ABSTRACT
This chapter evaluates the quality of three sources of irrigation water in Parakou city (Benin Republic), and their effects on soil and lettuce crop. Two factors were considered in the experiment: (i) water sources, with three levels (groundwater, GW; untreated municipal wastewater, MW; and treated wastewater, TW) and (ii) fertilization, with two levels (inorganic fertilizer at a recommended dose, +F, and the control, without fertilizer, -F). Soil and water samples were collected for physico-chemical analysis. We determined lettuce fresh yield, its nutrient uptake and leaves’ sanitary status at the end of the experiment. Lettuce fresh yield was four- and twofold higher under TW and MW compared to GW, respectively. The addition of inorganic fertilizer further enhanced Lettuce yield by 92% under TW and MW. GW quality was within the acceptable ranges of WHO recommendations, while TW and MW were not. Fecal coliforms, streptococci and helminth eggs were two to four times higher in TW and MW compared to GW. Heavy metals (lead, copper, zinc and iron) were similarly higher in TW and MW. The low quality of reclaimed waters (TW and MW) negatively affected the soil and lettuce leaves qualities, therefore the leaves need subsequent treatment before utilization.
