During freeze‒thaw cycling, aggregates undergo a dynamic change in breakdown‒formation (turnover), however, how the turnover occurs between aggregates of various particle sizes is not clear. To clarify the influence of freeze‒thaw cycling on the dynamic changes in the particle size of soil aggregates, soil aggregates from the Black Soil Region of Northeast China were selected as the research objects. The study conducted in situ dynamic monitoring experiments, innovatively applying the rare earth oxide (REO) tracer method to natural conditions of freeze‒thaw cycles (autumn freeze‒thaw period, freezing period, and spring freeze‒thaw period), accurately tracking the turnover paths and quantifying the turnover rates between aggregates of various particle sizes. The results revealed that the total value of the formation paths of the 2–5mm aggregates and 0.25–2 mm aggregates increased during the autumn freeze‒thaw period. The number of freeze–thaw cycles and accumulated snowfall were significantly positively correlated with aggregate stability, with an increase in the number of freeze–thaw cycles and accumulated snowfall resulting in an increase in the proportion of aggregates >0.25 mm, which improved aggregate stability. In addition, the total value of the breakdown path of macro-aggregates increased during the spring freeze‒thaw cycling period. Soil moisture was significantly negatively correlated with aggregate stability, with increased soil moisture resulting in a decrease in the percentage of aggregates >0.25 mm, which resulted in a decrease in aggregate stability. The study can provide a reference understanding for the effects of freeze‒thaw cycles on the structure of black soil and provide a theoretical basis for improving the quality of arable land.
How to cite: Zhang, Y.: Impact of freeze–thaw cycling on the stability and turnover of blacksoil aggregates, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4011, https://doi.org/10.5194/egusphere-egu25-4011, 2025.
[Aims] Apple–soybean alley cropping is one of the typical alley-cropping models in the Loess Plateau of China. The study aimed to alleviate interspecific competition intensified by the growth of fruit trees using the combination of drip irrigation emitter line and mulching to regulate soil nutrient distribution and analyze effects on nutrient utilization.
[Methods] A three-year field trial was conducted in apple–soybean alley-cropping systems, setting up three drip irrigation emitter line spacings (L1: one emitter line per soybean row; L2: one emitter line for every two rows; L3: one emitter line for every three rows) and two mulching methods (M1: mulching; M0: non-mulching).
[Results] Rapidly available phosphorus (AP), rapidly available potassium and total phosphorus contents varied greatly at the same spacing, whereas AP content varied greatly at different spacings. Compared with M0, yield, nutrient contents and use efficiency of M1 significantly increased. Most of the nutrients at the denser spacing (L1) were concentrated in the surface layer with uniform distribution. At the wider spacing (L3), nutrient distribution was uneven, resulting in fewer nutrients uptake and utilization by roots. The moderate spacing (L2) with mulching alleviated the interspecific competition by optimizing nutrient distribution and facilitating root niche separation between trees and crops. In the three years, M1L2 consistently displayed the highest yield, nutrient contents and utilization efficiency. Principal component analysis showed that M1L2 achieved the highest comprehensive score.
[Conclusions] The results recommended the use of M1L2 in young apple–soybean alley-cropping systems, with L1 as a preferable control measure if M0 is used.
How to cite: Zheng, H., Wang, R., Wan, Q., Wang, L., and Chen, L.: Nutrient distribution and utilization in apple–soybean alley-cropping systems under different drip irrigation emitter line deployments and mulching methods in the Loess Plateau of China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5740, https://doi.org/10.5194/egusphere-egu25-5740, 2025.
Abstract: To explore the spatial distribution characteristics of soil physical properties and soil erosion in sloping farmland with ridges in the black soil areas of northeast China, the slope farmland with ridges built with woven bags (RW) along the contour lines was selected as the research object, and the slope farmland was selected as a control (CK). Soil samples were collected from both RW and CK at uniform spatial intervals to measure key indicators of soil properties in the surface layer (0-15 cm), including soil water holding capacity, soil structure, and annual average soil loss (A). The results showed that: (i) RW exhibited a significantly higher overall field water-holding capacity compared to CK, with soil moisture characteristics more evenly distributed spatially. Soil bulk weight, fractal dimension and soil aggregate destruction in RW were reduced by 1.09%, 0.65% and 4.61%, respectively, compared to CK. Additionally, soil total porosity, capillary porosity, mean weight diameter (MWD), and geometric mean diameter (GWD) were more evenly distributed spatially in RW. (ii) On the up-slope, soil water content and DR>0.25 in the RW had higher increase than those of the CK. On the mid-slope, soil field water holding capacity, capillary porosity, MWD and GWD in the RW had a higher increase than those in the CK. On the down-slope, RW had a 7.67%-10.79% increase in soil water content, saturated water holding capacity, field water holding capacity, and capillary water holding capacity compared to CK, with total soil porosity and soil capillary porosity increasing by 2.84% and 15.51%, respectively. (iii) Annual average soil loss (A) of RW was reduced by 61.85%~99.64% compared to CK, based on the China Soil Loss Equation (CSLE). (vi) Soil water-holding capacity and soil structure characteristics of the RW showed benefits compared to the CK, with the benefits ranging from 1.01 to 1.09, while the benefit of A reached 2.46. This study is significant for understanding the spatial distribution of soil erosion on slope farmland in black soil areas and for the effective application of soil and water conservation measures.
How to cite: Wei, S. and Fu, Y.: Characteristics of soil physical properties and spatial distribution of soil erosion on ridge-slope farmland in the black soil areas of Northeast China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3988, https://doi.org/10.5194/egusphere-egu25-3988, 2025.
Abstract: [Objective]To investigate the impact of intermittent rainfall on the amount and sorting characteristics of black soil splash erosion, [Methods] This study is based on artificial simulation of rainfall, with two rainfall intensities (40mm/h and 70mm/h) designed. Five rainfall events were conducted for each rainfall intensity to analyze the splashing erosion amount and particle size distribution characteristics of black soil under different rainfall conditions. [results] Under two different rainfall intensities, there is a dynamic development process of alternating strength between no crust, weak crust, strong crust, weak crust, and new crust in the topsoil crust of different rainfall sites. Under two different rainfall intensities, the maximum values of splashed aggregate MWD and GMD appeared in the fourth rainfall, and the minimum values appeared in the first rainfall. The agglomerates with a particle size of 5-2mm did not migrate in each rainfall, and the splashed agglomerates were mainly composed of particles with a size of 2-0.25mm, accounting for 36.49%~58.61% and 49.10%~60.09% of the splashed erosion amounts of the two rainfall intensities, respectively. The erosion amount of the five rainfall events showed a trend of first increasing and then decreasing with the decrease of particle size, while the mass percentage with particle size<0.053mm showed a trend of first decreasing and then increasing with the increase of intermittent frequency. The mass percentage with particle size<0.053mm all showed the minimum value in the third rainfall event, which was 18.21% and 17.63%, respectively.[Conclusion] Rainfall can lead to the formation of soil crust, and the thickness of soil crust shows dynamic changes with the increase of rainfall frequency. In the third rainfall, the soil crust thickness is the highest, and at this time, the splash erosion amount has the minimum value, mainly greater than 0.053mm. The research results provide reference for the study of soil water erosion mechanism in the black soil area of Northeast China.
Keywords: intermittent rain; Black soil; aggregate; erode
How to cite: Zhang, X.: Sorting Characteristics of Black Soil Splash Erosion Aggregates under Intermittent Rainfall Conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3983, https://doi.org/10.5194/egusphere-egu25-3983, 2025.
Soil water and heat are critical factors for the sustainable development of alley cropping systems in the Loess Plateau, west Shanxi, China. Experiments were conducted from 2021 to 2023 to explore the impacts of water and heat coupling regulation on crop root distribution, physiological growth, and the interrelationships between soil water and heat. The treatments consisted of three irrigation upper limit levels, set at 50% (W1), 65% (W2), and 80% (W3) of field capacity for the top 0–60 cm soil layer, and two film mulching durations: from soybean sowing to the podding stage (M1) and throughout the entire growth period (M2). Additionally, three non-irrigation control groups were included: CK0 (no mulch), CK1 (film mulching from branching to podding stage), and CK2 (full-period film mulching). In years with ample rainfall (2021 and 2023), half-period mulching was found to effectively preserve soil water compared to full-period mulching, resulting in higher underground interspecific competition coefficient; conversely, in the drier year of 2022, full-period mulching proved more effective at retaining soil water, with a lower underground species competition coefficient observed. Elevated soil moisture increased root length density (RLD) across species, intensified belowground interspecific competition, and consequently reduced soil temperature. The underground interspecific competition index initially increased and then gradually decreased as irrigation levels rose, with the peak intensity of competition occurring at the W2 irrigation level. Principal component and multiple regression analyses indicated that a water input range of 1015.63–1093.75 m3·ha−1·a−1 combined with half-period mulching was most advantageous during the initial 3–5 years of the alley cropping system under local production conditions.
How to cite: Wang, L., Wang, R., and Luo, C.: Characteristics of soil water and heat, physiological growth and interspecific competition in apple–soybean alley cropping for different water and heat coupling on the Loess Plateau, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5599, https://doi.org/10.5194/egusphere-egu25-5599, 2025.
