Feeding a hungry world with trees

[Reproduced from Reuters alertnet]

A couple of decades ago, when my colleagues began urging African farmers to plant trees in the middle of their maize fields, many agricultural development specialists thought we were a bit deranged.

People can’t eat trees. So what good would planting one do for the food security of rural families and villages?

Before long, though, many of the farmers who had planted the soil-replenishing “fertilizer trees” that the World Agroforestry Centre had identified, were proving that all this made good sense. Within only a few years of planting these trees and shrubs, farmers were reaping abundant harvests of maize from fields whose exhausted soil had previously produced almost nothing.

Millions of farmers from around Africa have improved their soils and boosted their livelihoods by culturing nitrogen-fixing species such the indigenous African acacia, Faidherbia albida, or others like Gliricidia selum or Calliandra calothyrsus, introduced from Central America.

The usefulness of trees to agriculture has now caught on with African governments, as well.


Eleven countries in the Sahel, at the heart of the continent, are creating a Great Green Wall, a monumental agroforestry programme working toward environmental and development transformation in the region. The heart of this programme is the vast expansion of agroforestry parklands on farmers’ fields, where their food crops grow under the canopy of a forest of compatible trees.

This vast belt of evergreen agriculture, stretching from Dakar, Senegal, to Djibouti on the Horn of Africa, will employ the best of farmer-proven and scientifically-confirmed agroforestry techniques to halt desertification while alleviating poverty for thousands of local towns and villages.

This effort builds directly on the demonstrated success of the millions of farmers across this region who are already using fertilizer trees and shrubs to replenish soil nutrients on their farms. In the process, they are boosting the food security of their households and nations, while improving their livelihoods and “re-greening” the environment.

Fertilizer trees represent a long-term and sustainable solution for the declining agricultural yields that have plagued Africa. And, by the way, they are a solution that costs the farm family practically zero cash investment, and minimal risk. The current practice of government subsidies for mineral fertilizer helps in the short term. But what happens when the subsidies stop?


When I met Mariko Majoni, a Malawian farmer, a few years ago, he had exhausted his pension money on mineral fertilizers, which had increased his maize yields, but left his soil poor again when the money ran out. However, after he had acquired Gliricidia seeds from a local agroforestry research station, the health of his soil dramatically improved, and it became much better at retaining nutrients and moisture. Within two years of planting these trees, his maize yields had increased eightfold.

Planting fertilizer trees in cropland is an example of “evergreen agriculture” – an environmentally-sound farming system where food crops and trees grow harmoniously together. The practice reduces poverty, increases agricultural production, and contributes to environmental sustainability by conserving water and soil fertility, while enabling communities to adapt to drought and climate change.

Evergreen agriculture is primed to spearhead a transformative renaissance in agriculture. It has already regenerated millions of hectares of degraded land in the Sahel, as well as parts of East and Southern Africa, dramatically enhancing productivity and improving smallholder livelihoods.

The Great Green Wall, to which donors meeting in Germany this year committed $3 billion, will further the cause, while slowing desertification that affects millions.

Agroforestry makes farms more productive, restoring degraded lands while diversifying diets, providing wood fuel and animal feed. Wild food species such as the Sahelian apple, the bush mango and the African plum have been brought out of forests, domesticated, and are now grown on farmland, providing a resilient source of food to sustain families during periods of hunger and lessening reliance on expensive food imports.

In Guinea, villagers who once eked out a living in the forests now have a reliable food source and dramatically higher incomes. Meanwhile, tree cover is increasing and biodiversity is returning.


Agroforestry also helps combat climate change. According to the Intergovernmental Panel on Climate Change, the transformation of degraded agricultural lands to agroforestry is a promising way to sequester carbon. Agroforestry investments over the next 50 years could remove 50 billion tonnes of carbon dioxide from the atmosphere.

To feed an escalating global population, we must invest in pro-poor, anti-hunger, sustainable agricultural growth. And there are innovative solutions – like agroforestry – that are ready to roll out now.

What we need is more incentives and support for poor countries to transfer these truly practical and low-cost solutions to tens of millions more farms across Africa. The key is building awareness that there is another way, agroforestry for food security, and that it mainly involves the wider sharing of knowledge and good quality tree seeds.

I’m sure Mr. Majoni would agree.


Dennis Garrity

Dennis Garrity is former Director General of the World Agroforestry Centre. From 1992 to 2002 he served as the Centre’s Southeast Asia Regional Coordinator based in Bogor, Indonesia .Dennis has a BSc in agriculture from Ohio State University, an MSc in agronomy from the University of the Philippines at Los Baños, and a PhD in crop physiology from the University of Nebraska. He has worked extensively on the development of conservation-oriented agroforestry systems for sloping uplands and been active in developing institutional innovations related to farmer-led organizations in sustainable agriculture and natural resources management. Dennis served as agronomist/crop ecologist and head of the Agroecology Unit at the International Rice Research Institute in the Philippines between 1982 and 1992.

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