Recent advancements by national institutions in Japan have significantly enhanced the accessibility of geotechnical information, enabling researchers to utilize extensive datasets via online platforms. While these datasets have been widely employed in various studies, systematic analyses of relationships among variables within large-scale geotechnical data remain limited. This study aims to address this gap by analyzing relationships between variables using a comprehensive nationwide dataset of soil tests provided by the National Geo-Information Center (NGIC). The analysis of soil hydraulic conductivities revealed a strong dependence on the proportion of fine-grained components, such as clay and silt fractions. However, correlation analysis indicated that the strongest relationship, observed with the clay fraction, yielded a correlation coefficient of -0.51, suggesting a moderate association. Further investigation into variables such as dry density, natural water content, and void ratio demonstrated their dependence on the proportion of fine-grained fractions. Notably, the upper and lower bounds of these variables were influenced by fine particle content. A particularly significant finding was the observation that as the proportion of fine particles decreased, the void ratio also declined, leading to an increase in the permeability coefficient. These results provide valuable insights into the relationships between geotechnical properties and particle-size composition, offering a novel perspective on soil behavior. This study highlights the potential of utilizing extensive geotechnical datasets to advance our understanding of soil properties and their dependencies. The findings contribute not only to the theoretical understanding of geotechnical systems but also to practical applications in geotechnical engineering, providing a foundation for future research and data-driven approaches to soil analysis.

How to cite: Teruya, S., Ishida, K., and Sato, A.: Analysis of relationships among variables in nationwide big data of geotechnical information in Japan, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12841, https://doi.org/10.5194/egusphere-egu25-12841, 2025.

The loss of ecosystem services in semi-arid climate is closely linked to the rise of intensive agriculture and the disappearance of landscape elements that have served as buffer areas for hydrological processes and biodiversity over the last decades. As a response, environmental and agricultural policies and initiatives are now being implemented to restore these landscape elements and preserve those that remain in agricultural landscapes. Hedgerows are linear landscape elements that provide several ecosystem services. However, this positive impact varies depending on hedgerows’ characteristics and location.

This study analyses vegetation diversity and its impact on soil properties in eight hedgerows in Southern Spain's Cordoba province. To carry out this, 10m sections were defined in each hedgerow, considering two zones for soil sampling (inside the hedgerow, and within the agricultural field near it, hereafter outside the hedgerow). The evaluation of vegetation consisted of the identification of species of interest in terms of diversity, a general description of the current status of the hedgerow, and a floristic composition and dendrometric variables recording. The analysis of soil properties encompasses samples from different shallow depths (0-5 and 5-10 cm, or only 0-10 cm), and it included pH, soil hydraulic conductivity, bulk density, stability of aggregates, soil respiration by microorganisms, soil organic carbon and extractable phosphorus.

74 species were identified in total, with a high variability of the number of species recorded in most of the hedgerows, where 58% of the identified vegetative species appeared only in one of them, showing the relevance of this vegetative element in the preservation of vegetative species. Significant differences between inside and outside were obtained in all soil properties, except in extractable phosphorus and pH. Soil aggregate stability and organic carbon reached average values of 424.3 g kg^-1 and 3.0% inside, versus 265.8 g kg^-1 and 1.4% outside, respectively. There was a large variability in some of these properties among different hedgerows. For example, soil respiration varied from 229.7 to 1936.1 mg CO₂ kg^-1 day^-1 and 117.9 to 561.7 mg CO₂ kg^-1 day^-1 inside and outside the eight hedgerows, respectively. This contribution highlights many variables to be considered in hedgerows’ assessments and their complexity, such as the moment of establishment, current management of neighbouring plots, and state of conservation of the own hedgerow.

Acknowledgement: This work was funded by the Spanish Ministry of Science and Innovation (project PID2019-105793RB-I00), financial support from the European Union’s Horizon 2020 under the project SCALE (EUHorizon2020 GA 862695), and a predoctoral fellowship for the first author (PRE2020-093846).

How to cite: Muñoz, J. A., Guzmán, G., Montoliu, J., Hayas, A., Ramos, A., López, M., Mora, J., and Gómez, J. A.: Impact of hedgerows on the improvement of soil characteristics and vegetation diversity in the semi-arid agricultural landscape of Spain, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-430, https://doi.org/10.5194/egusphere-egu25-430, 2025.

