A more appropriate name for this material
is "spent mushroom compost". You can still see
pieces of straw and manure. The SMC has gone
thru a partial composting process and is a
predigested and fungal-decomposed organic matter.
Anyways, gardeners around these parts love SMC.
It might be a combination of the nutrients, organic matter,
and fungal components that it provides.... whichever,
gardens respond to SMC and it improves soil conditions.
The price they are charging is a bargain. You can
spread plenty of volume -- a 2+ inch top dressing --
then till it into your garden soil.
The ingredients are all natural. Maybe you are saying
that the feedstock ingredients originate from conventional
agriculture rather than organic farms.
Steve Diver
[permaculture] mushroom compost question,
Steve Diver, 03/23/2006