column included a photo of an underweight baby. The
sadness of this malnourished child is a cry to the soil,
for it is the soil that feeds the mother and the mother
that feeds the child. Our health ultimately depends
on the health and fertility of the soil we steward.
Traditional agriculturists understand that soil is
the most important aspect of crop support. The earth
nurtures plants just as a mother nurtures her child.
Reliance on synthetic fertilizers, on the other hand,
sacrifices soil (the mother) by seeking to feed the
crop (or child) directly. Feeding the mother will automatically
care for the child.
In talking about composting to extension agents in
Ghana, my goal was to include scientific information
while concentrating on practical, traditional African
composting methods. Composting aligns well with traditionally
held values in Ghana, and I emphasized that it was an
honored task, practiced by their forefathers.
As we assembled our compost pits, we enlisted the help
and support of the neighboring villagers. When we finished,
we gathered in a circle around the pile and I asked
the participants to join hands. Be grateful for a kind
mother who nurtures grateful hearts; this feeds our
soul. Show your gratefulness to the source of life by
recognizing Earth as the Mother and taking care of Her.
We promised to share the bounty of the compost.
Then I asked each participant to press his or her hand
into the pile. This represented how each of us had put
their hands and hearts into this project. The hand is
the gateway to the heart when our labor represents our
heartfelt emotions. These sentiments feed the living
compost on the nonphysical level.
Tropical soils: Challenges and opportunities
As I mentioned last time, about two-thirds of the world's
tropical soils are red acid soils, notoriously low in
plant nutrients. In Ghana, red acid soils constitute
about 80 percent of the soil base, and farmers complain
that it is getting harder and harder to wrest productivity
from the land. Improving agricultural productivity in
Ghana and other tropical areas clearly depends on improving
management of red acid soils.
reasons to make and use compost
Dr. Paul shared his motivations for composting
as part of his presentation on the importance
of soil health and composts role in maintaining
In a previous column I wrote about the ‘terra
preta do Indio,’ or Indian black soils. These
intriguing soils are derived from red acid oxisols and
ultisols, the oldest and generally least fertile of
all soil families. Unlike their parent soils, however,
the Indian black soils are extremely productive, and
demonstrate the great potential for transforming red
acid soils by increasing their soil organic matter content.
Although we see eroding and deteriorating soils in many
parts of the world, we can take heart because not only
can this be stopped, it can even be reversed under what
appear to be the most limiting of conditions.
This is the essence of Robert Rodale’s concept
of regenerative agriculture. Regenerative agriculture
is partly inspired by Sir Albert Howard’s experience
working with impoverished red acid tropical soils in
British colonial India. Modern windrow composting is
a variation on the "Indore Compost Method,"
refined by Sir Albert from ancient Indian composting
practices. In Africa, we need to go beyond sustainable
agriculture because with the present poor resource base
we will not be able to feed the growing population just
by being sustainable. Instead, we need to re-capacitate
or regenerate soils, farms, and communities. Sir Albert
called this the Law of Return--we must feed the soil
properly if it is to feed us properly.
The Rodale Institute® farm in Kutztown, Pennsylvania,
was founded on worn-out agricultural soils that have
now been regenerated. Through organic farming methods
such as the use of compost, cover cropping and rotations
we have not only sustained a thin, perishable soil layer
but built it to a point where we routinely surpass neighboring
Some soil scientists dismiss acid red tropical soils
as being incorrigibly unproductive. But these soils
do have valuable qualities: in general, they are deep,
well drained and can be worked with machinery shortly
after heavy rains. Just as we cannot afford to have
children left behind in their educational experience,
we definitely need to "leave no soil behind"
in the effort to support our growing world population.
From an agricultural development perspective, the question
should be: How do we most effectively convert acid red
soils into black, fertile soils? To a large extent,
the answer is, by boosting organic matter levels through
the use of compost.
Organic matter neutralizes constraints
of acid soils
Red acid soils exhibit both low fertility and potential
toxicity to plants. An acid red soil lacking in soil
organic matter can solubilize large amounts of metals,
notably aluminum and manganese. When these metallic
ions dominate the soil solution, they block the absorption
and activity of essential nutrients such as calcium,
resulting in reduced yields or even crop failure.
Increasing soil organic matter can solve both of these
problems together. Native clay and humic materials both
have an overall negative electrostatic charge, so they
are mutually repellant. Organic matter overcomes this
repellency by forming a stabilized product of native clay
and humic material, bridged together by polyvalent, positively
charged ions such as aluminum, iron, manganese and calcium.
||"Organic matter works to
expand the nutritional support potential of the
soil, fostering more optimum plant growth."
As the organic matter and clay complexes form, aluminum
ions are pulled out of the soil solution. Once aluminum
is captured in an insoluble complex of clay and organic
matter, calcium absorption and movement in the plant
roots and tops is no longer impeded.
Besides eliminating nutrient interference, soil organic
matter itself serves as a rich source of nutrients for
plant growth. Organic matter works to expand the nutritional
support potential of the soil, fostering more optimum
plant growth. It also allows more water to penetrate
the soil and remain there to be taken up by plants.
A soil optimized in organic matter helps protect plants
from periodic drought.
aluminum levels in soil make it difficult
for plants to put down healthy roots.
