Topdressing iron fertilizer coupled with pre-immobilization in acidic paddy fields reduced cadmium uptake by rice (Oryza sativa L.)

Gaoxiang Huang; Changfeng Ding; Zhaoyun Hu; Caihong Cui; Taolin Zhang; Xingxiang Wang

doi:10.1016/j.scitotenv.2018.04.369

Topdressing iron fertilizer coupled with pre-immobilization in acidic paddy fields reduced cadmium uptake by rice (Oryza sativa L.)

Sci Total Environ. 2018 Sep 15:636:1040-1047. doi: 10.1016/j.scitotenv.2018.04.369. Epub 2018 May 3.

Authors

Gaoxiang Huang¹, Changfeng Ding², Zhaoyun Hu³, Caihong Cui³, Taolin Zhang², Xingxiang Wang⁴

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
³ Agricultural Technology Extension Center of Yi'an District, Tongling 244100, China.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Ecological Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan 335211, China. Electronic address: xxwang@issas.ac.cn.

PMID: 29913566
DOI: 10.1016/j.scitotenv.2018.04.369

Abstract

Soil cadmium (Cd) contamination has become a serious problem in China. This study was conducted to test the effects of basal application of hydrated lime and iron fertilizer alone or together and topdressing of iron fertilizer at the tillering stage alone or coupled with basal application of hydrated lime, on reducing the accumulation of Cd in brown rice grown in an acidic paddy field slightly contaminated with Cd. The results showed that Cd in brown rice (BR-Cd) was dependent on not only the pH increase and CaCl₂-extractable Cd reduction in the soil due to lime amendment but also Cd sequestration by the iron plaque on root surfaces. However, lime significantly decreased the amounts of Fe and Cd in the iron plaque on the surface of rice root. Topdressing of ferrous sulfate at the tillering stage resulted in the highest Fe and Cd sequestration in the iron plaque. Compared with the control (0.71 mg kg^-1 BR-Cd), the basal application of lime and ferrous sulfate alone or together reduced BR-Cd by 45.8%, 18.3%, and 53.1%, respectively; topdressing of ferrous sulfate alone reduced BR-Cd by 23.6%, and topdressing of ferrous sulfate at the tillering stage coupled with basal application of lime yielded the lowest BR-Cd level with a 74.6% reduction. This result was further confirmed by field experiments at two sites in the following year.

Keywords: Bioavailability; Cadmium; Hydrated lime; Iron plaque; Rice.