Research

For grain maize, sugar beet, potato, soybean, sunflower and field vegetables (crop type to be determined), the irrigation requirements of the last 30 years (1995 to 2024) are to be determined for two selected reference areas. The reference areas are selected on the basis of the site conditions (a total of 17 areas are available for selection). The irrigation requirement is determined based on the standard method of the FAO (Allen et al., 1998) in accordance with the state of the art. The required weather data is taken from the Andau weather station (Geosphere Austria data hub). Soil data is taken from the digital Austrian soil map (eBOD). Cultivation data (cultivation dates, stages of development, harvest dates) are provided by the client. Information on cultivation areas from the AMA (freely available) will also be used to estimate the total water requirement. Research questions: How has the plant water demand and the irrigation demand of selected crops at selected locations in the Seewinkel region developed over the last decades? - What would be an optimal irrigation strategy under the given site conditions (climate, soil) and local agricultural crops? - What effects do different weather conditions and irrigation scenarios have on yield? rk steps: - Collection and processing of the required weather data from the Andau weather station (temperature (max, min), humidity, wind speed, radiation and precipitation on a daily basis) and presentation in an annual comparison. - Determination of reference evaporation according to FAO Allen et al. (1998). - Determination of soil properties from the digital soil map (eBOD) and estimation of retention properties (storage capacity) from eBOD (usable field capacity, nFK, of the BAW) and/or using pedotransfer functions. - Determination of plant evaporation and plant water requirements based on standard plant coefficients (Allen et al., 1998). - Determination of the irrigation water requirement for the selected crops for two reference areas, taking into account the plant water requirement and soil properties. Presentation and comparison of the results. - Determination of plant water requirements and irrigation water requirements based on AMA area data. Presentation and comparison of the results.

Climate change increases the frequency and severity of droughts and rainfall events in Austria. The drought-related soil water deficit and the change in rainfall patterns poses a risk for forests, leading to increased tree mortality and loss of ecosystem services. The complex interplay of climate change impacts on trees and the associated response of hydrological components such as precipitation, soil moisture, or runoff is difficult to entangle under temporally-varying, natural conditions. However, detailed knowledge of forest and water interactions are urgently needed in promoting tree-resistance against climate change. Here, we propose controlled manipulation experiments using rain-out shelters and sprinklers to simulate drought and heavy rainfall events in a highly-instrumented, long-term measurement network located in a beech stand of the mountainous Rosalia forest (Lower Austria). We will quantify the percentage of summer and winter precipitation that beech trees transpire, and fluxes of evaporation, transpiration, and groundwater recharge using stable water isotopes. To achieve this, soil and xylem samples will be taken and analysed in the laboratory, and the results of this analysis compared to in-situ high-resolution measurements of soil water and xylem water isotopes using liquid-vapor equilibrium techniques. Further, we will quantify hydrological components using water balance methods and fluorescence tracers. This project will result in estimates of changes in water fluxes under climate change using controlled manipulation experiments as repeated experiments. We will gain insights into forest hydrological changes of Austrian, mountainous beech trees, from which suggestions for forest managers for strategies to promote beech health threatened by increased droughts and heavy rainfalls can be derived.

Digital data and tools are increasingly part of agricultural practice and water management in Austria. Decision support systems can be used to control irrigation digitally and adapted to agrometeorological conditions. Apps and web-based services (e.g., ada.boku.ac.at, eo4water.com) have been developed to facilitate irrigation planning using publicly available satellite, weather, soil, and land use data (e.g., opendatacube.org, data.gv.at). Online probes (e.g., ehyd.gv.at) allow real-time display of groundwater levels or surface water discharges. Water withdrawals for irrigation purposes are recorded with different information density via water information systems (e.g. online water books of the federal states). Some digital tools are already in use, various research projects deal with partial aspects of this topic, data bases are available in different forms at a number of institutions. However, there is a lack of an overview of the current state of research, the available data bases and digital tools, as well as the developments and challenges in this topic area, which would enable targeted further developments and synergetic uses of existing data. Therefore, the current state of research, available data bases and digital tools, as well as current developments and challenges are to be compiled and presented in the form of web-compatible factsheets with the intensive involvement of the relevant stakeholders (agriculture, water management, research). For this purpose, in a first step, the relevant topic areas will be defined in communication with the stakeholders, the research sources will be determined, the criteria for the consideration and evaluation of information will be established, and a standardized form of presentation will be designed. The existing data bases and tools are evaluated for their concrete feasibility, synergy potential, and availability/accessibility for different stakeholders. Complementary to this, identified gaps are presented.