Resource efficient control of couch grass

Project responsible: Lars Andersson, Department of Crop Production Ecology (CPE), SLU. 
Project group: Göran Bergkvist and Björn Ringselle (PhD student), both at CPE, SLU; Helena Aronsson,  Department of Soil and Environment, SLU; Anders Eriksson, Swedish Rural Economy and Agricultural Societies. 

This project is integrated with a project financed by Swedish Farmers’ Foundation for Agricultural Research (SLF: Effective control of couch grass with reduced nutrient leaching - an adaptation to Integrated Pest Management) with the main aim to develop strategies for non-chemical control of couch grass (Elymus repens L.) with reduced nutrient leaching and energy use. Strategies are based on optimal timing and minimized stubble cultivation, using the competitive effect of a catch crop in combination with cutting. The project encompasses two field studies, one of which includes registrations of nitrogen and phosphorous leaching. In addition, the project constitutes an important part of a PhD project, jointly financed by SLU and The Swedish Farmers' Foundation for Agricultural Research (SLF).

In the SLF project, we use a grass species as catch crop. In this complementary project we have added one more aspect, namely the ability to fixate nitrogen. We consider this multi-functionality very interesting as it at least partly offers a solution to one dilemma of organic cropping; the need to catch nitrogen, and at the same time reduce leaching and control the perennial weeds. In the field experiments we will therefore use a grass/clover mixture as catch crop. We hypothesize that the good ability of the mixture to reduce the soil nitrogen and its superior ability to produce large amount of biomass in autumn makes it at least as good a competitor against couch grass as a grass monoculture.

A reference group is linked to the project: Ann-Marie Dock-Gustavsson (Swedish Board of Agriculture), Per Ståhl (Swedish Rural Economy and Agricultural Societies), Erik Ekre (Växa), Angelika Neumann (post-doc, SLU), and Maria Stenberg and Gunnar Torstensson (SLU).