Husks are a common agricultural waste in Indonesia, often discarded or burned, leading to environmental pollution and waste of resources. Therefore, this study proposes an innovative approach to optimize biochar production from rice husks. By determining the optimal pyrolysis temperature and duration, the research aims to produce the highest quality biocharThe pyrolysis temperatures tested were 400°C, 450°C, 500°C, and 550°C, with durations of 30 minutes, 45 minutes, 60 minutes, 75 minutes, and 90 minutes, respectively. The physical and chemical properties of the biochar such as pH, element content, cation exchange capacity (CEC), and biochar yield, were evaluated. An environmental impact assessment was conducted using the ReCiPe 2016 Endpoint H method, integrating life cycle assessment (LCA). The results revealed that a pyrolysis temperature of 550°C for 60 minutes enhanced carbon stability, pH, and nutrient retention. Additionally, the ideal pyrolysis duration significantly improved the biochar’s surface properties. According to the LCA analysis, the biochar produced shows great potential for soil improvement and environmental benefits, including the reduction of greenhouse gas emissions. This research provides a new framework for balancing biochar quality with its environmental impact and promotes sustainable agricultural waste management as part of a global effort to combat climate change.

How to cite: Wahyuni, T., Ngadisih, N., Purwantana, B., Martini, T., Susilawati, H., Meidaliyantisyah, M., Dewi, R., Maftukhah, R., Alfayanti, A., and Sasongko, N.: The role of temperature and duration of pyrolysis on the properties of rice husk biochar and its environmental implications, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14207, https://doi.org/10.5194/egusphere-egu25-14207, 2025.

Understanding the distribution of soil organic matter, carbon (C) and nitrogen (N) within aggregates and across soil profiles is critical for improving soil fertility, nutrient cycling, and long-term sustainability in agricultural systems. This study evaluates the short-term effects of various crop rotations and cover cropping systems on soil organic matter (SOM), aggregate-associated C and N fractions, and their vertical distribution in the soil profile. A three-year field experiment was conducted at the Agronomy Research Farm, Southern Illinois University Carbondale, with treatments including: (1) corn (Zea mays L.)-soybean (Glycine max L.) rotation without cover crop (CNSN), (2) corn-soybean rotation with rye cover crop (CRSR), (3) corn-wheat (Triticum aestivum L.)-soybean rotation without cover crop, and (4) corn-wheat-soybean rotation with a cereal rye (Secale cereale L.) cover crop (CWSR). Soil aggregates were collected from 0-5 and 5-15 cm depth and used for assessing aggregate size distribution, aggregate stability, SOM, soil C and N. Bulk density and soil C and N along with soil organic matter was measured from samples collected from 0-90 cm depth. CRSR and CWSN, significantly increased medium-sized aggregates (1-2 mm and 0.5-1 mm) as compared to the CNSN treatment. Including cereal rye into double cropping systems (CWSR) improved soil’s aggregate stability. Cropping systems, particularly those with winter wheat and cereal rye, increased soil organic matter in 2-4.75 mm aggregate fraction as compared the CNSN control. Soil organic matter concentration decreased with depth, with the highest values at 0-5 cm across all cropping systems. Soil bulk density by depths, soil C and N within aggregate and by depth will also be presented at the meeting. Our current findings indicate that utilizing CWSR could provide economic and soil benefits to growers in Illinois.

How to cite: Sheikhi Shahrivar, F., Ola, O., Javid, M., Brevik, E., Williard, K., Schoonover, J., Gage, K., and Sadeghpour, A.: Soil organic matter and carbon fractions within aggregates and in soil profile in double- and cover cropping systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13615, https://doi.org/10.5194/egusphere-egu25-13615, 2025.

