David R. Montgomery's
THE EROSION OF CIVILIZATION
is the editor of My London Your London, an independent
cultural guide featuring theatre, gallery and museum reviews,
and also blogs at Philobiblon,
on history, culture, Green politics and all things feminist.
a young undergraduate studying agriculture, soil science was
not one of my favourite subjects. But I did pick up a sense
that Australia was not so much farming as mining its soils:
there was rising salinity along the breadbasket Murray-Darling
basin; erosion from the impact of the hard-hoofed cattle and
sheep; desert winds were sweeping away marginal lands being
ploughed up for wheat.
was only when, as a journalist, I visited a permaculture farmer,
who went into the middle of a wheat field, yellow and crispy,
ready to harvest, and with no appreciable effort pushed a spade
into the earth, turning over dark, moist, hummus-rich soil crawling
with earthworms that I started to grasp how alternative approaches
to the industrial farming about which I had been taught might
have a point. And that the soil was the foundation of all, and
that the chemicals, the minerals balanced out was only the start
-- that soil was indeed a whole complex ecosystem of its own
-- microbes, invertebrates, a complex mix that wasn't going
to be fixed by getting the nitrogen/phosphorous balance right.
introductory chapter of David R. Montgomery's Dirt: The
Erosion of Civilization covers those basics nicely, beginning
with the touching tale of how Charles Darwin, in his last book,
working with his sons, demonstrated the vital role of earthworms
in soil formation and the maintenance of soil fertility, concluding
that "all the vegetable mould over the whole country has
passed many times through, and will again pass many times through,
the intestinal canal of worms." He calculated, more or
less correctly, that English and Scots worms moved half a billion
tons of soil a year.
that foundation, Dirt moves on to exploring the place
of soil in early human civilization. It includes the latest
research in archeology and genetics -- in its account of the
origins of agriculture, which Montgomery places at the headwaters
of the Euphrates from about 10,000 BC, best explored around
the settlement Abu Hureyra. For the 3,000 years prior, it had
been an Edenic environment of oak forests interspersed with
stands of wild grain, but during a sudden dry period, the communities
of hunter-gatherers who had become settled there chose to domesticate
wild varieties of rye and wheat. When the rains returned approximately
1,000 years later, barley and peas, and other crops were added
to the mix, allowing the village population to reach 5,000,
the largest concentration of humans yet known.
was the foundation of the great flourishing of Mesopotamia,
but it faced two great problems: salinization from irrigation
and silting up of irrigation channels as the growing population
moved into easily eroded upland areas in search of farming land
– a problem that has beset China for the past two thousand
years. Such erosion was also a problem in the Bronze Age and
classical Greece. Montgomery quotes Plato describing the region
around Athens: "The rich, soft soil has all run away leaving
the land nothing but skin and bone."
the detail is fascinating, it is by and large familiar territory
popularized by Jared Diamond. It is when Montgomery moves into
the modern era that he reaches new, and frightening, territory.
effects of inappropriate farming and drought of the American
dustbowl era are well known, but Montgomery goes back, and forward,
from there. He looks at how tobacco farming, based on slave
labour, locked its proponents into a cycle of declining soils
where the clean-till method of cultivation exacerbated erosion.
then he looks forward to the post World War II mechanization
of agriculture that resulted in the same kind of careless, mass
production agriculture that ploughed across the landscape with
no regard to its local characteristics. In the Palouse region
of eastern Washington, a 1950 survey found that all of the original
topsoil was missing from 10 per cent of farmland, and between
25 and 75% of the soil was missing from an additional 80% --
that a mere 10% was in something like its original state. Since
slope is a major factor, less than 50% of US croplands have
a slope of 2%, and therefore are at relatively low risk of erosion.
"The steepest 33% of US cropland is projected to fall out
of production over the next century."
that's a worry for more than the US. Before World War II, Western
Europe was the only grain-importing region. Latin America produced
nearly double the quantity of North America in the 1930s, the
Soviet Union was also a major exporter, Africa was self-sufficient.
Now, the only major grain exporters are North America, Australia,
and New Zealand. It is worth quoting the summary of the current
state of play: