Sustainable in Senegal
Soft and red, hard and black
Getting up close and personal with local soils in Senegal’s Peanut Basin with farmers who are managing them sustainably

By Nathan C. McClintock
July 14, 2005

After the millet harvest the remaining leaves are removed from the stalks and they are fed to the animals—who produce the manure that fertilizes the soil that supports next year’s crop in the Peanut Basin’s circle of life.

“They’re yellowish. Reddish. And soft. Dafa soon. Dafa xonq. Dafa nooy.” Farmer Fatoumata Kâ describes a jóór soil to me, the predominant soil found in her village Taiba Ndao, 20 or 30 miles from Senegal’s second largest city Thiès, deep in the heart of the Peanut Basin.

Fatoumata is a member of the village women’s group, Groupment de promotion feminine (GPF), that New Farm Senegal worked with to improve the soil, improve yields, and provide access to credit for livestock fattening and seed production. She answers my question confidently, as one of the more outspoken in the group of 30 or so women who comprise Taiba Ndao’s GPF.

There is the faint purple stain of antimony dye around her mouth, a common practice among Halpulaar, or Fulani-speaking people, across West Africa. She and Aby Sow, one of the other Halpulaar in this Wolof-speaking village, usually drill me with Pulaar greetings, but are serious during our focus group discussion. “Deg dafa ñuul, dafa deger. Deg soils are dark. And hard,” she continues. The others nod in agreement.

According to the French soil classification system, a jóór (or “dior” in the French spelling) is a “sol ferrigneux tropicale peu ou non-lessivé”, an unweathered tropical soil with high iron content. According to the USDA soil taxonomy, a jóór is an Entisol, a Ustipsamment to be specific. That means it is a “young” soil, unweathered from its parent material of sandstone bedrock, in an arid moisture and temperature regime. A deg (or “deck”) is more weathered with slightly higher clay, silt, and organic matter content. It is an Alfisol according to the USDA system.

Researchers and government officials still have work to do to improve communitcation with farmers. "It's useless," Farmer Ngoussane Fall (pictured above) said of the free phosphate the government gave to farmers to supplement deficient fields.

More important, however, is how local farmers themselves classify the soil and decide how to maintain its fertility. Often the divide between science and the real world seems impossibly vast. Scientific scrutiny in the lab or experimental field plot is by its nature centered on the microscopic, on teasing out the factors at play in a given system. Yet as most things in life are greater than the sum of their parts, a microscopic focus often misses the obvious. It’s like not seeing the proverbial forest for the trees, though that metaphor hardly seems appropriate in the scrubby Sahelian savanna

It’s easy for an agronomist to figure out what amendment produces the greatest yield on a given soil type, but this insight is of little human value if it remains tucked away in a scientific journal somewhere along with legions of other papers by the likes of “Dimpledirt, et al, 1983.”

The essential task for appropriate agricultural development is to put these findings into the fields of farmers struggling to produce crops with few resources. New soil-care techniques have to work as part of a farming system that recognizes the local constraints, ecological as well as social, economic, political, and cultural. Why waste time and money promoting a farming practice that violates a cultural taboo or gender division of labor, or is impossible due to lack of access to capital? It’s not that it’s unimportant to figure out if a soil is an Alfisol or an Entisol, but to help farmers to regenerate these soils, you have to understand how they see it themselves.

Fortunately, over the last couple of decades, government development agencies and non-governmental organizations (NGOs) alike have begun to recognize the importance of involving local farmers in the process of agricultural research and development. Baseline surveys are a now prerequisite to any attempt to introduce appropriate technology in the field.

I’ve traveled with the Rodale Institute’s staff to the villages they serve to get a better understanding of local soil management practices. I’ve had individual interviews and discussions with the women’s groups and smaller focus groups in the villages of Taiba Ndao, Diouffène, Keur Banda, Thiawène, Keur Sa Daro, Touba Peycouck, Mboufta, and Ndaimsil. I’ve been struck how similar soil classifications are across the Peanut Basin -- and how well adapted the practices are to the harsh climate.

Senegal Soils 101

Oury Diallo, left, a former technician with New Farm Senegal, and farmer Ibrahima Niang of Keur Banda collecting peanut biomass samples. They were comparing the effects of compost and manure on crop growth.

Farmers here classify soils according to color and texture. Jóór soils are “soft” (nooy in Wolof) and light-colored—red (xonq), yellow (soon), or white (weex). Soils classed as deg are hard (deger), and dark or black (ñuul). There was some variation in nomenclature between the villages. In Taiba Ndao, they used the word deg interchangably with xur to describe the darker soils. A xur is a low lying area, a basin, or where deg soils are generally found.

When I asked which type of soil was most fertile or productive (naat), farmers in all villages agreed that degs were the most fertile. However, this depends on rainfall. Under drought conditions, crops planted in jóórs yield better, whereas in years with ample rainfall, participants noted, “Deg moo gënë naat”, degs are more productive. The higher clay content of the deg allows for a greater water-holding capacity, extending the moisture exposure to plants after a rain.

Because a jóór soil is often 95 percent sand, water drains quickly away beyond the root zone. Under drought conditions however, the may quickly harden due to higher clay content, impeding root development and resulting in lower yields. So while degs are inherently more fertile than jóórs—they have a greater quantity of organic matter and a greater ability to hold nutrients—yields are more a function of rainfall than which soil a crop is planted on.

