Samples of Rifle peat were irradiated with gamma rays from a Co60 source at doses of 2, 8, 32, 64, 128, and 250 kiloroentgens (kr.). The irradiated samples were incubated for 54 days, and periodic determinations were made on the rate of CO2 evolution, P and N mineralization, pH changes, and development of bacterial and fungal populations.
The radiation doses employed had no significant effect on development of the bacterial population, pH, mineralization of P, and evolution of CO2. Growth of the fungal population and ammonia utilization was increasingly inhibited by doses of 8 to 250 kr.
Gross changes in the metabolism of the soil microflora did not take place. Higher dose levels than those used in this study apparently are required for the sterilization of organic soils.