Drainage systems are essential for cultivated fields, ensuring optimal growth conditions for crops by preventing root zone wet stress. However, these conventional drainage systems also lead to a significant loss of water, a valuable resource that could be used to sustain crops during dry (summer) months. To address this, climate adaptive drainage or controlled drainage is employed, raising the water table “when possible given the ongoing agricultural activities”. This approach enhances aquifer recharge and stores excess water for use during the summer. Nevertheless, it remains unclear for farmers and water managers whether climate-adaptive drainage will improve agricultural performance and, if so, how to precisely manage water levels throughout the growing season to optimize performance. 

In this study, we conduct a synthetic experiment using the SWAP model to investigate the complex interaction between drainage types under different meteorological conditions, soil characteristics, and crop types. Our research aims to provide insights into the effect of climate-adaptive drainage for both farmers and water managers.

Our findings highlight that controlled drainage significantly enhances soil water content in sandy and loamy soils, contributing to climate resilience. However, its effectiveness in clay soils is small. It is important to note that climate-adaptive drainage has the potential to raise groundwater levels across all soil types, posing a potential risk of oxygen stress on crops. Regardless of soil type, the implementation of controlled drainage results in increased surface runoff and groundwater recharge, associated with a reduction in drainage flux. While the augmented surface runoff  poses potential issues such as soil erosion and water pollution, the positive aspect lies in the enhanced groundwater recharge, crucial for maintaining water availability and supporting ecological systems.

How to cite: Rodríguez Lache, E. L., Blanchy, G., Mehmandoostkotlar, A., and Garré, S.: Exploring climate-adaptive drainage in water management: Enhancing soil moisture, crop resilience and groundwater recharge., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3837, https://doi.org/10.5194/egusphere-egu24-3837, 2024.

Soil moisture, as a key indicator of soil functionality, is significantly influenced by the evolution of soil-plant systems and the hydrologic cycle. Little long-term data is available about how land use and climate change affect the spatial and temporal distribution of soil water. In particular the variations in deeper subsoil layers are poorly documented. Here, the effects of five land use types, including two croplands with conventional and organic farming (CF and OF) and three grasslands with intensive and extensive meadow (IM and EM), as well as extensive pasture (EP) on soil moisture profiles were investigated at the Global Change Experimental Facility (GCEF), at Bad Lauchstädt in the German dryland belt. The facility harbors two climate treatments. The ambient climate and a future climate with increased temperature by ~0.55 ^◦C across seasons, and the altered precipitation patterns by ~9 % additional irrigation in spring and autumn, and ~21 % reduction in summer. The soil moisture profiles were bi-weekly monitored with a portable probe (TRIME Pico IPH) down to 110 cm for two continuous years.

Soil moisture content in topsoil and subsoil reflected the presence and size of transpiring plants, i.e. from October to next April, the soil water content was lower in grasslands than in croplands, which planted winter crops. During summer, there was a marked decrease in soil water content in the deeper soil layers of grasslands, while the crop on the cropland was already harvested. As a result, the recovery of soil water storage was faster during winter in croplands than in grasslands. Within croplands, OF had higher moisture than CF below 30 cm during the whole growing season and beyond due to less vigorous growth imposed by nutrient deficits. Within grasslands, differences in soil moisture only emerged in deeper soil (> 70 cm). In general, soil moisture in the shallow soil layers (0 - 20 cm) was very similar across land uses and climate scenarios and these clear differences only emerged in deeper soil. In the deeper soil (< 50 cm), croplands and extensively used grasslands showed an obvious increase of soil moisture in future treatment, especially during wet spring and summer.

Our results clearly indicate long-term differences in soil moisture between the land uses. Climate manipulation at the GCEF only manifests itself in the subsoil (> 50 cm), by contrast, topsoil (< 30 cm) was more controlled by short-term dynamics induced by evaporation and precipitation. These findings stress the importance of deep soil moisture monitoring for a more comprehensive assessment of the water budget. 

How to cite: Wu, M., Klauder, T., Tarkka, M., Vetterlein, D., and Schlüter, S.: The effect of land use types and climate change on soil moisture profile dynamics, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6546, https://doi.org/10.5194/egusphere-egu24-6546, 2024.

