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The role of soil in climate change

Soil has a tremendous potential to help mitigate climate change and contribute to most of the United Nations’ Sustainable Development Goals (SDGs), as expressed in the recent IPCC report on climate change and land. However, it is challenging to adapt and improve management practices for maximizing this potential, particularly when the main focus is to explore other services provided by soils, such as productivity. This is even more challenging considering the degradation status and/or risk of degradation of several soils worldwide, driven by anthropogenic activities (e.g. intensive agriculture and forestry, urbanization). The loss of organic matter and erosion are just a few examples of soil threats limiting climate change mitigation. Yet, increasing concerns have been devoted to restoring degraded land and soil in order to achieve Land Degradation Neutrality target, with impacts on increasing carbon storage. Over the last years, there has been an increasing interest on the potential of the soil to contribute to climate change mitigation and carbon neutrality. This has been noticed through several national and international initiatives, at civil (e.g. "4 per 1000" initiative) and political (e.g. Green Deal) level, and the establishment of partnerships (e.g. European Joint Programme SOIL).
This session aims to discuss the potential of soils to contribute to climate neutrality. We welcome recent research and advances on the topic, including experimental and modelling studies, and contributions addressing the following subjects:

• Short- and long-term changes on soil carbon stocks under different land uses, and their link with management and soil degradation processes;
• Impact of management practices and soil conservation techniques on soil carbon sequestration;
• Soil-water-plant-atmosphere interaction under different soil and weather conditions and climate variation;
• Impact of climate change on Land Degradation Neutrality, and interactions between Climate Neutrality and Land Degradation Neutrality;
• Integration of IoT into soil science to better support soil-related decision-making processes in achieving climate neutrality;
• Improving governance of soil sustainable management as a necessary condition for climate change mitigation and adaptation.

Convener: Carla FerreiraECSECS | Co-conveners: Tatiana Minkina, Wenwu Zhao, Nicolas Martin, Naira Hovakimyan, Zahra Kalantari
| Mon, 23 May, 11:05–11:50 (CEST), 13:20–14:50 (CEST)
Room G1

Mon, 23 May, 10:20–11:50

Chairperson: Carla Ferreira

Robert Thomas et al.

Flooding affects >300 million people each year and causes loss of life, damage to infrastructure, and long-term mental and physical health problems. Across many parts of the globe, climate change is projected to increase the magnitude, frequency, and intensity of rainfall events, thus exacerbating future flood risk and increasing the demand for flood alleviation schemes. Agricultural land covers 39% of Europe, and as such intercepts a significant fraction of precipitation. Agricultural intensification has increased soil compaction and decreased soil porosity and permeability, thus decreasing infiltration, storage and groundwater recharge. Here, we report on experiments that aim to constrain the effects of using cover crops to increase soil porosity and permeability and hence decrease runoff during rainfall events in three arable fields in East Yorkshire, UK.

Half of each field was treated with a cover crop between harvest and winter cultivation, and the organic matter of this crop was incorporated into the soil. The second half of each field was used as a control. A suite of methodologies is being used to assess the long-term influence of this extra organic matter content on soil structure, health and permeability:

  • An array of soil moisture loggers (Delta-T PR2/4, DalesLandNet MKII, GroPoint Profile 2625-N-T-4) was deployed in each field to provide long term soil moisture data at high temporal resolution;
  • Roaming soil moisture measurements (Campbell Scientific HydroSense II) were used to increase spatial coverage and resolution;
  • Laboratory measurements of soil density, ambient soil moisture content, porosity, permeability, and nutrient content (nitrogen, phosphorous and potassium); and
  • A 3D MODFLOW model parameterised with collected data was used to assess the long term impact of increased soil porosity and permeability on rainfall transmission in to surface water drainage systems.

Preliminary results suggest that enhanced organic matter – delivered through cover crops – increases soil nutrient and moisture retention and decreases the peak flow stage in adjacent drainage channels after intense rainfall events. These observations suggest soil restoration may provide an important mechanism for attenuating flood peaks under future climate scenarios.

How to cite: Thomas, R., Ahmed, J., and Johnson, J.: Cover crops as a method of enhancing soil moisture and nutrient retention on arable farmland, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13528, https://doi.org/10.5194/egusphere-egu22-13528, 2022.

Hadeer Elgendy et al.

According to the projections of the Intergovernmental Panel on Climate Change (IPCC) the impact of global warming would be detrimental for ensuring food security in the 21st century. High temperature stress in different agro-climatic zones uniformly decreases crop yield, primarily due to shortened life cycle and hastened senescence leading to considerable pre- and post-harvest losses. The only available solution for tacking this challenge includes breeding thermal stress tolerant cultivars with equivalent crop yield potential. Though this strategy has many handicaps, the foremost being huge time investments for generating stable cultivars. Hence, exploring all the possible alternatives is a high priority to ensure sustainable crop production. These results demonstrate the role of seed biopriming with a thermotolerant strain of Trichoderma sp. capable of surviving at 470C for the mitigation of thermal stress effects in tomato. Based on these results it was concluded that Trichoderma mediated reprogramming of oxidative stress markers and defense network to enhance thermal tolerance in tomato. The results of the aforementioned biochemical analysis were cross validated through histochemical and HPLC analysis. In addition, the complex route of plant-microbe interaction under both ambient and stressed conditions were also mapped using 2D gel electrophoresis and hydroponics approach. During this presentation, the fascinating journey beginning from the isolation, characterization, and identification of this thermotolerant strain of Trichoderma sp. to its formulation development will be discussed in detail.  

Acknowledgements: The research was financially supported by the Ministry of Science and Higher Education of the Russian Federation project on the development of the Young Scientist Laboratory (no. LabNOTs-21-01AB).

How to cite: Elgendy, H., Krepakova, M., Keswani, C., Voloshina, M., Nefedova, A., Minkina, T., Mandzhieva, S., and Sushkova, S.: Seed Biopriming with Trichoderma sp. as an Effective Strategy for the Mitigation of Thermal Stress Effects in Food Crops, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9850, https://doi.org/10.5194/egusphere-egu22-9850, 2022.

David Shkedi et al.

As previously foreseen, it seems like climate change effects have begun to take their toll on the environment globally, but especially in the Eastern Mediterranean-Middle East (EMME) region where a hot climate already prevails. Some of these effects include higher temperatures during summer season, greater heat stress, longer summers, lower soil moisture, greater water scarcity, more intense rainstorms, longer duration between rainstorms, reduced air quality due to greater pollution and more. Rainfall temperature is also a variable that potentially will be affected by changes in climate regime.

These alterations in climate regime might play an even greater role in soil erosion which has already become a concern on a global scale due to its impairing effects on human activity. Although, soil erosion variables have been studied extensively on various levels, very little has been researched on the effects of rainfall temperature on the soil. A few years ago, comparative research with a laboratory rainfall simulator was conducted on two soils, a clayey soil and loamy soil from Israel, in dry and wet conditions, under different rainfall temperature regimes. The researchers concluded that rainfall temperature has an impressionable effect on runoff and soil erosion that must not be ignored, and which is more pronounced in the clayey soil. Recently, and in accordance with these findings, follow-up research was conducted on two pre-wetted clayey soils, 43% and 64% clay content, respectively. The Terra Rosa soils were chosen from different locations in Israel and are similar to each other in salt concentration, organic matter content and land use (plots between olive trees in an olive grove), yet are different from one another in clay content, and possibly in clay-mineral type as well. The soils were pre-wetted and allowed to drain to field capacity state, and then were exposed to 21 mm/hr rainfall events at 3 different temperatures: 2, 20 and 35 degrees Celsius, respectively. Runoff and soil samples were collected throughout the experiments. Temperature was monitored at water tank, nozzle, soil surface and soil subsurface with thermocouples and a thermal camera. Each experiment was repeated 4 times on 2 different soils with 3 different temperatures, rendering a total of 24 experiments.

In this presentation, I will demonstrate our theory for the potential of rainfall temperature as an important variable on soil erosion and will present our initial findings based on our recent experiments.

How to cite: Shkedi, D., Sachs, E., and Pariente, S.: Effect of rainfall temperature on the erosion of clayey soils different in clay amount: experiments with a laboratory rainfall simulator, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10427, https://doi.org/10.5194/egusphere-egu22-10427, 2022.

Tamara Dudnikova et al.

The Don River Delta is a unique natural structure that performs an important ecological function as a spawning ground for endangered fish species. Shipping is a source of carcinogens of the group of polycyclic aromatic hydrocarbons (PAHs), including benzo(a)pyrene (BaP) - substances of the 1st hazard class. The maximum permissible concentration (MPC) of BaP in the soil is 20 μg / kg. The accumulation of PAHs in the floodplain soils of the delta is especially dangerous since the active washout of pollutants with the soil mass during the flood period (spring) coincides with fish spawning.

The object of the study was saturated alluvial meadow soils. Soil properties vary within the following ranges: pH - 7.3-7.5, organic carbon content - 1.2-2.0%, physical clay - 14.9-19.4%, silt - 4.9-8.9 %. Sampling was carried out to a depth of 0-20 cm. PAHs were extracted from the soil with hexane. Quantitative analysis of PAHs in the extract was carried out using an Agilent 1260 chromatograph. In this work, the content of 16 PAHs included in the list of priority pollutants of the US EPA was determined: naphthalene, anthracene, acenaphthene, acenaphthylene, phenanthrene, fluorene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, BaP, benzo(b)- and benzo(k)fluoranthene, dibenzo(ah)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-cd)pyrene.

This study presents the main patterns of PAHs accumulation in the floodplain soils of the Don River delta used by the shipping channel. The purpose of the study was to establish the influence of the technogenic factor on the accumulation of PAHs in the floodplain soils of the Don River delta. As a result of the study, it was found that, according to the content of PAHs, the soils form the following row: No. 1 - 400 μg / kg> No. 2 - 1729 μg / kg> No. 3 - 9376 μg / kg. A similar series is observed for the amount of BaP in the soil: No. 1 - 22 μg / kg> No. 2 - 201 μg / kg> No. 3 - 2013 μg / kg, which corresponds to an excess of MPC by 1.1, 18 and 100 times.

Thus, the PAHs content in soils increases downstream of the shipping channel. The maximum technogenic load falls on the soil of the monitoring site No. 3, located in the mixing zone of the waters of the Taganrog Bay and the delta of the Don.

The research was financially supported by the Ministry of Science and Higher Education of the Russian Federation project on the development of the Young Scientist Laboratory (no. LabNOTs-21-01AB).

How to cite: Dudnikova, T., Barbashev, A., Sushkova, S., Antonenko, E., Deryabkina, I., Shuvaev, E., Bakoeva, G., Elgendy, H., Johar, J., Bren, D., Yakovlenko, A., and Maltseva, T.: The technogenic factor of PAH accumulation in floodplain soils of the Don River Delta, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9822, https://doi.org/10.5194/egusphere-egu22-9822, 2022.

Gulnora Bakoeva et al.

Water regime determines the soil organic matter (SOM) content and dynamics and heavy metals (HM) availability for plants. Uncertainty natural hydrological regime is a consequence of combination of a phase of water supplying to the soil and a phase of water spreading into the soil, which causes biosphere diversity. Current gravitational frontal continually-isotropic irrigation paradigm stipulates huge consumption of the world freshwater reserves. Around 95% of this water uncontrollably spreads in landscape in result of natural hydrological regime simulation. This paradigm causes unsustainable soil organic matter regime and heavy metals uncontrolled penetration of HM into plant roots and then into trophic chains.

Improved biogeochemical cycle, including SOM and HM regime, is possible in the framework of Biogeosystem Technique (BGT*) transcendental methodology. An origin of the developed BGT* soil watering paradigm is an intra-soil pulse continuous-discrete water supply into the soil continuum, fulfilled sequentially. Discrete volume of water is supplied via syringe to the vertical cylinder of soil preliminary watering at a depth of 10 to 30 cm, diameter is of 1–2 cm. Within 5–10 min after injection, the water spreads from this cylinder of preliminary watering into surrounding soil via capillary, film and vapor transfer. Some amount of water is partially transferred gravitationally to a depth of 35–40 cm. The resulting soil watering cylinder is at a depth of 5–50 cm, its diameter is of 3–4 cm. Lateral distance between next injections along the plant raw is about 10–15 cm. The non-watered soil carcass surrounding the wetted cylinder remains relatively dry and mechanically stable. After injection, the structure of soil in the wetted cylinder restores quickly without compression from the stable adjoining volume of soil, and the soil structure memory remain functional. The mean matric potential of the soil solution is 0.2 MPa. At this potential, a leaf stomatal apparatus operates in regulation mode. Relatively high concentration of soil solution provides an increased rate of plant supply with nutrients. Transpiration rate reduced compared to the natural water regime or standard irrigation. Evaporation from soil surface is small as well. Soil solution seepage to vadose zone is excluded. Fresh water saving is up to 20 times.

BGT* soil watering paradigm reduces rate of intra-soil mass transfer, and uncontrolled lateral water redistribution to landscape. In its turn, this reduces SOM leaching from soil and improves conditions for the SOM priority synthesis, providing humic substances function, soil structuring, intra-soil reversible C sequestration, improved plant supply with fresh nutrients, better plant organogenesis, and soil biological productivity. Intra-soil application of plant protection preparation is possible.

Rather low matric potential insures higher ionic strength of soil solution. Corresponding manifestations of ion association and carbonate calcium equilibrium in soil solution provide association of HM with macro-ions PbCO30, (PbCO3)20, PbHCO3+, PbSO40 PbCl+, PbOH+, Pb(OH)20, CdCO30, CdHCO3, CdSO4 CdSO40, CdCl+, CdOH+ and other, and consequent irreversible passivation of HM via complexation in soil mineral-organic system.