Optimizing nitrogen (N) management in agricultural cropping systems is important for reducing nitrous oxide (N₂O) emissions. This study examined the effect of managing N application in a winter wheat (Triticum aestivum L.) double-cropped with soybean (Glycine max L.) on biomass, grain yield, and N₂O emissions. The experiment was conducted at the Agronomy Research Center (ARC), Carbondale in Southern Illinois University, IL using a Randomized Complete Block Design (RCBD). The treatments include N timing and rate, creating three N management intensities of low, medium, and high. Low-intensity treatment received 120 kg N ha^-1 in fall and spring, medium-intensity treatment received 186 kg N ha^-1 all in spring and high intensity treatment received 186 kg N ha^-1 in fall and spring. Results revealed that the treatment with medium-intensity input of N application did not have a significant effect on winter wheat biomass, grain yield, and N₂O cumulative fluxes in comparison to the high-intensity N management treatment. The results for average soybean grain yield under the various fertilizer inputs (3,087 kg ha^-1) were significantly different when compared to the no-cover crop (NOCC) (3,527 kg ha^-1) The cumulative N₂O fluxes were similar under all treatments for soybean and winter wheat. The summed cumulative N₂O fluxes were similar in both the medium and high N-intensity treatments during the soybean and winter wheat phases but higher than those of low intensity. Since the wheat yield was similar among all treatments, reduction in N₂O during wheat-soybean rotation suggests that low-intensity treatment ensures farm profit while reducing N₂O emissions.

How to cite: Ola, O., Guzel, O., Gage, K., Williard, K., Schoonover, J., Mueller, S., Brevik, E., and Sadeghpour, A.: The Impact of Nitrogen Management and Winter Wheat as A Double Crop on Nitrous Oxide Emissions in A Wheat-Soybean Crop Rotation., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14128, https://doi.org/10.5194/egusphere-egu25-14128, 2025.

Illinois nutrient loss reduction strategy is questing to reduce nitrate-N (NO₃-N) and phosphorus (P) loss by 25 and 15% by 2025. Fall applied ammonium-based P fertilizers could result in both NO₃-N and phosphate loss during the fallow period. Two ways to minimize these losses are by utilizing nitrification inhibitors and also assessing other sources of P including triple superphosphate (TSP) and dissolved air flotation (DAF) that separates solids from liquid manure. A four-times replicated experiment was initiated in fall 2023 with Randomized Complete Block Design and five treatments in Agronomy Research Center, Carbondale, IL. Treatments were fertilizers [Control, TSP, DAF (Dissolved Air Flotation), MAP, & MAPI (MAP + urease and nitrification Inhibitor)], timing (fall & spring) and application type (surface & tilled). Data on nitrous oxide emissions, moisture, temperature, NO₃-N leaching, and soil N were recorded during fall and spring prior to planting of corn (Zea mays L.) and agronomic observations (plant height, LAI & NDVI) were recorded on corn in fall. Soil N₂O-N emissions were higher in MAPI and DAF during early February and late April dates, which can be explained by N availability along with high moisture and high temperatures, respectively during those sampling dates. Over winter and spring, MAPI had consistently higher NO₃-N, NH₄-N and total N especially in the late sampling dates and leaching losses were less under DAF (23% and 34%, respectively) and TSP (56% and 63%, respectively) compared to MAP or MAPI, suggesting that nitrification inhibitor did not reduce leaching from MAP source when applied in fall. Corn growth was slightly higher under DAF compared to other fertility treatments indicating it can be a potential replacement to the synthetic P fertilizers.

How to cite: Koduru, S., Keshavarz Afshar, R., Javid, M., Brevik, E., and Sadeghpour, A.: Nitrate Leaching and Nitrous Oxide Emissions from Fall Applied Manure and Phosphorous Fertilizers in Southern Illinois, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13616, https://doi.org/10.5194/egusphere-egu25-13616, 2025.