When I asked farmers what crop they planted on a given soil type, they laughed and agreed that they don’t get much choice in the matter. If all your fields are jóórs, then you plant everything in jóórs! I appreciated their good humor and recognized that familiar, lighthearted acceptance of what God has divvied out as the fine thread of fatalism running through the Sahel, prerequisite to survival in such a fragile environment.

So I rephrased my question. If they have the choice, what do they plant where? Peanuts, which require sandy soil, are planted in jóórs. Millet grain in degs. Usually, however, because most fields are jóórs, farmers rotate annually between peanuts and millet. Fallowing has more or less disappeared from the rotation. Each year more and land is cultivated to make up for a drop in production that can be attributed both to declining fertility and declining rainfall over the last several decades.

If a field is fallowed at all, it is often only left for a year. Of those who carry on the practice, a few said their goal is to let the soil rest and regain its strength. Most, however, said that they simply lacked sufficient quantities of seed to plant all fields. Instead of fallowing, some farmers work a cowpea crop into the rotation. In many of the villages, women were in charge of this crop.

Rationing out manure

Under ideal conditions peanuts, like those shown above, would be grown in jóórs but since conditions are often less than ideal farmers fertilize where they can and plant where they must.

If there is a limited supply of sentaare manure, it is applied to the less fertile parts of the fields. “How do you identify these?” I asked. “The color of the soil, if it’s yellow or white,” they responded. In essence, a jóór takes priority when it comes time to apply manure. If the entire field is a jóór and manure is limited, farmers often cover half the field with manure one year, and amend the other half the following year. They often apply manure locally, taking into account the field-level variability in micro-topography and fertility, shown by poor yields (“if the head of the millet is thin”) and the presence of nduxum (Striga hermonthica; a parasitic weed endemic in the Sahel).

Following harvest, peanut stover (ngooñ) is collected to use as fodder for livestock, and is either sold or stored for use over the dry season. All the remaining green leaves are removed from millet stalks and fed to the animals. One woman in Diouffène said, smiling, “We feed the animals and they make manure that we then put back on our fields.” Sturdy millet stalks are cut and gathered for use in the construction of fences (sàkket) around the family compound. As the sàkkets eventually weather and collapse, they make it into the manure pile as well. Broken and small stalks are left in the field until the following May or June. At that time, all residues are pulled up to facilitate cultivation and sowing. Useful shrubs and weeds are collected and taken home, and the remaining brush is piled with the crop residues and burned.

When I asked about chemical fertilizer use, most people said that yields were better with chemical fertilizers, explaining that harvests were larger in years past when they had “Two sacks for every household.” Fertilizer subsidies were dropped six years ago and now none of the farmers I interviewed uses fertilizer. Dafa cher. It’s expensive.

While they acknowledged that fertilizer-induced yields were greater, they also recognized that they were temporary. A Thiawène farmer noted, “It only lasts that one year. With manure or compost, it lasts three years!” In Taiba Ndao, the group president said, “We have a lot of animals now and a lot of manure, so we don’t need fertilizer.”

Seeking balance with local amendments

Sustainable soil management requires a balance between good soil science and practical application.

Most Sahelian soils are very low in available phosphorus, as it is bound up by either aluminum or calcium in the soils. So I asked about the use of locally-mined rock phosphate. Most shook their heads, or said they didn’t know what it was. In Taiba Ndao they said that the men never bothered to pick it up when the government delivered it to nearby Thiénéba. In Thiawène and Diouffène they said the natural soil balancer was just clay powder and wasn’t useful. In Keur Banda, Ngoussane Fall claimed that he and some other farmers had used it and hadn’t seen any effect. “It’s useless! The government gives us the leftovers after they export the good stuff to foreign countries!” he added somewhat irreverently. I heard his conspiracy theory a couple more times in other villages.

Rodale extensionist Diagne Sarr shook her head every time, dismayed that the government failed to explain why they were providing farmers with free phosphate. “Il n’y avait pas de sensibilisation. There was no raising of awareness.” When I asked the farmers if they noticed a purplish color to the millet leaves, a sign of phosphorus deficiency, they said yes. She and technician Djibril Diallo used the opportunity to educate them about the importance of phosphorus to plant growth, likening it to breastfeeding a baby.

It’s obviously not an easy message to grasp, but a few of the groups we met with seemed to take it to heart. One of the fundamental differences between industrial farming systems and those found in near-subsistence systems like the one here in the Peanut Basin is that nothing is wasted. Farmers here are in many ways regenerative already, but struggle to manage their fields in ways that keep pace with the twin demands of population growth and declining rainfall.

Every new idea has to earn its place in the shared farming wisdom that allows farmers here to cope with their conditions. Only by understanding and respecting the intricate and finely woven relationships inherent in traditional local farming systems can development organizations propose appropriate improvements.

Using this philosophy, New Farm Senegal promotes sustainable soil management techniques based on good soil science applied to local situations by:

• Recognizing that millet stalks are used as fences and peanut stover as fodder.
• Identifying what works already and tweaking it, building on it.
• Using local terms such as “jóór” instead of “Ustipsamment,” “dark” instead of “humic,” “vitamin” instead of P205.

When farmers hear counsel that reflects and fits with the wisdom they already know, they will listen. Once one or two of them take the leap of faith necessary to apply a promising idea in their fields and see results, others will follow. They will try the method and watch to see what happens.

Things might get better Insh’allah, as they constantly say here. God willing.

Nathan McClintock holds an M.S. in sustainable agriculture from North Carolina State University. He is a freelance sustainable ag consultant, trainer, and journalist. He is currently assisting a farmers’ group Nepal in its transition to organic. He will be starting a PhD in agroecological geography at Berkeley this fall.