ABSTRACT The landscape legacy of historical metal-mining activity can persist for decades. The most frequent strategies used for the remediation of contaminated soils include: the use of synthetic membranes to isolate contaminants, direct revegetation, or lime amendments. Looking for more cost-effective bioremediation approaches, we performed a set of greenhouse studies to determine what combinations of soil amendments would lead to the best vegetative response, and potentially associated reductions in soil arsenic (As) levels. In our first greenhouse experiment, we planted Leymus cinereus (basin wildrye) in tailings, compared (after 12 weeks) plant growth, and foliar metal concentrations across treatments. Amendments included single or factorial additions of lime, 5% organic matter (+OM), and an arsenic-oxidizing (+oxbact) strain of Agrobacterium tumefaciens (Agtu). For the first experi...