When plants develop aluminum toxicity in an acid soil
environment, they look like someone cut off their root
tips. The condition is called terminal deficiency because
it affects the outermost cells and tissues. Blossom-end
rot in tomatoes is a form of terminal deficiency. (In
humans the effects of insufficient calcium are as dramatic
as in plants--the breakdown of bone structure called
Tip necrosis due to insufficient calcium can result
from the use of ammoniated fertilizer or prevented by
calcium fertilization. Acidity from ammoniated fertilizers
drives aluminum ions into solution, interfering with
calcium uptake and movement in plants. Adding calcium
can take aluminum out of solution and serve as a direct
source for plant nutrition. Calcium salts provided to
the plant through foliar applications, however, will
have no effect on root health, because calcium only
moves upward within plant tissue.
Calcium plays many crucial roles in plant physiology,
including bridging and linking cells by interacting
at cell walls and membranes. Water availability, in
turn, is critical to the movement of calcium within
plants--fluctuating water stress predisposes plants
to blossom-end rot. Soil organic matter, with its ability
to buffer water fluctuations, plays an important role
in preventing water stress.
Although a calcium salt solution can remedy both aluminum
toxicity and calcium deficiency, calcium salts cannot
help soil percolate or hold water the way organic matter
does. Knowing this, we can understand aluminum toxicity
as an induced calcium deficiency that can be resolved
by organic matter. Organic matter is the bulwark of
soil, maintaining both proper moisture availability
and aeration. No chemical salt can substitute for these
From all of these perspectives, soil improvement with
optimized organic matter makes sense. Salts can in some
instances remedy the symptoms of soil infertility, but
they provide none of the long-term benefits of increased
soil organic matter.
Black organic matter is the real
Conventional ammoniated fertilizers exacerbate existing
soil acidity. Ammoniated fertilizer does not feed soil
organic matter but instead stimulates decomposition,
resulting in lower soil organic matter content. The
nitrogen component of conventional fertilizer has no
duration from season to season and requires similar
or greater applications for every crop, every season.
|"Compost improved soil
organic matter and nitrogen levels while simultaneously
lowering nutrient losses to ground and surface water."
The Rodale Institute's Compost Utilization Trial compared
the effects of fertilizer, raw manure and compost on
crop productivity, soil health, and environmental quality.
Interestingly, although all approaches were equally
effective in optimizing crop productivity, compost was
the only approach that also improved soil health and
environmental quality. Compost improved soil organic
matter and nitrogen levels while simultaneously lowering
nutrient losses to ground and surface water. Compost
also increased crop nutrient content. Fortunately, composting
is a traditional technology practiced throughout the
In Africa there is little infrastructure to support
widespread liming and other conventional agriculture
approaches by small farmers. As a result, concentrating
on fertilizer “solutions” leads to the problem
Ghana's small farmers complain about: poor soils becoming
Raising soil organic matter opens the soil texture,
allowing both air and water to penetrate and stimulating
soil microbial life. In The Rodale Institute Farming
Systems Trial, we have found that improved soil organic
matter levels can increase water penetration by as much
as 50 percent. This contributes to the ability of plants
to make do on limited water supplies. In many developing
areas, including northern Ghana, water is not optimized
and improving the soil is the best way to stabilize
As natural materials, soil organic matter and compost
are very complex in their composition and action. This
complexity intrigues and confuses scientists. There
is no formula for humic material; rather it exists as
a mixed class of an infinite number of compounds, representing
a wide array of biological products from diverse organisms
and defying chemical definition.
"Man no be God"—and
neither is science
Hepperly and the group of Ghanaian extension
agents brought together by Farm Serve, a program
of Opportunities Industrialization Centers
In the Western scientific method, a lot of emphasis
is given to how things work, their mechanism of action.
The biological processes at work in organic agricultural
systems, however, are much more complex than the simple
actions of chemical salts.
If we limit ourselves to interacting only with things
we completely understand, we are left with a poor set
of tools indeed. Often, the things we do not understand
are more powerful than the things we do understand.
Many Western scientists simply do not want to deal
with things they don’t understand. Traditional
knowledge allows for a more humble approach, basing
practice on experience even when the mode of action
is not completely understood.
It would be most unfortunate to select technologies
of lesser potential because we believe we understand
them better. Rather than take that limited track, we
should put more effort on traditional processes, which
offer more even though they are less well understood.
Western technology is extremely powerful, but it should
complement indigenous knowledge, not replace it. Western
scientific methods need to be tempered by ethics, or
the technological result will ultimately be sterile.
Modern insecticides and fertilizers are examples of
sterile technologies. Both are also extensions of war
technologies. The fact that we understand precisely
how they work does not obscure the fact that they were
designed to kill. We need values to reverse the problems
we have created with such technologies.
One of my favorite things I saw while I was in Ghana
was a sign on the side of a passenger van that read,
“Man no be God.” When man uses technology
in self-serving and destructive ways, he takes an ignorant
and egotistical approach.
An unfortunate side effect of scientific endeavor is
egoistical thinking. Frequently, we know less about
our actions and how they affect natural balances than
we think. As we eliminate pesky insects, for instance,
we also eliminate pollinators and other beneficial organisms.
Basing our crop production systems on poisons and attempting
to replace the soil life force with simple chemical
salts are perfect examples of science and technology
The Hippocratic Oath enjoins physicians to "first,
do no harm." Agronomists and other crop advisors
should observe a similar rule. Even many advocates of
chemically intensive agriculture now understand that
substantial damage is being done to the environment.
It is better for us to work with nature and be aware
of its greatness. By casting life as the enemy, we set
up a conflict against ourselves, for we are part of
the web of life. In truth, we will "win" only
if nature prevails, and we fall short of our goals.
composting for soil improvement in northern Ghana
In the first of this series, Paul describes a three-week
volunteer effort to help West African villagers learn
about organic farming methods