Sustainable
in Senegal
Where we are:
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West Africa calls you back
West Africa gets deep into your marrow, haunts
you, calls you back.
After two years there in Peace Corps working
with farmers in Mali, I was yearning to return
to the region. In 2003, that call drew me to Senegal
where I spent a semester as an intern at The Rodale
Institute to compliment my graduate research in
sustainable agriculture. I wanted to see how TRI
was able to transfer its expertise to farmers,
helping to improve their livelihoods.
The Senegalese farmers I met were eager to share
their stories, their food, and their laughter.
Their resilience and creativity farming on the
edge of the Sahara can serve as inspiration to
us all. – Nathan C. McClintock
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It might seem crass to suggest
that the world’s greatest civilizations have been built
on foundations of their own waste. Perhaps. But civilizations
as we define them grew as a function of agricultural productivity.
And since humans first began scraping the ground and planting
seeds some 15 millennia ago, they have relied on decomposed
organic matter—manure, garbage, crop residues—to
replenish the soil’s fertility.
Sir Albert Howard, a British agronomist working on colonial
plantations in India in the 1920s, grew frustrated with the
growing incidence of plant disease and loss of humus in Western
monocultures. He noted, “The Chinese have maintained
soil fertility on small holdings for forty centuries.”
At the same time he recognized the inefficiency of the traditional
method of stacking manure in piles. In his 1943 memoir An
Agricultural Testament, Sir Albert, in his zealous, surly
prose declared, “The fungi and bacteria of the manure
heap are working under impossible conditions. They live a
life of constant frustration which can only be avoided by
giving them a balanced ration.”
English writer spreads compost gospel
After
experimenting with different methods of composting, he brought
the injustices of the dunghill to the world’s attention
in a 1931 publication detailing the so-called “Indore
method,” named for the state in India where he and his
colleagues conducted their research. The Indore method is
what we all know as composting—piles or pits of manure
or organic waste layered with dry matter to facilitate aeration,
watered regularly, and turned every month or so. Following
his clarion call, the Indore method spread to British tea
and coffee plantations throughout Africa, Asia and the Caribbean.
It is the first thing all Peace Corps ag volunteers learn
to do. And it’s central to the Rodale Institute’s
(RI) extension work to promote regenerative agriculture in
Senegal.
While composting is only a tiny part of Rodale’s program
to increase organic matter content in the sandy jóór
soils of the Peanut Basin, it is an integral one. Since the
Senegal office opened in 1987, tens of thousands of farmers
and extension workers have been trained in regenerative agriculture
techniques, a large portion of whom received instruction in
Sir Albert’s trusted method of pit composting. Trainings
are conducted with the expectation that the participants themselves
will go on to perpetuate the technology on their own as its
benefits become apparent. For example, following RI’s
work with the Projet de Gestion des Eaux de Casamance (PROGES),
farmers set up 800 composting pits based on the ten constructed
for training demonstrations. Rodale has also published pamphlets
and booklets in both French and Wolof detailing the technique.
Results from Rodale’s on-farm experimentation with
compost have been impressive. The 1990 annual report provides
the results of on-farm composting trials at N’Gombel
and Mboufta. Millet grain yields (1270 kg/ha) in plots fertilized
with compost were four and a half times greater than unfertilized
controls (230 kg/ha). In peanuts, the increases were not so
pronounced, but still favorable. Plots fertilized with compost
yielded 230 kg/ha more peanuts than plots fertilized with
manure, and one metric ton per hectare more stover, or ngooñ,
a valuable fodder for livestock.
At Mboufta, in the Departement de Tivaouane, north of Thiès,
an application of two tons of compost every two years has
yielded 3.5 times the millet than control plots, and 125 percent
of the local farmers practice of varying rates of manure application.
Promising results pointing to compost’s superiority
mark all of Rodale’s work in Senegal throughout the
last fifteen years or so, and were Sir Albert still around,
he’d certainly revel proudly in his triumph.
Why the better results from compost over manure? Is there
actually a difference between compost and manure that’s
been sitting in a pile? It’s a fine line that farmers
and extension workers run circles around. Basically, it depends
on whether or not the pile has heated up.
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Results from Rodale’s on-farm
experimentation with compost have been impressive. Millet
grain yields in plots fertilized with compost were four
and a half times greater than unfertilized controls. |
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Without getting too technical, life in a dunghill proceeds as
such. Microbial populations in the waste consume the readily
available carbon. As they metabolize it, CO2 is released, heating
the pile up. This heralds a whole new slew of thermophilic,
or heat-loving bacteria that consume the rest of the degradable
carbon. As activity slows down, the pile temperature drops,
allowing for colonization by fungi that consume much of the
remaining recalcitrant forms of carbon—lignins and cellulose.
The resulting crumbly, earthy humus is considerably more stable
than manure, meaning its nutrients are less likely to be lost
to leaching or volatilization into the atmosphere.
As compost matures, its nitrogen is mineralized, meaning
it moves from its organic form to ammonium and then nitrate,
the form that can be taken up by plants. If a pile of wet
manure just sits there unturned, it will likely become anaerobic
and smelly as precious nitrogen is lost as ammonia gas. Sir
Albert’s mission was to optimize the conditions for
decomposition. This could be seen as a gesture of magnanimity
to keep the microbial workers happy and productive, in a manner
or speaking.
