Dear collegues,
Do you think reasonable to measure field CO2 emission without a frame inserted into the soil where to place a static chamber?
The majority of protocols suggest to insert into the soil a frame in order to support the static chamber, avoid leakages and limit soil disturbance. However, agrotechnics, in many cases, needs to remove and replace frame along cropping season involving high field labor.
There is any alternative protocol or system to have a reliable measure of field CO2 emission without soil frame?
Thanks in advance for your comments.
In my opinion and according to my field experiences (closed chambers and EGM systems) it really depends on soil type, season, and field slope. In general, I would recommend using collars, maybe not very depth ones...
In our lab, we always install PVC or aluminum chambers into the soil to take CO2 gas samples, and then, we use the GC machine to measure CO2 concentration. The methodology is very simple, and we have published a couple of papers using this technique if you are interested. In our other experiments, we take fresh soil samples for lab incubation to measure the soil respiration. The fresh samples and two beakers, each containing NaOH and water, can be placed in a jar as long as you need. Hopefully this answers your question, and let me know if you need any further clarifications.
I don't like soil collars for several reasons (cutting roots, affecting moisture, shading etc. ). We published a paper on this in the European Journal of Soil Science some years ago) - best to avoid it. You can prepare the ground to fit a chamber without a collar , or you can fit a sealant around the base of the chamber (use bubble wrap, foam, etc.). Key is to be inventive.