- Agroforestry is an ancient agricultural technique being rediscovered all over the world as limitations of the globe’s highly industrialized agriculture become obvious.
- On the old and exhausted soils of Africa, trees’ power to nourish life is potentially integral to a reboot of the continent’s agriculture.
- Agroforestry is the intentional combination of woody perennials like trees and shrubs with crops and also livestock to create a resilient “food ecosystem” that benefits farmers, biodiversity and the climate.
- In an analysis for Mongabay, agroforestry expert Patrick Worms suggests that while news reports show forests burning in many places, one can take heart from the fact that trees are busily taking root upon the world’s vast swaths of farmland.
It was late afternoon deep in the dry season in Fatikh, a village in the Sahel region of Senegal. Out on his farm, El Hadj Ndiaye, a distinguished gentleman in an elegant emerald-green boubou, was happily extolling the virtues of the young trees dotting his fields, when his mood suddenly darkened.
His gaze had caught on a distant herd of cattle. More than a hundred huge-horned animals in dozens of tones of ocher, white and brown, already a lot thinner than they were at the end of the wet season, steadily drew nearer, foraging for whatever fodder was left on the fields. Soon, the target for Ndiaye’s anger became clear: it was Yack Diouf, the young Serer herder who was guiding his animals to the most promising spots with a few lazy taps of his switch.
Ndiaye, it soon became clear, suspected Yack of being one of those who would try to cut down his trees later in the dry season, once the fodder is all gone. Their verdant, protein-rich foliage would then be a serious temptation to the young men tasked with feeding the livestock of a powerful owner.
“Everyone wants to cut my trees,” he complained. “They say ‘you did not plant this tree, it grew by itself! It is not yours, it is God’s!’ Me and my sons must spend nights out here to protect them. And it’s not just the cattle, it’s also the women who covet them for firewood!”
Exasperated, he muttered that he would get rid of all of them. But he didn’t mean it, it soon became clear. Ndiaye’s trees were simply too useful.
His millet yields had shot up since he had managed the regeneration of his trees, many of them nitrogen-fixing legumes, from shoots sprouting from old root balls and dormant seeds. It wasn’t just the nutrients the trees could find deep underground and offer to the hungry crops via their leaf fall. It was also the distributed shade that allowed crops to keep growing during the hottest hours of the day, and the humidity that stayed in those fields longer than in those bereft of trees. Also, the breaks they formed kept his soils from being blown or washed away by wind or rain while capturing the soil stripped from his neighbors’ fields.
And to top it all? A steady supply of firewood for his wife’s kitchens, and of fodder for his animals. It was worth spending a few nights out in the open to protect this bounty.
These few minutes in a remote village at the edge of the Sahara taught me more about agroforestry than years of reading and traveling. It was all there: the massive advantage of having trees in fields, the trouble they cause via competing claims, and the reason donor agencies are becoming so fascinated by them. (I was there working for Regreening Africa, a project funded by the European Union that aims to regreen at least a million hectares, about 2.5 million acres, in eight African countries, and whose management is entrusted to my institution, World Agroforestry.)
Agroforestry is being rediscovered in the U.S. and elsewhere as the limitations of our highly industrialized agriculture become all too obvious. In retrospect, it may seem that this took a surprisingly long time to reveal itself.
But consider this: the U.S., Europe and other temperate zones were blessed. Deep, rich soils and plentiful, regular rains allowed them to forget about agroforestry, a farming technique that fed their industrial cities and world-conquering armies. From the 1920s onward, industrial agriculture reliant on tractors, diesel, inorganic fertilizer, pesticides and irrigation really did deliver abundant, cheap and nutritious food for decades before the downsides became all too obvious to ignore.
But out on the mostly old and exhausted soils of Africa, that luxury was simply never available. In those lands, attempts to replace these traditional farming systems with the green revolution package — hybrid seeds, inorganic fertilizers, pesticides, irrigation — proved disappointing, if not outright failures.
