title: The effect of municipal sludge compost on the mobility and bioavailability of Cd in a sierozem-wheat system in an arid region northwest of China.
abstract: The effect of sewage sludge on the mobility and the bioavailability of trace metals in plant-soil systems have aroused wide interested and been widely explored. Based on a wheat-cultivating experiment, the effect of municipal sludge compost (MSC) on the mobility and bioavailability of Cd in a soil-wheat system was studied. With the application of MSC, soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) in the soil increased significantly, while concentrations of trace metals (Cu, Zn, Ni, Pb, Cd) were below the China's minimum thresholds. The application of MSC could improve wheat growth. The application of MSC at the rate of 0.5 % had no significant effect on the chemical fraction distribution of Cd in soil. In two soil treatments, Cd mainly existed in the labile chemical fractions (exchangeable chemical fraction (EXCF) and carbonate chemical fraction (CABF)). However, the application of MSC could reduce accumulation of Cd by wheat. Cd contents in each part of the MSC-applied wheat were significantly less than that of non-MSC-applied wheat. In the tested soils, the extractable concentrations decreased in the order: EDTA > MgCl2≈ NH4OAc > DTPA. There were no significant differences between soil treatments in the amounts of extractable Cd when the extraction was done under neutral conditions, although significant differences were observed when the extraction was done under alkaline conditions. In this study, the DTPA extraction procedure provided a good indication of Cd bioavailability. Our results suggest that, in the short term at least, amending soils with MSC may benefit crop dry matter production while not increasing the risk of human exposure to Cd through consumption of wheat grown on MSC-amended soils.
authors.affiliation: College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Gansu Academy of Environmental Science, Lanzhou, 730030, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Bai
authors.affiliation: College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China. nanzhongren@163.com.
authors.forename: Zhongren
authors.initials: Z
authors.lastname: Nan
authors.affiliation: College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Chuanyan
authors.initials: C
authors.lastname: Zhao
authors.affiliation: College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Ma
authors.affiliation: College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Houcheng
authors.initials: H
authors.lastname: Wang
mesh_terms: D001682:Biological Availability; D002104:Cadmium / Q000032:analysis* / Q000378:metabolism; D002681:China; D006801:Humans; D006812:Humic Substances / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D014908:Triticum / Q000254:growth & development* / Q000378:metabolism
chemical_list: D006812:Humic Substances; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D010758:Phosphorus; D009584:Nitrogen
keywords: Arid region; Bioavailability; Cd; Mobility; Municipal sludge compost; Sierozem