Radioisotope Uptake Bb Selected Range Forage and Weed Species

Abstract

Two wheatgrasses, one annual grass, and one annual forb were used to evaluate the uptake of fourteen gammaemitting isotopes from an important range soil. Uptake of copper, molybdenum, and selenium ranged from moderate to very good from all soil horizons. Uptake of iodine and chromium was poor from the surface and lower soil horizons, respectively, but moderate to very good from other horizons. Other desirable characteristics of these isotopes for root-tracing studies are half-lives of from 12.8 hours to 128 days, and energy differences which permit detection of each isotope in the presence of others.