15, 2006: As scientists we often lament on the mass of
good research with relevant information that never sees the light
of day. In organic agriculture this is an even greater problem for
two reasons: 1) there is a critical need for peer-reviewed information
on healthy certified organic systems to overcome the organic research
deficit; 2) much of the data recorded is functionally lost due to
more conventionally minded reviewers who have no basis for appreciating
the profound role of biologically based organic practices on crop
In some ways The Rodale Institute Farming Systems Trial helps to
turn the tables a bit since there are few conventional studies which
have stayed the course for 26 years, as has this trial, giving it
a sort of “super validity.”
This spring I happened upon an exhaustive study of corn root systems
done at the Rodale Institute in collaboration with researchers at
Cornell University. The study was novel for its use of video cameras
to directly measure corn root proliferation in the soil at different
depths in experimental fields.
Working with Rodale Institute researchers, Dr. Victor N. Bushamuka
(a World Bank Graduate Research Fellow) implemented the study using
the video camera process developed by his advisor, Cornell’s
Dr. Richard W. Zobel. From 1989 to 1991, data points were taken
from three sites at the Rodale Institute and two sites in New York
to see how alternative agricultural practices affect the root system.
To date this work is only published as a Cornell University thesis
despite its novel method and dramatic results. ("Response of
maize root growth to tillage, fertilization, and weed control systems
under conventional and sustainable cropping systems.” 1993.
Master’s Thesis. 181pp.)
Coming to grips with an inconvenient truth
You would think that a study like this would be enthusiastically
publicized, analyzed and debated, but this has not been the case.
The data irrefutably supports a startling conclusion: alternative
agricultural practices support dramatically increased root growth.
I believe this challenging conclusion is why these findings haven’t
yet made their way into scientific literature.
This is science that deserves to make an impact, but first it has
to escape the thesis section of the Cornell Library. So here goes:
The FST is our long-term trial comparing three cash-grain systems:
two organic rotations and one non-organic, corn-soybean rotation,
based on the current recommendations for soybean and cash-grain
corn production from The Pennsylvania State University. Compared
in randomized and replicated plots are an organic system where manure
supplies fertility, an organic system where legume crops provide
fertility and the “conventional” cash-grain system.
The FST results reported by Zobel and Bushamuka showed that the
livestock (manure) organic system and the legume organic systems
both significantly increased the presence of lateral corn roots.
The manure system doubled the lateral roots of conventional corn
and soybeans measured in the first 25 cm (10 inches) of soil. In
just 10 years of organic transition management (1981-1991), the
amounts of roots were sharply increased in both organic systems
compared to the conventional corn/soybean row-crop system.
Although it may seem obvious that roots are a good thing, there
is a group of scientists that argue, conversely, that roots represent
a waste of plant energy which could be better portioned to plant
grain yield. This seems to me like saying legs are over-rated for
It’s true, I suppose, that you wouldn’t need roots
if you didn’t need to support the plant, feed the plant, and
get water into the plant. However, under natural field conditions,
those are real needs that crops have.
In data from the New York (Aurora) site, Zobel and Bushamuka looked
at the factors of cultivation versus herbicide and manure versus
fertilizer in all combinations. Like the Rodale Institute site,
at Aurora it was evident that manure was superior to fertilizer
for favoring lateral root density, and cultivation was superior
Most dramatic was the data results showing that combining the impacts
of fertilizer and herbicide applications proved synergistically
negative for corn root proliferation at the 30-cm (12-inch) depth.
Looking at the devastating reduction of roots when fertilizer
is combined with herbicide in these samples, we can appreciate the
wisdom of the early organic pioneers who disliked reliance on chemical
inputs and advised against their use. Indeed, long-term experimentation
and experience would show a wide range of subtle negative side-effects
not originally envisioned by the proponents of these “crop
protection and enhancement materials” at the beginning of
their unplanned experiment with the food system.
If I were a farmer entering a drought—or a corn plant, for
that matter—I would like the cushion of having more, not fewer,
roots. Considering there are thousands of synthetic chemicals that
interact with each other in unknown ways, the best way to avoid
unexpected negative consequences from these is to avoid and reduce
their use. Even their proponents look at them more and more as necessary
evils rather than as the easy solutions they once thought.
As long as roots have the last say, using more natural biological
management techniques and fewer chemical inputs is the way to improve
plant responses to the growing environment as we know it.