Soulides and Allison 1961

Soulides DA, Allison FE. 1961. Effect of drying and freezing soils on carbon dioxide production, available mineral nutrients, aggregation, and bacterial population. Soil Science 91: 291-298.

These authors conducted a series of experiments to investigate previously reported claims of a burst of CO2 production following drying or freezing of soils, with an associated change in soil bacterial populations. Drying soils killed large fractions of bacterial populations; freezing as well, to a lesser extent. Combined drying and freezing killed many bacteria, but did not sterilize soils. CO2 production was raised 20 to 40% over controls following drying and rewetting under different schemes, which these authors attribute to rapid breakdown of organic material by large numbers of bacterial cells in an early growth phase; CO2 production declines as populations stabilize.

I was hoping this paper would provide clues to the soil water levels tolerable by bacteria, but these authors do not discuss critical levels of moisture or temperature, beyond noting that severe drying is detrimental, and temperatures below 2ºC prevent most bacterial growth.