Recently I was asked to write this column for the Leopold Letter, the newsletter of the Leopold Center for Sustainable Agriculture.
Twelve thousand years ago, in the wake of a glacier, the land that would become Northern Iowa was a geologic wasteland. Glacial materials conveyed from the north had obliterated the biological diversity of the previous era. But then nature’s ecological processes began anew, creating-over twelve millennia-a prairie ecosystem with its fertile, productive soils.
How did that happen? Gradually, plants, animals and microorganisms colonized the desolate landscape, creating an increasingly diverse and complex ecosystem. The ecosystem’s plants and animals generated organic materials which soil microorganisms used to develop fertile soils from raw geologic materials.
It has been estimated that fifty million bison once roamed the prairies and plains of North America. Bison herds roving the prairie landscape are a useful model we can use to design animal production systems that are resilient, energy-efficient, and biologically diverse. (continues after the jump)Continue Reading...