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…

Leaf vine content in nutrients and trace elements in La Mancha (Spain) soils: influence of the rootstock

The use of rootstock of American origin has been the classic method of fighting against Phylloxera for more than 100 years. For this reason, it is interesting to establish if different rootstock modifies nutrient composition as well as trace elements content that could be important for determining the traceability of the vine products. A survey of four classic rootstocks (110-Richter, SO4, FERCAL and 1103-Paulsen) and four new ones (M1, M2, M3 and M4) provided by Agromillora Iberia. S.L.U., all of them grafted with the Tempranillo variety, has been carried out during 2019. The eight rootstocks were planted in pots of 500 cc, on three soils with very different characteristics from Castilla-La Mancha (Spain). In the month of July, the leaves were collected and dried in a forced air oven for seven days at 40ºC. Then, the samples were prepared for the analysis determination, carried out by X-Ray fluorescence spectrometry. The results obtained showed that in the case of content in mineral elements in leaf, separated by soil type, we can report the importance of few elements such as Si, Fe, Pb and, especially, Sr. The rootstock does not influence the composition of the vine leaf for the studied elements that are the most important in determining the geochemical footprint of the soil. The influence of the soil can be discriminated according to some elements such as Fe, Pb, Si and, especially, Sr.

Local adaptation tools to ensure the viticultural sustainability in a changing climate

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Assessment of the impact of actions in the vineyard and its surrounding environment on biodiversity in Rioja Alavesa (Spain)

Traditional viticulture areas have experienced in the last decades an intensification of field practices, linked to an increased use of fertilisers and phytosanitary products, and to a more intensive mechanization and uniformization of the landscape. This change in management has sometimes led to higher rates of soil erosion andloss of soil structure, fertility decline, groundwater contamination, and to an increased pressure of pests and diseases. Additionally, intensification usually leads to a simplification of landscapes, of particular concern in prestigious wine grape regions where the economical revenue encourages the conversion of land use from natural habitats to high value wine grape production. To revert this trend, it is necessary that growers implement actions that promote biodiversity in their vineyards. The aim of this study is to assess the impact of the implementation of cover crops, vegetational corridors, dry stone walls and vineyard biodiversity hotspots estimated through the study of arthropods. The work has been carried out in four vineyards in Rioja Alavesa belonging to Ostatu winery, where these infrastructures were implemented in 2020. The presence and diversity of arthropods was studied by capturing them at different times in the season and at different distances from the infrastructure using pit-fall traps in the soil and yellow, white and blue chromatic traps at the canopy level. This is a preliminary study in which all adult insects were sorted to the taxonomic level of order and Coleoptera were classified to morphospecies. The results obtained show that there is a relationship between the basic characteristics of the vineyard and the arthropods captured, with a positive effect, although also dependent on the vineyard, of the presence of infrastructure.

VineyardFACE: Investigation of a moderate (+20%) increase of ambient CO2 level on berry ripening dynamics and fruit composition

Climate change and rising atmospheric carbon dioxide concentration is a concern for agriculture, including viticulture. Studies on elevated carbon dioxide have already been on grapevines, mainly taking place in greenhouses using potted plants or using field grown vines under higher CO2 enrichment, i.e. >650 ppm. The VineyardFACE, located at Hochschule Geisenheim University, is an open field Free Air CO2 Enrichment (FACE) experimental set-up designed to study the effects of elevated carbon dioxide using field grown vines (Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon). As the carbon dioxide fumigation started in 2014, the long term effects of elevated carbon dioxide treatment can be investigated on berry ripening parameters and fruit metabolic composition.
The present study aims to investigate the effect on fruit composition under a moderate increase (+20%; eCO2) of carbon dioxide concentration, as predicted for 2050 on both Riesling and Cabernet Sauvignon. Berry composition was determined for primary (sugars, organic acids, amino acids) and secondary metabolites (anthocyanins). Special focus was given on monitoring of berry diameter and ripening rates throughout three growing seasons. Compared to previous results of the early adaptative phase of the vines [1], our results show little effect of eCO2 treatment on primary metabolites composition in berries. However, total anthocyanins concentration in berry skin was lower for eCO2 treatment in 2020, although the ratio between anthocyanins derivatives did not differ.
[1] Wohlfahrt Y., Tittmann S., Schmidt D., Rauhut D., Honermeier B., Stoll M. (2020) The effect of elevated CO2 on berry development and bunch structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon. Applied Science Basel 10: 2486

The use of rootstock as a lever in the face of climate change and dieback of vineyard

As viticulture faces challenges such as climate change or vineyard dieback, the choice of the variety and rootstock becomes more and more crucial. To study rootstock levers in the Bordeaux region, a parcel of Cabernet Sauvignon (CS) was planted with four rootstocks in 2014. Twenty repetitions of each of the following four rootstocks were set up: 101-14 MGt, Nemadex AB, 420A MGt and Gravesac. The number of bunches, yields and pruning weights of the vine shoots were measured individually on 240 vines from 2017 to 2021. Since 2020, nitrogen status assessed by assimilable nitrogen level, hydric status assessed by δ13C and berry maturity were measured on 80 samples taken from 20 repetitions of the four rootstocks. A lower yield was measured for CS grafted onto Nemadex AB due to the lower number of bunches and the lower weight of berries. The differences between the other three rootstocks are small, but CS grafted onto 420A MGt was the most productive. The CS grafted onto Nemadex AB had the lowest pruning weight while 101-14 MGt had the highest. In 2020, δ13C showed a more moderate water stress with 101-14 MGt and 420A MGt than with Nemadex AB. Surprisingly, the Gravesac was under more stress than the 101-14 MGt. The nitrogen status in the berries was better for Nemadex AB but this was perhaps due to the significantly lower weight of the berries.Rootstock 101-14 MGt attained the highest accumulation of sugars in the berries while 420A MGt allows to preserve higher acidity. The parcel is still young which may explain some of the results. These measures must therefore be continued over the next several years to fully assess the effects of these rootstocks on the development of the vines and the quality of the production under new climatic conditions.