Impact of Irrigation with Contaminated River Water on Growth, Yield, and Heavy Metals Accumulation in Planted Armenian Cucumber (Cucumis melo var. flexuosus (L.) Naudin.)

Cultivation of horticultural crops in riverbank soils which are enriched by deposition of nutrient-rich sediments is one of the most common practices in arid and semi-arid regions around the globe. However, contamination of river streams by urban, industrial, and agricultural runoffs resulted in the accumulation of excessive levels of certain nutrients and heavy metals in such crops. Keeping in view, the present study was conducted to understand the impact of Yamuna (non-contaminated) and Solani (urban sewage contaminated) Rivers streams on riverbank soils and planted Armenian cucumber [Cucumis melo var. flexuosus (L.) Naudin.] in a two-year (2022 and 2023) study. The results showed that C. melo cultivated in Solani River water irrigated soils had significantly (p < 0.05) higher growth, yield, and biochemical constitutes as compared to Yamuna River water irrigated soils. The bioaccumulation factor (BAF) studies showed that concentrations of eight heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were higher in C. melo grown in Solani River soils. However, the levels of heavy metals were found below the safe limits as indicated by dietary intake of metal (DIM), health risk index (HRI < 1), and target hazard quotient (THQ < 1) indices. Overall, this study evidenced that river water impacted by urban sewage could result in elevated levels of heavy metals in river water, soil, and cultivated food crops, thus, signifying their regular biomonitoring in order to mitigate any associated health risk.