Catch crops have a positive effect on humus build-up and the availability of nutrients in soil-plant systems. They also protect against erosion and help suppress weeds. CATCHY is part of the BonaRes funding initiative and one of the eleven research networks which have been funded by the Federal Ministry of Education and Research (BMBF) since 2015. The project focuses on the usage of catch crops as an agricultural measure to maintain soil fertility and yield security. The main objective of CATCHY is to investigate effects of catch crops in crop rotation putting central attention on soil structure, water balance, nutrient cycles, yield parameters and microbiomes. The entire funding period lasted over nine years and made it possible to set up and analyse multi-year field trials. One of the long-term trials was set up at Deutsche Saatveredelung AG (DSV) site in Asendorf and could be visited at the project’s closing event on 21 September 2023 and the follow-up Innovation Field Day.
The scientific community gathered at the closing event to learn about the nine years of research done in CATCHY and to share its outcomes. Dr. Ulf Feuerstein, Managing Director of Hof Steimke - Asendorf seed breeding station, opened the event "with a tear in his eye and a smile on his face".
In their welcoming addresses, both Mr. Feuerstein and the coordinator of the BonaRes funding initiative, Dr. Ute Wollschläger, described the special nature of the transdisciplinary work, the initial hurdles involved in finding a common language, and the ultimately great added value in terms of expertise. By bringing together different perspectives from agriculture, natural science and economics, it was possible to investigate the detailed relationships between very small-scale processes in the soil-plant system, soil science and plant cultivation aspects as well as the economic efficiency of the use of various catch crops and catch crop mixtures. In her welcome address, Prof. Barbara Reinhold-Hurek, CATCHY project coordinator at the University of Bremen, emphasised the important role of long-term experiments, such as those on the innovation field in Asendorf, when developing a complex understanding of processes.
After a brief introduction to the BonaRes funding initiative with an overview of the various projects, CATCHY research results were presented and discussed from various perspectives by the participating project partners from Weihenstephan-Triesdorf University of Applied Sciences and Arts, Leibnitz Institute of Plant Genetics and Crop Plant Research (IPK), Leibnitz University Hannover, University of Bremen and Deutsche Saatveredelung AG. One result of the soil science analysis of the impact of catch crops is the great importance of their composition. Depending on the plant family and mixture, the effects on biodiversity in the soil, nutrient availability, the long-term fertilisation effect and the course of decomposition processes vary greatly and must therefore be specifically adapted to the location in order to achieve the best possible results. The socio-economic analysis of intercropping also shows clear advantages for farms, both in terms of CO2 savings and in the calculation of costs and benefits.
In a short excursus on BonaRes’ project ORDIAmur, it was shown that marigolds as a catch crop can minimise the phenomenon of so-called post-planting disease in apple trees. Another application example from the University of Giessen showed good results with regard to the immobilisation of nitrogen through the cultivation of catch crops before the cultivation of potatoes.
The afternoon was rounded off with a panel discussion on further developments of catch crop cultivation. The panel consisted of the scientists from the CATCHY research project Norman Gentsch, Bernhard Bauer, Matthias Westerschulte, Peter Breunig, Barbara Reinhold-Hurek and Diana Heuermann. They gave an outlook on future research questions and answered questions from the audience. An example was the role of fungi in intercropping needs to be better researched in the future in order to assess the interaction of the different species and their effects on soil fertility. Future scenarios in which catch crops may be able to mitigate the stress on our agricultural soils caused by climate change were also discussed. A major role for the widespread applicability and success of catch crops lies not least in trend-setting subsidies for agricultural businesses, away from the promotion of individual measures and towards the promotion of measurable, sustainable changes.
At the end of the event, both panellists and scientists in the audience agreed that the interdisciplinary BonaRes network, which has grown over the past nine years, should continue to exist beyond the end of the research initiative in 2025 in order to work together on complex issues such as intercropping as a way to achieve more sustainable land use.
DSV BIODIVERSITY INNOVATION DAY
On 22 September 2023, the DSV also opened its doors to interested practitioners. Representatives from the agricultural sector were invited to an innovation day with the aim of presenting scientific results for agricultural practice. In the well-filled forum tent, scientists presented their results with a focus on their applicability on farms and were available to answer questions and receive suggestions. Matthias Westerschulte from Deutsche Saatveredelung AG summarised what the results of the CATCHY research project mean for practical arable farming.
The broad variety portfolio, innovative cultivation concepts and special features of DSV breeding were on display in the innovation fields around the Asendorf seed breeding station. In the field, there was also a vivid presentation of the results of the CATCHY crop rotation project on trial plots by scientists and employees with guided tours of the innovation field and the presentation of further research projects.