Mass of roots per unit depth increases in first three inches to a maximum and then decreases over a depth of 15 inches regardless of stage of growth or plant type.
	Killing causes live roots to become dead roots and begin to decay.
	A decrease of root biomass during year is assumed to be root sloughing and adds to the dead root pool.
	Root sloughing causes a build up of biomass in the soil that is a function of location, more where decomposition is less.
	A portion of the residue decomposed on the surface is arbitrarily added to soil biomass in upper 2 inches.