The research was supported by the Strategic Academic Leadership Program of the Southern Federal University ("Priority 2030").

How to cite: Bakoeva, G., Kalinitchenko, V., Glinushkin, A., Kislov, A., Minkina, T., Sushkova, S., Mandzhieva, S., Budynkov, N., Mukovoz, P., Larin, G., Rykhlik, A., Fedorenko, E., and Grishina, E.: Biogeosystem Technique transcendental intra-soil pulse continuous-discrete watering paradigm for soil organic matter sustainable regime and heavy metal passivation , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9941, https://doi.org/10.5194/egusphere-egu22-9941, 2022.

Ali Mehmandoost Kotlar et al.

The past dry summers of 2018, 2019 and 2020 have indicated the sensitivity of Flemish agriculture to drought. In the Flemish polders, this resulted not only in crop water stress, but also in increasing soil and water salinity levels due to the high evaporative demand and the occurrence of salt water lenses in the subsurface. Due to the increasing occurrence of weather extremes as a consequence of climate change, farmers will need to deal with both too little and too much freshwater in the future. Compared to conventional drainage systems, adaptive drainage can secure food production and lower the irrigation need by only draining water when it is strictly necessary and thereby leaving more opportunities for water retention and groundwater recharge.  

In the project OP-PEIL, we will investigate the impact of adaptive drainage on water fluxes and availability, water quality as well as on the cropping system itself (crop growth, disease pressure, yield and quality) during 3 years. We will use geophysical techniques to monitor the impact of adaptive drainage on the fresh/salt water interface in the drained field, as well as in the nearby landscape. Finally, we will set up numerical experiments using water balance models (e.g. SWAP- WOFOST and DRAINMOD) and the available historical climate, field management, and soil hydraulic properties data will be performed to evaluate more extensive climatological scenarios. By the end, this four-year project will raise awareness of farmers and stakeholders about the impact of adaptive drainage on agricultural practices in the Flemish Polders in Belgium.  


How to cite: Mehmandoost Kotlar, A., Everaer, B., Blanchy, G., Huits, D., and Garré, S.: The potential of adaptive drainage to control salinization in Polder context , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8643, https://doi.org/10.5194/egusphere-egu22-8643, 2022.

General discussion

Mon, 23 May, 13:20–14:50

Chairperson: Carla Ferreira

Diana Vieira et al.

Lately, there has been a lot of discussion on soil terminology, perhaps because policymakers have recognized the need to use soil as an ally tackling future climate demands, but mostly because this recognition will likely be translated from the EU Soil Strategy into a new soil health law for the EU. Such an initiative for soil is tightly connected to the EU Biodiversity Strategy for 2030, the Climate Adaptation Strategy, the UN 15.3 Goal for Land Degradation Neutrality, and other environmentally-related policy initiatives (Figure 1) stemming from the European Green Deal and from the UN Sustainable Development Goals.


Figure 1. Links between EU Soil Strategy and other EU initiatives. Source: European Commission, 2021.


At the end of 2021 the European Commission launched the EU soil strategy for 2030, giving the first step towards a consolidated understanding of what a healthy soil means, “(…) when they are in good chemical, biological and physical condition, and thus able to continuously provide as many of the following ecosystem services as possible (…)”. This definition is therefore expected to be translated into a collection and combination of various soil parameters and associated dynamic thresholds (in time and space). Allowing thus the determination of the spatial extent of healthy - and unhealthy - soils, being likely used to assess the EU progress towards the objectives set.

On top of the importance of such initiatives for our future, this is also a great opportunity for researchers and policymakers to understand i) where we stand in terms of major soil threats, ii) what the major current knowledge gaps for EU soils are, iii) and which are the areas at higher risk for land degradation that then require further restoration actions. The problem seems complex from a diversified European perspective, due to the policy landscape, [the lack of] harmonized data availability, as well as local and regional differences. Nevertheless, the EU needs to start building on the current environmental acquis.

The aim of this work is to present the current status of the EU soils making extensive use of the latest LUCAS soil monitoring campaigns and to identify and discuss with the scientific community the identification of key-thresholds for identified parameters, which will likely determine future land and soil management actions towards a healthy soil.

How to cite: Vieira, D., Muntwyler, A., Marechal, A., Orgiazzi, A., Jones, A., Schillaci, C., Ciupagea, C., Belitrandi, D., de Medici, D., de Rosa, D., Matthews, F., Martin Jimenez, J., Koeninger, J., Liakos, L., Montanarella, L., Labouyrie, M., Van Liedekerke, M., Panagos, P., Wojda, P., and Scarpa, S.: Healthy soils, a fresh start., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11432, https://doi.org/10.5194/egusphere-egu22-11432, 2022.

