHG) emissions—for wheat, maize, and rice production in China. This database was used to develop a machine learning model to predict crop yield, GHG emissions, and net C balance for the three crops, which was subsequently upscaled using gridded environmental datasets representing the major crop production systems across China. The results showed that the optimal OFS ratio varied between 10% and 90%, with most values concentrated in the range of 20–40%. Under the optimal OFS ratio, crop yields increased at the national scale, with greater yield gains observed for maize and rice than for wheat. In addition, optimal OFS significantly enhanced the net C balance of the three major cropping systems across China, generating additional carbon sinks of 1081.81, 930.05, and 510.76 Tg CO₂-eq for maize, rice, and wheat, respectively, compared with business-as-usual (BAU) scenarios. Overall, our results indicate that OFS represents an optimal field management strategy that not only enhances agronomic productivity but also improves environmental performance.
How to cite: Wang, Y., Liu, S., Han, J., Duan, X., Ma, Q., Liu, H., and Zhou, W.: Optimizing organic fertilizer substitution for yield-carbon tradeoffs in staple crops across China , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17767, https://doi.org/10.5194/egusphere-egu26-17767, 2026.
Posters virtual: Wed, 6 May, 14:00–18:00 | vPoster spot 2
EGU26-21561 | Posters virtual | VPS17
Impact of different pre-crops on soil nitrogen and growth of following winter wheatWed, 06 May, 14:21–14:24 (CEST) vPoster spot 2
Winter wheat yields are varying by preceding crop as shown for certain preceding crops like wheat itself, winter oilseed rape or different legumes. However, there is hardly any published data on the pre-crop effect of other economically important crops such as sugar beet and silage maize. Further, the mechanisms of the pre-crop effect are partially unknown.
In this study, winter wheat was grown after wheat, winter oilseed rape, sugar beet and silage maize over two winter wheat growing periods (harvest years 2024 and 2025) in a long-term crop rotation trial in Central Germany. Soil mineral nitrogen (SMN) in 0-90 cm soil depth was analyzed at sowing in October, in December, January and February. After the last SMN sampling, plots were split into no (N0) and regular nitrogen fertilization (Nopt). At harvest, grain yield and straw biomass were recorded as well as nitrogen uptake.
Levels of SMN at sowing in October were clearly affected by pre-crop type with higher values after oilseed rape and lowest values after silage maize and sugar beet. In December, SMN levels were similar to October, while in January differences between the pre-crops became smaller and were mostly levelled by February. At N0, in both years, wheat grain yield as well as straw biomass was clearly highest after oilseed rape with up to 100 % more total biomass than after the other pre-crops. Other pre-crops had similar effects on total biomass. At Nopt, differences between the pre-crops were overall much lower, yet highest yields were found after oilseed rape.
December SMN levels correlated with grain yields at N0 over both years, while a similar correlation was even found under Nopt conditions in one of the study years. Thus, it appears nitrogen supply originating from pre-crops affects winter wheat growth. This might be one way pre-crops affect wheat growth beyond regulation of disease pressure.
How to cite: Grunwald, D., Koch, H.-J., and Jacobs, A.: Impact of different pre-crops on soil nitrogen and growth of following winter wheat, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21561, https://doi.org/10.5194/egusphere-egu26-21561, 2026.
