title: Phytotoxicity and accumulation of chromium in carrot plants and the derivation of soil thresholds for Chinese soils.
abstract: Soil environmental quality standards in respect of heavy metals for farmlands should be established considering both their effects on crop yield and their accumulation in the edible part. A greenhouse experiment was conducted to investigate the effects of chromium (Cr) on biomass production and Cr accumulation in carrot plants grown in a wide range of soils. The results revealed that carrot yield significantly decreased in 18 of the total 20 soils with Cr addition being the soil environmental quality standard of China. The Cr content of carrot grown in the five soils with pH>8.0 exceeded the maximum allowable level (0.5mgkg(-1)) according to the Chinese General Standard for Contaminants in Foods. The relationship between carrot Cr concentration and soil pH could be well fitted (R(2)=0.70, P<0.0001) by a linear-linear segmented regression model. The addition of Cr to soil influenced carrot yield firstly rather than the food quality. The major soil factors controlling Cr phytotoxicity and the prediction models were further identified and developed using path analysis and stepwise multiple linear regression analysis. Soil Cr thresholds for phytotoxicity meanwhile ensuring food safety were then derived on the condition of 10 percent yield reduction.
authors: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Changfeng
authors: C
authors: Ding
authors: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors: Xiaogang
authors: X
authors: Li
authors: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Taolin
authors: T
authors: Zhang
authors: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors: Yibing
authors: Y
authors: Ma
authors: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China; Jiangxi Key Laboratory of Ecological Research of Red Soil, Ecological Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan 335211, China. Electronic address: xxwang@issas.ac.cn.
authors: Xingxiang
authors: X
authors: Wang
mesh_terms: D018533:Biomass; D002681:China; D002857:Chromium / Q000378:metabolism / Q000633:toxicity*; D018552:Daucus carota / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D059022:Food Safety; D016014:Linear Models; D012987:Soil; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002857:Chromium
keywords: Accumulation; Carrot; Chromium; Phytotoxicity; Soil thresholds