Wastewater Reuse for Irrigation: Main Effects on Horticultural Crops and Soil Processes

In order to test the main effects on horticultural crops and soil processes, a monitoring program was carried out on a open field located in San Michele di Ganzaria (Eastern Sicily) during the 2008 growing season. In terms of surface and subsurface drip lines performances and hydrological soil behavior, the wastewater irrigation did not gave worse results compare with fresh water irrigation. Higher aubergine and tomato crop production and quality were achieved using wastewater and subsurface laterals. A significant microbial contamination, was found just for the lettuce crops irrigated by both kind of water and type of laterals.

The physically based WEPP model, developed by the USDA since late ’80 and widely applied around the world, was implemented in a small agricultural watershed located in central Belgium, called Ganspoel. Seventeen runoff, peak flow and sediment yield events, measured at the watershed outlet, were simulated by the model. Even though the runoff volume predictions were well correlated to the corresponding observations, WEPP prediction capability was generally unsatisfactory also when different set-up methods of the soil effective hydraulic conductivity were used. The poor performance achieved for runoff volume and peak flow simulations affected sediment yield predictions.