title: Speciation and phytoavailability of cadmium in soil treated with cadmium-contaminated rice straw.
abstract: When grown on Cd-contaminated soil, rice typically accumulates considerable Cd in straw, and which may return to the soil after harvest. This work was undertaken to assess the pollution risk of Cd associated to the Cd-contaminated rice straw after incorporating into an uncontaminated soil. With the Cd-contaminated rice straw added at 0, 1, 2, 3, 4 and 5 % (w/w), an incubation experiment (28 days) with non-planting and a followed pot experiment sequent with two planting (rice and Chinese cabbage, transplanted after 28-day incubation) were carried out to investigate the changes of soil Cd speciation and phytoavailability. The results indicated that the Cd-contaminated rice straw addition significantly increased soil pH and dissolved organic carbon during the 28-day incubation. For the high availability of Cd in contaminated rice straw, diethylenetriaminepentaacetic acid (DTPA) extractable Cd significantly increased, and the percentages of acetic acid extractable and reducible Cd in soil significantly enhanced after the addition of Cd-contaminated rice straw. However, the Cd-contaminated rice straw addition inhibited the rice growth and induced the decrease of Cd in rice grain and straw by 12.8 to 70.2 % and 39.3 to 57.3 %, respectively, whereas the Cd contents increased by 13.9 to 84.1 % in Chinese cabbage that planted after rice harvest. In conclusion, Cd associated with Cd-contaminated rice straw was highly available after incorporating into the soil, and thus the Cd pollution risk via the Cd-contaminated rice straw incorporation should be evaluated in the Cd-contaminated paddy region.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan Province, China, 410125.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.forename: Dao-You
authors.initials: DY
authors.lastname: Huang
authors.forename: Qi-Hong
authors.initials: QH
authors.lastname: Zhu
authors.forename: Han-Hua
authors.initials: HH
authors.lastname: Zhu
authors.forename: Shou-Long
authors.initials: SL
authors.lastname: Liu
authors.forename: Zun-Chang
authors.initials: ZC
authors.lastname: Luo
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Cao
authors.forename: Ji-Yu
authors.initials: JY
authors.lastname: Wang
authors.forename: Zhong-Xiu
authors.initials: ZX
authors.lastname: Rao
authors.forename: Xin
authors.initials: X
authors.lastname: Shen
mesh_terms: D001937:Brassica / Q000378:metabolism; D002104:Cadmium / Q000032:analysis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000378:metabolism*; D018547:Plant Stems / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium