Dirt: The Erosion of Civilizations - Kootenay Local Agricultural Society

Seeking out virgin soils, Hilgard soon realized that different soils had
different characteristic thickness that corresponded to the depth of plant
rooting. He described how soil properties changed with depth, defining
topsoil and subsoil (what soil scientists now call the A and B horizons) as
distinct features. Most radically, Hilgard conceived of soil as a dynamic
body transformed and maintained by interacting chemical and biological
processes.
Both geologist and chemist by training, Hilgard argued that the secret
to fertile soil lay in retaining soil nutrients. “No land can be permanently
fertile, unless we restore to it, regularly, the mineral ingredients which our
crops have withdrawn.” 2 Hilgard admired the Asian practice of returning
human waste to the fields to maintain soil fertility by recycling nutrients.
He considered America’s sewers conduits draining soil fertility to the
ocean. Refusing to contribute to this problem, he personally fertilized his
own backyard garden.
In an address to the Mississippi Agricultural and Mechanical Fair Association
in November 1872, Hilgard spoke of how soil exhaustion shaped
the fate of empires. “In an agricultural commonwealth, the fundamental
requirement of continued prosperity is ...that the fertility of the soil
must be maintained. ...The result of the exhaustion of the soil is simply
depopulation; the inhabitants seeking in emigration, or in conquest, the
means of subsistence and comfort denied them by a sterile soil at home.”
Hilgard warned that improvident use of the soil would lead America to the
same end as Rome.
Armed with better implements of tillage it takes but a short time to
“tire” the soil first taken in cultivation. ...If we do not use the heritage
more rationally, well might the Chickasaws and the Choctaws question
the moral right of the act by which their beautiful parklike hunting
grounds were turned over to another race, on the plea that they did not
put them to the uses for which the Creator intended them. ...Under
their system these lands would have lasted forever; under ours, as
heretofore practiced, in less than a century more the State would be
reduced to the condition of the Roman Campagna. 3
Hilgard captivated the audience with his conviction and compelling
delivery—until he explained that maintaining soil fertility required applying
marl to acidic fields and spreading manure year after year. All that
sounded like more trouble than it was worth.
dirty business 189