Comparing Nitrogen Fertilization in the Vineyard versus Supplementation in the Winery in Pinot noir and Chardonnay
R. Paul Schreiner,* Tian Tian, Jungmin Lee, Patricia Skinkis, James Osborne, Elizabeth Tomasino, and Michael Qian
*USDA-ARS-HCRL, 3420 NW Orchard Ave., Corvallis, OR 97330
The goal of this project was to understand how nitrogen (N) status and fertilization in the vineyard affects vine productivity and wine properties, and how N supplementation in the winery affects wine properties in a red and white cultivar. Four wines using four replicates from the vineyard are being evaluated in each variety: A) no fertilizer or winery addition; B) no fertilizer, +DAP in the winery; C) no fertil-izer, +ORG-N in the winery; and D) N-fertilizer, no winery addition. N fertilizer increased vine N status in both varieties, but Chardonnay responded faster and showed greater change than Pinot noir. Must YAN levels increased in N-fertilized vines by 38% in Pinot noir (from 176 to 243 YAN) and by 90% in Chardonnay (from 99 to 189 YAN). Fertilizer use did not influence growth or yield of Pinot noir, nor growth of Chardonnay. Yield of Chardonnay in the +ORG-N in-winery (treat-ment C) was lower than in N-fertilized vines, but other treatments did not differ. Fruit solar exposure and vine water status were not altered by fertilizer use in either variety in 2016. After winery additions, the N-fertilized and winery-supplemented treatments (B, C, and D) had higher YAN than the control (A) in Pinot noir. In Chardonnay, the +DAP (B) and N-fertilized (D) musts had the highest YAN,
+ORG-N © was intermediate, and Control (A) must was lowest. The Pinot noir musts from N-fertilized vines fermented one day faster (p < 0.05) than all other musts, even though YAN was similar in +DAP and +ORG-N musts. In Chardonnay, the control musts with the lowest YAN took ~2.5 more days to complete fermentation than all other treatments, but this was not significant based on endpoint alone (p > 0.05). The sensory analysis of 2016 wines will begin in summer 2017.
Funding Support: USDA-ARS, Oregon Wine Board