Abstract: [Objective]To investigate the effects of intermittent rainfall conditions on pore structure and aggregate turnover in the black soil topsoil. [Methods]Black soil topsoil was selected as research object, using a combination of rare earth element tracer method + artificial rainfall simulation + CT scanning research method. To elucidate the response of topsoil aggregate characteristics, turnover characteristics of topsoil aggregates, and topsoil pore characteristics to rainfall intensity and number of rainfall events. [Results]Under intermittent rainfall conditions, isolated pores are concentrated in the topsoil layer. With the increase in the number of rainfall events, the connected porosity was always greater than the isolated porosity at a rainfall intensity of 40 mm/h, and the maximum values of connected porosity and isolated porosity alternated at a rainfall intensity of 70 mm/h. For large aggregates, as the number of rainfall events increases，when the connecting porosity decreases，the ability of 5-2 mm aggregates to break up into 0.25-0.053 mm aggregates becomes smaller, and the ability of 5-2 mm aggregates to break up into <0.053 mm aggregates increases . The opposite was true when the connectivity porosity increased. For small aggregates, as the number of rainfall events increases，the ability of 0.25-0.053 mm aggregates to break into <0.053 mm aggregates is stronger, while the ability of <0.053 mm aggregates to aggregate to form 0.25-0.053 mm aggregates decreases gradually. [Conclusion]With the increase in the number of intermittent rainfall, isolated pores were concentrated in the soil top layer, while the ability of large aggregates to gradually break up into small particle sizes gradually increased, but the ability of small aggregates to form large aggregates gradually decreased.
Keywords：intermittent rainfall；pore structure；aggregate turnover；rare earth element；CT scanning
How to cite: Lei, H.: The Influence of Intermittent Rainfall Conditions on the Pore Structure and Aggregate Turnover of Black Soil Topsoil, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3996, https://doi.org/10.5194/egusphere-egu25-3996, 2025.
Soil erosion can cause the dispersion and breakdown of soil aggregates. One key indicator of soil erosion resistance is soil anti-scourability. In black soil regions, the surface soil of cultivated land is particularly vulnerable to the scouring effects of runoff. This runoff can further break down and disperse soil aggregates. Therefore, studying the soil's anti-scourability, as well as the erosion characteristics of soil aggregates of different particle sizes in the surface soil of black soil cultivated land, is essential. To investigate the anti-scourability and aggregate loss characteristics of surface soil in cultivated land of the black soil area, the undisturbed soil (0-6 cm) was taken as the research object. The relationships between soil anti-scourability coefficient, scouring duration, scouring amount, and soil aggregate loss characteristics were explored, with 5 scouring amounts (6, 12, 18, 24, and 30 L/min) under indoor simulated runoff scouring experiments. The aim was to reveal the anti-scourability of the surface soil and the impact of runoff scouring on aggregate loss characteristics in cultivated land of the black soil area. 1) Overall, the total amount of soil loss gradually increased with the increase of scouring amount. The total amount of soil loss at a scouring amount of 18 L/min was 1.50 times that of 6 L/min. The soil loss decreased exponentially with decreasing scouring duration. 2) Under the conditions of scouring amounts of 6, 12, and 18 L/min, the soil anti-scourability coefficient increased as a power function with scouring duration. The soil anti-scourability coefficient was highest at a scouring amount of 18 L/min within 15 minutes, which was 2.01 and 1.38 times that at 12 and 6 L/min, respectively. 3) The loss characteristics of soil aggregates were differently affected by the scouring amount. Overall, the stability of soil aggregates gradually decreased with the increase of scouring amount, and the mass percentage of < 0.25 mm aggregates gradually increased. Conversely, the mass percentage of > 2 mm aggregates gradually decreased. The fraction size of 0.5-1 mm aggregate was the main lost fraction size under different scouring amounts, accounting for 26.84%-29.66%. 4) Compared to before runoff scouring, the mass percentage of <0.25 mm aggregates under the scouring amounts of 6, 12, and 18 L/min increased by 2.49, 14.17, and 4.18 times, respectively. 5) The erosion resistance of soils gradually decreased as the scouring amount increased. The fractal dimension of soil aggregates at a scouring amount of 18 L/min was 1.05 times that of 6 L/min. The total amount of soil loss in the surface soil of cultivated land of the black soil gradually increased with the increase of scouring amount. At the same time, the soil anti-scourability became stronger and the stability of soil aggregates gradually decreased. Additionally, the erosion resistance of soil under the 3 scouring amounts was ranked as 6 > 12 > 18 L/min. The research results provide insights into the changes in the surface soil anti-scourability in cultivated land of black soil and offer references for agricultural land use.
How to cite: Yan, J. and Fu, Y.: The surface soil anti-scouribility and aggregate loss characteristics in cultivated land of the black soil area, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3973, https://doi.org/10.5194/egusphere-egu25-3973, 2025.
Gully erosion poses greater threat to ecological and food security globally. The gully development rate and the contributions of primary influencing factors have not been thoroughly understood, primarily due to the complicated environmental conditions characterized by climate, soil, topography, and human activities. Therefore, this study was conducted to explore the gully development and contributions of its driving factors from 2013 to 2021 based on historical Google Earth images and field investigation in a typical rolling hilly watershed of northeast China. The climatic factors reflected by precipitation, topographical factors related to gully, and anthropological factors reflected by tillage ridge orientation and linear anthropological factors (LAF) including roads and shelterbelts were obtained. The tillage effect index (TEI), LAF effect index (LEI) and the distance from gully to LAF (DL) were calculated to analyze the influence of anthropological factors on gully development. The results showed that the linear, areal and volumetric gully development rates (RL, RA and RV) showed great variabilities in different periods with the average of 5.69 m year-1, 137.37 m2 year-1 and 428.54 m3 year-1, respectively. The accumulated RL, RA and RV increased exponentially or linearly with accumulated precipitation amount (P), erosive rainfall duration (RD), erosive rainfall (ER), maximum 30-min rainfall intensity (I30) and rainfall erosivity (RE) increased (P<0.001). The slope of the gully head (HS) was identified as the primary topographic factor influencing RL. Both RA and RV showed positive power relationships with the drainage area of the gully (CA) and the upstream gully head (HA). The human activity reflected by tillage ridge orientation, unpaved road and shelterbelts had different effects on RL and RA. The increased orientation angle between gully and tillage ridge (ROA) mitigated headcut retreat for normal precipitation year but it would aggravate headcut retreat in the periods of continuous heavy rainfall. Gully bank with the ROA of 30 - 90° was more prone to areal development. The TEI, LEI and DL had significantly positive linear, power or exponential relations with gully development rates. The PLSR and VPA analysis indicated that topography, the interaction between topography and human activity, and the coupled effects of precipitation, topography and human activity were the main contributor of RL, RA and RV, respectively, and accounted for 34%, 50%, and 40% of total variability of RL, RA and RA, respectively. This study can provide guidance for the control of gully erosion and the optimization of land use structure in the gully catchment.
How to cite: Liu, X.: Quantifying the contributions of precipitation, topography and human activity and their coupling to the development of permanent gully, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4655, https://doi.org/10.5194/egusphere-egu25-4655, 2025.
Soil aggregate stability and erodibility reflect soil resistance to erosion. Although the factors influencing soil aggregate stability and erodibility have been extensively studied, the driving effects of these factors and their interactions remain limited. 184 sampling sites were selected in topsoil (0-20 cm) of a small watershed (1.42 km2) in a Mollisol watershed to measure soil bulk density (BD), soil porosity (SP), soil moisture content (MC), soil organic carbon (SOC), total nitrogen (TN), >0.25 mm water stable aggregates content (WSA> 0.25), mean weight diameter (MWD) and K factor. Pearson correlation analysis, semi-variance function, redundancy analysis (RDA), and structural equation model (SEM) were used to quantify the impact of environmental variables (individual and interaction) on the spatial variations of WSA> 0.25, MWD, and K factor. The findings indicated that higher values of WSA> 0.25 and MWD are observed in the central and western watershed, while the K values tend to be lower in areas with high WSA> 0.25 and MWD values within the watershed. The Exponential model optimally described WSA> 0.25, MWD, and K factor with C0/(C + C0) indicating moderate spatial dependence for MWD (39.79%) and K factor (42.86%), while strong spatial autocorrelation for WSA> 0.25 (7.23%). Soil properties (moisture content, silt content, and bulk density), topography (elevation, SPI, and slope), and land use contributed 46.6%, 41.4%, and 9.1% of the spatial variation in WSA> 0.25, MWD, and K factor, respectively. SEM revealed that silt content, SOC, and water condition played a fundamental role in controlling the spatial variability of WSA> 0.25, MWD, and K factor. Topography exerted both direct or indirect effects by coupling land use or soil properties spatially. Land use had direct or indirect effects on WSA> 0.25 and K factor through regulating MC, but it primarily influences MWD indirectly through impacting MC. These results could clarify the roles and influencing paths of factors controlling the spatial heterogeneity of WSA> 0.25, MWD, and K factor, contributing to optimizing land management strategies.
How to cite: Wang, L.: Quantifying the contributions of factors influencing the spatial heterogeneity of soil aggregate stability and erodibility in a Mollisol watershed, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7553, https://doi.org/10.5194/egusphere-egu25-7553, 2025.
