PU Shuai ^1,2 , QIAO Xiaoli ^1,2 , MAO Xu ^1,2 , WANG Lin ^1,2 , HE Yu ^1,2 , QIU Guangle ³

(1. College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China;

2. Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, Guizhou University, Guiyang 550025,China; 

3. Institute of Geochemistry , Chinese Academy of Sciences, Guiyang 550081, China)

Abstract: To explore the impact of the crops on selenium ( Se) enrichment and migration, total Se contents in the major agriculturalproducts, i. e. rice and tea, as well as total and bioavailable Se contents in rhizosphere soils from a typical Se-rich area, northwestern Fenggang County, Zunyi City, Guizhou Province were investigated. The surface soil from the investigated area had a mean Se content of 1. 56 mg / kg, which is a typical Se-rich soil. Meanwhile, the bioavailable Se content in the soil ranged from 0. 007 64 to 0. 030 8mg / kg, which only accounted for 0. 5% to 4. 45% of the total Se content and was at a relatively low level. The major factors affecting the Se bioavailability were soil total Se content and soil pH value. Soil activation rate correlated negatively with soil total Se ( r =-0. 492, n = 106, p<0. 01) but positively with soil pH ( r = 0. 413, n = 106, p< 0. 01) .The Se enrichment in different parts of rice were generally in the order of root > seed > stem. The enrichment coefficient of rice root averaged 0. 221 which was respectively 2. 87 and 4. 44 times higher than those of grain and stem. The Se enrichment of tea leaves was in the order of old > new leaves and the Se enrichment coefficient of old and new tea leaves ranged respectively from 0. 018 4 to 0. 146 0 and 0. 003 2 to 0. 091 6. The rice grainmet the standard for Se-rich agricultural products (0. 04-0. 30 mg / kg) , whereas the vast majority of tea samples investigated were not in the range of Se-rich tea (0. 20-4. 00 mg /kg) .

Key words: total selenium; tea leaf; rice; enrichment; migration