Status Of Selenium In Soils From Yixing City, Jiangsu Province And The Uptake, Partitioning In Agricultural Plants

This study deals with Selenium(Se) bioavailibity in soil-agricultural product system. The works include the variation of total selenium and the affective factors to total Se in some selected cropland soils from Yixing Municipality, Jiangsu, the difference of Se uptake and accumulation in agricultural products . The main results are as follows:1. Soil selenium status plays an important role in selenium level of agro-products, which are often reported with deficiency in most regions of China. In this paper, variation of total selenium is studied in some selected cropland soils from Yixing Municipality, Jiangsu, China. Totally 13 whole soil profiles were sampled for studying depth distribution and 38 topsoil samples were collected for studying distribution frequency in randomly selected locations. The soil samples were digested using HNO₃ -HClO₄ -HF (V:V:V =8:1:2) and total Se contents were determined by atomic fluoresce spectroscopy. Total Se of the tested topsoil samples ranged from 033μg.g^-1 to 2.25μg.g^-1 and over 80% of the overall topsoil samples contained total Se over 0.45μg.g^-1, a critical value for Se-rich soils. While Se accumulation in topsoil was observed in all soils tested, the variation of total Se with depth depended highly on soil type and land use patterns. Total Se of dry croplands tended to be lower than of paddy soils and to be higher in soil series rich in SOM and iron oxyhydrates. Statistical data showed the dominance of SOM in Se binding and accumulation in the...