Selection And Regionalization Of Se-Enriched Crops In Typical Seleniferous Region Of Guizhou Province

Selenium(Se) is one of an essential nutritional elements for animals and humans,there is a close relation between Se-deficiency and Keshan disease, Kashin-Beck Disease,cardiovascular disease, cancer and other many diseases, it is toxic at high concentration. Se still has many other important biological functions, for example, low dietary ingestion of Se has been assumed to contribute to an increased risk of cardiovascular disease and cancer and to promote infectious viral diseases related to heart disease. Along with more understanding of physilogical functions and health influence of selenium, people pay more attention to the reseach of Se in crops which are the most important source of dietary Se.Crops are main sources of intake Se of humans, the concentrations of Se in crops are greatly related to the geochmical environment where crops grow. Many countries in the world exist Se-deficient regions. China is serious Se-deficient where about tow-third of areas are distributed in environment of low Se level in the world. Se intake of people in many areas are insufficient, therefore they need supplement of Se. The study on development and planting of enriched Se crops can help the production of a large mount of Se-enriched foods which can meet the need of supplying Se in low Se areas, therefore this study has an important significance for improving the health of people. A great deal of Se-enriched geological resource of Cambrain black rock and Permian coal bed etc. seleniferous strata are distributed in Guizhou province, which is one of the four Se-enriched areas of China. There are resources of enriched strata and soils in Kaiyang county, Guizhou province, therefore it has Se-enriched area which can be exploited to produce enriched Se crops. However, because of too limited research in this region, the distribution of the large amount of Se-rich soil resource and the plantion status of Se-rich plant resource have not been investigated and researched in detail.The objectives of this study are, through detailed investigation and studies of contents, chemical forms of Se in soils and crops which are distributed in Kaiyang, a typical high Se area in Guizhou and factors to control the concentration of Se in these crops, 1)to screen out the Se-enriched crops species which can be planted on a large scale in order to product out a great quantity of enriched Se agricultural products; 2) to find out the Se-enriched farm lands to be used to plant Se-enriched crops; 3) to guide the planting programe of local Se-enriched crops and promote economic development of Se-enriched agricultural products of Guizhou province.This study selected Hefeng Village and Fengsan Township as the investigational and studing areas. Through studying the geochemical characteristics of Se contents and its chemical forms in soils and crops in farm lands to grow main crops, tea garden in Kaiyang county, we investigated the total Se in crops and soils to plant them, and dicussed the the relationship between concentrations of Se in plants and chemical forms of soil Se as well as pH value of soils, secreened the species of enriched crops which can be planted extendly in local area, provided some proposal of plantation plan to plant Se-enriched crops in Fengsan and Hefeng of Kaiyang and provided theory guidance for development of local economy of Se-enriched agricultural products. The main results on this research are as follows:(1) The distribution status of Se content in the research area was basically made clear, the total Se content of farming soil changes from 0.46mg/kg to 2.31mg/kg,with an average of 1.42mg/kg,and the range of Se content of crops is 0.007-0.71 mg/kg, with an average of 0.14mg/kg, most soil Se reach Se-rich or Se-high level and crops reach Se-sufficient or Se-rich grade.(2) The Se content of crop is not only related to the total soil Se ,but also positively related to Se-rich coefficient of crop, water- solublized Se contents of soil and soil pH.(3) Encircled several pieces of land that fit to plant Se-rich crop such as Anping village,Liancha riverjinlong village of Fengsan town,and found out some Se-rich crop species that can be planted widely, such as ripe, corn, cayenne, soybean,cole .