The effects of different methods of soil management on the nutrient supply and the wine quality of organically grown Grüner Veltliner grapevines (wide-spaced high culture training system) were investigated in the winegrowing region Wagram of Lower Austria (municipality: Großriedenthal). Under permanent green cover the mineral nitrogen content in the soil was significantly lower than under green cover, which was loosened up or broken up. Regarding the nitrogen demand of the vine the best results of the mineral soil nitrogen content were found by loosening up the soil by the end of April and breaking it open two weeks later. Permanent green cover inhibited shoot length development and the total acidity of the must was lower. The content of yeast assimilable nitrogen and the yield were reduced, but must density as well as potassium and ash contents of the wine were slightly higher. There were no differences in the vinification of the grapes of the different origins. Significant differences in the sensory evaluation could not be related to different methods of soil cultivation.
Authors: Martin MEHOFER (1) and Helmut REDL†(2)
(1) Federal College and Institute for Viticulture and Pomology Klosterneuburg, Department of Viticulture, A-3400 Klosterneuburg, Wiener Straße 74, Austria
(2) University of Natural Resources and Life Sciences, Vienna, Department of Crop Sciences, A-1180 Wien, Gregor-Mendel-Straße 33, Austria
Keywords: grapevine, soil management, nutrients, nitrogen supply, must contents, wine quality