Catch-cropping is an agrarian tool for continuing soil health and yield-increase 

Project number: 031A559

Contact: Prof. Dr. Barbara Reinhold-Hurek, University of Bremen

Mail: breinhold@uni-bremen.de

Project team: University of Bremen, University of Applied Sciences Weihenstephan-Triesdorf (HSWT), Leibniz-Institute for Plant Genetics & Crop Plant Research (IPK), Leibniz University Hannover, Justus Liebig University Giessen, Deutsche Saatveredelung AG (DSV)

Duration: 01/04/2015 - 31/03/2021

Project aim 
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. 
Motivation 
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. 
Expected results 

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

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.

 

expected results phase 2

One of the major tasks is the search for groups of soil microorganisms that can be manipulated by selecting certain species combinations in catch crop mixtures. Root exudates will be investigated for their potential to affect the root growth of the main crops. After two catch crop rotations we expect to measure changes in the soil organic matter content, soil structure and crop yield architecture. In a common labelling experiment the nitrogen transfer to the main crops will be quantified. With this information in hand, it will be possible to search for proper species combinations that fulfil the nutrient demands of crops at different growing stages.