Africa: Trees Can Increase Farm Yields and Transform Agriculture Says Agroforestry Group

Dennis Garrity
1 November 2009
interview

Headquartered in Nairobi Kenya and working across sub-Saharan Africa, as well as in Latin America and Asia, the World Agroforestry Centre aims to enhance soil fertility and the livelihoods of poor families and communities by introducing – or improving the varieties of - nutrient providing trees into farm feeds. Dr. Dennis Garrity, Director General of the Centre, told AllAfrica that trees on farmland can play a transformative role in rural agriculture.

Tell us about your organization.

The World Agroforestry Center is the scientific leader in research and development on what is known as agroforestry, or the science and practice of trees on farms. It is all about trees that farmers use in their farming systems for a better livelihood, for better services, for products that they need and for income for their families.

Trees in the tropics are integrated into farming systems, unlike in the North where trees tend to be in separate forests, and farms are monoculture crop fields. On the hundreds of millions of farms in the tropics, farmers tend to put trees right into their crop fields in various ways that are compatible with their crop systems and enable them to produce more from a small area of land.

If this is a traditional practice, what does the Agroforestry Center contribute?

As in all of agriculture, science adds value by increasing productivity and improving lives. Agroforestry has been practiced for thousands of years in many parts of the tropics, and you find traditional agroforestry systems everywhere you go, particularly if you know where you're looking. But it's only been within the last 30 years that we've had the opportunity to provide scientific methods and analysis to these traditional systems. As a consequence [we can] provide new solutions, higher value, more productive agroforestry systems that in many ways can transform the opportunities, the futures of the poorest farm families in the world.

Can you give a couple of examples of what is most promising in those areas right now, where scientific research has added value to what farmers have traditionally done?

One of the most intriguing examples, which we're now developing in Africa continent-wide, is the use of what we call 'fertilizer trees' in farming systems: trees that are compatible with the crops but provide organic fertilizer - in effect creating a fertilizer factory, right in your field, to feed your crops and thereby feed your family. It increases the yields of corn, maize, sorghum, millets, wheat and other cereal crops, all of which need better nutrition for higher yields.

There are quite a number of different species [of trees]that can be used, but certain ones have particular advantages. We're emphasizing the value of those particular species as a fundamental component of the repertoire of most farmers.

We've got to find better ways of producing food under the realities of African agriculture systems. "Fertilizer trees", which are systems that farmers can apply with virtually no cash investment, are a way in which farmers can ramp up their soil fertility and their crop yields with little effort and no cash. This is the kind of solution that desperately poor farm families - particularly women-headed households, who are 70 percent of Africa's farmers - can apply. They can apply them today and can double and triple their families' food production.

Africa faces a fundamental challenge in declining per capita food production - a food security crisis - and in order to turn that around we had better get more innovative solutions. African crop yields have not been increasing for 50 years. They remain at the same flatline level of yield that they were a half century ago, and the population is multiples of what it was a few decades ago.

Why haven't the yields increased?

The fundamental reason is that farmers in Africa lack the nutrients that their crops need. New, high-yielding varieties of corn, wheat, sorghum, millet and other [crops] are available. Plant-breeding programs have enabled these varieties to be developed and to be extended to farmers over many years. But you're not going to raise the yield of your crops by planting a new variety alone. That variety has got to be nourished by the soil.

The fundamental problem is that farmers have not been able to use fertilizers effectively – either because they were too expensive, they were unavailable, or the climate is too variable, too risky for them to use fertilizers, because they are a cash cost. You're investing cash in fertilizer with the hope that it will produce higher yields.

Because of such frequent and severe droughts in most African countries, it's risky to apply fertilizers. You may lose your shirt one year, two years out of three, and your cash investment in fertilizer goes down the drain. You may go into serious debt that you can never draw yourself out of. So farmers are prone to being conservative and not taking risks that could affect the future of their families for decades.

What we find is that the soils of Africa continually degrade, lose their fertility and do not provide the nutrients that farmers need, even for minimal yields of their crops. So farmers throughout the continent face a cycle of poverty, generated simply because they can't afford to apply these nutrients to their crops; therefore they cannot increase their crop yields; therefore their soils are mined of nutrients and the crop yields decline. It's a destructive circle of poverty.

Is there another reason for finding alternatives to chemical fertilizers, beyond the cost? How about what has been learned in places that have relied on fertilizers, such as the environmental consequences of run-off?

Run-off of fertilizers, the poisoning of water due to nitrates, is a problem in countries where fertilizer use is high. Certainly it is not a problem in Africa, where fertilizer use is extremely low. So the consequent environmental problem of using fertilizers is a minimal problem on the African continent.