It wasn’t just that Africa’s old, degraded soils bereft of carbon are often too acidic for crops to efficiently take up essential nutrients such as nitrogen, potassium or phosphorus (making inorganic fertilizer useless or worse than useless: that excess nitrogen often ends up as nitrous oxide, a greenhouse gas 300 times more potent than CO2). It was the very model — predicated on replacing ecosystem services and labor with capital — that was unworkable.
Africa is not just poor, but enormous. Its land area is greater than that of the United States, India, China, Japan, and the European Union put together. On such a large, poor continent, distances are vast and infrastructure usually missing. Trucking diesel, fertilizer or pesticides is prohibitively expensive.
For similar reasons, there is little agricultural machinery, and consequently few mechanics capable of repairing it. Farmers frequently have no legal deeds to their lands, and thus no collateral.
At any rate, servicing loans measured in tens or hundreds of dollars is rarely profitable, which means there are no banking services in the countryside. In Africa, the equation was brutally simple: No trees? No crops.
By contrast, the rich world is conveniently compact, has more than a century of accumulated transport infrastructure to draw on, excellent banking services, clear land titles, and superb agricultural universities. There, the exact same package supplied such a bounty of cheap produce for so long that the extraordinary yields of the agroforestry systems that preceded them were almost entirely forgotten.
But today, the downsides of that kind of farming are becoming all too painful. Excess nitrogen fertilizer runs down watersheds to create vast dead zones in the Gulf of Mexico and elsewhere around the world. The rich soils of the U.S. Midwest or Ukraine, grown over thousands of years by billions of grazing animals, are almost gone, damaged by relentless plowing, blown away by the wind or washed away by storms.
Everywhere, farmland is becoming increasingly acidic, demanding additional liming. Vast monoculture plantations act like an open bar to pests and diseases, forcing farmers to spend more and more on pesticides. Aquifers are being sucked dry, raising the cost of irrigation as new wells must be dug ever deeper. Industrial farming is engaged in a vicious circle of ever more inputs at ever greater expense to try to keep up with the challenges it creates.
And often, it fails. About a third of the planet’s farmland has already been abandoned because of soil degradation.
None of this is news to specialists, and it is why the experience of farmers like Ndiaye is becoming so relevant even in the United States. Agroforestry, seen by mainstream farmers a couple of decades ago as nothing more than a marginal pursuit by hippies, permaculturists and other ne’er-do-wells, is now being promoted at the highest levels because of the promise it embodies: that we can come to grips with our mismanagement of this planet.
Belle of the ball
Trees can do it all, it seems. They suck carbon from the atmosphere and deposit it in soils and their bodies. They fertilize the land though the nutrients their deep roots pump up and deposit though leaf litter. Their roots channel rainwater deep underground, letting it recharge aquifers instead of gathering into a flood. Their shade protects against droughts by creating a microclimate that allows the crop’s stomata — the breathing holes on the surface of every leaf — to stay open and photosynthesis to continue (they would otherwise close to protect the plant’s water content, halting its growth). And they feed our insatiable appetite for everything from furniture to toilet paper.
Everywhere, it sometimes seems, trees are conquering farmland. Agroforestry is part of the recently announced European Green Deal. India is spending billions of dollars promoting it. France has a National Agroforestry Strategy. Stateside, agroforestry is key to the burgeoning regenerative agriculture movement, and is being promoted by the Intergovernmental Panel on Climate Change (IPCC) as a key mitigation measure against climate change.
Agroforestry is fast becoming the belle of the agricultural ball. To better understand the history and the potential of this ancient yet novel way of managing farming landscapes, nothing beats going to its ground zero: the semi-arid drylands of Niger.
This may seem surprising, at first. This vast, sparsely populated West African state is mostly desert. When it does hit the news, it is usually for all the wrong reasons: its huge and lawless wastelands shelter jihadists, smugglers and fighters of every stripe. It is in Agadez, capital of its north, that so many thousands of African migrants start their hellish trek across the Sahara to the slave camps of Libya or to a watery grave in the Mediterranean. And it is there that a toxic combination of desperation, banditry and religious extremism leads to insurrections sucking in the young men and women of U.S., French, German and other armies, sometimes to lethal outcomes. On Dec. 12, 2019, a battle with militants cost 71 Nigerien soldiers their lives.