Water balance is important to provide information and to conserve water. The flow of water in the system can be used to help and manage water supply, changes in management can increase water productivity in arid regions. For this study, soil water content was measured from one soil column within the orchards using time-domain reflectometry probes installed at different depths in the root zone of pecan fields. This data was analyzed to compare the irrigation systems. Water that passes the root zone was considered deep percolation. This research compared the amount of water stored on each field and water consumed by the trees for the last four irrigation seasons 2020 - 2023. Quantifying water from irrigation was essential to know how much water would recharge the Mesilla basin. Percolation was higher in the flood section, with 52 % of the total water applied, while in the drip, percolation was less than 5% of the total water applied moving down in the field for the 2021 growing season. In addition, there were differences in crop yield between the irrigation systems. This study estimated recharge and modeled water flow through the soil in drip and flood-irrigated pecan orchards to understand better surface water and groundwater interactions for improved river basin water management strategies and quantifies water stored in the ground lost through evapotranspiration. In addition, this project evaluates which irrigation scenario could best grow sustainable pecans in arid regions, reducing water use while maintaining crop production. It presents a balance of the two irrigation systems to understand the implications of climate change on the water cycle and achieve sustainability in the crops grown in the area.

How to cite: Preciado, J., Fernald, A., and Heerema, R.: Groundwater Recharge in Pecan Orchards Under Different Irrigation Systems to Reduce the Impacts of Climate Change in the Southwest USA, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6804, https://doi.org/10.5194/egusphere-egu24-6804, 2024.

Abstract: The Hetao Irrigation District (HID) is located in the arid region along the upper reach of the Yellow River and is an important grain production area in northwest China. Water diverted from the Yellow River is an indispensable water supply of the crop production in this region. Unfortunately, traditional irrigation, drainage and fertilization practices have resulted in severe soil salinization and inefficient of water use, which poses a great challenge to food security and water resources. Therefore, it is important to search a new practice that can achieve water saving, salinity control, and yield increase simultaneously. To this end, this study applied a framework that combined the SWAP model and a multi-criteria decision-making method.

First, we used a total of 21 station-years of experimental data from 12 spring wheat and spring maize sites for parameter calibration by the PEST package. The sensitive parameters of spring wheat and spring maize were obtained, and the evaluation showed that the SWAP model is capable of simulating seasonal variations of leaf area index, evapotranspiration, soil moisture and soil salt content. Specially, we showed that the parameters SALTMAX (threshold salt concentration in soil water) and TSUMEA (temperature sum from emergence to anthesis) were obviously different from the default values of wheat and maize in the SWAP.

Second, we designed simulation scenarios based on the combinations of irrigation, drainage and fertilization practices, constrained by the local customs and water supply from the Yellow River. The simulated crop yield, water use efficiency (i.e., the crop production per irrigation water amount), and soil salt content change were obtained by the SWAP model.

Finally, based on the SWAP-simulated results, optimal practices were obtained with the help of the VIKOR method, a multi-criteria decision-making method which has the advantage of objectively determining the weights of water use efficiency, crop yield, and soil salt content change. Compared with the traditional practices by farmers, the optimal practice can not only increase crop yield by 20 per cent and improve water use efficiency by more than 10 per cent, but also ensure the soil salt content does not increase.

Keywords: Irrigation; Drainage; Fertilization; SWAP model; VIKOR method

How to cite: Duan, S. and Lei, H.: Searching for optimal practices for water saving, salinity control and yield increase in an arid and salinity irrigated area of China using the SWAP-based method., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7726, https://doi.org/10.5194/egusphere-egu24-7726, 2024.

The Wappfruit project objective is to optimize the irrigation techniques for water and energy saving in fruit orchards in the Piemonte Region, Northwest Italy. The stakeholders of the project are Politecnico and the University of Torino, Piemonte Region, Agrion Foundation for Research in Agriculture, Astel S.r.l. (for the industrialisation of the experimental hardware developed by Politecnico di Torino), and three farms (“La Marchisa” and “Lorenzo Sacchetto” – apple orchards and “Paolo Vassallo” – actinidia orchard).  In each farm, two areas were identified, an “experimental area” where the new set-up was tested and a control area where the farmers continued the irrigation as usual.

