Soil Fumigation
http://www.soilhealth.com/soil-health/organisms/measuring/
“The substrate-induced respiration method: Two soil samples are collected, one remains untreated and the other is fumigated to kill all the organisms. A source of energy (e.g. sugar) is added to the untreated soil so that the organisms in the soil can be more active. When they are more active, they respire (breathe) more and so release more carbon dioxide. The amount of carbon dioxide released by the organisms in the treated soil is then compared to the untreated soil to calculate the probable mass of microorganisms in the soil.”
Needed for this analysis:
CO2 sensor
fumigant
sugar