Phosphorus (P) deficiency causes yield losses in tropical regions due to the strong P sorption of tropical soils attributed to the high amount of iron and aluminium oxyhydroxides and the low pH. Novel P fertilisers such as hydroxyapatite nanoparticles (HAP-NPs) have been proposed to improve the P application efficiency. Such nanoparticles (< 100 nm) potentially have higher mobility and bioavailability in strongly sorbing soils as they interact less with sorption sites and have a more controlled P release than soluble P fertilisers.
In a diffusion experiment using tropical soil (pH 5), the P mobility of liquid and powdered HAP-NPs was investigated and compared with that of liquid K2HPO4 and powdered TSP, all added at an equal P dose located at the centre of a soil column. A novel sampling method using Diffusive Gradients in Thin Films (DGT) was applied that could distinguish colloidal P from dissolved P. The soil was sampled with a back-to-back pairwise system of a classic and a nano DGT. The nano DGT consists of a normal DGT but with the addition of a dialysis membrane between the diffusive membrane and the binding layer to exclude all colloidal particles. Therefore, the difference in DGT-P between both DGTs could be attributed to P-loaded colloids or nanoparticles. In addition, standard soil extractions (1 mM CaCl2 and oxalate extractions) were performed to compare with the DGT method.
After one week of incubation, colour visualisation of the gels showed that the HAP-NPs were still mobile and colloidal when applied as a liquid. In contrast, the liquid K2HPO4 fertiliser no longer yielded mobile P. Both powdered HAP-NPs and TSP did not yield any mobile P after one week. Results after one month are pending, but the HAP-NPs are expected to produce more bioavailable P than K2HPO4 and TSP, as the HAP-NPs dissolve slower and adsorb less strongly to the soil's binding sites. These results will help to understand the fate of HAP-NPs in a tropical soil and how they may improve P application efficiency.
How to cite: Aerts, L.: The use of hydroxyapatite nanoparticles as novel phosphorus fertilisers to enhance phosphorus mobility in tropical soils, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17569, https://doi.org/10.5194/egusphere-egu25-17569, 2025.
Soil health is essential for a well-functioning, healthy food web that is vital for sustaining agricultural productivity. Evaluating soil health involves the assessment of physical, chemical, and biological indicators that reflect the soil's capacity to support plant growth, resist degradation, and sustain ecosystem functions. Soil health is viewed as a living system that can change and improve over time with the focus on long-term sustainability and recovery. Assessing soil health can help land managers, farmers, and environmentalists understand the current condition of the soil as well as make informed decisions for long term sustainable land managements. There are common approaches used to assess soil health and ecosystem recovery such as soil quality assessment where soil quality indicators are measured. Monitoring soil quality indicators over time is an essential step, involves the use of various tests and measurements that provide data on key soil attributes.
The present work aims to assess the impacts of some of the top-ranking soil properties associated with soil health in aiming to develop an integrated indicator of soil health for stakeholders which could help deliver essential ecosystem services. Overall, 15 soil properties were selected and analysed by calculating response ratios of each indicator paired with practices. The effects of vegetation cover vs no cover, the effect of different vegetation cover and different tillage systems were compared. Over 350 topsoil and sub-soil samples were collected from the TUdi partners’ mid- and long-term experimental sites differing in climate, land use, soil type and management. Our proposed list of sensitive indicators for the topsoil layer are available phosphorus, exchangeable Ca, total nitrogen, soil carbon, soil respiration, root length density and root dry weight. For the sub-soil layer, sensitive indicators are exchangeable sodium, root length density and root dry weight. By introducing two new soil biology indicators linked to plant root traits, this raises the possibility of measuring and comparing other easily measurable root traits in future research, to provide an integrated soil health indicator for soil monitoring. Providing such an inexpensive methodology, accessible to stakeholders with minimum training, should help stakeholders assess the ability of the soil to deliver the necessary ecosystem services.
How to cite: Csilla, H., Nick, O., John, Q., Ian, D., Laura, Z., Marco, P., Octavian Puiu, C., Gunther, L., Tomáš, D., David, Z., Raquel, F., César, P., Juan Carlos, G., José, G., Iria Benavente, F., Gema, G., Peter, S., Zsofia, B., and Bela, P.: Assessing the impact of some of the top-ranking soil properties associated with soil health , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20274, https://doi.org/10.5194/egusphere-egu25-20274, 2025.
Agricultural systems are inherently complex, as they are influenced by the interlinkages between biological, physical, and chemical processes, alongside uncontrollable factors such as weather and soil conditions. To overcome these challenges, dynamic system models have emerged as indispensable tools that can be effectively implemented in precision agriculture. Such dynamic models enable the optimization of variable-rate fertilization and, consequently, enhance crop management strategies while fostering environmental sustainability.
Given the significant increase in fertilizer use over the past decades, there is an ongoing effort to enhance better nutrient management and sustainable development in agriculture within the European Union. This includes the integration of nutrient recovery technologies, such as anaerobic digestion (AD) that converts organic waste into bio-based fertilizers, helping mitigate excessive nutrient loss in Nitrate Vulnerable Zones (NVZs). Additionally, introducing circularity into the fertilizer production system offers a viable solution by replacing the traditional, emission-intensive nitrogen fertilizer production methods with innovative, low-emission alternatives. However, improper application of these pre-processed fertilizers can lead to environmental issues, such as N and/or phosphorus leaching and greenhouse gas (GHG) emissions. Therefore, it is essential to (i) select the right product with least N loss (via leaching or emissions) to the environment among selected (ammonium sulphate, pig urine, liquid fraction of digestate and mineral concentrate) pre-processed bio-based fertilizers, (ii) opt the right application techniques (injection, drag hose, spraying, etc.) available for the variable-rate fertilization, (iii) provide farmers with the best optimal rate and timing for performing precision applications under changing climate.
To address this issue, we implement the CANDY (Carbon And Nitrogen DYnamics) model in a site-specific manner. The model is applied to ongoing field experiments in maize and potato fields (2023–present) at the 3-hectare Bottelare research farm, as well as two commercial farms in Lamstraat and northwest France (2.7 and 8 hectares, respectively). Different application rates of selected bio-based fertilizers (ammonium sulphate, pig urine, liquid digestate, mineral concentrate) are simulated for soil mineral and organic nitrogen (minN, SON), soil organic carbon (SOC), nitrous oxide (N2O) emission dynamics, and validated with observed values from soil properties (e.g. NH4/NO3, OC, etc.) and GHG measurements (N2O, CO2). This provides valuable data-driven insights of potential mitigation measures regarding N losses and further can be used to inform stakeholders (i.e. farmers).
How to cite: Amangeldy, N., Meurer, K., Franko, U., Boneke, E., and Mouazen, A.: Simulating variable fertilizer application ‘rates’ of synthetic and bio-based fertilizers in potato and maize fields to optimize nutrient management and validate environmental sustainability, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1127, https://doi.org/10.5194/egusphere-egu25-1127, 2025.
Uniform and excessive nitrogen (N) fertilization practices in agriculture often lead to spatial and temporal crop variability, resulting in inefficient nutrient distribution, environmental harm, reduced orchard yields, and fruit quality. This study investigates the effects of N fertilization levels on avocado ecophysiology using advanced remote sensing (RS) techniques, focusing on the estimation of Nitrogen Use Efficiency (NUE), Leaf Nitrogen Content (LNC [% dry weight]), Plant Area Index (PAI), and Canopy Nitrogen Content (CNC [kg per tree]) to estimate crop responses to over and under fertilization. NUE was calculated as Partial Factor Productivity (PFP) of N; kg of N in harvested avocado per kg N applied. This research includes three experimental systems: (1) a lysimetric experiment at the Gilat with five continuous N fertigation treatments ranging from 115 to 1400 kg-N ha; (2) Kfar Menachem Commercial Orchard, a controlled orchard with three continuous N fertigation treatments ranging from 70 – 570 kg-N ha; and (3) Kabri Orchard, a mature commercial avocado orchard (~10 ha) with standard N application (270 kg-N Ha). Key eco-physiological parameters were measured on the ground bi-monthly in tandem with UAVs during 2022-2023. The ground measurements included nutrient uptake (in the lysimetric experiment only), LNC, stomatal conductance, chlorophyll fluorescence, and growth rates. Yield, fruit quality, and shelf-life were assessed at harvest and after cold storage and shelf life. UAV flights integrated multispectral, thermal, and LiDAR sensors. Canopy metrics, such as height, volume, PAIwere estimated on the based segmentation model, and spectral indices related to vegetative growth, were extracted and incorporated into a CNC prediction model and used to evaluate spatial-temporal variability. Random forest models demonstrated high predictive accuracy on CNC (R² = 0.94, RMSE = 0.4 kg per tree). Results revealed significant site-specific leaf nitrogen responses, with notable NUE differences (p-value < 0.05). A strong negative correlation was observed between NUE and PAI (p-value < 0.05), underscoring the importance of precise nitrogen management. This research highlights the potential of advanced remote sensing and site-specific fertilization strategies to optimize precise N use, enhance avocado yield and quality, and mitigate environmental impacts. By addressing spatial variability and leveraging predictive RS modelling, this study contributes to sustainable avocado farming practices.