In the year 2023, the Wappfruit project has shown the potentiality of a smart irrigation solution composed of two kinds of IoT (Internet of Things) nodes employing LoRa technology and governed by a 24/7 server script, written in Python, that acquires soil matric potential and decides the opening and closure of the irrigation pumps in real-time. The soil matric potential thresholds, identified in 2022 and early 2023, (-60 kPa and -25 kPa at 20 cm of depth for the activation of the irrigation, respectively in the apple and Actinidia orchards; -50 kPa at 40 and 20 cm of depth and -18 kPa at 20 cm of depth, for the deactivation of the irrigation, again respectively for apple and Actinidia orchards) were verified again after a campaign in which soil parameters (saturated soil water content, infiltration velocity at saturation) were measured. These values were used for new model simulations that included irrigation. The thresholds for the apple orchards were confirmed, whereas new thresholds were identified for the Actinidia: -12 kPa (activation) and -5 kPa (deactivation). Results highlight that these thresholds can activate and deactivate the irrigation appropriately. The 2022 simulations show a matric potential in agreement with the measures collected (R between 0.51 and 0.88). Moreover, the 2023 simulations with modelled irrigation show a good agreement with the measures in the experimental area. Both the simulations and the real optimized irrigation generally show lower values if compared with the irrigation of the farmers (range: 13 – 217.5 mm/ha), with an exception in one apple orchard, where the model suggests more irrigation than expected, likely because of an overestimation of the water infiltration velocity. The hardware/software design and implementation have shown that low-cost low-power electronic devices and artificial intelligence can be reliable and very inexpensive for water and energy savings. The remote control of the system is another important achievement. Moreover, optimized irrigation does not affect the vegetation productivity and increases the fruit quality.

How to cite: Canone, D., Gisolo, D., Nari, L., Pettiti, F., Gentile, A., Ferraris, S., Barezzi, M., Garlando, U., and Demarchi, D.: Wappfruit, a project for the optimization of the irrigation in agriculture: final results, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18026, https://doi.org/10.5194/egusphere-egu24-18026, 2024.

Subsurface drainage is widely used in farmland. Entrance resistance occurs when water flows into a perforated drain pipe, reducing the drainage efficiency and resulting in a high water table. Using the real radius will overestimate the drainage discharge. Accurately calculating effective radius is essential for subsurface drainage calculation and simulation. New effective radius formulas for corrugated drains wrapped with a thin geotextile were proposed by dividing the entrance resistance into corrugation and perforation resistance. The accuracy of the formulas was verified by sand tank experiments. Sensitivity analysis was conducted to determine the factors that affected effective radius, indicating that corrugation was the main factor. When the radius and structure of the drain wall were determined, the opening area exhibited high sensitivity with interactivity between it and drainage discharge. The effect of the opening area and position of the perforations on the effective radius was evaluated for different drainage discharges. Putting the perforations on the bottom was better for drainage efficiency. For small drainage discharge of less than 0.1 cm³ s^-1 cm^-1, the opening area was not significant, and an opening area of 15 cm² m^-1 was sufficient. However, for greater drainage discharge, an opening area of 60 cm² m^-1 with three or more row perforations would be required.

How to cite: Yang, H., Guo, C., and Wu, J.: Effective radius of corrugated drainage pipes wrapped with a thin geotextile envelope, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19384, https://doi.org/10.5194/egusphere-egu24-19384, 2024.

The emirate of Fujairah, spanning approximately 1,450 km², is characterised by a landscape dominated by rugged mountains, encompassing 77% of its total surface area. Despite its average precipitation of less than 150 mm, Fujairah hosts a thriving ecosystem supported by national tree plantations, including Acacia nilotica, Acacia tortilis, Prosopis cineraria, and Zizyphus spina-christi. These plantations are crucial in providing ecosystem services, notably contributing to honey bee production.