Peter Maenhout et al.

Carbon sequestration in agricultural soils is an important strategy to mitigate climate change which gained renewed attention in the EU soil strategy for 2030. Stimulation of soil organic carbon (SOC) sequestration can be achieved via soil management strategies. However, these strategies may stimulate greenhouse gas (GHG) emissions such as nitrous oxide (N2O) and methane (CH4) and cause nitrogen (N) losses via leaching. While these trade-offs can offset the intended climate change mitigation via SOC sequestration, synergistic (positive) effects of certain soil management strategies may positively affect the mitigation potential as well. Despite the major importance of these trade-offs and synergies for the selection of sustainable and climate-proof soil management strategies, knowledge on the understanding of these effects remains limited.

In the Framework of Horizon 2020 – European Joint Programme SOIL, the ∑OMMIT-project aims to investigate the trade-offs and synergies for the most relevant soil management strategies applied in European agricultural systems. A dedicated literature study was made by eight agricultural research institutes across Europe, summarizing the results of reviews, meta-analyses, reports and original articles. The most important soil management strategies were identified and grouped into four categories: tillage management, cropping systems, water management, and fertilization and organic matter (OM) inputs (crop residues, cover crop, livestock manure, slurry, compost, biochar, liming). Search criteria including literature and land use type, time-period, and geographic origin resulted in a unique selection of 110 references (31 reviews, 46 meta-analyses, and 33 original papers). Meta-data, extracted knowledge gaps, research recommendations and main conclusions were compiled in a knowledge gap review which allows for better insight in existing trade-offs and synergies and provides guidance to future research.

This review highlights that the increase of both SOC stock change and the microbial biomass C and N, as well as the reduction in N leaching are positively affected by conservation tillage, crop rotation, permanent cropping, more efficient water management as well as using fertilization and OM inputs (e.g., cover crops, organic amendments, biochar, and liming). The effects on the N2O and CH4 emission mitigation are dependent on the specific soil management strategy (e.g., water management, fertilization and OM inputs) and require more research to allow to define (uniform) conclusions.

In conclusion, more dedicated research is needed for the soil management strategies that simultaneously examines SOC stocks, GHG emissions, and N leaching losses. Furthermore, we identified a lack of information on the impact of pedoclimatic conditions, specifically on the longer-term, on trade-offs and synergies. A more concerted use and installation of new long-term field experiments in different pedo-climatic European regions, seems essential for a comprehensive understanding of the impact of soil management strategies at the European level. Further, since soil management strategies are often combined and their interaction may affect the trade-offs and synergies, the impact of different soil management practices should be assessed simultaneously. Overall, the review provides a unique framework to aid the (re)design of dedicated field experiments and targeted measurements as well as simulations to improve our understanding of the identified knowledge gaps.

How to cite: Maenhout, P., Di Bene, C., Cayuela, M. L., Govednik, A., Keuper, F., Mavsar, S., Mihelic, R., O'Toole, A., Schwarzmann, A., Suhadolc, M., Syp, A., and Valkama, E.: Trade-offs between soil carbon sequestration and greenhouse gas emissions, and nitrogen leaching losses: addressing knowledge gaps, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4712, https://doi.org/10.5194/egusphere-egu22-4712, 2022.

Sven Verweij et al.

The main hurdle in instrumentalizing agricultural soils to sequester atmospheric carbon is a development of methods to measure soil carbon stocks on farm level which are robust, scalable and globally available. We present a method for soil carbon stock assessment using satellite data, stratified sampling design, direct soil measurements via mobile soil sensors and machine learning, which fulfills these criteria. The method has been tested and applied for multiple farms in Europe and the United States on agricultural fields with variable crop rotations, soil types and management history. Results show that the estimates are precise, repeatable and that the approach is rapidly scalable and is able to detect variation in soil carbon stock up to a 10 meter resolution. Carbon stocks in the top 30 cm range between 17-55 ton C/hectare. Error propagation analysis showed that the error associated with the soil sensor on the level of farm C stocks is less than 5%. This precision can be achieved with as few as 0.5 field samples per hectare for farms varying from 60 to 250 hectares, ensuring affordability and scalability of the method. The method is globally applicable because it uses covariates which are also globally available. These findings can enable the structural and widespread implementation of carbon farming with a standardized method. In future, as the calibration dataset increases, even less field data will be needed to obtain robust C stock estimates.

How to cite: Verweij, S., van der Voort, T., van Doorn, M., Fujita, Y., and Ros, G.: Enabling carbon farming: presentation of a robust, affordable and scalable method of carbon stock estimates, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2258, https://doi.org/10.5194/egusphere-egu22-2258, 2022.

