Cadmium (Cd) and arsenic (As), the two main inorganic pollutants in arable land in China, have strong biological toxicity and soil availability. It is easy to accumulate in rice (Oryza sativa L.) and affect health after entering the human body through the food chain. Iron fertilizer has been widely used to reduce Cd content in rice. Compared with inorganic iron fertilizer, chelated iron fertilizer has a better effect on reducing Cd accumulation in rice.

A research team led by Huang Daoyou from the Institute of Subtropical Agriculture, Chinese Academy of Sciences, revealed the mechanism of simultaneous reduction of Cd and As uptake and accumulation in rice by EDTA·Na₂Fe. Their recent study was published in Ecotoxicology and Environmental Safety on November 26th.

They found that EDTA·Na₂Fe reduced the Cd and As content in grain by reducing the availability of Cd and As in soil, improving the sequestration of Cd and As in iron plaque, and reducing the transport of Cd from iron plaque to root and As from root to grain..

Furthermore, the optimal simultaneous reduction effect of Cd and As in grains was achieved by basal application of moderate amount of EDTA·Na₂Fe (50mg kg^-1 Fe).

“This study provides a new idea for the treatment of the combined pollution of Cd and As in paddy soil,” said Associate Professor Xu Chao, a co-corresponding author of the study and researcher in ISA.“and has guiding significance for reducing the content of Cd and As in rice grains and alleviating the threat to human health.”

Contact: Xu Chao; Huang Daoyou

E-mail: xuchao1388@126.com; dyhuang@isa.ac.cn

Mechanism of reducing Cd-As accumulation in rice by addition of chelated iron(Imaged by Xu Chao)