Other stabilized earth products used asphaltic emulsions, a process also used successfully to stabilize roads made by churning up the soil and adding the stabilizer before rolling the road smooth with appropriate drainage slopes. The cement does require external energy inputs. My view is that if something is going to last as long as it should given the amount of labor invested, it justifies some energy consumption. Hopefully, someday, there will be a way to create cement using renewable energy that will be commercially viable. Perhaps it is being done already in more isolated places or where energy costs justify more investment in renewable sources today.
Dirt is put in the hopper with a backhoe.