Climate change poses a challenge for resource utilization and environmental pollution issues caused by agricultural production, especially in arid to semi-arid regions. Farmland water, carbon and nitrogen (WCN) balances are closely related to these resource and environmental issues. Thus, the Agro-Hydrological & chemical and Crop systems simulator (AHC) was used to assess the response of WCN balances to climate change in a spring wheat farmland of arid Northwest China and to propose adaptation strategies. Five Global Climate Models from the Coupled Model Intercomparison Project 6 and two Shared Socioeconomic Pathways (SSP1-2.6 and SSP5-8.5) were used to establish scenarios with the AHC model to simulate farmland WCN balances for the 2025–2100 period. Various irrigation amounts and nitrogen fertilization rates were tested as compensation strategies. Results indicated that precipitation showed an increasing trend, thus percolation increased and soil water consumption decreased from 2025 to 2100. However, for the carbon budget, although the soil CO₂ emissions tend to decrease, the net primary production (NPP) was also significantly reduced, which resulted in declining the net ecosystem carbon budget (NECB) under future climatic conditions. In addition, higher temperature and increased precipitation enhanced soil inorganic nitrogen leaching and N₂O emissions but reduced NH₃ volatilization from 2025 to 2100. Overall, the soil total nitrogen loss was increased over time, whereas crop nitrogen uptake (CNU) was significantly reduced. In relation to the SSP1-2.6 scenario, the SSP5-8.5 scenario accelerated the increase rates of soil water percolation and total nitrogen loss over time, as well as the decrease rates of CNU and NPP over time. The negative effects caused by climate change can be mitigated by reducing irrigation and increasing nitrogen fertilization. For the SSP1-2.6 scenario, 30% irrigation reduction and 30% nitrogen fertilization increase can effectively decrease soil water percolation and the related nitrogen losses while CNU, NPP and NECB increase in relation to the current management (240 mm irrigation and 200 kg ha^–1 nitrogen fertilization). For SSP5-8.5 the strategy with 45% irrigation reduction and 45% nitrogen fertilization increase can also decrease nitrogen losses and increase CNU, NPP and NECB.

How to cite: Li, Y., Herbst, M., Chen, Z., Chen, X., Xu, X., Xiong, Y., Huang, Q., and Huang, G.: Long term response and adaptation of farmland water, carbon and nitrogen balances to climate change in arid to semi-arid regions, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3923, https://doi.org/10.5194/egusphere-egu24-3923, 2024.

Vegetation cover has a great influence on hydrological response at field scale, and, consequently, on runoff and soil erosion processes. The maintenance of bare soil in vineyard inter-rows with tillage, as well as the tractor traffic, are known to expose the soil to compaction, reduction of soil water holding capacity and increase of runoff and erosion. The use of grass cover is one of the most common and effective practices in order to reduce such threats.

Rain-driven runoff (RO) and soil loss (SL) at sites with different cover have been investigated over last decades. It has been found that RO and SL often correlate with rain properties. This correlation, however, is highly variable among different sites and also for different time periods. In many studies rain is represented only by a few parameters such as e.g. maximum intensity and total precipitation. Size of rain drops is rarely analysed, although it is important for an accurate estimation of kinetic energy of rain. Polarimetric millimetre-wavelength radars are one of the instruments capable of drop size measurements. In contrast to in-situ rain sensors, such radars have much larger sampling area and can estimate range profiles of drop size distributions with high spatial and temporal resolution.

The objective of this work is to relate runoff and soil erosion to rain properties based on traditional monitoring techniques complemented by observations from a radar. With this aim, a site in the Alto Monferrato vine-growing area (Piedmont, NW Italy) was equipped with a 94-GHz radar in June 2023. The site has two vineyard-field-scale plots with inter-rows managed with conventional tillage (CT) and grass cover (GC), respectively. The radar is located about 100 m from the plots. The radar elevation was set to 30° so that the radar samples rain above the plots.