Great intentions, but…
RI has been wracked with the
same frustration in the past as so many other NGOs and development
workers. Oftentimes, once a project has finished, participants
will abandon their composting pits and go back to traditional
methods of manure application. In his 1982 classic Two
Ears of Corn, the how-to Bible of participatory development,
Roland Bunch writes, “The rusting hulks of well-intentioned
but long-forgotten give-aways are scattered all over the Third
World.” I’ve seen quite a few empty compost pits
during my first month in Senegal. When I ask farmers why they
stopped composting, they generally tell me that it takes too
much water, that they don’t have enough manure to fill
the pits, or that turning the compost is too labor-intensive.
The Rodale staff is well-aware of the problem of “dis-adoption”.
Earlier this year, they conducted a follow-up impact survey
of a project carried out between 1996 and 1999 in the Tambacounda
region, the southern reaches of the Peanut Basin. A partnership
between RI and the Association Communautaire pour le Développement
de Koumpentoum (ACDK), the three-year, $161,000 project funded
by USAID promoted regenerative techniques and local economic
capacity-building in the rainfed agriculture zone (“zone
pluviale”).
Four years later, they found that while 75 percent of the
Arrondissement de Koumpentoum practiced at least one of the
techniques promoted by RI, the adoption rate of compost was
much lower. Farmers complained of the same things that they’ve
been telling me. Digging the pits was too labor-intensive.
Inadequate supplies of manure. The high cost and limited availability
of cement. Adapting to these constraints, farmers in Darou
Salam Thièkène switched over to pile composting.
Compost piles, while slower to decompose, require little labor
and are often watered only by the rain.
More recently, during the first year of the Vanderbilt project,
six sacks of cement were given to each of the five villages
for the construction of two 2m3 pits. In 2001, the first year
of the project, four composting sessions were held, with 60
attendees (49 of them women). Over the course of the gardening
season, the villages produced 8,800 metric tons of compost
in the pits. However, outside of the communal plots, only
13 percent of the participants used compost as a soil amendment,
while 52 percent used manure.
Adapting to farmer constraints
Learning from their previous
experiences, Rodale emphasized pile composting during the 2002
sessions in an effort to increase compost adoption. The results
have been as sweet as the smell of the compost itself. In Keur
Banda and neighboring Diouffène, compost production among
group members is universal. All of it is produced in piles.
As I was led from compound to compound, I saw enormous piles
of decomposing manure, stalks, household garbage, alongside
smaller piles of humic, “ripe” compost, kompos
bu nuur.
One Keur Banda farmer, Amy Diop, complained to me that she
has so much compost that she can’t get it out to her
field without a cart. In Thiawène I asked, “Who
makes compost in this group?” “Ñun
ñëpp! All of us!” they replied heartily.
Next door in Ndiamsil, a farmer stood next to the gaping,
empty pit that had been the site of so much activity a decade
ago. “No, we stopped making compost,” he shook
his head slowly with resignation. Yet not 10 feet away was
a huge pile of composted manure and millet residue! Indeed,
it is often simply a question of blurred definitions. In most
rural compounds, manure, household garbage, cooking ashes,
and broken or decomposed millet stalks from fences are stacked
in a pile, a sentaare. Some people just leave this
throughout the duration of the rainy season to decompose on
its own, while others turn it every month or so. When I asked
if it smelled or was hot when they disturbed the pile, most
said that it had cooled off and turned back into suuf—soil—by
the time they scattered it on their fields. It might not be
produced under the optimal conditions, but it’s compost
nonetheless.
The key to successful development is to build on what people
already know. The movement from compost pits to piles is a
classic example of local adaptation of a technology to better
meet labor and material constraints. Pile composting is also
more closely akin to a traditional practice. In Thiawène,
the women recognized the superiority of their pile compost
over the family sentaare compost—millet fertilized
with the former was a darker shade of green. But they each
only had produced two to three cartloads of it, as opposed
to 10 to 12 cartloads from the sentaare. With a just
a little more attention—by turning it more often—the
sentaare could produce compost as rich as that produced
in the piles.
Championing manurial rights
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"Can anything be done at this
late hour by way of reform? Can Mother Nature secure even
a partial restitution of her manurial rights?” |
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“Can anything be done at
this late hour by way of reform? Can Mother Nature secure even
a partial restitution of her manurial rights?” Sir Albert’s
pleas, while a wee melodramatic, are pertinent to the case of
Senegal’s Peanut Basin nevertheless. As fallows get shorter
and disappear altogether, the sandy soils are in dire need of
organic matter if they are to continue to be productive.
When I asked farmers in Thiawène if the soil had become
less fertile in the last five years, they surprised me with
their response. “Déédéét,
léégi suuf si moo gënë naat.
No, now the soil is more fertile.” They explained that
with the increased application of organic matter over the
last few years as prescribed by Rodale’s workers in
the field, less of the precious topsoil is lost to the wind
and rain, and yields are getting better.
Sir Albert was right: “If the easiest road is first
taken, a great deal can be accomplished in a few years.”
So turn those dunghills and keep those carts rolling!
Nathan McClintock made a lot of compost as a Peace Corps
ag volunteer in Mali. He holds an M.S. in sustainable agriculture
from North Carolina State University. He just returned from
assisting a farmers’ group Nepal in its transition to
organic. He will be starting a PhD in agroecological geography
at Berkeley this fall.
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