La gestion du sol par rapport au système de conduit dans un vignoble en forte pente

Soil management in relation to training system in a steep vineyard. In the North-West Italy, close spaced and low trunk vines are vertically trellised and Guyot pruned. In these conditions the permanent grass cover may compete with grapevine leaves and clusters for air and light, and with grapevine roots for water and N. In a 'White Muscat' vineyard grafted on '420 A', the following techniques were compared: a)permanend grass cover controlled by moving; b) permanent grass cover controlled by foliar herbicides; c) no tillage using residual+ foliar herbicides. The maximum soil cover was found on the grass cuttimg tratment. A good but reduced cover was obtained by the foliar herbicides used alone, stimulating the vine vigor, and giving more yields with higher soluble solids concentration. The soil nitrifying microflora was less reduced by glufosinate ammonium than by glyphosate. The grass cover was minimum using residual herbicides; as a consequence the erosion risk was enhanced, the soil total N and organic matter were reduced, yield and gray mold damages were increased.