Below ground biomass has several effects, many of them interactive with other effects such as soil consolidation.
	The average amount of live and dead roots in 10 inches is the key variable for the effect of roots.
	The amount of buried residue in the upper three inches is the key variable for the effect of buried residue.
	The three inch depth is reduced as the soil consolidates to give greater credit to the build up of organic matter over time at the soil surface for no-till.