Principal Investigator: Zhao Fangjie

Funding Received: 2.48 million RMB

Sponsored by: National Natural Science Foundation of China

Project Period: January, 2017- December, 2020

Brief Introduction to the Project:

  Rapid industrialization in China over the last three decades has resulted in widespread soil contamination in China’s farmland. Substantial proportions of rice produced in some areas of southern China exceed the maximum permissible limits of Cd and As contents, threatening food safety in the country. Rice is a major dietary source of both Cd and As for the populations in China and other Asian countries. Chronic intake of elevated levels of Cd and As can pose considerable health risks to humans. The uptake of Cd and As by rice depends on a number of soil and plant factors, some of which can be influenced by paddy management. The current difficulties in predicting Cd and As accumulation in rice grain are to a large extent due to a lack of knowledge on the interactions and relevance of biotic and abiotic factors controlling contaminant bioavailability and uptake by rice. Therefore, a better mechanistic understanding of the biogeochemical processes of Cd and As in paddy soil is required. The objectives of this interdisciplinary project are to (i) investigate the biogeochemical processes controlling the speciation, solubility and uptake of Cd and As by rice grown in contaminated paddy soils, (ii) study the biotic and abiotic factors influencing Cd and As bioavailability during flooding-drainage cycles, and (iii) explore new paddy management strategies to reduce both Cd and As uptake simultaneously. The project builds on the existing collaboration between the applicant and Professor Ruben Kretzschmar at ETH Zurich, with highly complementary expertise in environmental chemistry, soil microbiology and plant physiology. The project will address important knowledge gaps in our current understanding of Cd and As biogeochemistry in paddy soils and, thereby, contribute to the development of improved paddy management strategies for minimizing Cd and As uptake by rice grown in contaminated soils in southern China.