Dirt: The Erosion of Civilizations - Kootenay Local Agricultural Society

ecause the Church seldom relinquished land bequeathed by the faithful.
Instead, bishops and abbots rented out God’s land to poor, land-hungry
peasants. By the fifteenth century the Church, which owned as much as
four-fifths of the land in some areas, overtook the nobility as Europe’s
largest landlord. Monarchs and their allies seeking to seize church lands
harnessed widespread resentment among tenants. Popular support for the
Reformation rested as much on desire for land as the promise of religious
freedom.
An increasing demand for crops meant less pasture, little overwinter animal
fodder, and not enough manure to sustain soil fertility. As the population
kept rising, intensively cultivated land rapidly lost productive capacity—increasing
the need to plant more marginal land. Shortage of vacant
land to plow helped motivate the rediscovery of Roman agricultural practices
such as crop rotations, manuring, and composting.
Renewed curiosity about the natural world also stimulated agricultural
experimentation. In the sixteenth century, Bernard Palissy argued that
plant ashes made good fertilizer because they consisted of material that the
plants had pulled from the soil and could therefore reuse to fuel the growth
of new plants. In the early 1600s Belgian philosopher Jan Baptista van Helmont
tried to settle the question of whether plants were made of earth, air,
fire, or water. He planted a seedling tree in two hundred pounds of soil,
protected it from dust, and let it grow for five years, adding only water.
Finding that the tree had grown by one hundred and seventy pounds,
whereas the soil had lost an insignificant two ounces, van Helmont concluded
that the tree had grown from water—the only thing added to the
process. Given that the soil had lost but a minuscule fraction of the weight
of the tree, he dismissed the potential for earth to have contributed to the
tree’s growth. I doubt that he ever seriously considered air as a major contributor
to the mass of the tree. It took a few more centuries before people
discovered carbon dioxide and came to understand photosynthesis.
In the meantime, agricultural “improvers” came to prominence in the
seventeenth century once the landscape was fully cultivated. Most of the
low hills and shallow valleys of the Netherlands are covered by quartz-rich
sand ill suited for agriculture. Supporting a growing population on their
naturally poor soils, the Dutch began mixing manure, leaves, and other
organic waste into their dirt. Working relatively flat land where erosion was
not a problem, over time they built up dark, organic-rich soils to as much
as three feet thick. Lacking more land, they made soil. As the Dutch had,
let them eat colonies 93