Vertical Transfer of Bacteriological and Parasitological Pollutants from Irrigation Water to Soil and Crops

In response to food needs and the growing desire to exploit local food, urban and peri-urban agriculture is meeting these needs by producing vegetables, fruits and other foods in cities and their suburbs. In addition to the increasing need for water due to droughts, this agriculture provides wastewater (WW) and treated wastewater (TWW) that is used for irrigation. This study was conducted to compare urban irrigation water: water from Oued Fez upstream and well water. As well as peri-urban irrigation water: water from Oued Fez downstream considered as WW and TWW from the treatment plant of the city of Fez. These in comparison with the rural irrigation waters: waters of Oued Bitit. The microorganisms investigated are total and thermotolerant coliforms, helminth eggs, Salmonella and chol era vibrio. The study took into account the transfer of these pathogenic bacteria at the level of soils and cultivated plants, cardoon and eggplant. The results showed a contamination out of national and international standards of the two types of coliforms that it is in winter or in summer in the TWW, WW, the water of Oued Fez and the water of wells located upstream of the city. This fecal contamination was found in soils and crops irrigated by urban and peri-urban water. The same was true for helminth eggs, but the number of eggs was greater in winter than in summer for soils. Cholera Vibrio was present in the different types of irrigation water in summer. But still in winter in WW and TWW. This bacterium was also present in soils, cardoons and eggplants irrigated by WW, TWW and Oued Fez waters upstream. Salmonella was present only in the TWW in summer. Only the plot irrigated with water from Oued Bitit in the rural zone was within the norms on the three levels of irrigated water, soil and plants and in both periods.