Fertilize or Supplement: The Impact of Nitrogen on Vine Productivity and Wine Sensory Properties in Chardonnay

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 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.