Differential selenium accumulation among forage plant species grown in soils amended with selenium-enriched plant tissue

ABSTRACT:

Field trials were conducted to evaluate the differential ability of selenium (Se) accumulation among alfalfa (Medicago sativa), tall fescue (Festuca arundinacea), birdsfoot trefoil (Lotus comiculatus), canola (Brassica napus), and wild brown mustard (Brassica juncea) grown in soil where Se-laden plant tissue (Brassica juncea) had been incorporated. Sixty days later, the mean total soil Se concentration at time of planting was 0. 7 mg Se kg⁻¹ soil (0.7 part per million). Plants were clipped 60 and 145 days after transplanting, respectively, then weighed and analyzed for total tissue Se, crude protein, and digestible dry matter. The order of tissue Se accumulation among plant species tested were wild mustard=canola> al-falfa>birdsfoot trefoil<tall fescue. Selenium concentrations ranged from 1.3 to 50 mg Se kg⁻¹ dry matter in the tall fescue and mustard/canola, respectively. Crude protein ranged from 16% to 27% for all species, excluding stem tissue from mustard and canola. Digestible dry matter of at least 90% was uniform among all plant species tested. Tall fescue, birdsfoot trefoil, and alfalfa appear to be suited as practical forage species to be grown on Se-enriched soils.