Shifting from reduced tillage (RT) to no-till (NT) often reduces phosphorus (P) runoff by minimizing soil erosion. However, it might increase nitrous oxide (N2O) emissions or nitrate-N (NO_3-N) leaching. Including a legume cover crop such as hairy vetch (Vicia villosa L.) before corn (Zea mays L.) is a common practice among growers in the Midwest USA. However, the effects of hairy vetch following soybean (Glycine max L.) harvest on NO₃-N leaching and N₂O emissions during the following corn season in soil with clay and fragipans are less assessed. This study evaluated the influence of cover crop (hairy vetch vs. no-CC control) and tillage systems (NT vs. RT) when 179 kg ha−1 nitrogen (N) was applied at planting on (i) corn yield, N uptake, removal, and balance; (ii) N₂O emissions and NO₃-N leaching; (iii) yield-scaled N₂O emissions and NO_3-N leaching during two corn growing seasons. We also evaluated factors influencing N₂O emissions and NO₃-N leaching via principal component analysis. Corn grain yield was higher in RT (8.4 Mg ha⁻¹) than NT (6.2 Mg ha⁻¹), reflecting more available N in the soil in RT than NT, possibly due to the favorable aeration and increased soil temperature in deeper soil layers resulting from tillage. Hairy vetch increased corn grain yield and soil N. However, it led to higher losses of both N₂O-N and NO₃-N, indicating that increased corn grain yield, due to the hairy vetch’s N contribution, also resulted in higher N losses. Yield-scaled N₂O-N emissions in NT-2019 (3696.4 g N₂O-N Mg⁻¹) were twofold higher than RT-2019 (1872.7 g N₂O-N Mg⁻¹) and almost fourfold higher than NT-2021 and RT-2021 indicating in a wet year like 2019, yield-scaled N₂O-N emissions were higher in NT than RT. Principal component analysis indicated that NO₃-N leaching was most correlated with soil N availability and corn grain yield (both positive correlations). In contrast, due to the continued presence of soil N, soil N₂O-N fluxes were more driven by soil volumetric water content (VWC) with a positive correlation. We conclude that in soils with claypan and fragipans in humid climates, NT is not an effective strategy to decrease N₂O-N fluxes. Hairy vetch benefits corn grain yield and supplements N but increases N loss through NO₃-N leaching and N₂O-N emissions.

How to cite: Adeyemi, F., Thilakaranthne, A., Tiwari, M., Adeyemi, O., Singh, G., Williard, K., Schoonover, J., Brevik, E., and Sadeghpour, A.: Assessing the Impacts of Tillage and Crop Rotation on Nitrous Oxide Emissions in Poorly Drained Alfisols., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14393, https://doi.org/10.5194/egusphere-egu25-14393, 2025.

This study aimed to investigate the spatiotemporal changes and trade-offs/synergies of ecosystem services within the Beiluo River Basin to provide a scientific foundation for rational resource allocation and sustainable development. Utilizing multi-source data and models, such as InVEST and CSLE, to quantitatively assess and analyze the spatiotemporal variations and trade-offs/synergies of three key ecosystem services—water yield, soil conservation, and carbon storage—across different periods. These periods include the relatively stable land use period from 1970 to 1990, the transitional period around 2000, and the ecological restoration period from 2010 to 2020. This study showed that：1) The overall water yield of the basin initially showed an increasing trend, followed by fluctuating decline, bottoming out in the 2000s. During the first period, the average water yield was 10.16×10⁸ m³ (37.75 mm), which decreased by 36.9% during the second period and by 25.53% during the third period compared to the initial period. Among the three land use types of forests, cropland, and grassland, the total water yield and water yield depth of cropland are always the highest, while the water yield depth of forest was always the lowest. 2) The total soil conservation displayed an upward trend with fluctuations, peaking in the 2010s. Over the first period, the average annual soil conservation was 305.62×10⁶ t (113.57 t/hm²), which increased to 364.52×10⁶ t in the transition period and significantly increased to 426.19×10⁶ t (157.75 t/hm²)during the third period. The soil conservation capacity of forests was significantly greater than that of cropland, and the construction of terraces and other engineering measures have greatly enhanced the function of cropland.3) The total carbon storage remained stable and then continued to increase, with a notable increase from the 2000s onwards, and a 24.09% increase in the 2020s when compared with the 1970s. Forests were the main carbon reservoirs, with their carbon storage significantly increasing, whereas that in grassland and cropland have decreased due to the reduction in their areas.4) Regarding changes in the spatial pattern, the areas experiencing a decrease in water yield and an increase in soil conservation and carbon storage were mainly concentrated in the high plateau and gully areas, as well as the hilly and gully regions. 5) At the basin scale, there was a trade-off between water yield and soil conservation, as well as carbon storage. Soil conservation and carbon storage, however, exhibited a synergistic relationship. The degree of synergy between soil conservation and carbon storage decreased over time, while the trade-off between water yield and the other two remained relatively stable. With the restoration of vegetation, the three key ecosystem service exhibited significant temporal and spatial variation characteristics, possessing relatively stable trade-off and synergistic relationships. The research results can provide a scientific basis for enhancing the comprehensive benefits of ecosystem services on the Loess Plateau.

