Selenium Biofortification of Rice and Radish: Effect of Soil Texture and Efficiency of Two Extractants

The addition of essential elements to human health by mineral fertilization is considered a promising strategy for biofortification. A greenhouse experiment was carried out where amounts equivalent to 0.0; 0.5; 1.0 and 2.0 kg/ha of selenium (Se), as sodium selenite, were added to two soils with contrasting textures to evaluate the increase in Se concentration on the edible parts of rice (grain) and radish (roots) plants. Two extractors (KCl and KH2PO4) were also evaluated in their efficiency in predicting available Se to the two species. Total Se concentration in plants increased significantly with the amounts of Se added to both soils showing that selenite can be used for biofortification of these crops. Selenium availability was higher on sandy soil than on sandy clay soil. Se extraction with KCl presented better performance than KH2PO4 in predicting Se phytoavailability for rice and radish.