Assessment of Selenium Bioavailability in Tea plantation soil to Bashan Tea species (Wanyuan, Southwest China) Using single extraction methods

摘要

Se concentration varies for different soil types, whether can be absorbed by plants is not related with the total amount of selenium, it is controlled by the bio-availability Se in soil. This paper is aim to look for the laws of the bio-availability Se in different soils, and find out an accuracy and effective method to extract the bio-available Se from different soil types. Digest the soil and tea leaves samples and used six methods (KH_2PO_4, NaHCO_3, HAC, MgCl_2, HC1, EDTA) to extract Se from the different soils, the result was measured by AFS. The mean values of total Se is 8.45μg/g in carbonaceous slates soil, 0.32μg/g and 0.41μg/g in malmstone soil, 0.78μg/g in shale soil. The maximum correlation coefficients(r) between the six extract methods and tea leaves about the extraction ratio of Se in four soils is 0.93188 with KH_2PO_4, 0.77097 and 0.83589 with NaHCO_3, 0.84231 with HAC. So it can be indicate that the total Se contents is carbonaceous slates soil>shale soil>malmstone soil, the best extract method for carbonaceous slates soil, malmstone soil and shale soil are KH_2PO_4, NaHCO_3, and HAC respectively.