Healthy soil and sustainable growing

["John D'hondt" <dhondt@eircom.net>]

--how do you suppose the plains of the Midwest got so deep and
> fertile?--bison in herds up to a million individuals grazing them and 
> pooping on them, one of the most beautiful examples of a symbiotic ecology 
> you could find anywhere.
> ~Harvey

To keep minerals in place it was also necessary for the bison to die and 
become compost itself, possibly helped by carnivores.
john