Impact of Water Management on Arsenic and Cadmium Accumulation in Rice Grown Nearby Abandoned Mines in Korea

Abstract

Managing arsenic (As) and cadmium (Cd) together in rice (Oryza sativa L.) plants is challenging and different strategies are being developed for mitigating As and Cd loading into the rice grains. This study investigated the effect of water management on As and Cd accumulation in brown rice. A field plot experiment was conducted with five water management regimes [Flooded control, alternate wetting drying (AWD–60 and 40), and row (R-60 and R-40)] using two rice cultivars (Dasan and Boramchan). All the four treatments significantly reduced the concentration of As in brown rice compared to the flooded control, with R-40 treatment showing the least concentration. AWD and row treatments reduced As levels by 45-60% and by 32-55% in Dasan and Boramchan cultivars, respectively. However, increased Cd concentrations were noticed in both row and AWD treatments. The Dasan rice cultivar under the AWD-60 treatment reduced As without greatly increasing Cd concentration in brown rice, while also maintaining a competitive grain yield. The grain yields of both cultivars were influenced by different water regimes. While the flooded control showed the highest grain yield, between the cultivars, Boramchan showed an increase in grain yield under AWD-40 and R-40 treatments, and Dasan cultivar displayed higher grain yield in AWD-60 and R-60 treatments. AWD water management may be a promising strategy to reduce both As and Cd accumulation in rice grains, however, it depends on the selection of rice cultivars.