RAPID CHANGES IN NITRITE AFTER GAMMA IRRADIATION OF FRESH SOILS

Increases in nitrite in ten gamma-irradiated soils have been investigated under aerobic conditions up to 7 days after treatment over the range 0.25-2.5 Mrad. The formation of nitrite showed significant correlations with the percentage of soil inorganic carbon and incubation time, and over 100 ppm nitrite-N accumulated within 3 days in Broadmoor series, which contained the most inorganic carbon. Only the very acid series failed to produce nitrite, but formation and persistence was poor in all soils below pH 7. Leaching with ammonium or nitrate ions after irradiation suggested that microbial reduction of nitrate was the mechanism responsible for nitrite accumulation, rather than inhibition of nitrite oxidation. © 1969, Cambridge University Press. All rights reserved.