Increasing productivity and sustainability in UK viticulture: investigating the potential impact of groundcover management practices on soil health, yields and juice quality, and emissions

The UK wine industry has expanded rapidly over the past 10-years, with an estimated 3,800ha now under vine. This has generated a sharp growth in sales of British wines, with the market now valued at £292m. This trend looks set to continue, and with many vineyards being in early stages of establishment, work to identify soil management practices best suited to the UK's cool climate is needed now.

Research based in traditional wine regions such as the Mediterranean has limited relevance to UK vineyards, so our research proposal is very timely.

The relationship between the vineyard soil environment and the quality of the resulting wine is referred to as the _terroir_ concept, the tenet of which is that a change to the soil environment will have a noticeable effect on the attributes of the wine produced. Viticulture in the UK is still a relatively young industry, and there is much to be learnt in terms of achieving optimum and consistent yields and juice quality while using the most sustainable practices.

Cover crops could play a significant role here, by enhancing soil health through their effects on soil carbon (C) content, hydraulic conductivity, biodiversity and soil structure. Legumes are commonly used in cover crop mixes, and they can bring the added benefit of increased soil nutrient availability, thereby reducing the need for fertiliser applications.

Mechanical weeding strategies offer a chemical-free alternative to standard herbicide regimes without compromising berry yield or quality. Soil health and soil C sequestration are major focuses of current agri-environment policies and payment schemes, therefore the implementation of cover cropping and mechanical weeding practices should bring both environmental and monetary benefits to UK viticulturists.

Project outputs will include evidence-based recommendations for growers on the best ground management approaches to suit UK vineyards. Industry-wide uptake of these practices would demonstrate to the public, the horticultural sector and retailers that the viti industry is committed to achieving environmental and net-zero goals. We propose to carry out the first full-scale experiments and commercial trials of cover cropping and mechanical weeding strategies in UK vineyards to identify and tailor optimal soil management approaches for the UK industry.

The trial sites will serve as long-term research facilities on commercial holdings in Kent, and our intention is that they host separate but allied future research on beneficial insects and soil pathogens. We intend to commercialise project outputs through an existing route.