Rice intercropping with alligator flag (Thalia dealbata): A novel model to produce safe cereal grains while remediating cadmium contaminated paddy soil

Abstract

Phytoremediation has been employed as a cost-effective technique to remove the cadmium (Cd) from soil andwater in several ecosystems. However, little is known about whether intercropping the remediating plants withrice (Oryza sativa) crop could reduce Cd accumulation in rice grains. We conducted greenhouse pot and concretepond trials to explore the effects of intercropping alligator flag (Thalia dealbata, Marantaceae) on soil Cd remediation,paddy soil and microbial properties, and rice production. Our results suggest that intercropping withalligator flag significantly decreased Cd absorption, transportation, and accumulation from the soil to the ricegrains (under 0.2 mg kg–1 at a soil Cd content below 2.50 mg kg–1). This decrease was due to the lowered Cdavailability and higher soil pH in the rice-alligator flag intercropping system. Although planting alligator flagresulted in the reduction of soil NH4-N and NO3-N, Cd content in the rhizosphere was the main factor restrictingmicrobial biomass, species, and community composition. Alligator flag could tolerate higher Cd contamination, and accumulate and stabilize more Cd in its tissues than rice. Our study suggests that alligator flag intercroppedwith rice has potential as a phytostabilization plant to produce rice safely for human consumption in moderatelyCd-contaminated soils.

Citation

Wang, Jiaxin; Lu, Xuening; Zhang, Jiaen; Ouyang, Ying; Wei, Guangchang; Xiong, Yue. 2020. Rice intercropping with alligator flag (Thalia dealbata): A novel model to produce safe cereal grains while remediating cadmium contaminated paddy soil. Journal of Hazardous Materials. 394: 122505-. https://doi.org/10.1016/j.jhazmat.2020.122505.