title: Moderate phosphorus application enhances Zn mobility and uptake in hyperaccumulator Sedum alfredii.
abstract: While phytoextraction tools are increasingly applied to remediation of contaminated soils, strategies are needed to optimize plant uptake by improving soil conditions. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. Microcosm experiments were conducted in greenhouse to examine the effect of different phosphorus (P) sources on zinc (Zn) phytoextraction by Sedum alfredii in aged Zn-contaminated paddy soil. The Zn accumulation, soil pH, microbial biomass and enzyme activity, available Zn changes. and Zn phytoremediation efficiency in soil after plant harvest were determined. Upon addition of P, Zn uptake of S. alfredii significantly increased. Mehlich-3 extractable or the fractions of exchangeable and carbonate-bound soil Zn were significantly increased at higher P applications. Soil pH significantly decreased with increasing P application rates. Soil microbial biomass in the P-treated soils was significantly higher (P < 0.05) than those in the control. Shoot Zn concentration was positively correlated with Mehlich-3 extractable P (P < 0.0001) or exchangeable/carbonate-bound Zn (P < 0.001), but negatively related to soil pH (P < 0.0001). These results indicate that application of P fertilizers has the potential to enhance Zn mobility and uptake by hyperaccumulating plant S. alfredii, thus increasing phytoremediation efficiency of Zn-contaminated soils.
authors.affiliation: Ministry of Education Key laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang province 310058, China. huanghg82@gmail.com
authors.forename: Huagang
authors.initials: H
authors.lastname: Huang
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Tingqiang
authors.initials: T
authors.lastname: Li
authors.forename: Zhenli
authors.initials: Z
authors.lastname: He
authors.forename: Xiao-E
authors.initials: XE
authors.lastname: Yang
authors.forename: D K
authors.initials: DK
authors.lastname: Gupta
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D005591:Chemical Fractionation; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005308:Fertilizers; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000494:pharmacology*; D031963:Sedum / Q000187:drug effects / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D010710:Phosphates; D012987:Soil; D012989:Soil Pollutants; D015032:Zinc