How to cite: Grozdov, I., Erel, R., Baram, S., Alkan, N., and Paz-Kagan, T.: Assessing Nitrogen Fertilization Impacts on Avocado Ecophysiology: Insights from UAV-Derived Remote Sensing and Nutritional Experiments Responses, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3574, https://doi.org/10.5194/egusphere-egu25-3574, 2025.
Soil acidification and low nutrient availability are critical challenges for agriculture in East Africa, often leading to aluminium (Al) toxicity and reduced crop yields. Amending arable land with local sediments has been shown to be a promising strategy to address these issues, although responses have been variable. We investigated the effects of local sediment amendments influenced by volcanic deposits on soil pH, nutrient availability, and barley productivity in field trials conducted in Eldoret, Western Kenya in the first year and compared it to lime amendments and straw return in the second year. Plots were amended with 1% and 3% of two local sediments (from Baringo and Nakuru). The 3% Baringo amendment significantly increased soil pH (from 4.7 to 7.0), enhanced available phosphorus (P) content (from 0.01 mg g⁻¹ to 0.02 mg g⁻¹), and reduced Al availability (from 3.03 mg g⁻¹ to 2.17 mg g⁻¹), resulting in the highest barley yield of 4.7 t/ha (+1061%). In the second year, growth was strongly inhibited by drought periods, but the trends were visible again with Baringo 3%. Similarly, lime at 0.15% improved soil conditions and barley yield (0.91 t ha-1), though less effectively than Baringo 3% (1.3 t ha-1). Control and Nakuru, as well as straw return did not improve the soil conditions and yield significantly. These findings highlight the potential of local sediment amendments to mitigate soil acidification and enhance crop productivity, particularly through carbonate dissolution and pH elevation, though outcomes depend on sediment composition and amendment rates.
How to cite: Scherwietes, E., Six, J., and Schaller, J.: Enhancing Barley Yield and Biomass in Kenya: The Effects of Local Sediments, Lime Amendments and Straw Return, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5878, https://doi.org/10.5194/egusphere-egu25-5878, 2025.
Rainfall simulators are indispensable in soil hydrology and erosion research, offering controlled conditions to investigate water erosion. Despite their widespread use, the absence of standardized methodologies leads to variability in design and rainfall characteristics across simulators. To address this challenge, key parameters such as drop size distribution and terminal velocity, uniformity of the spatial distribution of raindrops over the sprinkled surface area (Christiansen uniformity coefficient; CU), kinetic energy (KE), and rainfall intensity are used for comparative analysis. In this study, three rainfall simulators with varying transportability, nozzle system, and raindrop generation are compared. Laser distrometers and Tübingen Splash Cups (T-cups) were used to measure rainfall characteristics and kinetic energy.
The rainfall simulators produced rainfall intensity ranging from 38 to 95 mm h-1, and CU values between 60.5% and 75.8%. Most drops (>90%) were slower than 3.4 m s-1 for all simulations. The maximum number of drops was within the 0.25 – 0.375 mm class, generally smaller than that observed in natural rain, all at 1.4-1.8 m s-1 velocity. We found kinetic energy measured by T-cups to agree with values calculated with the Thies disdrometers, confirming its pertinence in rainfall studies. However, caution is advised when applying the T-cup equation under low kinetic energy scenarios, as it tends to overestimate KE.
Furthermore, we found that portable systems have distinct lower kinetic energy characteristics than indoor systems, and notable differences do not allow for the direct comparison of measurements. However, they have distinct advantages in direct field measurements and handling. The devices’ CU ranges from 60.5 to 75.8%, which falls within the range of those presented in the literature.
This study highlights the importance of accurately characterizing rainfall parameters before soil erosion modeling. The methodologies and insights provided tools for improved assessment of soil erosion risks, particularly considering its practicality in remote areas.
Keywords: Rainfall simulators, Soil erosion, Drop size distribution, Drop velocity, Raindrop kinetic energy
Research has been supported by project TUDI (European Union's Horizon 2020 research and innovation programme under grant agreement No 101000224), technology Agency of the Czech Republic (grants 8J23DE006 and QK22010261) and Czech Technical University in Prague (grant SGS23/155/OHK1/3T/11)
How to cite: Falcao, R., Krasa, J., Neumann, M., Kubát, J.-F., Gall, C., Seitz, S., and Dostal, T.: Evaluating Compact Portable and Indoor Rainfall Simulators for the Estimation of Rainfall Characteristics in Soil Erosion Studies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6127, 2025.
How to cite: Falcao, R., Krasa, J., Neumann, M., Kubát, J.-F., Gall, C., Seitz, S., and Dostal, T.: Evaluating Compact Portable and Indoor Rainfall Simulators for the Estimation of Rainfall Characteristics in Soil Erosion Studies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6127, https://doi.org/10.5194/egusphere-egu25-6127, 2025.
The sustainable management of crops in areas at risk of soil health degradation is crucial, particularly given their vulnerability in the current context of climate change. Decision Support Tools (DSTs) designed specifically for farmers are essential for assessing risks, analyzing the impact of agricultural practices, and defining strategies to mitigate negative impacts on soil health. In response to this need, the TUdi DSTs were developed (in app and web format), integrating functionalities tailored to address different types of soil degradation processes by different approaches related to soil biology, erosion, compaction, structure, organic carbon and fertilization. These DSTs are designed to restore and enhance soil health, and to optimize the use of fertilizers at the user level.
However, in scenarios of high soil health degradation, the tool’s results often highlight negative outcomes, potentially leading to rejection in its adoption. It is therefore crucial to assess user acceptance of such tools in advance. To tackle this challenge, in-person workshops were conducted, engaging both farmers and stakeholders from the agricultural sector. These workshops enabled the evaluation of the TUdi DST's acceptance, and the identification of improvements aimed at optimizing its usability and fostering its broader adoption. These efforts aim to ensure that the TUdi DST becomes an effective tool for supporting farmers in sustainable soil management, while contributing to the mitigation of climate change impacts on vulnerable agricultural systems.
Acknowledgments: this work was supported by the research project TUdi (Horizon 2020, GA 101000224).
How to cite: López Gonzalez, M.-L., Pareja, E., Benavente-Ferraces, I., Osann, A., Sánchez, J., Dostal, T., Krasa, J., Falcão, R., Zavattaro, L., Strauss, P., Carl Liebhard, G., Gómez, J. A., Guzmán, G., Domenech, I., Hudek, C., Bakacsi, Z., Nikolov, D., and Zhang, X.: TUdi Decision Support Tool to assist farmers in soil health management, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12364, https://doi.org/10.5194/egusphere-egu25-12364, 2025.
Soil erosion is a major challenge in agriculture, leading to land degradation, reduced fertility, and water pollution. Effective land management is crucial for controlling runoff, limiting sediment transport, and sustaining soil productivity. Among various conservation practices, vegetative buffer strips are particularly effective, enhancing infiltration, slowing runoff, and trapping sediment.
This study assessed the impact of different grass strip lengths on sediment retention under controlled conditions. Experiments were conducted on plots with varying proportions of grass cover (0%, 25%, 50%, and 100%). A suspension of water and fine sand was used to simulate runoff with high sediment concentration. Flow rates and experiment duration were standardized for comparability.
The results demonstrated that longer grass strips significantly reduced both surface runoff and sediment transport. Runoff was reduced by up to 29%, while sediment loads decreased by up to 85% compared to bare soil. These findings highlight the potential of vegetative barriers as an effective nature-based solution for sustainable land management.
Acknowledgements: Research has been supported by project TUDI (European Union's Horizon 2020 research and innovation programme under grant agreement No 101000224) and SGS23/155/OHK1/3T/11: Experimental research and monitoring of rainfall-runoff and erosion processes on agricultural soils.
How to cite: Vrana, M., Laburda, T., N. R. Falcão, R., Jachymova, B., Zumr, D., Krasa, J., Tejkl, A., Kubát, J.-F., Bauer, M., and Dostal, T.: Mitigating Soil Erosion and Runoff through Vegetative Barriers in Agricultural Areas, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9549, https://doi.org/10.5194/egusphere-egu25-9549, 2025.
Many regenerative agriculture practices (RAP) such as not tillage (NT), cover crop (CC), perennials and agroforestry (AF), organic farming (OF) have potential to limit negative environmental outcomes while enhancing soil health and sustaining diverse ecosystem services. However, the magnitude by which yield responses of different RAP are influenced by inherent soil properties, climate and topographical factors are not fully understood. To elucidate such interaction, field scale experiments related to these RAP were first collected across the globe by combining multiple meta-analyses and the yield response was extracted and then linked with global gridded soil, climate and topographical datasets. The findings showed that the RAPs were associated with an overall mean crop yield increase of 5 % with specific increase in crop yield by 48 %, 21 % and 0.28 % respectively for AF, CC and NT while a decrease of 2 % was recorded for OF. The use of RAPs had the greatest yield benefit in tropical, arid and temperate climates and when farming at mid to high elevation areas as well as in soils with low soil organic carbon. Specifically, increase in crop yield occurred consistently for AF, CC and NT in environments located in semi-arid area with aridity index between 0.20 and 0.50 and at elevation between 250 and 1000 m as well as in soils characterized by low soil organic carbon (< 5 g/kg). In addition, NT was associated with increase in crop yield especially when N input was considered in addition to cover crop and weeding in arid and tropical regions. Under the RAPs considered, cereal crops such as maize, rice and soybean resulted in significant crop yield increase especially for growing degree days within 4 000 to 10 000 degrees C. The findings shed new light on the ways in which soil characteristics, climate and topography in relation to RAPs interact to affect crop yield and such results can assist in the development of useful, fact-based recommendations for applying these practices to improve crop yields.
