February 16, 2007: Since 1981, the Rodale Institute
has conducted the longest-running scientifically controlled
comparison of organic and conventional crop production systems
in the United States. When it comes to drawing conclusions
from this research, timing is everything. What looked good
in the short term doesn’t look so good now. From this
point in time, it’s the organic farming practices that
now stand out for multiple long-term benefits—and for
increasing yield potential.
The Rodale Institute’s Farming Systems Trial (FST)
is designed as a scientifically valid suite of plots covering
13 acres of virtually flat land with moderate drainage and
shallow top soil. The conventional system uses land-grant
recommendations and a conservation tillage regime typical
of our region. Research has been conducted in collaboration
with the United States Department of Agriculture’s Agricultural
Research Service (ARS) and researchers from several land-grant
Conventional corn yield was superior in our early tests,
during the years when the soils being farmed organically were
going through the transition process and building up their
biological activity. Soon, the organic plots entered a long
phase (1985 until 1993) when yield was statistically the same
as the side-by-side plots of conventionally farmed soil.
Continuous soil improvements after two decades have resulted
in dramatic environmental improvements, production resiliency
during weather extremes, and—averaged over the past
12 seasons—slightly higher corn yields in the organic
system. From 1995 to 2006 organic corn yields (119 bushels
per acre) have out-yielded conventional corn yield (110 bu/A).
This period included both severe drought years and a record
wet summer. (The yield difference between organic and conventional
is statistically significant at P=0.03.)
The beginning years
If we had stopped the FST comparison work after two or three
years, we might have been tempted to agree with Nobel Laureate
Norman Borlaug. He has claimed that organic agriculture can
never compete with the yield of high-input conventional agriculture.
But with time, our research tells a very different story.
From 1985 to 1993, the FST mini-fields showed no overall difference
in corn and soybean yields between the organic and conventional
systems. Moreover, in drought years with less than 200 mm
(7.9 inches) of rain in July and August, corn yields were
28 to 34 percent higher in the organically managed soils.
Starting with the 2004 crop season—after 23 years of
organic and conventional management, and the growth of resulting
soil differences—the plots were farmed under a common
corn, soybean and wheat crop rotation. That summer, a record
rainfall resulted in a harvest that showed organic corn had
significantly higher yield (146 bu/A organic, 129 bu/A conventional)
and higher grain protein content than the conventional system.
(This yield difference was statistically significant at P=0.10.)
This transformation of the organic fields is somewhat like
the race of the tortoise and hare, but in this case the organic
systems now look to be winning the race on three fronts: soil
quality, drought tolerance and overall yield.
In our trials we have noted that soil quality—in terms
of carbon, total nitrogen, and biological activity—has
increased in each area under organic management, but not under
the conventional system. These soil changes explain why organic
soils have improved over time in our testing environment.
Gradual elevation of soil organic matter with continuous
use of soil-building practices is the foundation for many
changes that improve the productive capacity and biological
resiliency of organic systems.
It’s in this way that organic soil can potentially
out-compete conventional production systems over the long
run. It takes time to use healthy soil practices to restore
the biological life, but this time creates a biological and
structural foundation for future improvements.
A new reality?
Our research is from one farm in Pennsylvania, but we believe
the principles it documents have much broader application
to similar growing areas around the world. Despite the nagging
disbelief of chemical agriculture proponents, The Rodale Institute’s
research shows organic agriculture has as much potential to
actually feed the world in a sustainable manner as does conventional
commodity crop farming. Modern research has increased the
capacity of traditional organic farming beyond that which
had fed civilizations for 6,000 years.
Moreover, in the long-term perspective that includes peak
oil and diminishing groundwater resources, a bigger question
looms: In the span of recorded agricultural history, can the
relatively recent advent of high-input, chemically based agriculture
continue much longer without excessively degrading the very
natural environment we all depend upon?
Hard scientific evidence shows that agricultural productivity
can be judiciously enhanced through long-proven, ecologically
sound, soil-improvement methods without resorting to toxic
This new paradigm of productivity offers this potential:
if we want to help all farmers to develop systems which will,
in time, improve their yields while they increase the quality
of food produced, and while they decrease their input costs
and environmental impact, organic methods are needed by all
We will continue to monitor our FST plots to see if the indicators
of the past three years that show organic advantage are maintained,
strengthened or changed. We will also foster the application
of regionally adapted cover cropping and crop rotation practices
useable in any farming approach to support a better future
for farmers and for all food consumers.
By focusing on the basics of soil improvement, we can avoid
the pitfalls and dependencies of chemically intensive agriculture
as we offer the world a true green revolution.