It is not just the profitable migrant trade that attracts the baddies. There are gold mines to exploit, cocaine to transship from Latin America to Europe, and Westerners to kidnap for ransom.
But there is something else there, as well. Timbuktu, across the border in Mali, may have a priceless library, but Niger has something just as precious: probably the world’s most extensive human-managed parklands.
Since the terrible famines of the 1970s, some 9 million hectares (22 million acres) have been re-greened there, according to the U.S. Geological Survey’s Gray Tappan. These plains now look like huge forests of thorny trees, but are in fact productive farmland, yielding over a million more tons of grain than before. A desolate land, once bereft of life and fast on its way to desertification, has been utterly transformed.
It was a story I needed to see.
Zinder, the city at the epicenter of this transformation, held another attraction: Sahara Sahel Foods, a small company buying, processing and marketing foods drawn from dozens of local tree and shrub species. Run by a Swedish-Norwegian family living there since the mid-1980s, the company was a local success story, its products served at state dinners and displayed in the offices of ministers.
Visiting was easier said than done. My job brought me to Niamey, the capital, but no further. Most of the 890 kilometers (550 miles) to Zinder are deemed too dangerous to drive by Western embassies. Air Niger’s only plane was out of commission. Our local partners recommended hiring an armored personnel carrier and six policemen at a cost of $1,500 a day. Needless to say, this is the kind of change that a research institution like mine does not possess.
Josef Garvi, the CEO of Sahara Sahel Foods and a local celebrity (“Le Nigérien Blanc” extols his wares on TV in perfect Hausa and Djerma), suggested going by car. It would be safe, barring fate, he assured me: after all, he had been commuting along that road without trouble for decades. A few safety precautions later (don’t tell anyone where you are going, where you are or when you are leaving; no real-time status updates online, that sort of thing), and we were off.
Leaving Niamey on the road east quickly made it obvious how difficult farming can be in this treeless landscape. The small villages dotting the country are among the poorest one can see anywhere. It’s not that the area is exceptionally dry: at about 580 millimeters (23 inches), average rainfall is similar to central Oklahoma or the eastern Dakotas.
But unlike there, in Niger the rain comes in one rainy season followed by up to 10 months of intense heat. And the rain that does come is wasted. These exhausted soils devoid of organic matter have long since formed hardpans or been eroded down to rocky glacis. The water just runs off. An hour after a rainstorm, the ground is as dry as it was before. Raising crops here without irrigation is almost miraculous.
Hours later, arriving at Kouré, the landscape started changing. As we dropped toward Birnin Gaoré, the change felt almost biblical. We were leaving purgatory for a paradise of trees: we had entered the first of the legendary Faidherbia albida parklands.
Of all the trees that transformed Niger’s fate, none is more important. One would not guess so from its appearance: it grows slowly, and in its youth its somewhat bedraggled countenance of spindly, thorny branches growing hither and yon from a twisting, deeply ridged trunk hides its immense value.
For F. albida, named for a controversial French governor of Senegal, has a trick up its sleeve that no other tree anywhere can match: its phenology, its life cycle, is the opposite of every other dryland plant.
Far from coming into leaf and thirstily drinking its fill during the rainy season, this nitrogen-fixing tree chooses that time to go into dormancy. Its small, nutrient-packed leaves drop with the rains, the better to rot and release its nitrogen and minerals to the freshly planted crops. It stays dormant for the duration of the rainy season, thus not competing with young crops.
Even better, it is when the dry season starts to bite and the heat goes relentlessly up that F. albida comes back into leaf, casting a welcome shade on the crops, thus allowing them to keep growing. Its deep taproot will almost always find water and nutrients, and it generates a microclimate beneficial to farming.
