MICROBIAL ACTIVITY IN BLOCKING COMPOSTS. 1. MEASUREMENT OF CO₂ EVOLUTION AND O₂ CONSUMPTION

CO₂ evolution and O₂ consumption were monitored in blocking media amended with varying concentrations of glucose.

CO₂ was continually evolved from blocking media (1–2 mg CO₂-C per litre of medium per day at 11.5°C). When media were enriched with glucose, the rate of CO₂ evolution, after a lag period of 2–3 days, rapidly increased for a period of 3–8 days (up to 100 mg CO₂-C per litre of medium per day at 11.5°C in the case of the highest addition of glucose-equivalent to 2 mg glucose-C cm^-3 medium) before returning to a rate similar to that in unamended media.

Blocking media amended with glucose exhibited active periods of O₂ consumption, again following a lag period of 2–3 days.
Increases in O₂ consumption were sustained for longer periods in media amended with high concentrations of glucose (1–2 mg glucose-C cm^-3 medium).

Increases in O₂ consumption coincided almost exactly with rises in CO₂ evolution and these phenomena undoubtedly reflect the increased microbial activity resulting from the metabolism of glucose added to blocking media.

International Symposium on Substrates in Horticulture other than Soils In Situ

C.P. Turner, W.R. Carlile

https://doi.org/10.17660/ActaHortic.1984.150.8