Keywords: ecosystem services; InVEST Model; CSLE Model; trade-offs and synergies; Beiluo River Basin

How to cite: Zhang, Y., Zhang, X., Sun, W., Geng, W., Wang, H., Wang, M., Yu, K., and Liu, X.: Spatiotemporal Evolution Characteristics and Trade-offs/Synergies of Water Yield, Soil Conservation, and Carbon Storage Ecosystem Services in the Beiluo River Basin from 1970 to 2020, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5027, https://doi.org/10.5194/egusphere-egu25-5027, 2025.

Abstract: Terraces and vegetative measures significantly enhance soil organic carbon levels and improve the efficiency of soil carbon sequestration, serving as crucial soil and water conservation strategies. There are few studies on the differences and influencing factors of soil organic carbon sequestration benefits resulting from the combination of engineering measures and plant measures. Thus, the study analyzed the variations in soil organic carbon content(SOC) and its primary influencing factors across different vegetation cover types in terraces, and evaluated the soil carbon sequestration benefits of terraces. The study selected 96 sample plots in Wuqi County, Shaanxi province, including 37 Terraced Croplands (TC), 23 Terraced Grasslands (TG), 18 Terraced Forestlands (TF), 10 Terraced orchards (OL), as well as 8 Slope Croplands (SC) on hillsides. Soil samples were collected from soil layers at depths of 0-10 cm, 10-20 cm, 20-40 cm, 40-60 cm, 60-80 cm, and 80-100 cm, totaling 576 soil samples. In the laboratory, we measured indicators such as soil organic carbon, soil moisture content, soil bulk density, and soil mechanical composition. 1) The SOC in the 0-100 cm soil layer of the four types of land cover under the terrace ranged from 2.34 to 3.42 g/kg, with the order of TF> OL> TG> TC. 2) After SC is convert into TF, TG, TO and TC, it has improved the carbon sequestration benefits of soil. The carbon sequestration of TF, TO, TG and TC is 12.01, 8.78, 8.13 and 2.13 t/hm², respectively. 3) The vertical distribution of soil carbon sequestration benefits differs among various land cover types. The soil carbon sequestration benefit of terraced fields is higher in the 60-100 cm soil layer than the 0-40 cm soil layer. However, when terracing is combined with vegetation measures, the trend is reversed. 4) The SOC of TF, TG, TO TC, and SC exhibits a significant negative correlation with soil bulk density and an extremely significant positive correlation with soil moisture content, respectively. However, compared to SC, only the soil moisture content of TC and TO shows a significant increase. The implementation of terrace measures influences soil carbon sequestration benefits by increasing soil moisture, especially enhancing the sequestration in deep soil layers. When terraces are combined with vegetation measures, the soil carbon sequestration benefits are further enhanced, with a particularly greater impact on the sequestration benefits of surface soil. The results of our study could provide strong support for achieving the effects of relevant soil and water conservation measures and developing carbon sequestration methodology.

Keywords: soil and water conservation; soil carbon sequestration; terrace; Loess Plateau; monitoring and evaluation

How to cite: Yu, K., Zhang, X., Cheng, H., Wang, H., Geng, W., Liu, X., Wang, M., Zhang, Y., and Sun, W.: Carbon Sequestration Benefit and Influencing Factors in Terraces with Different Cover Types of Soil in the Loess Hilly Region, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6354, https://doi.org/10.5194/egusphere-egu25-6354, 2025.

Abstract:

