Planting rice (Oryza sativa L.) in As-contaminated paddy soils can lead to accumulation of arsenic (As) in rice grains, while the application of phosphorus (P) fertilizers during rice growth may aggravate the accumulation effect. However, remediating flooding As-contaminated paddy soils with conventional Fe(III) oxides/hydroxides can hardly achieve the goals of effectively reducing grain As and maintaining the utilization efficiency of phosphate (Pi) fertilizers simultaneously. In the present study, schwertmannite was proposed to remediate flooding As-contaminated paddy soil because of its strong sorption capacity for soil As, and its effect on the utilization efficiency of Pi fertilizer was investigated. Results of a pot experiment showed that Pi fertilization along with schwertmannite amendment was effective to reduce the mobility of As in the contaminated paddy soil and meanwhile increase soil P availability. The schwertmannite amendment along with Pi fertilization reduced the content of P in Fe plaque on rice roots, compared with the corresponding amount of Pi fertilizer alone, which can be attributed to the change in mineral composition of Fe plaque mainly induced by schwertmannite amendment. Such reduction in P retention on Fe plaque was beneficial for improving the utilization efficiency of Pi fertilizer. In particular, amending flooding As-contaminated paddy soil with schwertmannite and Pi fertilizer together has reduced the content of As in rice grains from 1.06 to 1.47 mg/kg to only 0.38-0.63 mg/kg and significantly increased the shoot biomass of rice plants. Therefore, using schwertmannite to remediate flooding As-contaminated paddy soils can achieve the dual goals of effectively reducing grain As and maintaining the utilization efficiency of P fertilizers.

Publication name	ENVIRONMENTAL POLLUTION, Volume 324, Article Number 121383, DOI 10.1016/j.envpol.2023.121383, Published MAY 1 2023, Early Access MAR 2023
Author(s)	Wang, Ru; Guo, Yinglin; Song, Yang; Guo, Yuting; Wang, Xiaomeng; Yuan, Quan; Ning, Zengping; Liu, Chengshuai; Zhou, Lixiang; Zheng, Guanyu
Corresponding author(s)	Zheng, Guanyu  gyzheng@njau.edu.cn  -Nanjing Agr Univ, Coll Resources & Environm Sci, Dept Environm Engn, Nanjing 210095, Peoples R China  -Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Peoples R China
Author(s) from IGCAS	Zheng, Guanyu; Yuan, Quan; Ning, Zengping; Liu, Chengshuai