Zahra Kalantari

Soil carbon sequestration in croplands has tremendous potential to help mitigate climate change; however, it is challenging to develop the optimal management practices for maximization of the sequestered carbon as well as the crop yield. We aim to develop an intelligent agricultural management system using deep reinforcement learning (RL) and large-scale soil and crop simulations. To achieve this, we build a simulator to model and simulate the complex soil-water-plant-atmosphere interaction, which will run on high-performance computing platforms. Massive simulations using such platforms allow the evaluation of the effects of various management practices under different weather and soil conditions in a timely and cost effective manner. By formulating the management decision as an RL problem, we can leverage the state-of-the-art algorithms to train management policies through extensive interactions with the simulated environment. The trained policies are expected to maximize the stored organic carbon while maximizing the crop yield in the presence of uncertain weather conditions. The whole system is tested using data of soil and crops in both mid-west of the United States and the central region of Portugal. Our study has great potential for impact on climate change and food security, two of the most significant challenges currently facing humanity.

How to cite: Kalantari, Z.: Optimization of Agricultural Management for Soil Carbon Sequestration UsingDeep Reinforcement Learning and Large-Scale Simulations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13307, https://doi.org/10.5194/egusphere-egu22-13307, 2022.

Carla S.S. Ferreira et al.

Leveraging soil carbon sequestration in croplands can support climate change mitigation; however, it is challenging to develop optimal management practices to maximize both sequestered carbon and crop yield. In intelligent agricultural management systems, large-scale crop models can provide an understanding of the complex soil-water-plant-atmosphere interactions and allow the evaluation of the effects of various management practices on carbon sequestration. This study aims to investigate soil carbon dynamics in maize cropland under different management practices, and discuss their potential to leverage the carbon sink capacity of agricultural soils. The Agricultural Production Systems sIMulator (APSIM) is used to investigate soil carbon dynamics in maize cropland of Baixo Mondego, an agricultural region in central mainland Portugal, under Mediterranean climate. The model was set up using soil properties retrieved from the INFOSOIL national database and run with daily climate data from 2001 to 2020 provided by local weather stations (i.e., solar radiation, maximum and minimum temperature, and rainfall). The maize yields’ records from an agricultural farm were used for model calibration (2017 - 2019) and validation (2020 - 2021). The model was then used to investigate the impact of different scenarios focusing on distinct fertilization management practices (i.e. fertilization rates, timing, and type of fertilizer) on soil carbon and crop yields. This study is part of a larger research project funded by C3.AI Digital Transformation Institute to develop an intelligent agricultural management system using deep reinforcement learning (RL) for agriculture sustainability and climate change mitigation. This project has great potential for impact on climate change and food security, two of the most significant challenges currently facing humanity.

How to cite: S.S. Ferreira, C., Kalantari, Z., Martin, N., Marcillo, G., Zhao, P., Wu, J., and Hovakimyan, N.: Agricultural Management and Soil Carbon Sequestration: the potential of APSIM model to support climate change mitigation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8874, https://doi.org/10.5194/egusphere-egu22-8874, 2022.

Emma Burak and Ruben Sakrabani

Over‑reliance and indiscriminate use of mineral fertilisers have contributed towards declining soil health. Further, mineral fertiliser production contributes close to 1% of UK’s greenhouse gas emissions. Organo-mineral fertilisers (OMFs) are currently being investigated as a more environmentally sustainable alternative to conventional mineral fertilisers as they reduce the amount of mineral fertilisers needed by combining them with organic materials that would otherwise be destined for landfill or incineration, promoting a circular economy by returning recycled nutrients to the soil. Here, we evaluated the efficacy of a novel OMF that incorporates carbon captured from gaseous point sources into their production. This product demonstrates a potential tool for combating both climate change and soil fertility by promoting soil carbon sequestration. To assess the efficacy of these new fertilisers we conducted a field experiment consisting of three batches of OMF (5, 10 and 15%N) and compared them to a conventional mineral fertiliser and an unfertilised control in two soil types with two crops (winter barley and winter wheat).

We found that all fertilisers produced significantly more yield than the control (p < 0.05) but that there was no significant or consistent difference between the fertilisers. There was no significant or consistent differences between the stimulated root growth for any treatments (p = 0.60) and the same for organic matter, microbial biomass, pH, available nutrients (N, P, K), total nutrients (N, C, P), and metals. This leads to the conclusion that organo-mineral fertilisers can perform at least as well as conventional fertiliser. Though more seasons are needed to evaluate the benefits to the soil.

How to cite: Burak, E. and Sakrabani, R.: Evaluating the efficacy of novel green fertilisers derived from combining carbon capture technology and organic waste materials  , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9258, https://doi.org/10.5194/egusphere-egu22-9258, 2022.