How to cite: Hounkpatin, O., Piipponen, J., Jalava, M., and Kummu, M.: Evaluating effect size distribution of different regenerative agriculture practices across soil, climatic and topographical factors, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17537, https://doi.org/10.5194/egusphere-egu25-17537, 2025.
One of the main outputs of the TUdi project is a catalogue of strategies and measures for improving soil quality. This document (alone or in combination with other project outputs) serves farmers to find suitable methods and measures for improving the quality of their soil.
This catalogue aims to present soil restoration and fertilization strategies with feedback from stakeholders in the EU and China. The catalogue consists of a list of practices soil degradation processes. The processes were defined with a multidisciplinary approach by scientists from different fields (soil physics, hydrology, plant and environmental sciences, nutrient management and agronomy) and they are described individually in big detail.
A list of measures and strategies that can be used to eliminate these degradation processes is presented. For individual measures, the catalogue contains a separate chapter with a detailed description of each measure. These chapters describe the principle of the methods/measures, the conditions for their implementation and the importance of individual measures in terms of individual degradation processes. There are also references to appropriate literature at the end of each chapter.
The aim of the catalogue is to support farmers in activities leading to soil improvement. For this reason, the catalogue includes a chapter dealing with financial support tools in individual countries cooperating within the TUdi project. A separate chapter is also devoted to legislative regulations and rules related to the issue of soil degradation and protection.
Research has been supported by project H2020 – TUdi (https://cordis.europa.eu/project/id/101000224)
How to cite: Jáchymová, B., Zumr, D., Dostál, T., Falcão, R., Krása, J., and Bauer, M.: Catalogue of soil restoration and fertilizations strategies across EU and China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8544, https://doi.org/10.5194/egusphere-egu25-8544, 2025.
The growing threats to soil health, particularly in regions increasingly impacted by climate change, demands innovative, science-based solutions. Organic amendments offer a pathway for improving soil health while enhancing SOM content. Addressing these challenges requires a comprehensive approach that bridges nutrient management practices with a deeper understanding of soil organic matter (SOM) dynamics. Therefore, farmers, as key actors in this process, need operational tools that not only highlight potential risks, but also provide strategies to ensure the long-term soil productivity and resilience. To support this, the TUdi Decision Support Tool (DST) combines crop nutrient requirement assessments with SOM evolution forecasting, using nutrient inputs as a factor in modeling SOM dynamics. This DST was designed as a practical decision-support tool for farmers and land managers, enabling informed decision-making to combat soil degradation and support sustainable land management practices.
In this study, we applied the TUdi DST in highly vulnerable region to soil organic matter (SOM) loss of Europe, to evaluate cereal and woody crop management. Under favorable (SOM > 2.5%) and unfavorable (SOM < 2%) scenarios of crops growing conditions were assessed to explore tailored strategies for mitigating SOM decline and enhancing carbon sequestration.
Acknowledgments: this work was supported by the research project TUdi (Horizon 2020, GA 101000224).
How to cite: Pareja-Serrano, E., Benavente-Ferraces, I., López González, M.-L., and Zavattaro, L.: TUdi Decision Support Tool: integrating nutrient management and organic matter dynamics for sustainable soil management, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12300, https://doi.org/10.5194/egusphere-egu25-12300, 2025.
A key management strategy for erosion control for woody crops grown under Mediterranean climatic conditions is temporary crops, which grow during fall and winter and are terminated in early Spring, to minimize the risk for water competition with the main crop (Gómez et al; 2014; Winter et al., 2018). Although most farmers opt for a cover crop of adventitious vegetation present in their farms, there are situations when seeding a cover crop is necessary. For instance, on degraded soils, or to enhance biodiversity. There is research by different teams for identifying and characterizing new specifies to be used as cover crops for woody crops (e.g. Gómez et al., 2020). Among the traits used for identifying the most suitable species or varieties are: emergence in early fall, early maturity in late winter or early Spring, rusticity, low height, …
The core question to be addressed by farmers and technicians when implementing this technique is to identify the proper termination date for the cover crop. This date needs to be set before depleting the soil water content beyond risking a yield decrease (Gómez et al., 2014) while, simultaneously, allowing seed maturity of the cover crop (to allow self-seeding and making this technique economically viable). Given the large variability in edapho-climatic and agronomic conditions in the Mediterranean region, this seed maturity date will vary significantly among areas, even within a relatively short distance (Gómez et al., 2020), more than the date of onset of the risk of water competition. As a result, farms in different areas will need to use, not only different termination dates, but also different strategies to manage the cover crop. For instance, leaving narrow strips un-terminated to produce seed if the cover crop termination needs to be done before seed maturity.
This communication presents the results of a study evaluating the phenology of different varieties of Brachypodium and its modelling using a simple phenological model based on growing degree days following that of Gómez et al. (2020). Using climate records and this model, this communication will also present the results of an analysis of different cover crop management strategies based on the regional climatic differences in Andalusia.
References
1- Gómez, J.A., et al., 2014. Modeling to Evaluate and Manage Climate Change Effects on Water Use in Mediterranean Olive Orchards with Respect to Cover Crops and Tillage Management. Practical Applications of Agricultural System Models to Optimize the Use of Limited Water. Advances in Agricultural Systems Modeling, 5: 237-265
2- Gómez, J.A., Soriano, M.A. 2020. Evaluation of the suitability of three autochthonous herbaceous species as cover crops under Mediterranean conditions through the calibration and validation of a temperature-based phenology model. Agriculture, Ecosystems and Environment, 291, art. no. 106788.
3- Winter, S., et al., 2018. Effects of vegetation management intensity on biodiversity and ecosystem services in vineyards: A meta-analysis. Journal of Applied Ecology 55: 2484-2495.
Acknowledgements: Financial support from grant TED2021-131496B-C22 (BRACHYCOVER) funded by MICIU/AEI/ 10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”; and from the European Union’s Horizon 2020 project TUdi (GA 101000224) .
How to cite: Gomez, J. A., Soriano, M. A., Guillén Jurado, J., and Hernández Molina, P.: Modelling phenological development of Mediterranean cover crop species as a tool for designing better management strategies in Southern Spain, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-233, https://doi.org/10.5194/egusphere-egu25-233, 2025.
The agricultural landscape in Southern Spain, particularly in the Córdoba countryside, is in an on-going transformation due to the expansion of woody crops, like olives orchards [1], which has implications for erosion risk in the area. In that sense, the use of remote sensing to determine actual soil management strategies is a useful technique [2] to calibrate erosion models’ factors, e.g. the cover and management factor in RUSLE [3].
This communication explores the performance of several algorithms for the identification of soil managements in olive orchards. For this, it were considered 3 classes: i) Bare soil (BS), with any combination of herbicide application and/or tillage; ii) Partial soil cover of the lane (alternate lanes of bare soil and cover crop, or narrow cover crop strips, less than 1 m wide, in all the lanes) by temporary cover crops (TCC), defined as those grown during the rainy season (autumn and winter) which are controlled in early spring); and iii) Full ground cover along all the lanes (FCC), also controlled as temporary cover crops. A total of thirty-four olive farms with a known soil management strategy were selected within the study area, located in the countryside of Cordoba (Southern Spain); more details in [1]. Fifty-percent of the farms were used for training, 25% for calibration and 25% for validation, balancing among treatments.
A comparison of five different techniques using the same Sentinel satellite imagery was performed. The techniques were: 1- Support Vector Machines (SVM); 2- Linear Discriminant Analysis (LDA); 3- Random Forest (RF); 4- Boosted Regression Trees (BRT); 5-Dense Neural Networks (DNN). The used dataset consisted of 8 vegetation indexes (ARVI, AVI, EVI, GNDVI, MBI, MCARI, NDVI, SAVI) and ten spectral-bands.
Preliminary results demonstrated that the dataset derived from vegetation indexes exhibited greater accuracy for the five techniques (range 80-99%) than those based on combining several spectral bands (range 40-75%). This assertion was valid for distinguishing between BS and combined TCC&FCC and among BS, TCC and FCC. There was a similar performance among techniques for distinguishing between BS vs. TCC&FCC. For distinguishing among BS, TCC and FCC, LDA and DNN showed the best results. Overall the predictive capability using spectral indexes worsen for distinguishing among three treatments (around 80%) as compared for BS vs. TCC&FCC (around 99%).
This study provides a comparative framework for assessing the response of spectral indices and spectral-bands to different soil management strategies widely used in Mediterranean conditions.
Acknowledgements: This work is supported by the projects SCALE (EJP Soil Horizon 2020 GA 862695), TUdi (Horizon 2020, GA 101000224) and PID2019-105793RB-I00 (Spanish Ministry of Science and Innovation).
References:
[1] Guzmán et al. 2022. Expansion of olive orchards and their impact on the cultivation and landscape through a case study in the countryside of Cordoba (Spain). Land Use Policy, 116, 106065.
