Continuous monitoring of rhizosphere respiration after labelling of plant shoots with 14CO2

摘要: The present work describes an original method to follow rate of 14CO2 and total CO2 production from rhizosphere respiration after plant shoots had been pulse-labelled with 14CO2. We used a radioactivity detector equipped plastic cell for flow detection beta radiation by solid scintillation counting. was coupled infrared gas analyser. compared trapping in NaOH counting liquid scintillation. First, we demonstrated that (1 M) trapped 95% the gaseous sample. Then, determined efficiency 41% activity samples as static sensitivity 14CO2- 0.08 Bq mL−1 air precision 2.9% measured 0.9% method. presented two applications which illustrate relevance 14CO2-flow investigations using 14C trace photoassimilates within plant-soil system. examined kinetics when concentrated acid is added NaH14CO3. This most commonly label 14C. monitored 5-week old maize cultivated soil whose conclude alkali traps should be cumulative determination because they are cheap accurate. On other hand, finer temporal resolution consequently relevant tool study C dynamics at short time scale.