Melani Cortijos-López et al.

Land abandonment is outstanding as one of the main causes of soil degradation in Mediterranean mid-mountains. This process is closely linked to the rural exodus that took place in the middle of the last century, that led to the activation of natural revegetation mechanisms and massive shrub encroachment. Consequently, several ecosystem disservices have been identified, such as homogenization of landscape, loss of biological and cultural diversity, decrease in water-human-consume resources, reduction of agropastoral resources and higher wildfire risk. However, the effects on soil environment are multiple and controversial. Thus, a case study in the Leza Valley (La Rioja, Spain) has been selected to analyse the effects of post-land abandonment management through shrub clearing practices in soil quality, carbon dynamics and carbon sequestration, in order to give a second chance to these marginalised areas while fighting against Global Change.

For the soil sampling, 5 land uses have been selected: control pasture, 3 shrub clearing sites of different ages; and shrubland after cropland abandonment (6 replicates at different depths, 0-40 cm, have been collected at each study site). Physico-chemical and biological properties of the soil have been analysed in the laboratory, distinguishing between basic and acid soils. Furthermore, a theoretical map of hypothetical future shrub-cleared areas and its potential to sequester carbon has been created.

Preliminary results showed  significant differences between post-land abandonment practices. Time since intervention has resulted a key factor in carbon dynamic evolution, and an increase in carbon storage and concentration with management has been recorded.

To sum up, management through shrub clearing has demonstrated to be an adequate strategy to offset carbon emissions to the atmosphere in soils of abandoned areas in the Mediterranean mid-mountains, offering socio-economic and ecological benefices while becoming an important tool against Global Change.

This research is part of the MANMOUNT project (PID2019-105983RB-100/AEI/ 10.13039/501100011033) funded by the MICINN. Melani Cortijos-López is working with an FPI contract (PRE2020-094509) from the Spanish Ministry of Economy and Competitiveness associated to the ESPAS project.

How to cite: Cortijos-López, M., Sánchez-Navarrete, P., Errea, P., Lasanta, T., and Nadal-Romero, E.: Post-land abandonment management through shrub clearing practices as a tool for enhancing soil quality and carbon storage. , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4808, https://doi.org/10.5194/egusphere-egu22-4808, 2022.

András Bidló et al.

Temperate forest ecosystems store significant amounts of organic carbon. Site conditions, species composition, and age of stands largely influenced the amount of stored carbon. International and Hungarian studies have shown that nearly half of the carbon stored in the soil in organic matter forms in forest ecosystems. The main goal was to determine the amount of carbon stored in loess soil. Our preliminary studies have shown that climatic conditions (and the forest composition determined) have a huge effect on the carbon stock of soils. To demonstrate this effect, forest stands on loess bedrock under different climatic conditions were selected for the study. Soil drilling was performed in 40 stands and soil samples were taken by 10 cm layers from 0-110 cm depth. In addition to the soil samples, we also determined the litter mass and composition of the forest stand.
Results showed that the loess soil was leached under the forest stands, so its pH was 5.8 on average (min: 3.9; max.: 8.5). Only deeper levels contained 13% CaCO3 (min: 1.1%; max.: 37%) in the profiles. The texture of the soils was loam or clayey loam with good water holding capacity; therefore, the soil types were Luvisol and Cambisol soils. The average amount of carbon stored in the soils was 1.04 % (min.: 0.02%; max.: 7.3%)  In the future, we will try to clarify the relationship between soil organic carbon stocks and weather conditions.

Project no. 141603 has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the MEC_R_21 funding scheme.

How to cite: Bidló, A., Végh, P., and Horváth, A.: A large-scale study of the carbon stock of Hungarian forest soils, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7762, https://doi.org/10.5194/egusphere-egu22-7762, 2022.

António Ferreira

Soils are by definition important carbon sinks, in particular for non-tropical types of climates, an important part of carbon in ecosystems are located on them. Under climate change, those carbon sinks are placed under stress due to often-subtle changes that modify the conditions for their function and rend them particularly vulnerable to dereliction, reducing the capacity to act as carbon sinks at the long term.

In agricultural soils, the intensification of cropping systems and the reduced addition of organic matter results in a sharp reduction of soils’ organic content, with important impacts on soil functioning, namely in what concerns water and nutrient cycles, which will reduce soil fertility and carbon content on the long run. This will transfer slowly but steadily soil’s organic carbon to the atmosphere, reinforcing climate change.

