Breeding for species mixtures: 50 Years, One Key Metric - Exporting Switzerland's Competitive-Ability Approach from Pasture to Arable Systems?

Crop associations (CAs), the cultivation of multiple crop species together as intercrops, offer significant benefits for sustainable agriculture. However, a major bottleneck for broader adoption is the lack of CA-oriented cultivar testing and breeding.
For more than fifty years in Switzerland, varieties have undergone testing not only in pure but also in mixed stands, and thus provided a rare example of integrating CAs in an official variety testing scheme. The primary objective is to gain insights into the competitive strength of the tested varieties. This information holds particular significance in the formulation of clover-grass mixtures, as over 90% of cultivated fields in Switzerland, dedicated to meadows and pastures, have traditionally been sown with clover-grass mixtures. This longstanding practice reflects the agricultural importance attached to understanding the interplay between different varieties in mixed cropping systems. As part of a mini paper on “Cultivar testing as a key to boost uptake of crop associations in breeding and farming” (see related EU CAP Focus Group output at https://eu-cap-network.ec.europa.eu/focus-group-crop-associations-including-milpa-and-protein-crops_en), an interview with Dr. Daniel Suter, Head of Variety Testing for Forage Crops in Switzerland, delved into the intricacies of forage crop variety testing and its implications for agricultural practices and breeding strategies. The purpose of this interview is to provide valuable information that might help to transfer this successful application of CA cultivar testing to forage crop testing schemes in other countries and possibly extrapolate insights to other cultivation systems such as arable farming.