This study attempts to support the increase of vegetation cover in Fujairah through sustainable land management practices of using water harvesting and planting native trees by employing cutting-edge technology. Through the integration of Remote Sensing and Geographic Information System (GIS)-driven Multi-Criteria Evaluation (MCE), the research identifies optimal areas for planting native honey trees. Emphasising sustainability, the methodology incorporates water harvesting techniques that eliminate reliance on traditional irrigation methods for plantation.

Local and international datasets encompassing biophysical parameters such as land use, digital elevation models, slope, topographic wetness index, soil texture, and climate data are combined. Additionally, the study considers optimal ecological conditions for native trees, including temperature and soil pH. The resulting suitability maps, treated as future land cover maps, are employed alongside soil sample data to estimate carbon storage and sequestration potential.

Furthermore, the research investigates indigenous water harvesting knowledge in Fujairah through a comprehensive survey. This survey explores community awareness, historical context, current applications, technical specifics of water harvesting and native tree plantation practices, environmental considerations, and potential obstacles and solutions.

The findings aim to inform a holistic approach to sustainably enhancing Fujairah's vegetation cover, providing valuable insights for environmental conservation and community engagement.

Keywords: Suitability mapping, water harvesting techniques, Sustainable land management, and Ecosystem Services

How to cite: Belaid, Y., Worqlul, A., Haddad, M., Al Moalla, A., and Lamghari Ridouane, F.: Enhancing Vegetation Cover in Fujairah through Sustainable Honey Tree Plantations and Water Harvesting Technique: A Multi-Criteria Suitability Mapping, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20020, https://doi.org/10.5194/egusphere-egu24-20020, 2024.

Within the EU Horizon project OPTAIN (OPtimal strategies to reTAIN and re-use water and nutrients in small agricultural catchments across different soil-climatic regions in Europe, optain.eu) project, the effects of Natural/Small Water Retention Measures (NSWRMs) on water regime, soil erosion and nutrient transport are evaluated at both, catchment- and field-scales for present and future climate conditions. Our goal is to perform an integrated, model-based assessment of the effectiveness of NSWRMs at field scale and cross-validated these results from those obtained from the catchment-scale modelling. The field-scale assessment is based on the adaptation of the SWAP mathematical model to seven pilot sites across three European biogeographical regions and on combined NSWRM – projected climate scenario analyses. The scenarios are designed to evaluate the efficiency and potential of different natural/small water retention measures in improving soil water retention and reducing flash floods and the loss of soil and nutrients under changing climate conditions. We present the harmonized SWAP modelling workflow and the combined scenario analyses, including the implementation of various in-field measures in the SWAP model. Examples of model calibration, validation and scenario results for selected pilot sites will be given.

How to cite: Farkas, C., Shore, M., Horel, Á., Cüceloglu, G., Czelnai, L., Mirosław-Świątek, D., Turek, M. E., Cerkasova, N., Szabó, B., Zajiček, A., Nemes, A., Weiland, S., Fucik, P., Holzkaemper, A., Idzelyté, R., and Marval, S.: Effectiveness of natural soil water retention measures at field scale under current and future climate – case studies in three European biogeographical regions, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20913, https://doi.org/10.5194/egusphere-egu24-20913, 2024.

Many agroecosystems are experiencing an increase of agricultural water demand which risks depleting the natural reservoirs, viz lakes and aquifers. The increasing temperature reduces glacier extent and snow accumulation, thus reducing the dry—season water availability, and challenging the agricultural systems and the food security, particularly in arid and semiarid regions.

Aiming at contributing to defining effective strategies that are able to provide robust and parametric parsimonious estimates of the irrigation water demand of the agroecosystems at the planning level, we propose a framework based on the joint use of Melisenda’s aridity index, Benfratello’s water balance and Budyko’s curve to define the crop proneness to the hydrological sustainability.

The strategy is based on Benfratello’s (1961) explicit and conservative method to assess the soil water balance and the irrigation deficit in semiarid Mediterranean climates. The method is parametrized by means of an aridity index (Melisenda, 1964) to assess the soil proneness to water surplus formation, and the results are compared with the natural ecosystem deficit as provided by Budyko’s (1974) curve. Coupling these climatic water balances with a crop based estimate of the maximum required evapotranspiration, as given by the FAO procedure, it is possible to assess the expected crop irrigation deficit.