[2] Almagro et al. 2019. Improving cover and management factor (C-factor) estimation using remote sensing approaches for tropical regions. International Soil and Water Conservation Research., 7(4), 325–334.
[3] Renard et al. 1997. Agricultural Handbook 703, USDA-ARS. Washington, DC.
How to cite: Domenech-Carretero, I., Guzmán, G., and Gómez, J. A.: Identifying soil management strategies in olive groves through satellite imagery using conventional and machine learning approaches., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1085, https://doi.org/10.5194/egusphere-egu25-1085, 2025.
Overuse of fertiliser in global food production has led to severe environmental impacts, including nitrogen (N) pollution, water quality degradation, and eutrophication, particularly in lakes and coastal waters worldwide. These challenges highlight the need for sustainable agricultural practices that enhance N use efficiency and reduce environmental loading. Nutrient-loaded biochars (NLB) offer a promising solution by sequestering atmospheric carbon in the soil, providing slow, continuous nutrient release, and reducing nutrient loss. Research indicates that NLBs enhance N use efficiency and crop yields. Additionally, biochar and fertiliser combination increases soil N retention and microbial activity. Some biochars have also been shown to improve biological N fixation in legumes by improving soil structure, nutrient availability, and balance and optimising plant-microbe interactions. However, their specific effects on faba beans (Vicia faba L.) remain understudied.
This study aims to investigate the influence of NLBs on biological nitrogen fixation in faba beans and N use efficiency in boreal agricultural soils by using the 15N natural abundance method. The study was conducted on long-term biochar field experiments at the University of Helsinki's Viikki Research Farm with two distinct soil types: fertile Stagnosol and nutrient-poor Umbrisol. NLBs were prepared in three ways: spruce biochar was activated with nitric acid or tap water, then nutrient-loaded with organic N (from cattle slurry and meat bone meal) or inorganic N (from mineral fertiliser).
The study used split-plot designs, with three different biochar treatments in the Stagnosol and only slurry-activated biochar in the Umbrisol, applied at two rates: 0 biochar control and the highest rates (15 t ha-1 in Stagnosol, 50 t ha-1 in Umbrisol). Fertiliser treatments included two mineral levels (30% and 100% of recommended rates) for the Stagnosol and two types (no fertiliser and mineral fertiliser) for the Umbrisol. 72 plots were used: 48 in Stagnosol and 24 in Umbrisol, with additional 0 biochar control plots (6 + 7 respectively) established for growing oat (Avena sativa L.) as a non-N-fixing reference crop for soil N isotopic baseline to estimate N fixation in faba beans. Faba beans were cultivated in the experimental plots. We measured aboveground biomass, CN content, N yield, and isotopic ratios (15N/14N) by a Leco CN analyser and isotope ratio mass spectrometer at the flowering stage of faba bean and oats.
Preliminary results are expected to provide a good insight into the potential of NLBs to increase biological N fixation. The study findings could lead to innovative approaches for improving soil fertility and contributing to more sustainable practices in boreal agriculture and globally. Growing legumes in NLB-amended soils could be a good practice to increase plant available N and, thus, the subsequent crop yield, reducing farmers' need to purchase external mineral fertilisers. Moreover, the findings can also support climate change mitigation and ecological balance in boreal regions.
How to cite: Ferdous, Z.: The effects of nutrient-loaded biochar on biological nitrogen fixation in faba beans, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6218, https://doi.org/10.5194/egusphere-egu25-6218, 2025.
Cover crops are widely employed in woody cropping systems as a strategy for soil protection and restoration, aimed at preventing soil erosion and degradation. However, their successful implementation faces significant challenges across diverse edaphoclimatic conditions, such as arid and semiarid environments and highly degraded soils.
This study aims to evaluate the effects of various agricultural inputs (organic fertilizers and amendments) on cover crop characteristics (emergence, plant phenology, and aboveground biomass), as well as soil physico-chemical and biological properties (pH, electrical conductivity, infiltration, bulk density, soil moisture, macroaggregates, organic matter content, enzymatic activity and soil respiration). For this purpose, pot and field-scale trials were established using a mix of three native species commonly used as soil cover in Southern Spain—Bromus rubens, Brachypodium dystachion, and Calendula arvensis. These species were sown under six different treatments: i) unfertilized control, ii) biochar, iii) compost, iv) compost coapplied with biochar, v) pelletized organic fertilizer, and vi) pelletized organic fertilizer coapplied with biochar. For the pot trial, two replicates per treatment were set up inside a shaded structure; for the field trial, 24 microplots (1 x 1 m2 each) were established following a randomized block design with four blocks. Weekly assessments have been conducted to monitor phenological stages and ground cover extent. At the end of the plant growth cycle, soil properties will be analyzed to assess treatments effects. To ensure cover crop germination, support irrigation was provided to all pots and microplots immediately after sowing.
We will present preliminary results from these trials, with plans to continue in future years. These findings will serve as a demonstration and experimental resource providing insights for practitioners and stakeholders interested in implementing cover crops in woody crop systems under challenging soil conditions. Based on these initial results, further adjustments and improvements will be introduced in the coming years.
Acknowledgements: ECOMED (PR.AVA23.INV202301.035) and TUdi (H2020 GA101000224) projects.
How to cite: Cárceles, B., Benavente-Ferraces, I., Gómez, J. A., Plaza, C., Ramos, A., Soriano, M. A., and Guzmán, G.: Organic fertilizers and amendments to promote soil restoration and cover crop development, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1145, https://doi.org/10.5194/egusphere-egu25-1145, 2025.
According to the European Environment Agency, Southern Europe is one of the regions facing the most serious soil degradation issues, mainly due to adverse edapho-climatic conditions and unsustainable agricultural practices [1]. In Spain, the National Soil Erosion Inventory reports an average agricultural soil loss of 30 t ha-1 yr-1 [2], with the highest soil erosion rates observed in woody crops with bare soil management [2]. The intensification of tillage and the use of herbicides to control herbaceous vegetation has yielded agronomic benefits for olive groves in the short term. However, in the long term, it generates both negative agronomic impacts and environmental imbalances.
After years of research and collaboration with olive growers, the benefits of ground cover are increasingly recognized and accepted. This trend is increasingly supported by the Common Agricultural Policy 2023-2027 and the well-known P6 and P7 eco-schemes [3]. However, at farm scale, successfully establishing ground cover requires tailoring technical and economic management to the specific soil, climate, and olive grove conditions, as well as machinery, personnel, and economic constraints. In fact, there is a mismatch between environmental needs and policy regulations, and the required technical advice at farm scale. This is particularly relevant because, depending on local condition, the implementation of cover crops in woody crops in Mediterranean conditions can be costly and decrease crop yield [4].
This communication presents a decision support guide for cover crops implementation in olive groves, providing a series of basic principles, decision rules and management examples, with costs estimations, from surveying 39 olive growers across different regions of Spain. The guide is divided into four sections: I. Basic Concepts. This section briefly explains a set of elementary principles concerning the effects of ground covers, seeding rate determination, etc. II. Management Criteria. This section aims to identify appropriate strategies for specific initial conditions in olive groves, depending on the goals and constraints. III. Illustrated Examples. This section presents particular examples from olive groves that can be adapted to other groves. IV. Costs. This complex topic addresses the peculiarities of management and access to variable public funding. It explains how the costs have been calculated for the examples. The guide also includes a cost calculator which aims to be a practical tool designed to support olive growers in adopting more sustainable and economically viable practices. It allows for customized cost estimation of management and potential seeding with fertilization, by entering specific data from the agricultural operations [5].
Acknowledgements: Operational group BIOLIVAR; H2020 TUdi (GA 101000224) and ECOMED (PR.AVA23.INV202301.035) projects.
References:
[1] The European environment — state and outlook 2020: knowledge for transition to a sustainable Europe.
[2] Estrategia Nacional de Lucha Contra la Desertificación.
https://www.miteco.gob.es/content/dam/miteco/es/biodiversidad/temas/desertificacion-restauracion/estrategia_nacional_lucha_desertificacion_web_2022_tcm30-542085.pdf
[3] Regulation of eco-schemes in Spain: Real Decreto 147/2023, de 28 de febrero.
https://www.boe.es/eli/es/rd/2023/02/28/147/con
[4] Profitability of erosion control with cover crops in European vineyards under consideration of environmental costs.
https://digital.csic.es/handle/10261/215919
[5] Link to download the calculator:
https://digital.csic.es/handle/10261/364793
How to cite: Montoliu, J., Soriano, M. ª. A., Guzman, G., and Gómez, J. A.: Decision Support Guide for the Implementation of Cover Crops in Olive Groves., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-699, https://doi.org/10.5194/egusphere-egu25-699, 2025.
