Soil proprieties and alfalfa (Medicago sativa L.) responses to sustainable treated urban wastewater reuse

The present work aims to perform an experimental reuse study of raw and sustainable treated urban wastewaters in the irrigation of alfalfa (Medicago sativa L.) under semi-controlled conditions. The obtained results highlight a significant effect (p < 0.05) of water quality on soil monitored parameters. Compared to control soils irrigated with groundwater (GW), those irrigated with treated urban wastewaters from the modified activated sludge process (PTW) and raw urban wastewater (RW) showed significant increase in their organic matter (OM) and nutrients content. Indeed, in comparison to GW organic matter (OM) of RW and PTW was 5,37 and 3,84 times higher; Kjeldahl nitrogen (TKN) was 3,50 and 2,81 times higher and total phosphorus (TP) was 4,00 and 3,25 times higher, respectively. The results showed also a significant effect of water quality on yield, macro and microelements concentrations of alfalfa plant. Hence, the highest yield, macro and microelements uptake of the plant were obtained in response to irrigation with PTW and RW compared to control soil GW. Concerning trace metallic elements concentrations, pots irrigated with RW and PTW showed relatively higher concentrations than those of GW pots.