title: Soil fluoride fractions and their bioavailability to tea plants (Camellia sinensis L.).
abstract: Drinking teas containing high fluoride (F) imposes fluorosis risk. The soil F bioavailability is an important factor influencing its uptake and contents in teas. The present work was conducted to investigate F fractions in soil and their bioavailability to tea plants. Tea seedlings were cultivated on 6 typical soils treated with a mixture consisting of dolomite, lime, peat and KCl at variable rates in the pot experiment. Soils and young shoots were collected in pairs from 63 sites of 21 plantations in a field experiment. Soil fluoride was sequentially separated into hot water soluble [Formula: see text], exchangeable [Formula: see text] (by 1 mol L-1MgCl2, pH = 7.0), F bound to Mn and Fe hydroxides [F(oxides,s)], and organic matter [F(OM,s)] or extracted independently by water [Formula: see text] or 0.01 mol L-1CaCl2solution [Formula: see text]. Averaged [Formula: see text], [Formula: see text], F(oxides,s)and F(OM,s)accounted for 51, 14, 5 and 30 % of the total sequential extracts, respectively. There were significant correlations among [Formula: see text], [Formula: see text] and F(OM,s). Fluoride contents in leaves correlated with [Formula: see text] (r = 0.71, p < 0.001), [Formula: see text] (r = 0.93, p < 0.001) and F(OM,s)(r = 0.69, p < 0.01) but not other fractions in the pot experiment and with [Formula: see text] (r = 0.43-0.57, p < 0.001) and [Formula: see text] (r = 0.42-0.79, p < 0.001) in the field experiment. It was concluded that 0.01 M CaCl2extractable fluoride can be a good indicator of soil F bioavailability to tea plants. The significant correlations among some of the F fractions suggested that F in solution, AlF complexes (AlF2+, AlF2+) and those bound to organic matter likely represent the available pools to tea plants.
authors: Tea Research Institute of Chinese Academy of Agricultural Sciences and the Key Laboratory for Plant Biology and Resource Application of Tea of the Ministry of Agriculture, Hangzhou, 310008, Zhejiang, China.
authors: Xiaoyun
authors: X
authors: Yi
authors: Tea Research Institute of Chinese Academy of Agricultural Sciences and the Key Laboratory for Plant Biology and Resource Application of Tea of the Ministry of Agriculture, Hangzhou, 310008, Zhejiang, China.
authors: Sha
authors: S
authors: Qiao
authors: Tea Research Institute of Chinese Academy of Agricultural Sciences and the Key Laboratory for Plant Biology and Resource Application of Tea of the Ministry of Agriculture, Hangzhou, 310008, Zhejiang, China.
authors: Lifeng
authors: L
authors: Ma
authors: Tea Research Institute of Chinese Academy of Agricultural Sciences and the Key Laboratory for Plant Biology and Resource Application of Tea of the Ministry of Agriculture, Hangzhou, 310008, Zhejiang, China.
authors: Jie
authors: J
authors: Wang
authors: Tea Research Institute of Chinese Academy of Agricultural Sciences and the Key Laboratory for Plant Biology and Resource Application of Tea of the Ministry of Agriculture, Hangzhou, 310008, Zhejiang, China. jruan@mail.tricaas.com.
authors: Jianyun
authors: http://orcid.org/0000-0003-2295-6364
authors: J
authors: Ruan
mesh_terms: D001682:Biological Availability; D028241:Camellia sinensis / Q000378:metabolism*; D002681:China; D004784:Environmental Monitoring; D005459:Fluorides / Q000032:analysis / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D005459:Fluorides
keywords: 0.01 M CaCl2 extractable fluoride; Correlation analysis; Fluoride content; Sequential extraction; Water extractable fluoride