Can caraway and coriander help agriculture in climate change?

Agriculture has to adapt to drier and hotter summers. In periods of drought, the use of more technology, fertiliser and artificial irrigation reaches its limits. Certain plants in crop rotation could potentially make better use of water and nutrients in the soil, improve soil quality and thus secure food production and farmers' incomes. With support from the state, a LOEWE project led by the University of Kassel is researching the potential of mixed crops of wheat with spice plants.

Bild: Adobe/Steve.
Withered wheat in a field in Germany.

Germany is currently experiencing a recurring hot summer. The extreme year of 2018 showed just how drastic heat and drought can be for agriculture. Grain harvest losses were almost a third regionally. Scientists under the leadership of the University of Kassel are now researching the possibility of integrating deep-rooted crops into crop rotations, specifically: planting caraway, fennel and coriander in the same fields as wheat. The State of Hesse announced today (30 June) that it will fund the project with 4.8 million euros as part of its State Offensive for the Development of Scientific and Economic Excellence (LOEWE).

According to the hypothesis, caraway, fennel and coriander can reach water and nutrients in deep soil layers with their taproots. In mixed cultivation with shallower-rooted wheat, the soil volume could be used more extensively - with a given amount of water and nutrients, more yield would be possible. But there is more: the research team led by Prof. Dr. Miriam Athmann, head of the Department of Organic Agriculture and Crop Production at the University of Kassel, is now investigating the extent to which caraway, coriander and fennel have a "hydraulic lift" effect. This effect is known from some tree species that release water absorbed from deep soil layers back into the upper soil layers. Thus, they improve the availability of water and nutrients for neighbouring shallower-rooted plants. Perennial wheat, which has only been available for a few years, is being tested as a mixed crop partner for perennial fennel. So far, perennial crops are hardly represented in arable crop rotations, but are more resilient to drought stress due to their distinctive root systems. With their flowers, they could also make a significant contribution to biodiversity - an area where agriculture has a significant impact and thus a special responsibility.

"The cultivation of deep-rooted crops is not very widespread in Central European agriculture," explains Miriam Athmann. "It has not yet been researched whether they are better able to cope with climate change, especially in mixed cultures, and what contribution they make to maintaining biodiversity. We want to change that."

Vice-President Prof. Dr. Michael Wachendorf, is responsible for research and, as an agricultural scientist himself, involved in the project. He was pleased about the award for "this highly relevant project. How agriculture deals with climate change is a question of survival. Our results can contribute to this. The project fits perfectly into our research profile, in which we focus on sustainable transformations."

Field trials will be carried out at four Hessian locations in the future, including the Frankenhausen domain, University of Kassel's experimental farm.

The LOEWE project TRIO (Transformative Mixed Crop Systems for One Health) will run for four years. In addition to Athmann's and Wachendorf's departments, the Kassel departments of Ecological Plant Protection (Prof. Dr. Maria Finckh), Agroecosystem Analysis and Modelling (Prof. Dr. Christoph Gornott) and Botany (Prof. Dr. Birgit Gemeinholzer) are also involved. Project partners are the Justus Liebig University of Giessen and the Geisenheim University of Applied Sciences; associated partners are the Potsdam Institute for Climate Impact Research, the Leibniz Centre for Agricultural Landscape Research, the Hessian State Office for Agriculture and the associations Forschungsring and Ökoplant.


Press release of the HMWK



Prof. Dr. Miriam Athmann

University of Kassel

Head of the Department of Organic Agriculture and Plant Production

Phone: +49 5542 98-1587

E-mail: m.athmann@uni-kassel.de