Effect of irrigation water contaminated with uranium mill tailings on Sudan grass, Sorghum vulgare var. sudanense, and fourwing saltbush, Atriplex canescens

A greenhouse experiment was carried out to estimate the effects of irrigati on water quality on chemical uptake and productivity of Sudan grass (Sorghu m vulgare var. sudanense) and fourwing saltbush (Atriplex canescens). Water and soil were obtained from an inactive U ore processing site near Tuba Ci ty, Arizona. Two observation wells provided the irrigation water. One was l ocated upgradient from the contaminated site, and was located in the center of the plume downgradient from the area contaminated by the milling operat ions. A 50/50 mix of the two well waters was used as a third treatment. Con centrations of Se and U in aboveground tissues of saltbush were significant ly (P < 0.05) elevated when irrigated with the undiluted contaminated water , but not to unacceptable levels. In the case of Sudan grass, Mo, Se, U, NO 3-N, and S were significantly (P < 0.05) elevated in the contaminated water treatment, and all except NO3--N were elevated with the diluted contaminat ed water, but again within acceptable limits. Saltbush productivity was not significantly (P > 0.05) affected by the three irrigation treatments. Suda n grassaboveground biomass results suggest that the undiluted contaminated plume water could be used for effective crop production, although productiv ity was significantly better with the nutrient-amended baseline water and t he diluted contaminated water. Root biomass was significantly greater in th e baseline water irrigation.