Research Of Geochemical Charateristics And Use Of Selenium-Rich Soil In Jinhua

Jiangtang town, Langya town and the Jindong of Jinhua is selenium-rich soil distribution area, selenium is an essential trace element for human body, and the selenium enrichment has its special formation environment, development of selenium-rich soil geochemical characteristics and development study of Jinhua rich agricultural development has important significance. Based on these three areas of selenium in soil as carrier, in Jiangtang town (JT), Langya town (LY) and Jindong (JD) three sites collected samples using100. By soil science, environmental geochemistry, sedimentary and other research methods, on three areas of selenium-rich soil geochemistry, agricultural geology characteristics and exploitation and utilization of selenium rich soil, and on the basis of selenium-rich area of agricultural development and agricultural features of the plan were discussed in Jinhua. Through the research, the preliminary draw the following main conclusions:(1) The study of geochemical characteristics.The average Se content was0.69mg/kg in this area, enrichment coefficient of1.8, Selenium-rich soil area based on152km2of Jiangtang town, Langya town and Jindong in Jinhua, By selenium-rich soil classification standard, combined with the existing data and the situation of development and utilization, as II selenium-rich soil zone.Macro element content with SiO2> Al2O3> Fe2O3> K2O> MgO> TiO2> Na2O> CaO> P2O6> MnO, relative to the upper continental crust element averages, Al, Fe, Ca, the relative enrichment of K, Na, Mg relative lack of, reflect the soil in the climate conditions susceptible to leaching characteristics, soil layer easy migration elements are substantially leaching. With SiO2, Al2O3, Fe2O3, a total of more than86%, of which the highest content is SiO2.Overall, CaO, MgO and MnO variation coefficient, the distribution is very uneven, the most homogeneous distribution of K2O and TiO2.From the shallow layer soil macro element content, three Se-rich area, there are some differences between the profiles. JT, JD profile in the SiO2content is high, the average content of over73%, including JT SiO2variation coefficients, the distribution is not uniform, LY smallest coefficients of variation, the most homogeneous distribution! K2O, MgO, Na2O, CaO and other refractory component content difference is not big, content of1.0%～1.4%,0.3%～0.6%,0.21%～0.22%, between0.18%～0.21%, but the coefficient of variation of differences, in which Na2O the biggest change, JT section of the LY profile is not uniform, the most homogeneous distribution. From the content of TiO2, JT and LY were higher, close to1%, while JD content is the lowest, only0.01%, but three of the variation coefficient changes little, with well distributed.From deep soil elements, also showed a similar feature, by SiO2, K2O, MgO, Na2O, CaO higher content, TiO2content is generally low.In addition, the three major elements of the correlation of soil were discussed, the correlation analysis showed that in soil samples by SiO2and the content of Fe2O3linear correlation relationship between poor, while SiO2and Al2O3content with strong linear correlation, there is significantly negative correlation.Three soil trace elements content has the following features:Cu, Pb, Zn, Zr are lower than the world soil median; Cu, Zn content were lower than Chinese soil median; Cr, Zr content is close to Chinese soil medium; the content of Pb lower than Chinese soil median; Cr, Zr, Pb were significantly higher than that of UCC, while other elements are less than UCC. Co, Mn distribution difference is relatively large, very uneven, Cr, Pb, Cu, Zn, Rb, Ba were more evenly distributed, Zr, Y, Sr distribution difference is very small, uniform distribution.Shallow soils, the content of Zr in three profile in the content are the highest, Cr, Co, Cu, Sr, Ba in JT profiles in the content are the highest; Cr, Cu, Sr, Ba in JD profiles in the lowest content. In deep soil, Cr, Cu, Sr, Ba in JT profiles in the content is still the highest, Cr, Co, Cu in the LY section in the content is the lowest.Study of regional available state K, available Mn, available N, available Cu, available P content star above the critical value, the note content rich, other available element content is lower than a critical value, explains the research area of B, Mo, Zn relative lack of.(2) Selenium-rich soil utilization research in Jinhua. In the soil crop must be a large number of trace elements, is suitable for planting, conducive to crop growth. N, P, K, Mn, Cu, Se, Zn content is very rich, for the cultivation of natural selenium-rich agricultural products provide a good foundation.Jiang tang town, Langya town of Wucheng District and Jindong are high selenium area, with middle area of Pujiang, Wuyi, Lanxi,with low area of Yiwu, Dongyang and Yongkang, selenium-rich soil distribution imbalance.In Jinhua, there are some problems in the development of selenium-rich soil, soil environmental quality decline, the soil polluted by heavy metals,44%samples of soil is relatively clean,27%of the sample is mild pollution,15%of the sample is moderate pollution,14%of the sample point to severe pollution degree. Rich Selenium produce low yields, quality difference is big, the standard is not unified, effect of selenium-enriched agricultural production is the main influential factor of chemical fertilizer use quantity, average annual vegetable planting area and organic matter content.Rich selenium area characteristics of agricultural advantage industry layout in Jinhua, by fuzzy comprehensive evaluation, found most appropriate development of Se enriched tea industry in Jindong, grape area and rich selenium vegetables, there town is suitable for the development of tea and selenium-rich vegetable in Langya,with barely development of tea in Jiangtang, but can develop rich selenium vegetables.