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The characteristics of the six different agricultural soil from Michigan were as follows. Colwood and Capac soil were loam, Gilford and Ceresco were sandy clay loam, Sission was clay loam, and Spinks was sandy loam. pH of Gilford sandy clay loam was 6. G whereas that of the soil ranged 5.4∼5.9. Gilford sandy loam found to contain a relatively higher amount of organic matters as compared to other soils. Furthermore, the numbers of bacteria in Gilford sandy clay loam were significantly higher than those in other soils. The populations of fungi in Gilford sandy clay loam and Colwood loam soils were significantly greuter than those in other soils. On the other hand, the densities of actinomycetes in Gilford sandy clay loam and Ceresco sandy clay loam soils were significantly different from those in other oils. The population of anaerobic bacteria varied depending on the soils; Ceresco sandy clay loam, Capae loam, Colwood loam soils have higher numbers of bacteria, whereas Gilford sandy clay loam was very lesser than the other soils. In the ^(14)C-glucose respiration by soil microorganums after 10 hrs, the respiration rate was decreasing in the order of Ceresco sandy clay lam, Spinks sandy loam, Colwood loam, Sission clay loarn, Capac loam and Gilford sandy clay loam. Germination of test propagules on natural soil soil was 0∼5%, and it was germinated 90∼98% on autoclaved soil and PDA. The propagules differed in thier germination response to nutrients added to the soils. In general, more nutrients were required to promote germination on Capac loam and Gilford sandy loam soil than Spinks sandy loam soil. Especially Mortierella n. sp. required more nutrients for germination to obtain the same ratio as Helminthosporium victoriae.
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