The impact of alternate wetting and drying and continuous flooding on antimony speciation and uptake in a soil-rice system

• Published in: Chemosphere (Oxford) 2022-06, Vol.297, p.134147-134147, Article 134147
• Main Authors: Wu, Tongliang, Cui, Xiaodan, Ata-Ul-Karim, Syed Tahir, Cui, Peixin, Liu, Cun, Fan, Tingting, Sun, Qian, Gong, Hua, Zhou, Dongmei, Wang, Yujun
• Format: Article
• Language: English
• Subjects: Alternate wetting and drying; Antimony; Antimony - analysis; Continuous flooding; Edible Grain - chemistry; Floods; Humans; Oryza; Rice; Soil; Soil Pollutants - analysis; Speciation; Uptake
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.134147

The accumulation of trace elements in rice, such as antimony (Sb), has drawn special attention owing to the potential increased risk to human health. However, the effects of two common irrigation methods, alternate wetting and drying and continuous flooding, on Sb behaviors and subsequent accumulation in rice is unclear. In this study a pot experiment with various Sb additions (0, 50, 200, 1000 mg Sb kg−1) was carried out with these two irrigation methods in two contrasting paddy soils (an Anthrosol and a Ferralic Cambisol). The dynamics of Sb in soil porewater indicated that continuous flooding generally immobilized more Sb than alternate wetting and drying, concomitant with a pronounced reduction of Sb(V) in porewater. However, a higher phytoavailable fraction of Sb was observed under continuous flooding. The content of Sb in the rice plant decreased in the order of root > shoot > husk > grain, and continuous flooding facilitated Sb accumulation in rice root and shoot as compared with alternate wetting and drying. The differences of Sb content in root, shoot, and husk between the two irrigation methods was smaller in aboveground parts, and almost no difference in Sb was observed in grain between the two methods. The findings of this study facilitates the understanding of Sb speciation and behavior in soils with these common yet different water management regimes. [Display omitted] •Continuous soil flooding decreased Sb in porewater with pronounced Sb(V) reduction.•Continuous soil flooding increased phytoavailable Sb and total Sb in root and shoot.•Sb in grain was below acceptable limit and not affected by two water treatments.