Vine response to compost addition on a sandy-loam soil in the north-east of italy. Effects on root system, vegetative growth, yield and grape quality of Cabernet-Sauvignon cv

In this study two different compost types and two application methods were studied over 5 years (2009-2013) on mature Cabernet Sauvignon vines grown in a commercial vineyard in the AOC Piave area, northeastern Italy. The treatments compared were: IM: inter-row application of compost from cattle manure, at a rate of 4 t/ha/y fresh weight (fw); IW: inter-row application of compost from vineyard pruning waste, at 4 t/ha/y (fw); UW: under-row application of compost from vineyard pruning waste, at 4 t/ha/y (fw); C: control with no amendment/fertilization. Effects on soil characteristics and on vine performances, including root density and distribution, were assessed. IW treatment showed the best overall performance, displaying well-balanced root/shoot growth, increased yield, and satisfactory grape quality. Inter-row addition of compost from cattle manure (IM) and localized addition of compost from pruning wastes (UW) stimulated ether high vegetative growth or high root development and in both cases, a reduction in fruit quality was observed, likely due to competition between vegetative organs (shoots or roots) and the fruit.