Entry, J.A., L.S. Watrud, and M. Reeves. 2001. Influence of organic amendments on the accumulation of 137Cs and 90Sr contaminated soil by three grass species. Water, Air and Soil Pollut. 126:385-398.
Bahia grass (Paspalum notatum), johnson grass (Sorghum halpense) and switchgrass (Panicum virginatum) were compared for their ability to accumulate 137Cs and 90Sr from three different contaminated in the presence and absence of either sphagnum peat or poultry litter amendments. Above-ground plant biomass did not differ between plants that were not exposed to these radionuclides and those that were exposed to soil containing 137Cs or 90Sr. After three harvests, bahia, johnson and switchgrass plants accumulated 17.2 to 67.3% of the 90Sr added to the soil. Poultry litter and peat moss amendments increased above-ground plant biomass activity of 137Cs or 90Sr in plant tissue, % accumulation of 137Cs or 90Sr from soil and the plant bioconcentration ratio at teach harvest compared to the control (no amendment) treatment. The greatest increases in plant biomass, and radionuclide accumulation were observed with poultry litter for each of the three grass species. Johnson grass had greater above-ground plant biomass, activity of 137Cs and 90Sr in plant tissue, % accumulation of 137Cs or 90Sr from soil and bioconcentration ratio in each soil amendment, at teach harvest compared to bahia and switchgrass. Greatest accumulation of 137Cs and 90Sr was measured in johnson grass grown in soil that was amended with poultry litter. These results suggest that plant species selection and agronomic practices may need to be considered to maximize phytoremediation of radionuclide-contaminated soils.