Vineyard soil matters: exploring the influence of soil physical and chemical properties on Eastern U.S. grape production

The relationship between soil and wine quality has been recognized for generations but has had limited scientific validation. Vineyard soils in the eastern United States are largely unstudied although proper site selection and good soil management have the potential to improve fruit composition for high-quality wine production. Soils that provide excessive plant-available nutrients and water often produce vigorous vegetative growth and negatively influence fruit chemistry. We investigated three aspects of Eastern vineyard soils, including potassium availability, methods of reducing infiltration, and the influence of topsoil on fruit chemistry. Our first goal was to determine the best soil sampling, processing, and extraction methods for predicting potassium availability in Mid-Atlantic vineyard soils. Excessive potassium can result in high pH fruit, which negatively affects wine quality, but until now the best methods for predicting soil-available potassium had not been investigated. We found that moist-extracted soil sampled from 0-38 cm appear to best be suited predicting vine tissue potassium. Our second goal was to test methods of reducing rain infiltration at critical times during the growing season. One of the soil stabilizers we tested successfully reduced infiltration in field trials. Vineyard trials in 2021 were compromised by dry weather, but further research is ongoing. Our final project involved a three-year investigation where we attempted to isolate the influence of soil properties on grapevines and fruit composition by monitoring vines and fruit in single vineyard blocks. The most consistent result was positive relationships between topsoil and fruit titratable acidity, suggesting that the fruit was ripening earlier in vines growing in thinner topsoil. Topsoil depth better explained differences in fruit titratable acidity than other explanatory variables including crop load and sunlight exposure of fruit. Overall, this research increased our understanding of the soil properties that influence vine growth and fruit chemistry in the Eastern US. The results will help growers improve sampling methods, fruit chemistry, and increase resilience to soil and climate related challenges.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Fiola, Jaclyn Caroline

Chairs dc:contributor.committeechair

• Stewart, Ryan D.
• Evanylo, Gregory K.

Committee members dc:contributor.committeemember

• Stewart, Amanda C.
• Wolf, Anthony K.

• Terroir
• Soil extractions
• Wine quality
• Nutrient analysis
• Vine tissue analysis

Statement dc:rights

• Creative Commons Attribution-NonCommercial 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc/4.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:35731

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/113135