Revegetation is vital for enhancing soil carbon sequestration. However, the impacts of revegetation and terracing measures on soil organic carbon (SOC) and SOC sequestration (SOCS), and the differences in the effects of revegetation on SOC and SOCS when implemented on sloped fields versus terraced fields, are still unclear. Thus, we conducted a field survey on cropland (CL), grassland (GL), and forestland (FL) on both sloped fields and terraced fields in Wuqi county, China’s Loess Plateau. The results showed that SOC content in FL at 0–10 cm, 10–20 cm, 20–40 cm, 40–60 cm depths were 1.70, 1.28, 1.28, and 1.19 times respectively higher than in CL. Similarly, SOC content in GL at the same depths were 1.30, 1.13, 1.18, and 1.20 times higher than in CL. In terraced, SOC content at 40–60 cm, 60–80 cm, 80–100 cm depths were 1.22, 1.28, and 1.20 times respectively higher than on sloped fields. Revegetation primarily significantly affected SOC at 0–10 cm depth on sloped fields (GL: p = 0.04; FL: p < 0.01), and more deeply (0–100 cm) on terraced fields (GL at 40–80 cm: p < 0.05; FL: p < 0.01). Furthermore, revegetation on sloped fields generated the highest SOCS at 0–40 cm depth, with a subsequent decrease as depth increased to 40–100 cm depth. Conversely, on terraced, SOCS increased with soil depth within the 0–100 cm depth. These results indicated that revegetation primarily enhanced SOCS in the surface soil (0–40 cm), and terracing measures stabilized the SOCS in the surface soil and further enhanced them in deeper soil horizons (0–100 cm). Therefore, in the context of soil erosion control and ecological restoration, the combined implementation of vegetation restoration and engineering measures can effectively stabilize and enhance SOCS, thereby fully leveraging the role of soil in mitigation climate change.

Keywords: Soil and water conservation measures; Carbon sequestration; Land use change；Vegetation restoration; Engineering measures; Deep soil organic carbon

How to cite: Cheng, H., Feng, H., Zhang, X., Yu, K., Wang, H., Geng, W., Liu, X., Zhang, Y., Wang, M., and Sun, W.: Terracing Measures Stabilize and Enhance Soil Organic Carbon Sequestration Benefits of Revegetation on the Loess Plateau, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7631, https://doi.org/10.5194/egusphere-egu25-7631, 2025.

The Weibei Upland is an important area for apple production in China and globally. In this study, soil samples were collected and analyzed from 27 representative apple orchards in Luochuan, Baishui, and Qianyang in the northern, eastern, and western parts of the Weibei Upland to determine the levels of Pb, Cd, Cr, As, Cu, and Hg, and to assess their ecological and health risks.

The results of the survey showed that the concentrations of all six heavy metals in the soil of apple orchards in the region were below the risk control values, with arsenic being the heavy element with the highest risk. The comprehensive ecological environmental risks of the investigated orchards are all in clean condition (Nemero index<1). Heavy metals in orchard soils in the region have a high childhood cancer risk and are much higher than in adults.

The survey further demonstrated that geographical location had a significant effect (P < 0.05) on the ecological and non-carcinogenic risk of heavy metals in local orchards, but agricultural management practices did not have a significant effect on the ecological and health risk of local orchards（P > 0.05）.

The results of this study may provide a scientific basis for the sustainable management and environmental protection of apple orchards in the Weibei Upland, and it is recommended to strengthen the regulation of the use of heavy metals in the production and cultivation of apple orchards in this region in order to reduce heavy metal pollution and risks.

How to cite: sun, W., Zhang, X., Bai, G., Geng, W., Wang, H., Wang, M., Zhang, Y., Yu, K., Liu, X., and Gómez, J. A.: Sustainable agricultural management does not reduce heavy metals and associated risks in apple orchard soil, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9281, https://doi.org/10.5194/egusphere-egu25-9281, 2025.

Abstract: Clarifying the complex dynamics of ecosystem service (ES) flows and identifying the key locations of the ecosystem service supply-demand chain is crucial for achieving sustainable management of ecosystem services. However, the understanding of how ES flows respond in ecological restoration projects is in urgent need of deepening. Taking the Loess Plateau in Northern Shaanxi, China as an example, this study quantitatively analyzed the effects of the Grain-for-Green Program, the world's largest vegetation restoration project, and the check-dam construction, the key soil and water conservation project.

       The results show that between 2000 and 2020, compared to the sum of the benefits generated by the two projects implemented separately, the inter-regional ES flows in the areas where these two projects were jointly implemented increased significantly (p<0.01) in terms of carbon sequestration, water source conservation, flood regulation, and soil water retention. The ES carbon flow increased year by year and then tended to stabilize, while the ES water flow showed a fluctuating downward trend with the increase of years, the trend degree of water flow rate change is -1.33×10³ m³/(km²·a). The impact of different projects showed spatial heterogeneity across the entire region, with a significant increase in regional ES flows observed in the western areas. Quantitative analysis indicated that when the Grain-for-Green Program and silt dam construction were jointly implemented, the regional ES flows of all services were higher, and the synergistic fields were more extensive. The research results can provide references for the ecological protection and restoration of the Loess Plateau region.

