Posted
January 12, 2006: According to the humorist Will
Rogers during the heart of the great depression and dust bowl
“We keep makin’ people but we ain’t makin’
any new dirt!” In the intervening 70 years we’ve
gained more people and lost more “dirt,” despite
improvement in soil conservation. Now comes word that we may
be on the verge of finally being able to do what Rogers thought
was impossible.
The overall arithmetic of soil creation is a balance between
all losses by erosion and nature’s painstakingly slow
soil creation process. Because agricultural erosion –
through overuse and undernourishment -- has mostly overwhelmed
nature’s soil production, the net result has been the
shrinking of our global soil resource base and a degradation
of our natural resources. If we are to prosper in the foreseeable
future, we need to cut the losses and accelerate the gains.
Stop the bleeding, build the soil
As we’ve known all along, organic matter is the glue
that holds soil in place so it doesn’t wash or blow
away. Once virgin woods or prairie is opened it will lose
about 1 percent of its original organic matter per year, soil
scientists say. After 50 to 75 years it will stabilize in
a new depleted level. Once organic matter is mined out of
the soil, fertilizer can supply nutrients but not the water
and air-holding capacity crucial for productive agriculture.
To halt its loss, soil needs to be covered. Research here
at The Rodale Institute® shows that properly managed cover
crops (legumes, grains, grasses or mixtures) can reverse soil
organic matter loss and actually build new soil organic matter
(SOM) – dark and rich. Soil-building crop rotations
also reduce atmospheric greenhouse gas emissions, giving agriculture
a role in combating the growing impacts of global climate
change by putting the black back.
The Rodale Institute Farming Systems Trial® (FST), a
long-term study comparing different farming systems, shows
that we can gain about 1,000 pounds of carbon per acre per
year with cover cropping and crop rotation under organic management.
This is about twice the sustained carbon gain from standard
no-till planting for corn or soybeans. FST shows insignificant
amounts of carbon are deposited in our conventional tillage
corn and soybean rotations with chemical fertilizer and pesticide
inputs.
And there are even better ways to enhance SOM, such as our
biological no-till system which combines reduced tillage with
intensive cover crops and rotation.
Looking to our ancestors for the future
Back in April I wrote a column titled Carbon
is the key. I described the ability of nutrient poor,
red tropical soils to be transformed into productive black
earth. This apparently took place by hand labor on a large
scale more than 1,000 years ago on in an area the size of
modern France in the Amazon Basin. The productive persistence
of this black from poor red soil has been traced to the addition
of charcoal.
Much of the work on improving our soil has focused on increased
plant production. If,
however, the carbonaceous plant material is not stabilized
it will not necessarily stay in the soil. Our long-term trials
show that composting allows for much greater accumulation
of carbon in soil, while compost also recycles needed nutrients
to plants over time. Manure’s nutrients, in contrast,
are more quickly released with relatively little residual
carbon.
We are trying to improve our composting process so carbon
can be retained more effectively in soil. The Amazon black
soils show what’s possible. Whereas many plant residues
persist in the soil for months or days and compost can last
for years, charcoal‘s soil lifetime has been measured
in many centuries.
Freeing hydrogen from biomass
The largest man-made contributor of carbon dioxide in the
atmosphere is the burning of oil, gas and coal from subsurface
deposits. An attractive alternative is using plant resources
to harvest hydrogen which, when burned, produces water --
not carbon dioxide.
Increasing interest is being expressed in a hydrogen economy
which will be based on renewable energy resources. In a combustion
process called pyrolysis, which excludes oxygen, hydrogen
in plant materials can be harvested as a source of energy
while conserving carbon and other nutrients as char. If this
biomass-based system can reach sufficient scale and scope,
farms and farmers can be our next energy providers while gaining
the materials which will regenerate the soil while growing
more crops.
Recent
research1 shows
the process produced three times the hydrogen it consumes,
making it a net energy producer. Further it yielded a nitrogen-enriched
char-type fertilizer. This material is highly resistant to
microbiological decomposition while also acting as a biological
stimulant by providing the “house” for microbial
life.
To learn more on the agricultural and energy aspects of this
process, check out the web site of Epridra, Inc., (www.eprida.com)
which describes itself as “a technology development
company and social purpose enterprise.” Check out The
Epridra Cycle to run an animation showing the biomass
to fertilizer, sequestered carbon and energy loop.
Regeneration raises the bar
Robert Rodale urged us to stay curious, observant and determined
to develop systems based on nature’s principles. His
goal was to find ways to approach the idea of regeneration,
that is, to improve the capacity of the very systems we are
using. When we regenerate we use resources intensely yet benefit
them as a result.
Increasing global and sector competition for dwindling fossil
fuels is producing anxiety, higher prices and innovation.
As farmers and citizens faced with where to invest our support
for new energy sources, why not look for options that have
the potential to also renew and regenerate our soils, water,
and air.
We need to set regeneration as our goal and accept nothing
less. 
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