Sunflowers, recognized for their exceptional tolerance and accumulation capacity for heavy metals, are widely used as a model plant in phytoremediation technologies. However, due to the physicochemical properties of heavy metals and the physiological differences among plant tissues, the accumulation of heavy metals in different plant organs exhibits significant variability. Considering that heavy metal contamination in natural environments often involves complex mixtures rather than single pollutants, investigating the accumulation and distribution characteristics of sunflowers in soils contaminated with multiple heavy metals is of critical importance. In this study, pot experiments were conducted to systematically compare the germination, biomass, heavy metal accumulation, and organ-specific distribution of sunflowers grown in soils contaminated with single heavy metals (As, Cd, Cu, Ni, Pb, and Zn) and those with mixed heavy metals. The results revealed no significant differences in germination rates or total biomass of sunflowers between single and mixed contamination conditions. Similarly, the total accumulation of heavy metals in sunflower plants did not differ significantly. However, the distribution of heavy metals among plant organs showed notable differences: under mixed contamination, the accumulation of As, Ni, and Pb in sunflower roots was significantly higher compared to single-contamination conditions, while the distribution ratios of Cd and Cu in plant organs were unaffected by the type of contamination. This study elucidates the impact of mixed contamination on heavy metal distribution and provides critical scientific insights for the practical application of phytoremediation in complex contamination scenarios, offering a framework for optimizing remediation strategies and improving efficiency.
How to cite: Zhao, X. and Li, G.: Impact of Single and Mixed Heavy Metal Contamination on Accumulation Patterns and Organ Distribution in Sunflowers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8466, https://doi.org/10.5194/egusphere-egu25-8466, 2025.
Soil extracellular enzyme activities play a crucial role in soil organic matter decomposition and nutrient cycling. Soil erosion is a major threat to soil health and sustainable crop productivity worldwide, the use of chemical fertilizers is an important management practice to combat soil degradation and increase crop yields. How soil extracellular enzyme activities respond to the combined soil erosion and fertilization, and whether these enzyme activities can be used as indicators of soil health under erosion, remains unclear. Based on a long-term field simulated erosion experiment (2005-2022) in the black soil region of northeast China, 12 soil extracellular enzyme activities [ including 5 C-acquiring enzymes: β-1,4-glucosidase (BG), β-D-cellobiohydrolase (CBH), β-xylosidases (BX), α-glycosidase (α-GC) and invertase; 3 N-acquiring enzymes: β-1,4-N-acetylglucosaminidase (NAG), leucine amino peptidase (LAP) and urease; 1 P-acquiring enzyme: acid phosphatase (ACP); and 3 oxidative enzymes: catalase, phenol oxidase (POX), peroxidase (POD)] and relevant soil physicochemical and microbial properties were carried out along the simulated erosion gradient under both unfertilized and fertilized conditions during the fallow season. The results showed that: (1) Simulated erosion significantly decreased the activities of invertase, urease, ACP, and POD, and had no effect on the activities of the other 8 enzymes. Long-term fertilization significantly increased the activities of urease and NAG and decreased ACP, catalase, and POD activities. No interactions between simulated erosion and fertilization were found for all measured 12 extracellular enzyme activities. (2) The decreased activities of invertase and urease were mainly caused by the decrease in soil organic matter (SOM), no matter fertilized or not. Decreased ACP activity was mainly attributed to SOM under fertilization, but to pH and BD under no fertilization. POD activity was mainly determined by alkali-hydrolyzed N (AN) under fertilization, but none of the measured soil properties can explain the changes in POD activity under no fertilization. (3) The activities of invertase, urease, and ACP were significantly and positively correlated with multiyear average crop yield across the simulated erosion gradient under both fertilization conditions, POD activity was only positively correlated with average yield under fertilization. The results highlight that invertase, urease, and ACP activities can be used as potential indicators of erosion-induced black soil degradation, fertilizer application can improve soil health of degraded black soils partly by increasing invertase and urease activities and crop yield.
How to cite: Li, Y., Zhao, H., Wang, Z., and Guzmán, G.: Responses of soil extracellular enzyme activities to simulated erosion and fertilization in the Chinese black soil region, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9738, https://doi.org/10.5194/egusphere-egu25-9738, 2025.
Until the 90s, South Korea was a heavily inorganic fertilizer agriculture system, but it has since shifted to eco-friendly agriculture that uses less fertilizer and more livestock manure compost. For sustainable agriculture, efforts are being made to improve soil quality and nutrient balance. In addition, changes in the agricultural environment are being monitored to build a D/B of soil properties. In this study, we summarized the changes in agricultural soil properties over the past 20 years in Korea and investigated the soil quality changes based on the soil quality assessment model developed in previous studies. Soil analysis results were used from the agricultural environment monitoring project from 1999 to 2022, excluding volcanic soils, and the analyzed properties were pH, EC, organic matter, available P2O5, and exchangeable cation (Ca, Mg, K). The land use types were categorized as paddy, upland, orchard, and plastic house, and the agricultural land area as of 2022 is 776 kha for paddy, 490 kha for upland, 130 kha for orchard, and 77 kha for plastic house. The pH has increased continuously, which is the impact of the national project to supply calcareous fertilizers to increase the low pH. EC is very high in the plastic house and is constantly increasing, with the same trend in free phosphoric acid. Due to the nature of the plastic house, it is protected from rainfall and large amounts of fertilizer are applied, so fertilizer is constantly incorporated into the soil. Soil organic matter has increased steadily over the past 20 years due to a government-supported project to compost excess livestock manure. The available P2O5 is the result of phosphorus in the soil from phosphate fertilizer use and large amounts of livestock manure. This is currently causing problems such as salt accumulation in the plastic house. After applying the soil quality assessment model to evaluate the soil quality, the soil quality score of the soil was found to be increasing. This is because we have reduced the use of fertilizers, increased the organic matter content of the soil by supplying compost, and supplied amendments to increase the pH to increase the overall soil fertility to an appropriate level. However, the soil quality indicators of facility cultivation sites were found to be low due to high EC and phosphate, and it is urgent to prepare and disseminate soil management measures to solve this problem. It is believed that the change in the direction of soil management of agricultural land at the national level over the past 20 years has had a positive effect on soil properties and soil quality, and in the future, soil management that can contribute to carbon neutrality and maintain adequate productivity while increasing soil quality in line with the carbon neutrality era is necessary.
How to cite: Yang, J. E., Yoon, J.-H., Kim, H. S., and Kim, H.: Changes in the soil properties and quality of agricultural soils in South Korea over a period of 20 years, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12703, https://doi.org/10.5194/egusphere-egu25-12703, 2025.
Posters virtual: Fri, 2 May, 14:00–15:45 | vPoster spot 3
EGU25-4758 | Posters virtual | VPS15
Evaluation of the effects of long-term natural and artificial restoration on vegetation characteristics, soil properties and their coupling coordinationsFri, 02 May, 14:00–15:45 (CEST) | vP3.10
Vegetation restoration is the most important factor to restrain soil and water loss in the Chinese Loess Plateau, and its effect is long-term. Among them, the coupling and coordination relationship between vegetation and soil is the key to the smooth implementation of ecological restoration and the project of returning farmland to forest and grassland. However, people have neglected whether the choice of vegetation restoration method is suitable for the development of ecological environment in this region, and whether vegetation and soil coexist harmoniously. In this paper, the typical watersheds with similar terrain environment but different vegetation restoration methods were selected as the research objects, which were Dongzhuanggou (natural restoration, NR) and Yangjiagou (artificial restoration, AR). Through vegetation investigation and soil physical property experiment, the comprehensive evaluation function was used to quantify the impact of restoration methods on vegetation characteristics and soil properties, and the vegetation-soil coupling model was used to explore the coordinated development of vegetation and soil under different restoration methods. The results showed that there were significant differences between the two restoration methods in terms of vegetation characteristics (P < 0.05). The vegetation diversity indices of NR were 1.59–4.81 times that of AR. For root characteristic indices, NR was 1.05–2.25 times that of AR. For soil physical properties, there was no significant difference between the two restoration methods (P > 0.05). The comprehensive evaluation function of vegetation (VCE) and soil (SCE) under NR were 0.74 and 0.42, respectively, while those under AR were 0.55 and 0.63, respectively. The comprehensive function showed that the vegetation population performance under NR was slightly better than that under AR, while the soil restoration effect was opposite. Under the two restoration methods, the vegetation-soil coupling relationship was barely coordinated (NR: 0.53; AR: 0.54), and both were the intermediate coordinated development mode. The vegetation diversity, tending level and soil management level should be improved simultaneously during the process of vegetation restoration on the Chinese Loess Plateau.
How to cite: Feng, L.: Evaluation of the effects of long-term natural and artificial restoration on vegetation characteristics, soil properties and their coupling coordinations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4758, https://doi.org/10.5194/egusphere-egu25-4758, 2025.
