Diversity in the root zone: the key to stable crop yields?

In the RhizoTraits joint project, Bayreuth researchers are looking at old crop varieties, researching root characteristics and investigating whether a mixture of varieties can increase yield stability in the climate crisis. The second phase of the project, which has now started, is being funded by the Federal Ministry of Education and Research with a total of €1.9 million, around half of which is going to Bayreuth.

What for?

It is undisputed that droughts and heatwaves are increasing due to the climate crisis. This has a drastic impact on crop cultivation and therefore on food production worldwide. The yield stability of important crops such as maize and wheat is already declining, partly due to lower and more irregular rainfall. In the joint project RhizoTraits, which is coordinated by the University of Bayreuth, researchers are therefore investigating the properties of the root zone of the crop plant maize in order to make future cultivation systems more resilient and yield-stable.

At the Bayreuth site, everything revolves around the biological, chemical and physical properties of the soil in the immediate vicinity of the root: the rhizosphere. The quality and quantity of our crop yields is largely determined by interactions between roots, microorganisms and the soil in the rhizosphere. “These interactions are also largely responsible for how well crops can cope with stress, such as drought,” explains Andreas Wild, research associate at the Chair of Agroecology at the University of Bayreuth.

Maize on a research area. (c) UBT/N. Tyborski

In the recently completed first phase of the project, the researchers investigated old maize varieties, so-called landraces, and modern hybrid and population varieties with regard to their root systems and rhizosphere properties. They found that old varieties exhibit increased plasticity in the properties of their roots and rhizosphere under drought conditions, which could facilitate adaptation to changing environmental conditions. Basically, the old and modern varieties showed differences in their strategy for water and nutrient uptake: the old maize varieties have longer and slimmer roots, while modern varieties rely more on symbiosis with root fungi.

In the second phase of the project, the researchers now want to understand these different strategies in more detail. “We want to test whether the strategies remain stable under changing climate and soil conditions,” says Prof. Dr. Johanna Pausch, Professor of Agroecology and coordinator of the joint project. In addition, a mixture of several maize varieties with different adaptation strategies and their effects on yield stability are being investigated. For this purpose, cultivation areas are distributed throughout Bavaria: “We are growing the plants on different soils, whereby we expect differences between the rainier south and the drier regions around Würzburg,” explains Pausch.

In addition to the experimental approach, the Bayreuth researchers are also evaluating historical yield data. The historical data shows a decrease in maize yields from southern to northern Bavaria, presumably due to lower rainfall and less favorable soil properties. The second phase of the project will now investigate in more detail how the yields of individual varieties behave. In addition, various modeling approaches will be used to create yield forecasts for future climate scenarios and to analyze the influence of varieties and variety mixtures on important ecosystem functions such as carbon storage.

The researchers are convinced that such an integrative approach will not only help to better understand the yield stability of future cultivation systems, but also to optimize them. In particular, the cultivation of cleverly composed variety mixtures could be a quick and easy-to-implement measure to adapt agriculture in certain regions to the consequences of the climate crisis.

Other project partners in the consortium are the Technical University of Munich, the Bavarian State Institute for Agriculture and the Karlsruhe Institute of Technology. The second project phase runs from 01.05.2024 to 30.04.2027 and is funded by the Federal Ministry of Education and Research with a total of €1.9 million, around half of which will go to Bayreuth.

Research groups involved at the University of Bayreuth:
– Agroecology, Prof. Dr. Johanna Pausch
– Ecological services, Prof. Dr. Thomas Köllner
– Ecological Microbiology, Prof. Dr. Tillmann Lüders

Wissenschaftliche Ansprechpartner:

Prof. Dr. Johanna Pausch
Professorship Agroecology
University of Bayreuth
Phone: +49 (0) 921 / 55-2292
E-Mail: johanna.pausch@uni-bayreuth.de

Weitere Informationen:

http://www.bayceer.uni-bayreuth.de/rhizotraits/