In recent years, various grassland regions in Austria have repeatedly experienced periods of drought, sometimes leading to significant yield reductions. The trend towards more frequent and extreme droughts will intensify in the future due to climate change, with increasingly higher temperatures and unevenly distributed rainfall. Appropriate adaptation measures for grassland management are therefore necessary – irrigation could be one such measure.

As experience in other countries, especially South Tyrol, shows, artificial irrigation bridges dry periods with their negative effects on grassland yields, with the aim of preventing total crop failure and lasting damage to the turf.

While irrigation in arable farming, fruit and vegetable production has a long tradition with extensive experience, know-how, and technical developments, comparatively little research has been conducted on grassland irrigation. In particular, investigating the interplay between plant physiological and hydrological aspects can provide important foundations for determining the type, quantity, duration, and timing of grassland-specific irrigation measures. Of particular interest is how the framework conditions will change in a future climate and how these changes will affect irrigation parameters. These aspects will be systematically investigated over the next three years in the IrriGrass project.

Project content

IrriGrass is an extension of the ClimGrass experimental facility (Impacts of climate change on the productivity and biogeochemistry of the permanent grassland ecosystem), where it is possible to investigate the framework conditions of irrigation even in a simulated future climate and thus answer the following questions:

• How will a future temperature increase as part of global warming, combined with an increased atmospheric CO2 concentration, affect the water requirements of a typical grassland that is exposed to varying degrees of water stress?
• How does the water demand differ under current and future climate conditions for grassland communities optimized for productivity on the one hand and drought tolerance on the other? 

During growth, rain canopies are used to block natural rainfall on some of the ClimGrass plots, where a drought-tolerant and a conventional plant population are artificially irrigated in gradations on a total of 48 mesocosms (delimited areas with a diameter of 30 cm) equipped with temperature and humidity sensors.