Terroir 2020 banner
IVES 9 IVES Conference Series 9 Thinner topsoil improves vine growth and fruit composition in Mid-Atlantic United States vineyards

Thinner topsoil improves vine growth and fruit composition in Mid-Atlantic United States vineyards

Abstract

Aim: The aim of this study was to investigate the impact of topsoil thickness on dormant pruning weights, cluster compactness, and fruit composition (°Brix, titratable acidity, pH) in the Mid-Atlantic of the United States. 

Methods and Results: An Albariño vineyard in Frederick County, Maryland was previously terraced, resulting in topsoil (A-horizon) thickness differences while other factors are constant (weather, vine spacing, training, cultivar/clone/rootstock). We surveyed topsoil thickness along two transects using a combination of hand dug pits and soil probes, determining “topsoil” based on soil color and structure. The topsoil thickness we surveyed ranged from 0 to 30 cm. For reference, the vineyard’s mapped soil series, Mt. Zion, has 13 to 15 cm of topsoil.

Each panel of six vines served as an experimental unit, and we sampled 29 panels total corresponding to the topsoil measurement locations in 2019. We collected dormant pruning weights as well as cluster compactness (berries per cm rachis) and fruit chemistry (pH, titratable acidity, and °Brix). Fruit from vines growing in thinner topsoil had significantly lower titratable acidity and higher °Brix (R= 0.24). The correlation between topsoil and fruit titratable acidity was particularly strong, with topsoil thickness explaining 66.1% of variation in titratable acidity. There was not a significant relationship between topsoil thickness and fruit pH, but vines in thinner topsoil exhibited looser clusters (R2 = 0.27) and lower pruning weights (R= 0.58). 

Conclusions: 

Preliminary results suggest that fruit from vines growing in thinner topsoil ripen earlier. Compared to vines growing in thicker topsoil, they had lower titratable acidity and higher °Brix. Thinner topsoil also resulted in lower dormant pruning weights which indicates smaller vines, and looser clusters which may help with disease pressure. Understanding topsoil’s contribution to vine growth and fruit composition will help inform decisions about vineyard site selection, soil management, harvest time, and the overall terroir of a site. 

Significance and Impact of the Study: The viticulture industry in the Mid-Atlantic United States is growing, but their ability to support high-quality wine grape production may be hindered by certain soil properties. Many Mid-Atlantic soils are highly fertile and have relatively high available water holding capacity. In combination with the Mid-Atlantic’s humid continental climate, these soil properties can provide excessive plant-available water and nutrients to grapevines. Such excesses often produce vigorous vegetative growth (i.e., vigor) and detrimentally impact fruit composition and potential wine quality. Topsoil management could be an approach for growers to influence hydrology and fertility of vineyard soil. Choosing sites with less topsoil and/or managing topsoil thickness may help growers optimize their fruit chemistry and potentially predict and/or influence fruit ripening. 

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Jaclyn C. Fiola*, Ryan D. Stewart, Tony K. Wolf, and Greg K. Evanylo

School of Plant and Environmental Sciences, Virginia Tech, 185 Ag Quad Lane, Blacksburg, VA 24061

Contact the author

Keywords

Soil fertility, soil hydrology, soil management, Mid-Atlantic 

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Aptitude du cépage Chenin à l’élaboration de vins liquoreux en relation avec certaines unités terroirs de base de A.O.C. Coteaux du Layon

Massif and the first sedimentary formations of the western aureole of the Paris Basin. If it is found all over the world (California, Israel, South Africa), it is in this region that it best asserts its identity. It is one of the most interesting grape varieties due to the variety and complexity of the wines it can produce. It can give very dry or very sweet, still or sparkling wines, fresh when young and sublime when ageing, expressing the characteristics of each vintage as much as those of the terroir. The Chenin is a faithful witness of its geographical, geological, pedological and climatic environment; he is the foil of the land. It has strong aptitudes for the production of sweet wines conditioned by overripe grapes often botrytised in the AOC Coteaux du Layon.Massif and the first sedimentary formations of the western aureole of the Paris Basin. If it is found all over the world (California, Israel, South Africa), it is in this region that it best asserts its identity. It is one of the most interesting grape varieties due to the variety and complexity of the wines it can produce. It can give very dry or very sweet, still or sparkling wines, fresh when young and sublime when ageing, expressing the characteristics of each vintage as much as those of the terroir. The Chenin is a faithful witness of its geographical, geological, pedological and climatic environment; he is the foil of the land. It has strong aptitudes for the production of sweet wines conditioned by overripe grapes often botrytised in the AOC Coteaux du Layon.

Exploring the impact of yeast derivatives on aromatic and sensory profiles of white and red wines: a multifactorial analysis

Specific inactivated yeast derivatives (SYDS) are obtained from s. cerevisiae yeasts by various processes (thermal, mechanical, and enzymatic) and have diverse oenological applications to improve wine quality. However, different impacts on wine sensory and aromas were reported, depending on syds types and fractions, wine matrices, and experimental settings. Few works have examined the impact of SYDS on aromas considering also those on wine macromolecules influencing organoleptic properties.

Interactions « Terroir x Vigne » : facteurs de maîtrise du micro-environnement et de la physiologie de la plante en rapport avec le niveau de maturité et les éléments de typicité

Le vigneron européen est de plus en plus à la recherche de la valorisation de son terroir par la personnalisation de la typicité de ses produits. Dans ce contexte, il est apparu depuis longtemps que la part des facteurs technologiques ou humains est d’une importance capitale face aux conditions de l’envirormement naturel. Le terroir se construit plus qu’il ne se subit.

Oospore germination dynamics and disease forecasting model for a precision management of downy mildew 

Downy mildew, caused by Plasmopara viticola, is the most economically impactful disease affecting grapevines. This polycyclic pathogen triggers both primary and secondary infection cycles, resulting in significant yield losses when effective disease control measures are lacking. Over the winter, the pathogen survives by forming resting structures, the oospores, derived from sexual reproduction, which produce the inoculum for primary infections. To optimize grapevine downy mildew control and obtain the desired levels of production while minimizing chemical inputs, it is crucial to optimize the timeframe for fungicide application. Disease forecasting models are useful to identify the infection risk.

Dispersive liquid-liquid microextraction for the quantification of terpens in wines

In a highly competitive worldwide market, a current challenge for the beverage sector is to diversify the range of products and to offer wines and spirits with typicity and character.

During alcoholic fermentation, wine yeasts generate a large variety of volatile metabolites, including acetate esters, ethyl fatty acid esters, higher alcohols, volatile fatty acids and volatile sulfur compounds that contribute to the aroma profile of wine. These molecules, refered as fermentative aromas, are the most abundant volatile compounds synthetized by yeasts and the metabolic pathways involved in their formation have been well characterized. Furthermore, other molecules with a major organoleptic impact may be produced during wine fermentation including terpene derivatives. However, little information is available on the contribution of yeasts to the formation of these molecules, in particular on their ability to synthethise de novo the terpens derivatives or to produce hydrolytic enzymes involved in the release of varietal precursors.