22 Dre Le T, Alexander, Chief of the Department of Agriculture Soil Survey Laboratory, Beltsville, Maryland, has suggested that the low results for alfal- fas grown on the two-Plainfield sand soils (farms #11 and #12) may be due to greater root depth which would result in their getting most of their calcium well below the surface and hence out of reach of the majority of the strontium-90 activity. Table 5 Comparison of Sr70 Ievel in Related Alfalfa and Soil Samples Avail. Ca Farm 0-2" depth Sr90 Soil Ievel, SrPlant Level, 31.2 (0-21), 9.8 + Ook 30.5 + 1.7 3.2 ~2007 (0-8"), 6.83 + 0,08 13.6 + 0.8 (~0.8) 15.0 (0-2"), 26.7+ 1.0 19.2 + 1.0 0.72 (0-6.5"), 12.3 + 0.) 7205 + 0.33 (~0.2) (g/ft2) McKee (#9) McHenry Coes Tll, Swanson (#3) Winnebago Co,, Ill, Holcomb (#h) Rock Coes Wis. Kurpeski (#7)% McHenry Cosy ~Ielt - in SU. Tll. ~8,.2 (0-6"), 15.0 * 0.5 2545 + 1.3 (~0.7) 6.92 (0-2"), 49.9 + 1.5 38.0 + 2,0 0.76 ody (0-2"), 65,1 + 2.6 ke7h + O21 0.073 “L367 (0-2), 64.5 + 1.3 2.73 + 0.18 0.042 Jolumbia Co., Wis. \ustin (#8) McHenry Co., Ill. Van Winkle (11) Will Co., Ill. Will Co., Ill. Ratiox* . ?remo (#6)% Carver (#12) in S.U. = * Field recently plowed, #* Ratio = S.U. Plant/S.U. Soil over 0-2" denth. (For the three unplowed soils, the 0-2" depth concentration of Sr70 is arbitrarily taken as 2.5 times that determined for the greater depth.