| Selenium is a essential trace element for human beings and animals. Previous r esearches have found that it will cause deficiency-related illnesses when the sel eniurn intake of human beings and animals is insufficient or too low, such as Kes han disease and Kashin-Beck disease and white muscle disease, etc. The Se whic h human body needs mainly derived from soils and enter the body via the food ch ains through vegetables, microorganisms, foodstuff and meat. China is a selenium-poor country, where the areas that are selenium deficiency or low selenium acco unt for 72 percent of the whole country and two-thirds of Chinese people’s int ake of selenium is inadequate. In the recent decade, researches on the distributio n, morphology and bioavailability of selenium in soil have attracted increasing atte ntion in the field of applied geochemistry in China.Previous researches have revealed that the bioavailability of soil selenium is very low in some acid soil in southern China, and the possibility of selenium-rich agricultural food’s output in the selenium-rich soil area is not high enough. As for the problem,7 red soil samples and 2 paddy soil samples of selenium-rich areas were collected from Longhai and Zhao’an of Fujian Province, Wanni ng and Qiongshan of Hainan island. In the lab, we implemented the control ex periments of increasing bio-availability of soil selenium with lime, coal slag as additives added into these soil samples. The lime group is set to Ot,0.5t, 1.0t, 2.0t,4.0t,8.0t per hectare, corresponding, Og,0.0208g,0.0417g,0.0833g,0.1 667g,0.3333g per 100g, and the coal slag group is set to Ot 5.0t, 10.0t,20.0t, 40.0t,80.0t per hectare, Og,0.2083g,0.4167g, O.8333g,1.6667g,3.3333g p er 100g. Three months later at 25 ℃ ambient temperature, geochemical indicato rs of experiment samples were determined including pH, organic matter, cation exchange capacity （CEC） and other physical and chemical properties and majo r elements, trace elements, bio-available Se, to observe the influence of these t wo additives on the physical and chemical properties of these soils and the bio-availability of soil selenium.The experiment results are as follows:（1） the pH of lime-additive group i ncreased 1-2 units, and the contents of CaO and total carbon increased a little after the regulating experiment; （2） the pH of coal slag group increased about 1～3 units, and the organic matters and other components increased as well sine e the composition of coal slag was more complex than that of lime; （3） the hi ghest Se bio-availability of the experiment soils increased 0.3～1.0 times than th e initial Se bio-availability after adding lime; （4） the coal slag enhanced the se lenium’s bio-availability of red soils form Fujian Province, ranging from 0.2 to 1.6 times; the red soils form Hainan island were not suitable for the addition of coal slag to improve the effectiveness of soil Se, whereas, it reduced the bi o-availability of Se in red soils; （5） there was a certain range in the enhance of soil selenium’bio-availability, the vast majority within 10%, the individual s oil higher than 10%, which maintained a balance with the total selenium,Overall, in the acid red soils, adding soil conditioners such as lime or coa 1 slag can change the pH, organic matters, cation exchange capacity （CEC）. M ore significantly, to a certain extent, this research reveals that the addition of r egulating additives such as lime or coal slag into red soils can also achieve th e goal of enhance bio-availability of selenium While lime has a certain effect to all kinds of selected soil, coal slag has a certain effect to red soil in the F ujian Province, but poor effect for the Hainan Province’s red soils with higher SiO2 and gravel content. Instead, it will reduce the bio-availability of seleniu m when applying coal slag additives into the soils in Hainan island. |