In Africa’s drylands, these trees often make the difference between farming and desert. From Senegal in the west all the way across to Djibouti in the east, and from Ethiopia in the north down to Zimbabwe in the south, F. albida is the tree that has done more than any other to transform the fate of Africa’s cereal agriculture. And it is in Niger that the outside world first recognized its immense importance.
Development organizations like World Vision had long ago understood how important trees were to dryland agriculture. The evidence was, after all, obvious: most of the trees were cut for cash during the famines of the 1970s, but even as rainfall returned to normal, agricultural production in the freshly treeless fields did not recover. They thus engaged in large-scale tree-planting efforts across the region, to no effect whatsoever.
Seedling mortality rates were ferocious, exceeding 99%. Without expensive irrigation, it soon became clear, planting was a waste of time. It was in Maradi, our next stop, that a young Australian, Tony Rinaudo, first had a crucial insight: the trees were not gone, they had simply moved underground.
The rooting systems of most of the trees cut a decade before were still alive, tapping into deep aquifers, and sprouting dozens of tender shoots from their stumps. The shrubs he could see everywhere were in fact coppiced trees, struggling to regrow. Cut away most of the shoots, keep only the strongest ones, and voilà! Soon, a vigorous tree grows right back.
Armed with this knowledge, Rinaudo spent the rest of his career promoting what he dubbed farmer-managed natural regeneration, or FMNR. It is this technique that regreened the immense areas measured by Tappan.
Past Maradi, the road soon entered a mosaic landscape: villages of small, square mud houses strung along the roadway, usually sheltered by neem trees. Woven granaries clustered in the village square to better protect the precious harvest from thieves. And in between, the famous parklands.
F. albida, known locally as gao, grew in the parklands, of course, but other useful plants grew, too: aduwa (Balanites aegyptiaca), the desert date, whose milk I was to discover is perfect on a hanza (Boscia senegalensis) muesli; kalgo (Piliostigma reticulatum); in the lowlands, doum (Hyphaene thebaica) and gigina palms (Borassus aethiopum) — the former sometimes coppiced right down to a grass-like aspect to better harvest the leaves for weaving, the latter a silent witness to a bygone age, when their huge seeds would have been spread in elephant droppings.
And, sometimes, no trees at all.
For trees to thrive in an agricultural landscape, it is not enough for farmers or development agencies to be convinced of their use. Animals must be kept away from young shoots, and farmers must, like El Hadj N’Diaye in Senegal, be assured of the benefits of their trees.
Perhaps most crucially, tree tenure must be clear. In French West Africa, administrative systems are based on French colonial codes, themselves developed in Napoleonic times. Lumber being a strategic resource for the navy, France required landowners to file for permits to prune or cut their trees.
While this may have made sense in Normandy, it is a disaster in Africa. There, forestry agents are poor, and the temptation to squeeze farmers for transgressions — imaginary or real — is ever-present. A fine for illegal pruning is pretty much the same whether one has taken a few twigs for the kitchen fire or stripped all the branches to sell as firewood at the roadside, so people prune them right down to the trunk, killing many in the process.
It can get downright Kafkaesque: in Côte d’Ivoire, the ownership of trees depends on who planted it. “Wildlings” and other regenerated trees belong to the state, and planted ones to the farmer. There is no debate about exotics like mango or citrus, but how is a farmer to prove that a native timber tree, sometimes worth thousands of dollars, was one he planted?
The country has been mostly stripped of its ancient rainforests, and thus the forestry department will soon turn up to claim ownership of the few remaining valuable trees. Worse, it will damage the farmers’ cocoa fields in the process of harvesting those giants. Not surprisingly, farmers get rid of any wildlings daring to pop up.
While the rich world is not exempt from these issues (in Europe, for decades, the subsidy payments of the common agricultural policy were based on the area of land farmed, minus the crown area of any trees, and in some countries farmers can have their tenure removed if their trees are deemed beautiful enough by the local council), the U.S. generally does things better.
“Regulation-wise, we’re pretty lean, which is one of the advantages of a largely deregulated free market,” said Harry Greene, the CIO of Propagate Ventures, an agroforestry consultancy. “Investors can even own trees as real assets on land they don’t own. When a farmer owns the land, as far as tree planting goes, they can usually do whatever they want with it.”
Tenure was one of the magic buttons that allowed the areas around Zinder and Maradi to be transformed, with community participation another. As Tony Rinaudo tells it, the farmers knew full well how useful trees could be. All they needed was to be left alone by the forestry department. Convincing it to draw back became a significant part of his work and that of his University of Maradi colleague, Abasse Tougiani.
Farmers also needed to come to an agreement about a regreening strategy. After all, poor farmers cannot afford barbed wire. Protecting fragile seedlings and young shoots meant that another way would have to be found to keep browsers away.
The trick is called social fencing: a grazing plan, agreed by all and enforced by the chief, dictating where animals are allowed to graze and when. Often, this involved negotiating with pastoralists like the Fulani, whose lifestyles had them travel across thousands of kilometers.
It is easy to guess how difficult this could be, and Rinaudo tells of villages where it took the better part of a decade to come to an agreement. But once an agreement is reached, transformation can be swift. The results, I could see, were spectacular almost everywhere in the region (the treeless villages we were driving through were simply saddled with a bad chief or a few feuding families).
Zinder is a pleasant, low-slung town of ocher mud houses and shade trees, centered around the sultan’s palace and the old slave market. Surrounding the city in all directions are gorgeous parklands dominated by F. albida. The story has it that the old sultan — was it three generations ago? Five? No one seems to know for sure — recognized the immense value of the trees and decreed that anyone daring to cut one down would have their hands chopped off. Whatever the truth of that story, the landscape is dotted with fine old trees, clearly predating the famine.
The Garvis have been the only Westerners in Zinder for years now, with everyone else chased away by the threat of jihadism. The clan’s patriarch and Josef’s father, Arne, has studied the local flora for more than three decades; his trial stations and test plots have pushed close to the edge of the Sahara, showing that locally adapted trees can grow and be useful way beyond their commonly accepted range. I was astonished to see a baobab (Adansonia digitata) growing in an area getting by on less than 250 mm (10 in) of rainfall.
Forgotten foods revived
Sahara Sahel Foods, managed by Josef and his wife, Renate, draws on Arne’s work to attempt something grandiose: undo centuries of food norms imposed by Arab and European colonizers. In these semi-arid areas, people traditionally ate a diet comprised of the fruits, nuts and seeds drawn from dozens of local species, complemented by the products of hunting, gathering and pastoralism. These typically grow on shrubs or trees adapted to long periods of drought, extreme heat, and the pressure of browsing animals like camels.
These foods were varied, nutritious and almost always available, even in the worst drought years. But they were deemed to be unclean by the Arabs, fit only for animals. They introduced the cultivation of millet, the cereal most adapted to these very dry conditions. The French saw no reason to change this.
This turned out to be a disastrous decision, both from the point of view of food security and nutrition. In drought years, millet may not set seeds, and even in years with plentiful yields, millet porridge on its own would not offer the full range of nutrients people need. It is this that Sahara Sahel Foods is trying to change.
In this, Renate and Josef are following settled science. At World Agroforestry, we have shown that the easiest, cheapest and most resilient way of providing a nutrient-dense diet to smallholders is to encourage “agrobiodiversity,” the mixing and matching of crops and livestock with fruit and nut tree species chosen for their nutritional characteristics and fruiting times.
“That way, a family can have access to micronutrients and, sometimes, enough calories even in the hunger season,” said Stepha McMullin, who leads this research and has developed dozens of tree suites adapted to semi-arid, semi-humid and humid African contexts. “We’ve found that focusing on locally adapted tree species, both indigenous and exotic, can act as a real resilience-booster in fragile landscapes.”
Renate and Josef are developing and marketing products drawn from more than 50 local species, and are focusing on pseudo-cereals like hanza, whose caloric yields from wild stands are easily double those of millet, and whose nutritional profile puts it in the shade. A breakfast of popped hanza muesli with aduwa and gawasa (Neocarya macrophylla) nuts, marula (Sclerocarya birrea) and Christ’s thorn (Ziziphus spina-christi) seeds, the lot steeped in aduwa milk, did more than set me up for the day: it proved the nutrition point. Hanza is a far richer meal than most cereals.
The markets they are creating for these forgotten foods is transforming livelihoods in other ways, too: the tree products are harvested by women, for whom this activity is usually the only source of cash. Sahara Sahel Foods’ warehouses were full during my visit, and the queue of women wanting to sell much longer than the company’s ability to process the goods.
Yet growing the company was a challenge. In Niger, securing simple things — bottles for juices, cardboard boxes to ship products, or cold storage — is hard or impossible. I saw labels churned out on a home printer on standard paper, hand-cut with scissors and pasted on bottles with office glue. And overcoming centuries of culture is hard. These may have been traditional foods, but that was a long time ago.
In many ways, the challenges faced by the Garvis are a microcosm of the challenges faced by agroforestry around the world. Anyone who looks at it will agree that it is obviously a fantastic idea that needs to spread, but it faces a huge number of challenges. The education most farmers in the rich world get is focused on agronomy, machinery, irrigation, fertilization, and dealing with the regulatory challenges. They receive no training on how to manage trees, or even why they should.
In the poorer parts of the world, this is compounded by the very low quality of the advice that most farmers get. If you come out of an African agricultural college, you will first try to get hired by a research institution, a major development group or a seed company, because those offer by far the best salaries. If you must work for the ministry of agriculture, you will try to secure a desk job in the capital. It is mostly those without connections and with poor degrees that are sent out into the countryside.
This is compounded by another hurdle: seed and fertilizer companies advertise, trees don’t. Because agroforestry does not depend on the purchase of inputs but mostly on management decisions taken by a farmer, there is no ready business model to finance its spread. There is thus no income to finance research, marketing or lobbying for agroforestry. This is a problem everywhere, not just in the poor world. In most industrialized countries, farmers’ unions are familiar with industrial agriculture, but not with tree management.
Despite these challenges, agroforestry is progressing. Young farmers in particular are fascinated and are exploring the various ways of adding trees to their systems. They are driven by three insights. First, trees do not just help the production of crops, but also provide additional income streams from nuts, fruits or timber. Second, managing an agroforestry system demands a more hands-on approach than managing a monocrop: it speaks to the geek in every young farmer. And third, there is the looming threat of global warming.
Agroforestry trees do not just offer protection against increasingly frequent episodes of extreme weather, but they are also able to lock up enormous quantities of carbon. More than 30 gigatons, equivalent to 110 GT of atmospheric CO2 or more than two years of global emissions from all sources, are already being stored by trees on agricultural lands. And yet almost 60% of the world’s farmland has few or no trees on it.
Finally, agroforestry has been shown to be one of the most cost-effective ways of bringing the roughly 30% of the globe’s farmland that has been abandoned because of degradation back into production. There is thus little doubt about its potential as a major carbon drawdown solution.
This, too, attracts young farmers. They belong to a generation which is not only aware of the enormous threat facing their future and that of their children, but can see a potential financial opportunity as country after country starts rewarding land managers for storing carbon in their soils.
That, and growing interest from the private sector, will help agroforestry spread more rapidly in the future. In the rich world, it is a technology that will increasingly be added to the farmers’ traditional armory of mechanization, genetics and chemistry.
In the poor world, as Niger’s example shows, its benefits speak for themselves. At first, agroforesters thought a few tens of thousands of hectares had been regreened. Ten years ago, remote sensing suggested it was more like 5 million hectares (12 million acres). Today, we know it’s at least 10 million hectares (25 million acres).
As the world’s forests burn, we can take heart from the fact that trees are invading our farmland.
This report is part of Mongabay’s ongoing coverage of trends in global agroforestry, view the full series here.