We measured soil respiration on various soil samples (Article Unexpected results in Chernozem soil respiration while measu...
). As expected the CO2 values increase or stagnate in all samples with the exception of one due to the CO2 production was measured in a closed system according to the pressure change.In a closed system where the pressure decreases due to oxygen consumption, the values of CO2 production must increase or stagnate with the passage of time, but this was not the case with
one of the samples.
Here, a decrease in CO2 occurred. The following possible explanations were excluded:
• Presence of algae: there was no light in the incubator, so there was no photosynthesis.
• Changing pressure caused by changing temperature: the temperature was constant in the setup.
• Absorption by the water in the sample: all other samples that produced increasing amount of CO2 had the same or comparable moisture content.
One reason that seemed more likely was that CO2 oxidizing microbes or methanotrophs may have been present in the soil, using the produced CO2 periodically. This is unusual, since most of the studies report the presence of these bacteria in seawater, paddy field or industrial processes and not in well-ventilated Chernozem soil.
Nagendra Nath Das
thank you for your interest, we are waiting for some promising explanations.