4.5. Chamber deployment duration and number of gas samples
The duration of chamber deployment and the number of gas samples collected during each
deployment affect the accuracy (and statistical significance) of the calculated gas fluxes (see
Chapter 6). A shorter deployment time is preferred for healthy rice growth, because the air
temperature becomes elevated within the closed chamber and the CO2 concentration
decreases. On the other hand, a longer deployment time and a greater number of gas
samplings improve the accuracy of the flux calculation. According to Sander and Wassmann
(2014), most researchers deploy the chamber for 30 min and collect gas samples three or
four times per deployment. On the basis of empirical knowledge, we recommend deploying
each chamber for 20–30 min during the rice growing period so as to not interfere with rice
growth. On the other hand, a longer time (