Selenium concentration in plant material, drainage and surface water as influenced by Se applied to barley foliage in a barley red clover potato rotation

Foliar application to barley of 10 and 20 g Se ha(-1), as sodium selenate, increased Se content of barley grain and straw and red clover forage. There was no significant effect of Se application on Se content of potato petioles or tubers in the third year of the rotation. The Se content of drainage water was increased during the fall and spring following Se application to barley. The highest Se concentration of 0.185 mu g L-1 found in this study is well below the Canadian drinking water standard of 10 mu g L-1 The Se concentrations of surface water bodies 0.5-1.0 km down slope from 10 pasture fields to which Se had been applied at 10 g ha(-1) the year before, were not significantly different from surface water bodies 3-8 km from the treated fields. Selenium concentrations of all the surface water bodies ranged from 0.003 to 0.266 mu g L-1, well below the maximum acceptable Se concentration for drinking water.