Effects of alkaline and bioorganic amendments on cadmium, lead, zinc, and nutrient accumulation in brown rice and grain yield in acidic paddy fields contaminated with a mixture of heavy metals.
Paddy soils and rice (Oryza sativa L.) contaminated by mixed heavy metals have given rise to great concern. Field experiments were conducted over two cultivation seasons to study the effects of steel slag (SS), fly ash (FA), limestone (LS), bioorganic fertilizer (BF), and the combination of SS and BF (SSBF) on rice grain yield, Cd, Pb, and Zn and nutrient accumulation in brown rice, bioavailability of Cd, Pb, and Zn in soil as well as soil properties (pH and catalase), at two acidic paddy fields contaminated with mixed heavy metals (Cd, Pb, and Zn). Compared to the controls, SS, LS, and SSBF at both low and high additions significantly elevated soil pH over both cultivation seasons. The high treatments of SS and SSBF markedly increased grain yields, the accumulation of P and Ca in brown rice and soil catalase activities in the first cultivation season. The most striking result was from SS application (4.0 t ha-1) that consistently and significantly reduced the soil bioavailability of Cd, Pb, and Zn by 38.5-91.2 % and the concentrations of Cd and Pb in brown rice by 20.9-50.9 % in the two soils over both cultivation seasons. LS addition (4.0 t ha-1) also markedly reduced the bioavailable Cd, Pb, and Zn in soil and the Cd concentrations in brown rice. BF remobilized soil Cd and Pb leading to more accumulation of these metals in brown rice. The results showed that steel slag was most effective in the remediation of acidic paddy soils contaminated with mixed heavy metals.
School of Life Sciences, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China.
Huaidong
H
He
Department of Biology and Chemistry, State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR, People's Republic of China.
Nora F Y
NF
Tam
School of Geography and Planning, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China.
Aijun
A
Yao
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China. eesqrl@mail.sysu.edu.cn.
Rongliang
R
Qiu
Centre for Education in Environmental Sustainability and Department of Science and Environmental Studies, The Hong Kong Institute of Education, Hong Kong, SAR, People's Republic of China.
Wai Chin
WC
Li
School of Life Sciences, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China. lssyzhh@mail.sysu.edu.cn.
Zhihong
Z
Ye
D002104:Cadmium / Q000032:analysis / Q000378:metabolism*; D060729:Coal Ash; D002523:Edible Grain / Q000254:growth & development* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis / Q000378:metabolism*; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism; D012621:Seasons; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D015032:Zinc / Q000032:analysis / Q000378:metabolism*
D060729:Coal Ash; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D015032:Zinc
Acidic paddy soils; Amendments; Bioavailability; Heavy metals; Rice; Soil properties