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 was compared to that of winery N addition on enological characters 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), and addition of N to the vineyard soil (Soil N), or to foliage (Foliar N) were evaluated. The Foliar N treatment was evaluated in 2017 and 2018 only, 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 years 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 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 Soil N musts than in No N musts, with the Foliar N, +DAP, and +Org N treatments intermediate between Soil N and No N treatments. Wine sensory analysis revealed that 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 in Chardonnay, they may not produce a wine with similar sensory characteristics.