Can the ECHO probe be calibrated to measure the water content of organic matter and compost?
We have successfully calibrated the ECHO probe in an organic potting soil as well as a sphagnum peat moss. The results of these calibrations can be found at: http://www.decagon.com/appnotes/ecorganic.pdf . Both of these media were consolidated when they were tested. Accurate calibration would be much more difficult if the medium were loose, such as compost. During soil calibrations, we found that variations in bulk density did not appear to have an effect on calibration. However, the critical need for good soil-to-probe contact would limit the probe’s effectiveness at measuring compost water content unless rigorous testing procedures were implemented (i.e. measuring at a consistent depth in a compost pile where the material could make good sensor contact).
