Effects of mulching materials on soil and perfomance of cv. Nero di Troia grapevines in the Puglia region, Southeastern Italy

The responses in soil conditions, vine growth, and physiological, yield, and composition components of cv. Nero di Troia to the application of synthetic and organic mulches were studied for two years (2006–2007 and 2007–2008). The effects of the application in the vine rows of two synthetic mulches (geotextile as polypropylene and black polyethylene) and an organic mulch (exhausted olive pomace 3- and 6-cm thick) were compared to a control (weed mowing) in an organic vineyard. Throughout the trial, we conducted soil and leaf analyses, weed surveys, and phytotoxicity tests and measured vegetative activity, leaf gas exchange and water status, yield, and composi- tion components. The exhausted olive pomace showed positive effects on some soil fertility variables and on vine physiology (stomatal conductance, transpiration, and net assimilation). Black polyethylene and geotextile provided good control of the weeds, especially in the first year, but positive results were also obtained with the exhausted olive pomace. Yield and composition components of grape were unaffected by any of the organic and synthetic mulches compared to weed mowing. The exhausted olive pomace provided good control of weeds, improved the fertility of the soil, and could be acceptable in terms of sustainability. The mode of action of the exhausted olive pomace was both physical and phytochemical through the release of phytotoxic compounds.