QIN Wangwu 1,3 , SHAO Shuxun 1 , XIA Yong 1 , TIAN Yifu 2 , WANG Dazhou 2 ,
YU Deshun2, LIN Jian2 ,LIN Qinghua2
(1. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang550081, China;
2. State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry Chinese Academy of Sciences, Guiyang 550081,China;
3. University of Chinese Academy of Sciences, Beijing 100049,China)
Abstract: Selenium ( Se) -rich resources are very precious, and the development and use in Se-riched functional agriculture is a novelway to revitalize the countryside. Shuicheng is located in the high Se geological background area in Guizhou Province. This study characterized Se biogeochemistry for the tea plantation in the high Se-rich area in Shuicheng District to efficiently exploit local Se-rich resources for developing and producing Se-rich agricultural products. The studys results reveal that the average Se concentrations in rocks of Permian Emeishan basalt and Longtan Formation coal bearing strata were respectively 0. 267±0. 155 mg / kg and 1. 193±2. 698 mg /kg. The stone coal of Longtan Formation has the highest Se concentration with a value of up to 11. 499 mg / kg. These Se-rich rocks delivered abundant geological sources of Se for the formation of Se-rich soil in tea plantations. The total Se concentration in tea plantation soils ranged from 0. 547 to 4. 954 mg / kg, with an average of 1. 682±0. 953 mg / kg. Around 50% of the tea plantation soils intvestigated, which had Se levels between 1-2 mg / kg, were classified as secondary Se-rich soils. The Se concentration in soils was controlledby its parent materials and positively correlated with the organic carbon content ( r = 0. 27) . The average bioavailable soil Se concentration was 0. 142± 0. 043 mg / kg, which accounted for 8. 31% of the total Se concentration, averagely and related closely to pH ( r =0. 69) . The average Se concentration in tea was 0. 086±0. 049 mg / kg, which was below the national standard of Se-rich tea. In order to promote the tea industry in Shuicheng, the following agronomic measures are recommended aiming to increase tea Se levels to meet the standard of the national Se-rich tea: 1) to raise the pH of the tea plantation soils to enhance Se bioavailability in soils; 2) to perform Se biofortification via applying exogenous Se fertilizer; 3) to plant tea varieties with a trait of high Seaccumulation.
Key words: selenium-rich areas; biogeochemistry; Shuicheng; selenium-rich tea