During the summer and autumn seasons of 2023, 26 rain and 13 runoff events were observed. The preliminary results of the conventional analysis show that in this period runoff is directly related to erosivity index (EI30) both in CT and GC plots, and, only in GC treatment to maximum rainfall intensity over 10 minutes and antecedent rainfall in previous 7 days. Maximum rainfall intensity over 30 and 60 minutes, on the contrary, has a negative direct proportion with runoff. Soil erosion for both treatments was also directly related also with maximum rainfall intensity over 10 minutes and antecedent rainfall in previous 7 days and, in addition has a negative proportion with rainfall energy. It should be noted the relevant role played by rainfall intensity over short time interval and the antecedent rainfall, resulting in increased soil moisture. Relationships are different from those obtained in the same site in a previous study, reflecting the peculiarity of summer 2023, characterized by few rainfall events occurred on very dry soil. Information obtained from W-Band radar monitoring allows to investigate relationships in a deeper way among rainfall characteristics and generation of runoff and soil erosion.

How to cite: Biddoccu, M., Capello, G., Myagkov, A., Nomokonova, T., Maschwitz, G., Canone, D., and Ferraris, S.: The contribution of W-band radar monitoring for understanding of runoff and soil erosion response at field scale, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6040, https://doi.org/10.5194/egusphere-egu24-6040, 2024.

The BODIUM model (König et al., 2023) is a systemic soil model which aims to simulate the effect of changing agricultural management practices on soil functions such as yield, water storage and filtration, nutrient recycling, carbon storage and habitat for biodiversity. For this purpose, the influence of crop rotation, soil cultivation, fertilisation as well as the effect of a changing climate is taken into account site-specifically.

A version of this model, the BODIUM4Farmers, is intended to serve farmers as an on-site decision support tool for long-term planning of soil management measures in response to actual economic and ecological requirements. The model considers site- and farm-specific conditions and requires a number of input variables: a description of the soil profile, weather and management data.
In cooperation with farmers and agricultural advisors, we are currently developing an optimised interface that allows farmers to use the tool as efficiently as possible. Co-design workshops with users from agricultural practice have provided important impulses on technical realization such as database connectivity and graphical user interface design. Furthermore, we discussed potential future management options to be implemented for users in the tool and how to present results in an easy-to-understand manner.
With this contribution, we introduce BODIUM4Farmers, present the current state of development and encourage discussions and feedback from scientists experienced in science-to-practice transfer.

König, S., U. Weller, B. Betancur-Corredor, B. Lang, T. Reitz, M. Wiesmeier, U. Wollschläger, and H.-J. Vogel (2023): BODIUM – a systemic approach to model the dynamics of soil functions. Europ. J. Soil Sci., doi:10.1111/ejss.13411

How to cite: Rüschhoff, J., Weller, U., König, S., Franke, L., Diel, J., Wollschläger, U., and Vogel, H.-J.: BODIUM4Farmers: A tool to assess the impact of management measures on soil functions, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10140, https://doi.org/10.5194/egusphere-egu24-10140, 2024.

Current soil sampling methods are expensive, time consuming and destructive. These constraints result in a standard practice that combines samples from a W transect across a field, into one composite sample for laboratory analysis. This presents a challenge for farmers, policy makers and industry, as this method of sampling doesn’t give the required detail about the variability of soil properties across the field. The heterogenous nature of soil means that differences between monitoring results across years could be due to changes in sample location, and the natural variability of the soil. This is of particular concern for farmers and policy makers monitoring soil carbon under the transition to sustainable farming methods, as they want to be sure that the change they see is due to management changes, not inherent variability.

Simple, handheld, near-infrared (NIR) spectroscopy devices can be used in the field by practitioners. They are cheap, quick and non destructive. This allows for more samples to be taken across a field, and GPS allows repeat sampling of the same location over time. This paper looks at how accurate in-field soil spectroscopy performs compared to laboratory results, how variable soil properties are across a field, and how different sampling methods (W transect, random sampling) capture that variability.

How to cite: Underwood, J., Keith, A., Leggatt, A., and Collins, C.: Can in-field NIR spectroscopy provide an option for soil carbon monitoring?, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14225, https://doi.org/10.5194/egusphere-egu24-14225, 2024.

Tillage is an agricultural practice that aims to create a favorable environment for crop production. Nonetheless, the intense field traffic by tillage, in the worst-case, is considered a detrimental anthropogenic practice to the soil. By impeding soil water movement, tillage might exacerbate the impact of droughts. To limit drought impacts, adapting tillage practices is one management option.

In this study, we aimed to evaluate the effect of tillage practices on soil moisture. For this purpose, we deployed 28 point-based plant care soil moisture sensors at 20 and 40 cm soil depths, in a farm field in Lower Saxony, Germany on silt loam divided into three different sections based on tillage type with different tillage depths (moldboard – 30 cm, chisel plow – 25 cm and disk harrow – 10 cm) implemented consistently for more than twenty years. The effect of tillage types on soil moisture was analyzed for different crop development phases of sugar beet and drought severity levels in 2022. For the latter, the soil water deficit index was used, which is computed based on soil moisture content at field capacity and permanent wilting point. Additionally, we ran DSSAT model simulations to evaluate the potential of nature-based solutions, such as no tillage and mulching, on maximizing soil moisture conservation during drought period.

Our result showed a temporal variability in soil moisture content between the three different mechanical tillage depending on the drought severity level. Moreover, our DSSAT simulation indicated that mulching tends to improve soil moisture content and to reduce runoff and soil evaporation.

How to cite: Irkiso, A., Chemura, A., Kuhwald, M., and Thieken, A.: Assessing the effect of conventional and conservation tillage methods on soil moisture under drought progression, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17919, https://doi.org/10.5194/egusphere-egu24-17919, 2024.

All agricultural areas in the European Union, as one of the largest water-using sectors, are under increased threat from the growing frequency of extreme water-holding events due to climate change. These focus on alternative water resource management, spectral data integration and soil moisture modelling. Furthermore, the irrigated area in Hungary covers 2% of agricultural land, mostly with outdated irrigation technology. This research will evaluate farm-level water resource management and irrigation technology developments and research results based on the results of the Hungarian test area.

The study area was conducted on a 85 ha maize field on sandy soil, located in a nitrate-sensitive area (based on European guidelines) and owned by the private company. The case study site situated at the alluvial cone plain is covered mainly with quicksand which is not optimal for maize production from a water management point of view. Irrigation is implemented by a GPS controlled, VRI technology controlled, reversible linear irrigation system with zone and nozzle irrigation control. However there is limited available water resources at the site, therefore alternative water sources utilization system was set up for irrigation to adapt to climate change and reduce fertilizers. The basis of the alternative water resources are excess water, treated wastewater, biogas fermentation sludge which is collected in a water reservoir with 114000 m³ capacity.

In this research the role of these alternative water resources were evaluated in the hydrological system and in the water cycle. A wide variety of remote sensing platforms were used in this research, as satellites, drones, and laboratory instruments. These remote sensing (pigment and plant phenology) data formed the basis of time series studies. The results can contribute to a spatially and temporally optimal stress monitoring of plants and their water supply at the same time. Beside better irrigation management due to the used irrigation techniques as up to 30-50% of the required water can be replaced by using alternative water resources.

This research was financed by project no. TKP2021-NKTA-32, which has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the TKP2021-NKTA funding scheme. This research was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences.

How to cite: Nxumalo, G., Kiss, N. É., Fehér, Z. Z., Magyar, T., Bódi, E. B., Szabó, A., Pásztor, D., Tamás, J., and Nagy, A.: Optimizing of alternative water resources reutilization on extreme sandy soil, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18763, https://doi.org/10.5194/egusphere-egu24-18763, 2024.