> Amadeus Schmidt wrote:
>
> > Would you expect that the grassland (it would be wood in most cases)
> > has a productivity equal to or similar to a corn field?
>

Probably in Europe grassland tends to become woods if left alone,
but the American plains are grassland plain and simple; the only trees
grow along the rivers and streams.  The tallgrass prairie is highly
productive; grasses grow as high as 5 feet without any supplementation
other than animal dung.  All grasslands are more productive when
appropriately grazed (and thus manured).  And as the millenia pass,
the grassland maintains and improves its soil base.  Whereas the
corn monoculture exhausts the soil and requires tremendous artificial
inputs (mostly derived from petrochemicals).

    Lynnet