TABLE 4 TABLE 3 PLUTONIUM CONTENT, o % 238pu, AND CONCENTRATION RATIOS PLUTONIUM CONCENTRATION AND CONCENTRATION RATIOS OF VEGETATION FROM THE ORNL FLOODPLAIN OF WHEAT STRAW AT VARIOUS TIMES DURING THE GROWING SEASON Sampling Month Pu a . (pci g™!) a % 238py Pu Concentration Vegetation March 05 38 2.3.x 107? April -02 61 9.3 * 10 June -09 58 4.2 x 107 a b (pci g@!) CR Tree 2x 107? 6x 10°? Shrub 1x 10°? 2x 1074 Herbaceous --2 5 x 10 2 x 10 Native Plants +3 Vegetable Crops Foliage -~1 1 x 10 Soybean 1 x 10 Tomato 3x 107! 5 x 1073 -1 2 x* 10 -3 Bushbean 2x 10 -3 Fruit Snapbean 6 x 10 -3 —4 1x 10 Shelled bean 9x 10> 1x10" Tomato 5 x 10°? 1x 10°" Soybean 4x 107 7x 1074 Soybean (minus pod} 3x 1073 5 x 10° "Values are means of 3 to 24 replications; standard errors typically range from 20% to 50% of mean estimates (Dahlman et al., 1976). b CR = [Pu] gg/(Pul soil. “cR values of cultivated crops are based on soil concentration of 63+ 0.4 (S.E.) pci g!. 312 313