EGU25-2988 | Posters virtual | VPS15
New insights into the swelling of black soil aggregatesFri, 02 May, 14:00–15:45 (CEST) | vP3.11
Soil aggregates swell when infiltrated by water, and their size can increase in two ways. First, aggregates can attach to one another with water acting as a bridge (i.e., adsorption), and water can enter the aggregate pores (i.e., swelling). This is defined as the “adsorption-swelling” effect. Second, clay can fill the pores of macroaggregates and microaggregates (i.e., filling) when adsorption occurs. This is defined as the “adsorption-filling” effect. However, the size range of aggregates affected by these effects and the extent of their influence on aggregate swelling are still unclear. Therefore, different initial size fractions (5 ~ 2, 2 ~ 1, 1 ~ 0.5, 0.5 ~ 0.25 and 0.25 ~ 0.053 mm) of soil aggregates from the black soil zone of Northeast China were studied. The size range of swollen aggregates, the “adsorption-swelling” rate (V) of initial size fractions, and the “adsorption-filling” rate (E) of size fractions < 0.053 mm were measured and calculated in three experimental treatments that involved the following procedures: i) wet-sieving of each initial size fraction in deionized water (WS); ii) wet-sieving of each initial size fraction of air-dried aggregates after they were soaked in absolute ethanol (WSas); and iii) the size fraction < 0.053 mm air-dried aggregates were mixed with each initial size fraction of air-dried aggregates in absolute ethanol and then wet-sieved (WSaf). The results were as follows: i) the size fraction 2 ~ 0.053 mm were swollen. ii) V decreased exponentially with decreasing initial particle size, with a maximum value of 32.30% at a size fraction of 2 ~ 1mm; and iii) the “adsorption-filling” effect of size fraction < 0.053 mm was obvious in the size fraction < 2 mm swelling aggregates with a maximum of 29.54%. The “adsorption-swelling” and “adsorption-filling” effects had greater impacts on soils with high contents of the size fractions 2 ~ 1 and < 0.053 mm. This study provides a theoretical basis for understanding the swelling mechanisms of soil aggregates.
Key words: soil aggregates, wet-sieving, swelling, adsorption, filling
How to cite: Zhao, Y., Wang, H., Chen, X., and Fu, Y.: New insights into the swelling of black soil aggregates, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2988, https://doi.org/10.5194/egusphere-egu25-2988, 2025.
EGU25-5027 | Posters virtual | VPS15
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 2020Fri, 02 May, 14:00–15:45 (CEST) | vP3.12
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.
EGU25-3104 | Posters virtual | VPS15
Soil health evaluation of rehabilitation lands based on Cornell Soil Health AssessmentFri, 02 May, 14:00–15:45 (CEST) | vP3.13
Objective: Returning farmland to forests is an important ecological construction project in China. Establishing a soil health evaluation system to evaluate the soil health of returning farmland to forests under different vegetation restoration in the black soil region of Northeast China can provide data support for scientific evaluation of the ecological benefits of returning farmland to forests. Methods: Taking the surface soil of two major vegetation types (pure birch forest and elm-lonicera mixed forest) in the black soil region of Northeast China as the object of study, and using the soil of cultivated land as the control. Combination of field sampling and indoor experiments was used to investigate the characteristics and differences of physical, chemical and biological properties of the soil under the conditions of different vegetation restoration. Based on the Cornell Soil Health Assessment, the soil health evaluation of different vegetation was carried out. Results: i) In the 0~10cm soil layer, the soil bulk density of pure forest and mixed forest decreased significantly by 15.14%~19.18%, and the saturated water holding capacity increased significantly by 33.35%~58.53% compared with the control. In the 10~20cm soil layer, the soil bulk density of pure forest and mixed forest decreased significantly by 6.71%~9.04% compared with the control, and the difference of saturated water holding capacity was insignificant compared with the control.(ii) In the 0-10cm soil layer, the soil carbon, nitrogen and available potassium contents of pure forest and mixed forest increased significantly by 21.75%-29.15%, 35.05%-47.71% and 35.12%-121.63% respectively compared with the control. In the 10-20cm soil layer, the soil carbon, nitrogen and available potassium contents of pure forest and mixed forest increased significantly by 53.57%-54.78%, 93.29%-120.34% and 60.71%-183.28%. iii) In the 0-10cm soil layer, the soil microbial carbon and nitrogen content of pure and mixed forests significantly increased by 97.46%-183.43% and 60.54%-142.54%, respectively compared with the control and in the 10-20cm layer, the soil microbial carbon and nitrogen content of pure and mixed forests significantly increased by 18.63% - 82.55% and 59.00% - 101.34% compared with the control. iv) In the 0-10cm soil layer, the results of soil health scores were mixed forests (11.80 points) > pure forests (8.80 points) > CK (5.47 points). In the 10-20cm soil layer, the results of soil health scores were mixed forests (8.41 points) > pure forests (7.03 points) > CK (4.03 points). Conclusion: The soil health scores of pure and mixed forests were significantly higher than those of the control, and the soil health scores of mixed forests were the highest.The effect of vegetation on the restoration of top soil was more significant after the return of farmland to forest.Vegetation mainly improved soil health by increasing the stability of soil structure.It is suggested that plant species can be enriched in the restoration of degraded soils, and the plant configuration method of mixed tree-irrigation can be used to better restore soil health.
How to cite: Liu, B.: Soil health evaluation of rehabilitation lands based on Cornell Soil Health Assessment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3104, https://doi.org/10.5194/egusphere-egu25-3104, 2025.
EGU25-6354 | Posters virtual | VPS15
Carbon Sequestration Benefit and Influencing Factors in Terraces with Different Cover Types of Soil in the Loess Hilly RegionFri, 02 May, 14:00–15:45 (CEST) | vP3.14
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.
EGU25-7631 | Posters virtual | VPS15
Terracing Measures Stabilize and Enhance Soil Organic Carbon Sequestration Benefits of Revegetation on the Loess PlateauFri, 02 May, 14:00–15:45 (CEST) | vP3.15
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.
EGU25-9281 | ECS | Posters virtual | VPS15
Sustainable agricultural management does not reduce heavy metals and associated risks in apple orchard soilFri, 02 May, 14:00–15:45 (CEST) | vP3.16
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.
EGU25-10934 | ECS | Posters virtual | VPS15
Effects of vegetation restoration measures on soil nutrients and erodibility in loess hilly region, ChinaFri, 02 May, 14:00–15:45 (CEST) | vP3.17
Abstract: The depletion of soil nutrients and the increased erodibility of soil have exacerbated the degree of soil degradation, thereby impeding the sustainable development of ecosystems. Vegetation restoration, as a widely implemented measure to prevent soil degradation, is valued for its role in enhancing soil nutrients and reducing soil erodibility. To investigate the impact of vegetation restoration measures on soil nutrients and erodibility in the Loess Hilly Region, this study selected Wuqi County, the pioneer county of China's Grain-for-Green Project, as the research site, with sloping farmland serving as the control. Four types of vegetation restoration were chosen: artificial forests (Armeniaca sibirica, Pinus tabulaeformis, Robinia pseudoacacia), artificial mixed forests (Pinus tabulaeformis mixed with Armeniaca sibirica, Pinus tabulaeformis mixed with Robinia pseudoacacia), shrub forests (Hippophae rhamnoides), and abandoned grasslands. The physicochemical properties of the soil at depths of 0—5 cm, 5—20 cm, and 20—40 cm were measured. The Comprehensive Soil Nutrient Index (CSNI) and the Comprehensive Soil Erodibility Index (CSEI) were combined, and a weighted summation method was used to calculate the Comprehensive Soil Quality Index (CSQI), thereby reflecting the impact of vegetation restoration on the improvement of soil nutrients and erodibility. The results indicated that the vegetation types with the highest CSQI were Pinus tabulaeformis mixed with Armeniaca sibirica (3.43), Pinus tabulaeformis mixed with Robinia pseudoacacia (3.22), Robinia pseudoacacia (2.85), Armeniaca sibirica (2.37), Pinus tabulaeformis (2.22), Hippophae rhamnoides (3.06), and grassland (2.93). The CSNI was primarily influenced by the Soil Structure Stability Index (SSSI), sand content, and the content of silt + clay, while the CSEI was controlled by soil organic matter (SOM), macroaggregates, and microaggregates. Overall, vegetation restoration can effectively enhance soil nutrients and improve soil erodibility. Mixed forests, compared to single-species forests, shrublands, and abandoned grasslands, are more effective in improving soil aggregate stability and resistance to erosion. This study provides a reference for assessing vegetation restoration measures.
Keywords: Soil degradation, Soil nutrients, Soil erodibility, Soil quality, Vegetation restoration, Loess Plateau
How to cite: Geng, W., Zhang, X., Hu, Z., Duan, C., Wang, H., Wang, M., Sun, W., Liu, X., Zhang, Y., Yu, K., and Strauss, P.: Effects of vegetation restoration measures on soil nutrients and erodibility in loess hilly region, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10934, https://doi.org/10.5194/egusphere-egu25-10934, 2025.
EGU25-11388 | ECS | Posters virtual | VPS15
Response of ecosystem service flows to the ecological restoration project of Loess Plateau in northern Shaanxi ProvinceFri, 02 May, 14:00–15:45 (CEST) | vP3.18
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.
EGU25-14699 | ECS | Posters virtual | VPS15
Using WaTEM/SEDEM to characterize the spatiotemporal trend of the erosion and sediment transportation and the driving factor in a Loess Hilly-gully watershedFri, 02 May, 14:00–15:45 (CEST) | vP3.19
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.
EGU25-15369 | ECS | Posters virtual | VPS15
Assessing the effectiveness of biodegradable mulching film in vineyard: a case study in Southern ItalyFri, 02 May, 14:00–15:45 (CEST) | vP3.20
EGU25-5365 | Posters virtual | VPS15
Spatial distribution characteristics of ridge plant belts on soil water-holding capacity and soil structure in sloping farmlandFri, 02 May, 14:00–15:45 (CEST) | vP3.21
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.
