The grapevines N fertilization levels in Southern Brazil use to be accounted as function of N leaf and leaf petioles rates for a limit yield expectation, without any information about the inner N dynamics in the grapevines. This experiment was carried out in 2002/03, to estimate the N destiny as N broadcasted on the vineyard soil with Chardonnay and Riesling Renano grapevines, at a Udorthent soil in, Bento Gonçalves, Southern Brazil. The vines received the application of 15.91g N plant-1, 40 kg N ha-1, with 4% atoms 15N, in bud break. The buds and leaves were collected in the central parts of the year branch eight different times in the Chardonnay grapes and seven times in the Riesling Renano grapes. The grapevines in the last collection of the leaves were separated in leaves, fruits, year branches, branches with two years and stem, and then were oven-dried, weighted and analyzed total N and 15N contents. The results showed that the larger percentage of N in the leaves of the Chardonnay and the Riesling Renano grapevines, since the beginning of the bud break until harvest is derived of different forms of N from those applied in the bud break. The highest quantity of N accumulated in the annual and perennial part of the grapevines is derived of the soil N, being very small the amounts of N applied in the bud break stored in the perennial parts.
N fertilization; N uptake; N distribution; 15N isotope; grapevine
