The study over three harvests aimed to determine the effects of different nitrogen supplementation regimes on Chardonnay vine growth and yield, juice YAN levels, fermentation kinetics and final wine sensory properties.
Project layout:
Chardonnay grapes from Oregon, USA (21.5 – 23 °Brix)
– No vineyard and winery treatment
– Addition of nitrogen to the soil
– Addition of nitrogen to foliage
– Addition of DAP during fermentation
– Addition of organic nitrogen (NutriFerm Arom Plus) during fermentation
All treatments were fermented with Lalvin D47
Chemical and sensory analysis
Main results:
– Soil nitrogen increased leaf and petiole nitrogen content in all three years and increased growth, canopy and yield in two years.
– Foliar nitrogen had a minor effect on leaf and petiole nitrogen content and did not affect vine growth or yield.
– Both soil and foliar nitrogen addition increased must YAN with soil nitrogen addition having the most significant effect.
– Must DAP addition had a similar effect as soil nitrogen addition on YAN levels.
– The addition of organic nitrogen had a similar effect as foliage addition.
– Soil nitrogen addition fermentations proceeded the fastest.
– Soil nitrogen-added wines had the most tropical fruit characteristics.
Significance of the study:
The nitrogen source can influence vine productivity and the final wine sensory properties. In this experiment, adding nitrogen to the soil proved to be the most beneficial for vine growth and wine aroma. If enhanced vine growth is not desired, foliar nitrogen addition is a good alternative to increase must YAN. The study also showed that winery additions do not substitute YAN obtained in the vineyard since sensory differences were obtained between the winery and vineyard-supplemented wines.
Reference:
Tian Tian, Meghan Ruppel, James Osborne, Elizabeth Tomasino, R. Paul Schreiner. Fertilize or Supplement: The Impact of Nitrogen on Vine Productivity and Wine Sensory Properties in Chardonnay. Am J Enol Vitic. July 2022 73: 156-169; published ahead of print March 21, 2022 ; DOI: 10.5344/ajev.2022.21044
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