KINETICS OF CARBON-DIOXIDE EVOLUTION IN RELATION TO MICROBIAL BIOMASS AND TEMPERATURE

Intensification of agricultural practices on calcareous soils leads to drastic changes in biogeochemical processes due to modifications of CO2 partial pressure in soil pores. CO2 evolution was measured in Typic Rendoll soils of the Champagne Crayeuse, (France) at 4 temperatures. A model implies that the rate of CO2 evolution is maximum at the start of the incubation, while the observed maximum in bacterial biomass occurred about 5 d later. There is an almost continuous spectrum of values for the amounts of easily decomposable organic matter generated by any disturbance; the time constant for its mineralization is of the order of a very few days. -from Authors