Keywords: Ecosystem Service Flows; Ecological Restoration; Soil and Water Conservation; Supply and Demand

How to cite: Hu, Z., Zhang, X., Geng, W., Zhang, Y., Duan, C., Wang, M., Wang, H., Liu, X., Sun, W., and Yu, K.: Response of ecosystem service flows to the ecological restoration project of Loess Plateau in northern Shaanxi Province, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11388, https://doi.org/10.5194/egusphere-egu25-11388, 2025.

Abstract: Understanding the spatiotemporal changes of sediment yield in watersheds over long time scales and their influencing factors is of great significance for soil and water conservation. Taking the upper Beiluo River Basin(7325 km²)as an example, the WaTEM/SEDEM model was used to analyze the spatiotemporal characteristics of soil erosion and sediment yield in the watershed from 1980 to 2016, as well as the driving factors, providing a scientific theoretical basis for soil and water conservation on the Loess Plateau. The results show that there have been significant changes in land use in the Beiluo River Basin. Compared to 1980, by 2016,the area of forest and grassland in the upper Beiluo River increased by 1188.60 km², a growth of 25.08%, while the area of cultivated land decreased by 1118.64 km², a reduction of 45.86%. In areas where farmland was converted to forest, the sediment yield of the watershed showed a significant decline. The sediment transport in the study area decreased from an average of 50.99 million tons per year in the 1980s to a multi-year average of 9.3434 million tons per year in this century,and the corresponding sediment transport modulus decreased from 6963 tons/(km²·year)to 1275.65 tons/(km²·year). The intensity of soil erosion was mainly characterized by severe and intense erosion before 1980, while after that, it was mainly slight erosion, followed by extremely intense and light erosion, with the smallest proportion of severe, intense, and moderate erosion. The WaTEM/SEDEM model is applicable to this study area, with a Nash coefficient reaching 0.7. Farmland conversion to forest and ecological restoration are the main driving factors for the reduction of erosion and sediment yield in the study area over the past 40 years. The erosion in the Beiluo River Basin from 1980 to 2016 showed an overall weakening trend. The results indicate that the policy of farmland conversion to forest on the Loess Plateau has been remarkably effective, and ecological vegetation construction should continue to be actively carried out.

Keywords:Soil erosion; WaTEM/SEDEM model; Driving factors; Loess Plateau

How to cite: Duan, C., Zhang, X., Wang, H., Geng, W., Hu, Z., Zhang, Y., Wang, M., Liu, X., Sun, W., Yu, K., Krása, J., Jáchymová, B., and Falcão, R. N. R.: Using WaTEM/SEDEM to characterize the spatiotemporal trend of the erosion and sediment transportation and the driving factor in a Loess Hilly-gully watershed, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14699, https://doi.org/10.5194/egusphere-egu25-14699, 2025.

