Fertilize or supplement: The impact of nitrogen on vine productivity and wine sensory properties in Chardonnay

Authors: TIAN, T - Oregon State University; RUPPEL, M - Oregon State University; OSBORNE, J - Oregon State University; TOMASINO, E - Oregon State University; Schreiner, Roger - Paul

Submitted to: American Journal of Enology and Viticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2022
Publication Date: 7/1/2022
Citation: Tian, T., Ruppel, M., Osborne, J., Tomasino, E., Schreiner, R.P. 2022. Fertilize or supplement: The impact of nitrogen on vine productivity and wine sensory properties in Chardonnay. American Journal of Enology and Viticulture. 73(3):148-161. https://doi.org/10.5344/ajev.2022.21044.
DOI: https://doi.org/10.5344/ajev.2022.21044

Interpretive Summary: Nitrogen is a key nutrient to manage in both the vineyard and winery because it alters vine productivity and influences wine quality by altering yeast metabolism. Nitrogen is added in the winery when berry nitrogen is low to ensure successful fermentation assuming that winery nitrogen addition produces the same quality of wine as compared to boosting fruit nitrogen in the vineyard. While vineyard or winery nitrogen management have been examined separately, no research has compared how vineyard nitrogen use and winery nitrogen use alters wine quality in the same study. This research tested whether vineyard nitrogen fertilization using soil or foliar applied nitrogen would alter wine properties in the same manner as winery nitrogen addition from two different sources over three growing seasons. Results from this work showed that boosting fruit nitrogen by fertilizing the soil produced the most unique wines with greater tropical fruit aromas, and that winery nitrogen additions cannot be used to obtain a similar wine even when the fermentation rate is similar. These findings will be used by grape growers and winemakers to better manage nitrogen inputs in the whole wine production system to produce a desired style of wine and maintain or boost vine productivity.

Technical Abstract: The impact of nitrogen (N) fertilization in the vineyard on vine productivity, fermentation, and wine sensory properties as compared to winery N addition on enological characters was evaluated in Chardonnay between 2016 and 2018. Five treatments, including no vineyard or winery N addition (No N), addition of diammonium phosphate in the winery (+DAP), addition of organic N in the winery (+Org N), addition of N in the vineyard to the soil (Soil N), or to the foliage (Foliar N) were evaluated. The Foliar N treatment was evaluated in 2017 and 2018, while the other four treatments were assessed in all years. Soil N increased leaf and petiole N status in all years, and increased canopy growth and yield in year two and three. Foliar N had only a minor influence on leaf or petiole N status and did not alter vine growth or yield. Both Soil N and Foliar N elevated the level of juice yeast assimilable nitrogen (YAN), although the extent of increase was greater for Soil N. Addition of DAP in the winery boosted juice YAN similar to the Soil N treatment and addition of organic N was similar to the Foliar N musts. Fermentations proceeded more quickly in the Soil N musts than No N, with the Foliar N, +DAP, and +Org N treatments intermediate between Soil N and No N treatments. Wine sensory analysis revealed that the Soil N wines were most distinct with greater tropical fruit aromas. These findings show that while winery N additions provide similar fermentation kinetics to vineyard N fertilization, they may not produce a wine with similar sensory characteristics as obtained using vineyard N fertilization in Chardonnay.