粤东凤凰山茶区土壤氟化学形态特征及其影响因素

CHEMICAL FORMS OF FLUORINE IN SOILS FROM 12 TEA GARDENS OF FENGHUANG MOUNTAIN,EAST OF GUANGDONG PROVINCE

采用连续化学提取法对粤东凤凰山茶区12个较大型茶园共60份土壤样品氟的5种化学形态分布进行研究.结果发现,土壤中氟的5种化学形态分布的规律为残余态>>铁锰结合态>有机态>水溶态>可交换态.水溶态氟含量与可交换态氟含量、残余态氟含量及总氟含量呈显著正相关性,而铁锰结合态含量与有机束缚态之间呈显著正相关性,残余态与总氟之间呈极显著正相关性.同时研究发现,土壤pH值、有机质、交换性钙含量、交换性镁含量、交换性钾含量和交换性钠含量对土壤氟的化学形态分布具有重要影响.另外,茶叶中的氟含量与土壤水溶态氟有极其显著的正相关性,与有机质、pH值有显著正相关性,而与可交换态氟、铁锰结合态氟、有机束缚态氟、残余态氟没有相关性.

Forms of fluorine in 60 soil samples collected from 12 tea gardens of Fenghuang mountain in the east of Guangdong Province were studied using the sequential chemical extraction procedure.The fluoride forms in soils were separated into five fractions：water soluble fluoride（Ws-F）,exchangeable fluoride（Ex-F）,fluoride bound to Fe/Mn oxides（Fe/Mn-F）,fluoride bound to organic matter（Or-F）,and residual fluoride（Res-F）.The content of different fluoride forms decreased in the order：Res-FFe/Mn-FOr-FWs-FEx-F.Correlation analyses showed that Ws-F was significantly correlated with Ex-F,Res-F and total F.Fe/Mn-F was correlated with Or-F.Res-F was signicantly correlated with total F.The research found that soil pH,organic matter,Exchangeable Ca,Mg,K and Na were the important influential factors to the distribution of fluoride forms.In addition,fluoride content in the tea leaves was significantly correlated with Ex-F,pH and organic matter,and was not correlated with Ex-F,Fe/Mn-F,Or-F and Res-F.