ADDING SELENIUM-ENRICHED PLANT-TISSUE TO SOIL CAUSES THE ACCUMULATION OF SELENIUM IN ALFALFA

Greenhouse experiments were conducted to determine selenium (Se) uptake by alfalfa (Medicago sativa L.) grown in soils amended with Se-laden mustard plant tissue. The experimental design was a completely randomized block with treatments consisting of 5, 10, 20, and 40 g of added dried Se-containing mustard tissue to the soil, which resulted in soil Se concentrations of 1.0, 1.6, 3.0, and 5.7 mg Se/kg, respectively. Four clippings of alfalfa were made and the vegetative portions analyzed for dry weight and total Se. Plant dry weight yields and heights of plants were significantly reduced only at the highest Se treatment rate. Mean tissue Se concentrations increased from 1.8 mg Se/kg DM at the 5 g treatment rate to 6.0 mg Se/kg DM at the 40 g treatment rate. Based on this study, alfalfa can accumulate Se during establishment year when Se-laden mustard plant tissue is added to the soil.