Accumulation of 137Cs and 85Sr by Florida forages in a uniform environment

This paper describes experimentation conducted in an effort to define the possible role of differences in root uptake of 90Sr and 137Cs among forage crops in explaining variable milk concentrations of these radionuclides, particularly 137Cs. Nine forage species commonly used in the Florida area were grown for 95 days under greenhouse conditions in soil contaminated with 85Sr and 137Cs. All species accumulated between 0.4 and 2.0 nCi/g of 85Sr; no statistically significant interspecies differences were observed. Significant interspecies differences in 137Cs accumulation were found, with white clover accumulating about 65 nCi/g, bahiagrass 48 nCi/g, pangolagrass 28 nCi/g, and dallisgrass, oats, crabgrass, and 3 bermudagrass varieties about 35 nCi/g. Pangolagrass did not accumulate more 137Cs than did the other forage species under the conditions of this study. The relation of these results to the previously established influence of pangolagrass on the high 137Cs concentrations in Tampa, Florida, milk is discussed.