Mitigating arsenic uptake in irrigated rice through water management: mechanisms in the rhizosphere.

This project deals with arsenic (As) uptake in rice plants in relation to possibilities to reduce rice grain As by irrigation strategies. Rice grains have typically 10-fold larger As concentrations than wheat or barley grain because As mobility and bioavailability in soil sharply increases upon waterlogging soils used to grow rice, i.e. the reduction of As(V) to the mobile As(III) in these soils enhance soil-plant transfer. There is evidence to suggest that intermittent irrigation may reduce grain As, i.e. periodic dry spells aerates the soil and lower average As mobility. This projects wants to focus on the mechanism of water availability in the root zone on As uptake in rice with due attention to the soil chemistry in the root zone. The oxygenation of the root zone of rice is spatially highly variable and the local As mobility near active roots is unknown. A novel DGT based device with 73As autoradiography will be developed to visualize As mobility in 2D in the rhizosphere of rice. This method will be used to interpret treatment effects of intermittent irrigation in greenhouse and field studies with rice.

Keywords:Rice

Disciplines:Soil sciences, challenges and pollution, Agriculture, land and farm management