title: Suppression of cadmium uptake in rice using fermented bark as a soil amendment.
abstract: The contamination of rice paddies with heavy metals has become a serious concern due to their high toxicity to human health. In this study, we developed a chemical-free, fermented bark amendment (FBA) and used it for organic rice cultivation. The application of FBA resulted in the fixation of heavy metals, especially cadmium (Cd), in the soil and suppressed their uptake in brown rice. The suppression of Cd uptake was most effective, since its uptake in rice from FBA-supplemented soil was 10 times lower than that from untreated soil under ordinary water-filling conditions. These results could be explained by the rapid conversion of sulfate ions to sulfide ions, which subsequently react with Cd producing insoluble sulfide species, as well as Cd adsorption to the decomposed bark in soil. The FBA did not affect the uptake of metals, such as calcium and iron, which are necessary for the growth of rice. Thus, the FBA may suppress Cd uptake in rice, and its effectiveness is related to application time and water regime.
authors: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan. Electronic address: mori@gunma-u.ac.jp.
authors: Masanobu
authors: M
authors: Mori
authors: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors: Kenta
authors: K
authors: Kotaki
authors: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors: Fumine
authors: F
authors: Gunji
authors: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors: Naoyuki
authors: N
authors: Kubo
authors: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors: Shizusa
authors: S
authors: Kobayashi
authors: Department of Civil and Environmental Engineering, Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors: Tsukasa
authors: T
authors: Ito
authors: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors: Hideyuki
authors: H
authors: Itabashi
mesh_terms: D000327:Adsorption; D005285:Fermentation; D005308:Fertilizers; D019216:Metals, Heavy / Q000737:chemistry / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism*; D024301:Plant Bark / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism
chemical_list: D005308:Fertilizers; D019216:Metals, Heavy; D012989:Soil Pollutants; D013431:Sulfates; D013440:Sulfides
keywords: Adsorption; Cadmium; Chelation; Microbes; Rice; Woody biomass