Forest soils suffer an even more catastrophic impact from climate change, since the regions more vulnerable have a higher frequency and intensity of the big eraser, when the forest systems fail to be in equilibrium with the climate: forest files. They are responsible altogether by the emissions of various compounds to the atmosphere, comparable to the anthropic emissions in a bad forest fire year. The soils derelict by fire lose an important part of environmental services they provide, namely suffer a significant reduction of their capacity to sink carbon. This adds to the instantaneous loss of carbon to the atmosphere during the fire and downstream to aquatic ecosystems thereafter.

We explore methodologies to reduce those losses in wet Mediterranean areas, aiming to increase the carbon sinks to reduce the atmospheric concentrations.

How to cite: Ferreira, A.: Soil and climate interactions in the Mediterranean. Are we heading for disaster?, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13285, https://doi.org/10.5194/egusphere-egu22-13285, 2022.

Maria Eliza Turek et al.

An increase in the occurrence of drought events potentially aggravate conflicts between agricultural water use and other human and ecological demands for water resources. Increasing the natural soil water retention capacity can help to defuse these conflicts and at the same time strengthen climate mitigation, biodiversity, and food security. Although a variety of measures may be taken to increase soil water retention in agricultural systems, their effects in response to climate extremes are largely unknown. As part of the OPTAIN initiative (OPTimal strategies to retAIN and re-use water and nutrients in small agricultural catchments across different soil-climatic regions in Europe, www.optain.eu), this project aims to evaluate the soil water dynamics affected by these measures and their extent of influence on the cropping system, looking for possibilities to increase the resilience to drought stress under current and future climatic conditions. The steps include (1)  utilizing information from a long-term lysimeter experiment to setup, calibrate and validate a detailed model of soil water dynamics (SWAP) for a typical Swiss cropping system, (2) specifying soil water retention measures through modifications of input parameters based on a literature review (and additional field measurements), and (3) apply the model to conduct a series of simulation experiments with varying combinations of soil water retention measures and future climate scenarios. Study findings will identify soil water retention measures with the largest potential to mitigate drought stress limitations to agricultural productivity, helping to make future arable production systems in Switzerland less dependent on supplement irrigation.

How to cite: Turek, M. E., Prasuhn, V., and Holzkämper, A.: Agro-hydrological modeling of soil water retention measures to increase crop system resilience to extreme events, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2919, https://doi.org/10.5194/egusphere-egu22-2919, 2022.

Elena Fedorenko et al.

The air pollution with fine particulate matter (PM) of dimension 2.5 µm or less (PM2.5) causes lung and other diseases. The problem of prevention of water and terrestrial systems pollution with PM dry deposits is multifaceted. The ionized O2 is capable to intensify the atmosphere turbulence, PM2.5 сoalescence, and increasing the PM dry deposition velocity. Unfortunately, outdated environmental technologies are incapable to secure this. The quality of air is linked to the pedosphere and plant kingdom. Addressing the problem of environmental quality, including the PM2.5 content reduction in the atmosphere, the Biogeosystem Technique (BGT*) transcendental (nonstandard and not a direct imitation of Nature) methodology has been developed. The BGT* focus is an enrichment of the Earth's biogeochemical cycle. The heuristic approach to land use and air cleaning is a new niche for development to improve the soil system and ensure a high rate of air cleaning. BGT* ingredients are the intra-soil processing, which provides the soil multilevel architecture; intra-soil pulse continuously discrete watering for optimal soil water regime and freshwater saving up to 10-20 times; intra-soil dispersed environmentally safe recycling of the PM sediments and other pollutants; controlled microbial community and biofilm-mediated interactions in the soil. BGT* enriches the biogeochemical cycle, provides a better function of the humic substances, biological preparation and microbial biofilms as a soil-biological starter, priority plant and trees nutrition. BGT* methodology is capable to increase plant resistance to phytopathogens. BGT* provides the formation of higher underground and aboveground biological products, thus increasing reversible C biological sequestration from the atmosphere in the form of additional aboveground biomass and soil organic matter. BGT* provides a higher rate photosynthetic production of light O2 ions, a coalescence of PM2.5, PM0.1 to the PM10 and larger particles, sedimentation of the PM, and a soil transformation of PM sediments into the nutrients. BGT* allows sustainability of the biosphere, enables a high quality of the atmosphere, stabilizes the climate system of the Earth, and is capable to promote a green circular economy.

The research was supported by the Strategic Academic Leadership Program of the Southern Federal University ("Priority 2030").

How to cite: Fedorenko, E., Glinushkin, A., Kalinitchenko, V., Swidsinski, A., Meshalkin, V., Gudkov, S., Minkina, T., Chernenko, V., Rajput, V., Mandzhieva, S., Sushkova, S., Kashcheev, A., and Aysuvakova, T. P.: New approach to soil health management and air quality: One Earth One Life , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9961, https://doi.org/10.5194/egusphere-egu22-9961, 2022.

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