This study aims to clarify the spatial distribution characteristics of ridge plant belts on soil water-holding capacity and soil structure in sloping farmland, providing a scientific basis for optimizing ridge plant belt configurations and soil and water conservation measures in Northeast China's black soil region. Sloping farmland with ridge plant belts was selected as the research object (Ridge 1: ridge spacing of 12.5 m; Ridge 2: ridge spacing of 19.5 m), and sloping farmland was selected as the control. Soil samples were collected at uniform spatial intervals from both sloping arable land with ridge vegetation strips and the control area to measure key soil properties in the surface layer (0–15 cm), and to quantify the differences in the spatial distribution characteristics of soil water-holding capacity and soil structure in sloping farmland with different spacings of ridge plant belts.  (1) Compared to the control, the sloping farmland with ridge construction showed a significant increase in total porosity, capillary porosity, saturated water holding capacity, field capacity, and capillary water holding capacity, with a relatively uniform distribution across the slope with ridge. In addition, compared to the sloping farmland with ridge 2, the soil on the sloping farmland with ridge 1 showed an increase of 0.96-1.11 times in total porosity, 1.21-1.31 times in capillary porosity, 1.03-1.25 times in saturated water holding capacity, 1.22-1.78 times in field capacity, and 1.33-1.52 times in capillary water holding capacity, respectively. (2) The soil mechanical stable aggregate content, MWD (mean weight diameter), water-stable aggregate content, and GMD (geometric mean diameter) in the sloping farmland with ridge showed significant improvements across all fields. Compared to the controls, the sloping farmland with ridge increased by 1.01-1.15 times, 0.94-1.61 times, 1-1.17 times, and 1.05-1.55 times, respectively. This indicates that the sloping farmland with ridge effectively improves soil structure compared to the control. Moreover, compared to the sloping farmland with ridge 2, the soil mechanical stable aggregate content, MWD, water-stable aggregate content, and GMD in the sloping farmland with ridge 1 increased by 1.08-1.14 times, 0.95-1.28 times, 1.07-1.15 times, and 1.14-1.40 times, respectively. Constructing ridges can improve water retention capacity structure characteristics of soil,with a more significant improvement effect observed in relatively small distances smaller distances between ridges, providing a scientific basis for the optimization of water and soil conservation measures for ridge and vegetation belts and sloping cultivated land in the black soil area of Northeast China. The construction of ridges on sloping farmland can improve the soil water-holding capacity and soil structural characteristics. In this study, sloping farmland with a smaller ridge spacing demonstrated a more significant improvement in soil quality. This research provides a scientific basis for optimizing water and soil conservation strategies in the black soil region of Northeast China, emphasizing the importance of ridge spacing in enhancing soil quality and water retention capacity in sloping farmland.

How to cite: Shao, S.: Spatial distribution characteristics of ridge plant belts on soil water-holding capacity and soil structure in sloping farmland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5365, https://doi.org/10.5194/egusphere-egu25-5365, 2025.

Soil water fluxes, including soil moisture, water storage, and recharge flux, are essential components of energy exchange at the Earth's surface and are fundamental to modeling land surface processes. Accurate estimation of soil hydraulic properties (SHPs) at the field scale is critical for simulating these fluxes, particularly within the vadose zone. Consequently, a robust understanding of soil water dynamics and associated processes relies on the precise characterization of SHPs. The experimental determination of these properties at different spatial scales are challenging and often time-consuming, especially in the case of vertically heterogeneous soils. Studies showed that the vegetation indices can provide sub-surface hydrological information. For example, the Leaf area index (LAI) of forest cover was found to be strongly correlated with the groundwater levels. This indicates that vegetation has the potential to act as a proxy for understanding many surface and sub-surface soil water processes. Inverse modeling approaches provide an opportunity to use vegetation information to estimate SHPs. The present study is aimed at developing and testing methodologies for estimating SHPs for multi-layered soils, specifically field capacity and wilting point, in an agricultural watershed. This is accomplished using variables like surface soil moisture, surface soil temperature, and canopy variables (Leaf Area Index and evapotranspiration) as proxies in different weighted likelihood combinations and carrying out the inverse modeling using the soil water balance model STICS. The methodology has been developed for three layered soil profiles (0 to 10 cm, 11 to 50 cm, and 51 to 100 cm) with combinations made from four major soil textures: sandy loam, sandy clay loam, clay loam, and clay, making 12 soil combinations. A sensitivity analysis of canopy variables relative to soil water storage properties was carried out to determine the best choice of canopy variable for estimating soil water fluxes using the EASI Method.  The results show that the soil moisture and canopy variables showed a strong correlation with SHPs, indicating that these variables could provide reliable estimates of soil water fluxes. In which the leaf area index shows more sensitivity towards the subsurface layers (sensitivity index~0.4). The study showed that the likelihood combinations of variables with higher weights to canopy variables provided better estimates of SHPs in the deeper layers. With the use of the likelihood combinations made by surface and canopy variables, we achieved mean relative absolute errors of 4% for the surface layer properties and 10% for the root zone SHPs, especially in water-stressed conditions. Since the variables used in this study are potentially accessible from the remote sensing data, the application of this methodology at large spatial scales is feasible, thereby generating spatial maps of sub-surface soil properties at regional scales, which can aid in the improved modeling of sub-surface soil moisture.

How to cite: Vk, A. and Krishnan, S.: Vegetation as proxies for improving the estimation of soil water fluxes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-446, https://doi.org/10.5194/egusphere-egu25-446, 2025.