The effects of alternative herbicide-free cover cropping systems on soil health, vine performance, berry quality and vineyard biodiversity in a climate change scenario in Switzerland

Summary

Herbicide-free soil management practices are needed to mitigate climate change, increase biodiversity and improve soil quality while minimizing detrimental effects on grapevine’s stress tolerance and fruit quality. Within a multidisciplinary 4-year project we aim to a) evaluate the impact of cover crops on environmental and agronomic parameters and b) propose and develop innovative practices for different viticultural contexts in Switzerland. In the first phase we assessed 30 commercial vineyards across Switzerland, where growers are already using various herbicide-free soil management practices (permanent ground cover on the inter-row plus tillage on the under-vine, spontaneous vegetation or winter cover crops). In all plots, soil status, soil microbiome diversity, plant diversity and biomass, vine physiology and berry quality were assessed.
Amongst the tested treatments, winter cover crops appeared to be the most sustainable soil management option, assuring the ecosystem services provided by a cover crop while limiting nitrogen and water deficiency, as was the case of spontaneous vegetation. However, the installation and management of the cover crops need to be considered since detrimental effects on soil health might occur.