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
(paul.schreiner@ars.usda.gov)

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