ASSESSMENT OF THE AGRONOMIC VALUE OF SEWAGE SLUDGE COMPOST APPLIED ON WINE-GROWING SOILS

A study was conducted from November 2005 to November 2008, to determine the efficiency of sewage sludge compost, applied as mulch, in the prevention of runoff and erosion in wine-growing plots. The study was established in the vineyard of La Clape, located in the south of France in a Mediterranean-climate region. Three soil management treatments were compared: bare soil, grass cover crop and application of mulch. Measurements focused on quantities of runoff water and soil losses by erosion, physicochemical and biological status of the soil, and vine plants performances. Results highlighted the ability of the mulch of sewage sludge compost to reduce runoff and erosion as well as to improve the organic status of the soil and its biological activity. Grass cover also enabled to limit erosion in the same amounts as the mulch but its efficiency in terms of runoff was significantly reduced by the summer water stress which did not allow an optimal development of the sowed species.