Wine connoisseurs might describe the taste of a wine as earthy, round, robust, crisp, mellow, oaky, or any number of specialist terms. Much of the taste is attributed to its terroir – a term encompassing the complete natural environment in which a particular crop is produced, including factors such as the soil, topography, and climate.
The terroir is the basis for protecting certain regional products – in Europe this is known as ‘protected designation of origin’ (PDO) which guarantees the product’s reputation. Famous examples of wine with a PDO are Champagne, Bordeaux and Beaujolais, to name but a few. England is not yet well-known for its wine-growing regions, though vineyard land in the country has doubled in the last decade amid climate change.
To understand land suitability and better management practices for vineyards, it is crucial to understand the factors that impact soil quality – including soil structure development (such as how particles are assembled and how air and water circulate through them), microbial activity (microbiological processes of soil microorganisms that improve organic nutrients) – and how these link to plant physiology or functioning.
In the case of ‘new’ wine regions like south-east England, the lack of long-term soil and management data makes it even more important to develop experiments and models that help the establishment of new vineyards in the best conditions. A project led by NRI’s Dr Marcos Paradelo, in collaboration with NIAB-EMR, a horticultural research organisation in East Malling, Kent, UK, is investigating how soil changes when new vineyards are established, to propose better management practices to improve soil health and maintain terroir characteristics. The project includes measuring the relationship between soil structure, the microbiome (an interacting community of bacteria, viruses, fungi and other organisms) and plant physiology in the NIAB EMR concept vineyard. Established in 2015 over an area of 10,000m2, the vineyard makes it possible to deliver randomised and replicated trials to ensure the research is robust and supports viticulturalists. The team is studying the effects on soil properties of the year of planting, the rootstock variety, and weeding control (with herbicides, a mechanical weeder or strimming), using a Chardonnay variety.
The project has been helped by facilities for soils analysis. Officially opened in September 2020, NRI’s new Soils and Agronomy lab is specially equipped for the physical characterization of soil samples. In addition, the project began by winning an open call from the EU initiative Fields4ever (fields4ever.biomemakers.com) which provides microbial analyses for free. Fields4ever will carry out 100 microbiome analyses, sequencing the bacterial and fungal DNA in the soil. This is to understand the microbial diversity in the soil, which affects different functions of soil health and terroir. The microbiome data will be merged with a range of physical measurements. The team has also explored the management effects on soil properties, and grape quality. The team will use the results to engage with winegrowers to discuss and plan interventions for sustainable soil management. This project aims to help winegrowers in south-east England to adopt sustainable management practices that protect soil and enhance wine quality; it is hoped this work will be used as a benchmark for soil health in English vineyards.