Catch-cropping is an agrarian tool for continuing soil health and yield-increase
Project number: 031B1060C
Contact: Prof. Dr. Barbara Reinhold-Hurek, University of Bremen
Project team: University of Bremen, University of Applied Sciences Weihenstephan-Triesdorf (HSWT), Leibniz-Institute for Plant Genetics & Crop Plant Research (IPK), Leibniz University Hannover, Deutsche Saatveredelung AG (DSV)
The main objective is to employ catch cropping for developing innovative farming systems to preserve and improve soil fertility. We aim to develop a better understanding of cause-effect relationships affecting soil fertility parameters, biological functions and interactions in soil and rhizosphere. This could also contribute to an enhancement of marginal locations. Therefore, the focus of CATCHY is on catch cropping considered as an essential part of an integrated concept. This functional orientation is supplemented with an agronomic and economic management interaction.
An essential part of an integrated concept to stabilize or improve soil is the integration of catch crops on fields that are kept fallow over fall and winter. Catch cropping is a long-term task of amelioration in the crop rotation system, having a positive impact on biological, chemical and physical soil properties, and thus sustainability of the production system, as well as on yield formation of subsequent main crops. While currently catch crops are mostly represented by only single species, we will develop knowledge-based solutions for optimizing farming strategies and soil use management with the help of diverse catch crops.
The results will be the basis for development of system-optimized commercial catch crop mixtures. Agronomic cropping systems shall be optimized with regard to sustainability, particularly with respect to parameters of soil functions. Concepts and contents of consulting services shall be adapted and transformed with regards to resource-optimized soil management systems. Integrated are also analyses of cost effectiveness and acceptance of the guidelines for agronomic practices that will be developed by us.
project results from phase 1 and 2
Soil biogeochemical cycles in cropping systems can be optimized by catch crop mixtures. The benefit of diverse catch crops derived from different shoot levels, larger rooting volume and a more even root distribution in different soil depth, but also from multiple interactions of a more diverse soil microbiome. The soil microbial communities are probably affected by cultivating catch crops over time and the microbial nitrogen cycle appears to be boosted after application of diverse catch crops. Nutrient release from catch crop residues depend on litter quality and can be manipulated by plant species combinations. First results indicate, that the nutrient release can be synchronized to the nutrient demand of the following main crop.
Catch crops have different impact on crop yield architecture. The enhancement of cop yields or silage maize harvest for example, requires combinations with different plants or plant mixtures. At the same time, each catch crop variant produced individual microbial fingerprints. Rhizodeposits and products of catch crop litter decomposition effects the microbial community composition in the rhizosphere of the following crop. Thereby nutrient uptake, mineralization and delivery to the following crop depend on the litter quality, biomass production and root performance of the catch crops. Catch crop mixtures can compensate individual weaknesses of monocultures and legumes are essential partners for sustainable crop yield increase. The Project results showed, that biodiverse catch crop mixtures are important tools in sustainable cropping systems and adoption of crop yields resilience to climate change.
expected results phase 3
First results highlighted the relevance of catch crops for improvement of soil structure, pore volume and crop water availability. Analyses of cover crop metabolites will inform about their role in allelopathic effects between plants in mixtures as well as crop rotations. The microbiome studies focusses on the effect of catch crops on stimulation of antagonistic organisms for crop pathogen control. Calculation of the carbon footprint in catch crop rotations and their greenhouse gas mitigation potential will set the baseline for monetary compensation in the framework of the Carbon Farming initiative. In combination with economic feasibility analyses, this should guarantee a broader acceptance of catch cropping from the farming community. A strong dissemination activity will communicate the project results to farmers and stakeholders through multiple channels.