What we and many others believe is that African farmers needn't be concerned about poisoning their water supplies or their environment with fertilizers. Quite the opposite. Fertilizers would improve the environment of Africa, because fertilizers would enable farmers to intensify their crop production systems, improve their livelihoods and give them a leg up in being able to protect their environments better.

We believe that African farmers should use as much fertilizer as they can afford to use. But since they have little option to use enough fertilizer, we're looking at all the opportunities that can help them get started along the path of regenerating their soils and creating new soil health that can be the basis for their prosperity.

Are there complementary things that farmers can use in the meantime, besides planting trees, besides whatever fertilizers they can afford? How about composting, putting organic materials into the soil?

Absolutely. One of the main opportunities in Africa for alternative soil fertility is livestock manure.  In most African farming systems, livestock are a major part of the farm and the farm economy, and African farmers already appreciate the value and utility of using manure as a source of nutrients.

The problem is, there's nowhere near enough of it. [Farmers] simply don't have enough organic material on the farm to be able to provide the minimal levels of nutrients that they need to ramp up their crop yields to the levels that could be successful.

So whereas Africa could easily generate three, four or five times the food production that it has now - if there were adequate nutrients to supply to the crops - what we see is poverty, hunger, food insecurity, because those nutrients are just not available to farmers.

How do you propagate what you're doing? How do you translate it from research into projects that work on the ground? How do you get seedlings – if that's what you distribute – to farmers? Or are there seedlings that can be cultivated or propagated in villages, for example? How does it all work?

As in the western world, the institutions like ours that produce the science, the knowledge for better practices for farming, are translated to farmers through extension services. Extension services are put in place to provide farmers the advice, the information they need to make improvements in all aspects of their farm. There are extension agents hired for the purpose of advising farmers, and they're usually paid by the government. The tragedy in Africa is that extension systems have been declining through lack of attention, lack of government investment, because extension systems are public systems.

So there are ways in which we try to work around that. In Africa there is a vibrant NGO community that plays a major role to help provide a complementary source of information and advice to farmers. The private sector is increasingly becoming a source of extension information. The local seed dealer, the fertilizer dealer, the dairy adviser also provide farmers with information, as well as the public media, the press, radio, television, newspapers and other sources. In terms of getting our message and the new variety of trees that we produce out to farmers in the remote rural areas, we take a holistic approach, working with all of these different types of institutions.

We also have a major program to work with whole villages through their organizations. Village-level organizations are important in African farming because they are a mutual support system. Often it is the women's groups, the church groups, the local farmers' clubs that provide farmers the kind of mutual support that they need when extension is weak and government support is poor.

For example, the Landcare movement of democratically governed, village-level institutions provides a basis by which farmers, particularly women, can get together and discuss their problems, can set objectives and can find ways of drawing in the support they need to make progress in their farming systems. Landcare is now active in 17 countries, many of these in Africa.

Globally we have a structure to support Landcare programs around the world, as they develop, to provide a very vibrant source of networking, so that people can get information. Landcare is, in a sense, a proxy for having your local computer websites, because most farmers don't have access to the web.

Can you tell us a little about conservation agriculture?

Conservation agriculture is commonly practiced in the United States, South America and other parts of the world. In fact there are over a hundred million hectares of conservation agriculture practiced globally at the present time. Unfortunately, in Africa, the adoption is very low, only perhaps a few hundred thousand hectares so far. But what we know is that in many, many agriculture systems in Africa, by practicing the principles of conservation agriculture, farmers can reduce their labor, increase their yields and permanently improve the health of their soils.

How do they do that? By actually minimizing or reducing or eliminating the tillage of the soil and growing one's crops without plowing one's soil, or hoeing, as in the case of small-scale farmers. So it is a system of agriculture that eliminates the need to turn the soil over every year before you begin planting.

You can imagine the savings in energy, whether it's human energy of a woman hoeing a hectare of maize field in Malawi, or a tractor using fossil fuel energy in turning over the soil. It requires new practices and new knowledge of how to manage weeds, crops, soils, in order to be successful. But what we know from research that's going on throughout Africa is that this could be transformative in increasing yields, while reducing the drudgery of hoeing or tilling the soil.

In terms of boosting the income of farmers, tell us about the Allanblackia tree in Liberia.

A few years ago the chemists at the multinational company Unilever were examining the chemistry of different types of oils from different plants around the world. Unilever is a major world producer and processor of palm oil, soybean oil and other kinds of oils that we use every day. They found that this particular African tree produces an oil-rich seed that has an oil property that is extremely rare. It is very high in stearic acid, which is an important human nutrition element, but it's lacking in almost all other oils in the world.

