This is an extremely important
report. I have included Philpott’s take
on it and the article from the Rodale institute.
The take home is that unequivocally,
industrial synthetic farming is clearly inferior to industrial organic farming
and rather importantly will continue to diverge because of the persistent
decline in carbon content in the synthetic soils.
This removes any further need to
hedge ones choices. An organic protocol
will out perform its competitor consistently.
Read the articles carefully. There
is a lot of specific data that needs to be understood.
I personally go a lot further and
also call for application of biochar soil dressing as an ongoing soil building
protocol to sharply reduce the need if not eliminate the need for adding any
form of fertilizer at all.
Most noteworthy, we discover that
the organic soils are slowly increasing their carbon content, so even without
the biochar, the soils improve.
Organic farming just as productive as conventional, and better at
building soil, Rodale finds
BY Tom Philpott
25 MAR 2011 6:07 PM
Organic agriculture is a fine luxury for the rich, but it could never
feed the world as global population moves to 9 billion.
That's what a lot of powerful people -- including
the editors of The Economist -- insist. But the truth could well
be the opposite: It might be chemical-intensive agriculture that's the
frivolous luxury, and organic that offers us the right technologies in a
resource-constrained, ever-warmer near future.
That's the conclusion I draw from the latest data of the
Pennsylvania-based Rodale Institute's Farming Systems Trial (FST), which Rodale
calls "America 's
longest running, side-by-side comparison of conventional and organic
agriculture." Now, Rodale promotes organic ag, so industrial-minded
critics will be tempted to dismiss its data. But that would be wrong -- its
test plots have an excellent reputation in the ag research community, and the
Institute often collaborates with
the USDA's Agricultural Research Service.
Housed on Rodale's 330 acre farm, the FST compares three systems for
growing corn and soy, the first two organic and the third conventional: 1) one
based on rotating feed crops with perennial forage crops for cows, and
fertilizing with manure; 2) another based on rotating grains with cover crops,
with fertility coming from nitrogen-fixing legumes; and 3) a system reliant on
synthetic fertilizers and pesticides.
Rodale's researchers have been comparing crop yields and taking soil
samples on these test plots for 27 years. Their latest findings? The three
systems have produced equivalent corn yields over the years, while
"soybean yields were the same for the manure and conventional system and
only slightly lower for the legume system."
So the old canard about how organic ag produces dramatically less food
than chemical ag has been debunked, yet again.
Corn in the organic-legume (left) and conventional (right) system
during the dry summer of 1995. Both were planted on the same day, with the same
variety but only the conventional corn is showing signs of water stress.
Organic corn yields that year were 29 percent higher than those of the
conventional corn.Photo and caption: Rodale InstituteBut it gets more
interesting. As the globe warms up, increased droughts are likely to reduce
global crop yields. The ag-biotech industry is scrambling to come out with
"drought-resistant" GMO crops. But organic ag might already have that
covered: "In 4 out of 5 years of moderate drought, the organic systems had
significantly higher corn yields (31 percent higher) than the conventional
system."
Moreover, while conventional ag struggles with the "superweed" problem,
brought on by Monsanto's herbicide-tolerant GMO crops, organic ag is showing it
can coexist with weed pressure without sacrificing yield: "Corn and
soybean crops in the organic systems tolerated much higher levels of weed
competition than their conventional counterparts, while producing equivalent
yields." Meanwhile, herbicide use in the conventionally managed plot
fouled groundwater:
Herbicides were only detected in water samples collected from the
conventional system. In years when the conventional rotation had corn following
corn, during which atrazine was applied two years in a row, atrazine levels in
the leachate sometimes exceeded 3 ppb, the maximum contaminant level set by EPA
for drinking water. Atrazine concentrations in all conventional samples
exceeded 0.1 ppb, a concentration that has been shown to produce deformities in
frogs.
\
In terms of building robust ag systems in an era of climate change, the
results related to soil are probably the most interesting. It turns out, the
organic outperformed conventional in both building organic matter and retaining
soil nitrogen. In the past 15 years of the study, the organic systems have
continued building soil carbon, while the conventional system actually lost
carbon. (For more on the question of soil carbon and soil, see my
piece from last year's special series on nitrogen.)
The soil-carbon factor probably explains why organic outperforms
conventional in drought years: carbon-rich soil tends to retain water better.
And indeed, the results bear that out:
Water volumes percolating through each system were 15-20% higher in the
organic systems than the conventional system, indicating increased groundwater
recharge and reduced runoff under organic management.
Inevitably in the comments section below, someone will ask about the
manure. How much land does it take to support sufficient cows to produce enough
manure to replenish organic fields? But the Rodale results show that
nitrogen-fixing legume crops can greatly reduce the contribution needed from
livestock.
