Viewing post #2861853 by Entwined

I am unable to post a link to the paper, however last month there was a paper published entitled:
Effects of Different Potting Media on the Growth of Commercial Cacti
by Kittiphan Ritthidechrat and Chamaiporn Anuwong

This research aims to study the appropriate growing media for the
growth of cacti that can reduce production costs and promote cacti's growth.
The research used four genera of cacti, i.e., Gymnocalycium, Astrophytum,
Mammillaria, and Echinopsis, which were famous in the commercial market in
Thailand

There may be a flaw in the paper regarding the measurement of root volume, insofar as increased root growth does not always correlate to larger or faster plants, as their own images show with Echinopsis. However the paper has good information and is highly relevant to this topic. It can be found as Research Gate.