4, 4.1L Appendix Coilecticn of Soil Samples for Strontium-90 Assay(43) by Lyle T. Alexander Chief, Soil Survey Laboratory Plant Industry Station Beltsville, Maryland The sampling procedure described here is designed to get samples that will measure the total amount of strontium-90 that has fallen out in & given, area » Tt will not evaluate the unusual case where excessive accumulations occur in low spots, at the foot of slopes, or in flooded aTeas o The site should be nearly level with moderate to good permeability. There should be little or no runoff during heavy rains and no overwash at any time. Such sites are frequently found on smooth ridge erests, level farm lend and in well kept lawns and grounds around institutional buildings. The site should not be near enough to buildings or trees to be sheltered during blowing rains. Vegetation and Animal Activity Amounts of rission products reaching the ground are undoubtedly influenced by vegetative cover. Bare ground, an alfaifa field and a bamboo grove do not intercept equal emounts of fallout. It is thought that a grass isi or pasture makes ea good vegetative cover for sampling areas. The graze aiso helps prevent loss by runoff of water. Well grassed areas usunlly have better permeability than corresponding sreas See als. 212. “%.., Eu, Haréy, E.P., and Follister, Hel., Proce Ini' co. on the Ecol. of Radtoisotopes, Univ. of Radiode: opss L2 Soil with Particular Emphasis on Strontiun-90, Minness 4, Coop 13-23, 1959. DT isAiden eae (13)