Our strategy is two—step. The first step is mapping Melisenda’s index, to identify the climatically—wet areas and the potentially climatically—dry areas. In potentially dry areas field capacity may not be refilled during the dry season, if it is greater than a critical value. It is worth noting that the greater is the field capacity, the smaller is the surplus water, and the greater is the crop water availability during the dry season. These maps may be produced both for the actual cultivations, and for some reference crops, viz millet, barley, rice and wheat, which are important for food security, to depict the local hydrological attitude to them.

The second step is the calculation of the monthly and annual irrigation deficit by means of Benfratello’s water balance. The irrigation deficit does not depend only on the annual precipitation and on the annual crop water demand, but also on their annual regime. Benfratello’s irrigation deficit is then compared with the ecosystemic water deficit, provided by Budyko’s curve. The closer is the crop behaviour to Budyko’s curve, the closer is its water demand to the ecosystemic one, considered as a reference natural water demand.

In order to test the sensitivity of the procedure at characterising the water balance also in presence of small climatic differences, we applied it with promising results to two important and comparable Mediterranean agricultural districts, the Bonifica della Capitanata (Southern Italy, 4,410 km², mainly cultivated with herbaceous crops, olives, fruit and grapevine trees) and the Mygdonia water basin (Northern Greece, 2,100 km², 1,030 of which are cultivated mainly with cereals). The Köppen—Geiger climate type is mainly Cfa for both areas. De Martonne aridity index depicts a semi—dry to Mediterranean condition for the Capitanata and a mainly Mediterranean condition for the Mygdonia.

How to cite: Barontini, S., Caffi, M. G., Hanif, M. F., Kolokytha, E., Malamataris, D., and Peli, M.: A framework based on Melisenda’s aridity index and on Budyko’s curve to assess the crop proneness to the hydrological sustainability, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20983, https://doi.org/10.5194/egusphere-egu24-20983, 2024.

Rice is the world's most important food crop, as it is a staple food for more than half of the world's population, and the global demand for rice is expected to increase. More than 1,000,000 hectares in the Mediterranean basin are devoted to rice cultivation. The most important producing countries are Italy (IT) and Spain (SP) in Europe (over 310,000 ha), and Egypt (EG) and Turkey (TR) among non-EU countries (over 600,000 ha). In the Mediterranean region, rice production is of great socio-economic and environmental importance, as rice is often a crucial product for internal consumption and export, especially in Egypt, where it is considered strategic for food security. Despite of this, the peculiar flooding conditions in which rice is traditionally grown lead to the use of huge water volumes, as well as to the potential release of greenhouse gases and pesticides into the environment. For this reason, the introduction of water-saving irrigation strategies could reduce water consumption and decrease the harmful environmental impacts associated with rice flooding, while maintaining yield and rice grain quality.

In the context of the MEDWATERICE project (https://www.medwaterice.org/; PRIMA-2018), alternative irrigation methods to WFL were tested in case studies implemented in five Mediterranean countries (Italy, Spain, Portugal, Turkey, Egypt). Irrigation strategies for each CS were selected with the support of local Stake-Holder groups and applied in experimental fields measuring/estimating all the water balance terms on a daily basis. Wet seeding and alternate wetting and drying (AWD), dry seeding and delayed flooding (DFL), reduction of inlet/outlet discharges (WIR), a better control of ponding water level through automated gates (DFL-aut), hybrid irrigation (HYBRID), sprinkler irrigation (SPRINKLER), surface drip (DRIP) and subsurface drip irrigation (SDI) were implemented for at least two years in the period 2019-2021 alongside the traditional WFL, to investigate their environmental and economic sustainability and social acceptability.

How to cite: Gharsallah, O., Facchi, A., Arbat, G., Cufí, S., Ramírez de Cartagena, F., Romani, M., Rienzner, M., Tkachenko, D., Mira, C., de Lima, I. P., Gonçalves, J. M., Aboukheira, A. S., Shebl, S., and Enginsu, M.: Innovative irrigation strategies for rice in the Mediterranean areas, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18956, https://doi.org/10.5194/egusphere-egu24-18956, 2024.