TURNIP EXPERIMENT An experiment was set up by Dr. Lyle T. Alexander of the U. S. Department of Agriculture eet 9.4 eee It is also of interest to note that the Sr®® values indicate that some of the top soil activity is younger than the bottom fraction. to help toward the understanding of the soil to vegetation Sr® cycle. The soil was prepared, Top soil Double top soil (not part of experiment) Normal soil . Subsoil The subsoil plots are surrounded by sheet iron 8 inches wide and 6 feet long. The plots are 6x6 feet. The following materials were incorporated in the soil prior to the rains that preceded seed- ing: To the subsoil: Dolomite, 2.57 lb; high calcium lime, 4/10 1b; 5-10-10, 3 lb; ammonium nitrate, 1/8 lb To the top soil plots: Dolomite, 1.65 lb; 5-10-10, 2 1b Shogoin turnips were seeded on August 5 at the rate of 5 gms. per plot. The seed was im- ported from Holland in 1951. 5.5 DISTRIBUTION OF Sr” IN ANIMAL BONE Several tests have been run on the distribution of Sr® in various bones of a single animal. This is important in testing the validity of single samples used to characterize the entire animal. An early series of analyses at HASL showed that for a yearling calf the distribution was uniform except for the hoof. Additional data are presented in Table 58 to show this uniformity. The variation of Sr* This is not necessarily in disagreement with the data of others indicating nonuniformity in adult human skeletons. In the case of the young animals and probably in the case of children who have lived their entire lives in a contaminated environment, one would expect uniformity. In the case of the adult whose exposure began after formation of the skeleton, it would not be surprising that a considerable degree of nonuniformity would be exhibited. 5.6 Sr®*° IN HUMAN MILK A program for determining the concentration of Sr*®in huma. milk was begun in early 1957 at HASL. An attempt was made to obtain samples of the cows’ milk comprising a part of the mother’s diet at the time. These data are reported in Table 59. Unfortunately, the quantity of milk obtainable is relatively small, and the error of analysis is correspondingly large. In addition, it was not always possible to obtain the milk sample representing the diet. For the area where the largest number of samples was available (Boston), there are twelve paired values where both the human and cows’ milk showed measurable levels. The average ratio of Sr® in human milk compared to that in cows’ milk for these twelve samples is 0.37, with a range from 0.22 to 1.5. This ratio can be considered as only a preliminary estimate since this was not a controlled experiment, and the cows’ milk sample is not a complete representation of the diet. 126 ae ed bEet a of the entire skeleton. ee content per gram of calcium is remarkedly uniform over the number of bones tested, and it is felt that any of the larger bones of animals, at least for yearlings, is a representative sample sx Normal soil a . Normal soil . AO Oo mw bP 1. Subsoil we The three subsoil plots for this experiment were prepared on Saturday and Sunday, July 31 and August 1 by removal of 7 inches of top soil and replacing with material from 7 to 16 inches. From northeast to southeast the plots are in the following order: deere preyed +. ectacinpe He rain A we emp Cth ti oly tale Fo as, and the vegetation was grown at Beltsville, Md. The following design of the experiment was taken from Alexander’s memo to files of Aug. 5, 1954: