Alfalfa, Sweetcorn, and Wheat Responses to Long‐Term Application of Municipal Waste Water to Cropland

Abstract

AbstractThe objective of this study was to assess, over two growing seasons, the long‐term effects of applying municipal waste water on agricultural land under semi‐arid conditions on selected crops. Alfalfa (Medicago sativa L.) cv Ranger, sweetcorn (Zea mays L.) cv Jubilee, and wheat (Triticum vulgare L.) cv Fremont, were grown on land to which waste water had been applied for > 15 y. Plants grown on effluent‐irrigated sites had greater growth rates, dry weights, and yields than did plants grown on irrigated control sites. Chemical analyses for metals in plant parts showed that Na was higher in plants growing on the waste water site, whereas Cu, Fe, and Zn were much higher in plants harvested on control sites. Metal concentrations observed in plant materials were below hazardous levels reported in the literature. In general, no significant, detrimental, long‐term effects of applying municipal waste water on land under semi‐arid conditions were detected. In fact, available P levels increased in effluent‐irrigated soils.