And anyway, let me turn that question around. Where do industrial
agriculturalists intend on getting the synthetic nitrogen for their system --
from what energy source? The main feedstock is natural gas; but the easy
natural gas has been tapped in the United States . That leaves us
reliant on geopolitically
unstable foreign suppliers -- or on domestic shale gas, which relies
on the water-fouling
process of hydrofracturing. And where do they plan on getting phosphorous?
In the end, organic ag looks like the robust and wise approach to
responding to population growth and climate change, and chemical ag looks like
the gambler's approach -- a luxury for the well-heeled folks who own shares in
the agribiz industry.
Tom Philpott is Grist’s senior food and agric
Rodale Institute Farming Systems Trial
Founded in 1981, the Farming Systems Trial (FST) is
About the trial
We selected corn/soybean production as our research focus because
large tracts of land, particularly in our region and the
Manure Organic
This system represents an organic dairy or beef operation. It
features a long rotation including both annual feed grain crops and perennial
forage crops. The system’s fertility is provided by leguminous crops and
periodic applications of manure. This diverse rotation also creates a primary
line of defense against pests.
Legume Organic
‘
This system represents an organic cash grain system. It features a
mid-length rotation consisting of annual grain crops and cover crops. The
system’s sole source of fertility is leguminous crops and the rotation
provides the primary line of defense against pests.
Synthetic Conventional
This system represents the majority of grain farms in the
Some key findings include:
Yields
Corn yields over 27 years of the trial were equivalent between the
organic and conventional systems.
Soybean yields were the same for the manure and conventional system
and only slightly lower for the legume system.
In 4 out of 5 years of moderate drought, the organic systems had
significantly higher corn yields (31% higher) than the conventional system.
Corn and soybean crops in the organic systems tolerated much higher
levels of weed competition than their conventional counterparts, while
producing equivalent yields.
Corn in the organic-legume (left) and conventional (right) system during the dry summer of 1995. Both were planted on the same day, with the same variety but only the conventional corn is showing signs of water stress. Organic corn yields that year were 29% higher than those of the conventional corn.
The soil
Soil carbon and nitrogen have increased significantly in the organic
systems, but not in the conventional system.
Based on preliminary 2009-2010 soil sampling data, the organic
systems have shown the largest increases in soil carbon since the beginning
of the trial.
In terms of carbon sequestration the manure system is leading,
followed by the legume system.
Increases in soil carbon were greatest in the first 13 years of the
trial. Soil carbon continued to build in both organic systems during the 15
years following 1994, but at a slower rate than the first 15 years.
The conventional system has shown a loss in carbon in more recent
years.
Water
Water volumes percolating through each system were 15-20% higher in
the organic systems than the conventional system, indicating increased
groundwater recharge and reduced runoff under organic management.
Overall, nitrate-nitrogen leaching was fairly low and the same for
all systems.
Water leachate samples from the conventional system more frequently
exceeded the legal limit of 10 ppm for nitrate-nitrogen concentration in
drinking water compared to the organic systems.
Herbicides were only detected in water samples collected from the
conventional system. In years when the conventional rotation had corn following
corn, during which atrazine was applied two years in a row, atrazine levels
in the leachate sometimes exceeded 3 ppb, the maximum contaminant level set
by EPA for drinking water. Atrazine concentrations in all conventional
samples exceeded 0.1 ppb, a concentration that has been shown to produce
deformities in frogs (Hayes et al., 2002).
Energy
Total energy use in the organic systems was less than in the
conventional system.
Energy use in the conventional corn-soybean system was dominated by
the production of nitrogen fertilizer and herbicide inputs, while seed and
fuel use generated the greatest energy demands in organic systems.
Economics
Several economic studies of the early years of the Trial (1980’s and
1990’s) showed that net returns for the two grain operations, the legume and
conventional system, were the same (assuming that all farm products received
the same price at market).
Seed inputs and equipment costs were higher in the legume system
whereas fertilizers and pesticides were the most costly inputs in the
conventional system. (These economic analyses do not include the manure
system; only cash grain systems were compared.)
Even with the inclusion of the transition costs (such as potential
loss of yields in start-up years) and family labor costs, the organic price
premium required to equalize the organic and conventional returns was only
10% above the conventional product. Throughout the 1990s, the organic price
premium for grains exceeded that level, and premiums ranged between 65% and
140%.
Agronomic, environmental, energy and economic analyses of the systems
are all currently being updated to include the new rotations and tillage
regimes as well as current information regarding inputs and prices.
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