The objective of this study was to evaluate the nitrogen (N) availability in a soil with history of growing vines and submitted to application of mineral and organic sources of nutrients. In October 2010, samples of a Sandy Typic Hapludalf soil were collected in a vineyard and in a natural pasture soil, in the municipality of Rosario do Sul (RS). The treatments consisted of: natural pasture and vineyard soil as control; vineyard soil + organic compost; vineyard soil + polymer coated urea and vineyard soil + urea. The soils were incubated and subsamples were taken at 0, 38, 70, 102 and 141 days of incubation to determine N-NH4+ and N-NO3- contents. Concentrations of mineral N, net mineralization, N mineralization in relation to the total N and mineral buildup were calculated. In vineyard soils submitted to application of the polymer coated urea and urea, most N mineralization occurred in the initial period. Nitrogen release from the organic compound has better synchronicity with the vine requirements. The soil reserves of total nitrogen potentially mineralized may supply the vine demand for N.
organic compost; polymer coated urea; Vitis vinifera L
