Root mass and vertical root distribution of five semi-arid plant species.

The root masses of big sagebrush, Great Basin wild rye, Russian thistle, streambank wheatgrass, and crested wheatgrass were determined at 20 cm depth increments from plants grown in high clay content soils in cylindrical containers. All species had roots in the deepest (100-120 cm) depth increment. Crested wheatgrass had the greatest average (+/- SD) total root mass (775 +/- 211 g). Results provide data for some scenarios for fate and effect models for shallow-land burial of low-level radioactive wastes in semi-arid environments.