Effect Of The Selenium Fertilization On Oolong Tea For Se-enriching

Through the experiments of soil applied with sodium selenium and spraying sodium selenium in tea leaves in the ecology tea garden in Anxi country of Fujian province, studied the effects on the selenium content of soil and oolong tea from different methods of selenium. The main contents and conclusions as follows:1. Comparing with little effect of leaf-spraying way, two months'sodium selenium fertilization to the soil obviously increased the on selenium contents of soil by soil applying sodium selenite at 400, 700, 1000 and 1300g/hm2, and the best treatment was soil applying sodium selenite at 1000g/hm2, it was increased by 2.31 to 2.52 times as CK. Then there was no difference in the selenium content of soil and oolong tea between autumn and spring.2. Sodium selenium fertilization had different effects on grass and water sheds around the tea garden, which favored in improving selenium content of grass, and the improvement for leaf-spraying was better than that for soil fertilization. There was no pollution left.3. After applied sodium selenium to the soil, the selenium content of tea by soil applying sodium selenite at 400, 700, 1000 and 1300g/hm2 were all increased obviously, while there was a positive correlative relation between the contents of selenium fertilizer and the soil selenium as well as the oolong tea's ability in selenium absorbing and conserving , but with a narrowing-down increase range. As for tea selenium content of treatment by soil applying sodium selenite at 1000 and 1300g/hm2, both of them had nearly researched the standard of Se-enriched tea(≥0.3 ug/g). The organic selenium of tea accounted 73.8%～87.3% of the total. There was a big different range between 0.030～0.103 ug/100ml for selenium content of tea infusion, but the dissolved rate for selenium content of tea was between15.2%～17.2%.4. The leaf-spraying helped in Se-enriching, which was feasible for production of Se-enriched oolong tea. leaf-spraying for spraying 50g/hm2,70g/hm2,90g/hm2,110g/hm2 could improve the tea selenium content enormously, and best for the treatment 8 (90 g/hm2); the tea selenium content became lower with the time went by and that for the time during 15th day～22th day was high, but the addictive Se is little, so the spraying time could be controlled in the range of early 15 days or 22 days.