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
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
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.
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.