So here you have a tree that's producing an oil in which you could have as a source of stearic acid that would complement and correct the nutrient deficiencies in other types of oils. That's interesting. Besides that, they discovered the physical properties of this oil are also unique and very valuable in food products. This oil is actually solid at room temperature. So it can be used in various blends with palm oil, soybean oil, other vegetable oils to make products with different consistencies, different textures, to make it good to eat.

So they came to the World Agroforestry Center and said, 'We're really interested in this oil. We know that local villagers in parts of West Africa, Central and East Africa, have used it traditionally as a source of vegetable oil, as a source of lighting for their homes like in kerosene lanterns. We'd like to try to work to make this oil into a globally marketed product. We think that it could be a major new industry for Africa.' So we said, 'Great. What do you need to do?'

'Well, we need to domesticate this tree. We need to collect the germ plasm in the different varieties of the tree, analyze the quality of their oil production, select varieties, learn how to propagate the tree effectively - a real problem in the past - and to otherwise create a crop that is a new oil crop from a tree that grows naturally in tropical African areas all throughout the continent.'

So we formed a partnership and began working with many other organizations, including the national agriculture research and extension systems in countries like Ghana, Cameroon, Tanzania. And in a vast alliance, we are in the process of creating what is now estimated to be a new billion- dollar-a-year industry in which African farmers, small-scale farmers, plant this tree in their farming systems as one of many other types of crops and trees that they grow, as an alternative income source.

We're getting seedlings out to farmers, particularly women, who will plant them and grow them and harvest them and provide them to traders who will aggregate them and sell them to the oil processing firms like Unilever for a profit.

Unilever has invested in this, along with a number of other donor organizations that were interested in how this new industry could help alleviate poverty in Africa. We've got an alliance now that's functioning to create this oil crop just as fast as we can.

All the organizations, including Unilever, are committed to focusing on ensuring that smallholders are those benefitting from this new industry. It's not envisioned to be a large monoculture type of agricultural production system. It's envisioned to be a crop that smallholders throughout Africa can include in their farms and make additional profit and income as a result.

We were talking earlier about trees that had an ability to fertilize the soil around them. Could you tell us some more about this? How about the acacia Faidherbia albida?

Strictly speaking it's not an acacia anymore but in all respects except for one it looks, feels and quacks just like an acacia. But there is one particular property that African farmers have observed and have benefitted from over the years that makes it totally unique.

This tree, unlike all other trees that we know of in the world, will go dormant when the rains start. When the rains begin in Africa, the Faidherbia albida trees will drop all their leaves and become bare, skeletal. Because it has this property farmers are able to use it in their farming systems in a very, very profitable way. The tree drops all of these nitrogen-rich leaves, tons of them, and that becomes a rich source of fertilizer for their maize crops, their sorghum, their millets, other cereal crops – and it's absolutely free of charge.

What farmers have always done in certain parts of Africa is to ensure that when these trees naturally germinate and come up in their fields, they protect them. They don't chop them out; they nurture them so that when they grow they provide a natural source of fertilizer for their crops.

In countries like Niger, Burkina Faso, Senegal, Chad, Ethiopia and Malawi, farmers have for many generations nurtured these trees in their fields. Scientists began to get very interested. We've been studying the tree. We figure there are several million, perhaps five million farmers who actually have these trees in their farming systems. But there are perhaps 50 million farmers in Africa. So we're anxious to bring the message to those additional farmers about the opportunities that await them in using these trees.

In most cases you find that the yields of these crops that are grown under the canopy or near these trees will increase anywhere from one and a half to three times the yield of the same crops grown outside the influence of the trees, in the same fields. These observations now give us confidence that there is a wide range of environments where these trees can produce such positive results.

Agronomists have been recommending that a farmer plant about 100 of these trees per hectare in a checkerboard pattern, in a 10-meter by 10-meter spacing - a grid pattern. So you can do all of your operations between the trees, and as the trees grow, the canopies begin to converge. You get a nice distribution of the trees across the field, producing the benefits of increasing crop yields as you go. These trees will actually grow to the ripe old age of 70 to 80 years before they die.

In the meantime you have other benefits. The leaves and the pods of these trees are an excellent source of livestock fodder. Farmers also like the trees for producing fuel wood, which is often very scarce in the villages, and timber for light construction and use in household building construction as well. Not to mention the fact that you can get various medicinal products from the tree.

There are a number of other important fertilizer trees that we believe farmers should consider integrating into their fields along with Faidherbia. Reseach throughout Africa has been piloting the concept of improving the whole management system of soils and crops by using the principles of conservation agriculture.

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