Efficacia delle Fasce Tampone e della Gestione del Suolo per il Controllo dei Nitrati in Vigneto

Buffer strip use in vineyard could represent an environmental strategy for nitrate control of surface and deep water due to agricolture managment. Buffer strip determines a reduction of soil erosion and consequently can reduce nutritive and pollulant elements losses. With the aim to evaluate buffer strips and soil managment effectiveness on nitrate control in vineyard, a trial was carried out in a South-West part of Sicily characterized by an high nitrate losses sensitivity, an annual rainfall of about 516mm and an average temperature of 18°C. In a vineyard on about 7% slope and 90m lenght a 10 meter buffer strip was seeded using a Lolium perenne permanent meadow. Vineyard was managed both traditionally and alternative management using Durum wheat cover crop and Vetch cover crop. Monthly nitrate were monitored along vineyard slope and buffer strips for all soil management options studied to evaluate buffer strip effectiveness for nitrate control. To study nitrate movement an isotopic N fertilization(using labeled Nitrogen- 15N) was done on March just on the top of bufer strips. Lolium perenne biomass and his isotopic nitrogen content was alsomonitered. Vetch cover crop management, especially after bomass moving into the soil, promoted a nitrogen excess in comparison to traditional and durum wheat, but generally nitrate nitrate values increase from the top to the bottom of the vineyard. Buffer strip efficiency ranged between 70 and 40% demonstrating that a nitrate control is possible only if cropping system diversification "field measures for diffusive pollution sources control" and specific " structural practices such as measures relative to landscape structure (fences, permanent buffer strips, etc.)" will turn a common agricolture practice.