Trees of life for food security

Principles of agroecology can get us out of the food crisis in simple steps. Tree biologist Roger Leakey explains.

Roger Leakey

We hear doom and gloom about the now ever-present Global Food Crisis, exacerbated by worsening climate change, and it’s possible to conclude that there isn’t a viable solution. This is exacerbated by the dichotomy of views on ways to address the future of food. The menu seems to be either a genetically-modified silver bullet from biotechnology or, at the other extreme, pure organic farming.

I believe the solution is a combination of modern technologies and organic systems with greater attention to agroecology and income generation from new cash crops. But we need to recognize that the biophysical and socio-economic issues are different in temperate and tropical environments.

Agroforestry involves growing trees with annual crops, such as these mango trees in a paddy rice field in Nepal.
After a career working in numerous remote corners of the tropics, I have been involved in developing what is now a tried and tested vision of what we could be doing. And it is working on the scale of tens of thousands of farmers in hundreds of villages.

Recognizing the problem

The context of the problems here is important. We need to understand that hundreds of millions of poor farmers in the tropics are trying to support their families on around 2-5 hectares of cleared land without access to income, fertilizers and other technologies – a recipe for land degradation, hunger and declining livelihoods.

The desire of the poor for survival and food security, and the pursuit of profit by the entrepreneur, often lead to deforestation, overgrazing and to soil degradation. These in turn lead to a downward spiral involving the loss of biodiversity, the breakdown of agroecosystem functions, declining soil fertility, and so to dismal crop yields and food insecurity, hunger and desperate poverty.

Agroforestry can help limit soil erosion, as in this pineapple and tea plantation on a mountain slope in Vietnam.
This cycle of land degradation and social deprivation creates a Yield Gap – the difference between potential and actual yield – affecting hundreds of millions of poor smallholder farmers in the tropics. To reverse this cycle requires much more than increased yield potential of our current staple crops, like rice and maize. Instead, we have to find low-cost means of improving soil fertility, by harnessing biological nitrogen fixation, and also ecological function by rebuilding agroecological processes: both aspects of better crop husbandry.

There is over 25 years of research experience led by the World Agroforestry Centre (ICRAF) on the use of a number of leguminous nitrogen-fixing trees and shrubs in what are called ‘improved fallows’, ‘relay-cropping’, and more recently in ‘evergreen agriculture’.

A meta-analysis in 2008 of 94 research studies found that maize yields rose from between 1-2 tonnes to 2-4.5 tonnes per hectare. Likewise development projects have reported yield improvements after two years of two to three-fold. Even on a small farm, this yield increase is enough to free up space for other income-generating crops or farm enterprises.

‘Trees of Life’ for income generation – An African solution

Adding nitrogen-fixing trees and shrubs to the farming system initiates the diversification of the farming system creating agroecological benefits. This diversification can then be extended by responding to the suggestions of African farmers, who when questioned in the mid-1990s on what they would like from agriculture in the future, consistently said that they would like to be able to cultivate the indigenous trees – the Trees of Life – that produce the traditionally-important food and non-food products of day-to-day importance.

Many of these are rich in micro-nutrients and are often traditional medicines and are widely traded locally and regionally. I have described the domestication of these new cash crops in my book, Living with the Trees of Life – Towards a Transformation of Tropical Agriculture. It involves a participatory, self-help and empowering approach with local communities in the driving seat.

Fruits of the forest: palm nut fruit at Lubuk Beringin village, Indonesia.
The final step of this highly adaptable generic model for more sustainable agriculture involves the commercialization of the products for increased income generation. For example, there are now over 400 products in European markets from the Baobab tree.

Nevertheless, the biggest growth area for this commercialization is the creation of cottage industries in-country where demand typically exceeds supply, and where short shelf life makes wide-scale marketing a problem. There is urgently needed work on appropriate techniques for local processing and value-adding to extend their shelf life and hence their year-round availability as a source of important dietary micronutrients.

Done appropriately, processing of this sort also creates business and employment opportunities which further help rural populations to enter the cash economy. This gives farmers income to purchase fertilizers and pesticides and so raise the yield of crops on soils suffering from phosphate and other mineral deficiencies up towards their biological potential; so closing the Yield Gap.

The future

The story so far has been effectively achieved over the last 15 years in a participatory programme of agroforestry, tree domestication, social change and transformation south-west Cameroon – a project which has picked up a Equator Prize for one of its communities and the National Geographic – Buffett Award for Leadership in Conservation for its programme leader, Dr Zac Tchoundjeu.

A climate-smart farm in Western Kenya which uses various agroecological principles, including a tree-nursery, growing fruit trees and intercropping.
In another example, Unilever is developing Allanblackia trees as a new oil crop for Africa, with its domestication being  implemented in local communities practicing agroforestry so that a fair share of the benefits flow back to the producers. Hopefully this will become a successful model for other company investments in new tree crops, which might then be used to up-scale and intensify agroforestry approaches to multifunctional agriculture.

So, it seems to me that despite all the doom and gloom about deforestation, poverty, hunger and malnutrition in the tropics, there are a set of 12 principles that combine to create a relatively easy way out of the food crisis. However, it will require a change of mind-set and the development of political will if the ‘Trees of Life’ are to be a catalyst for positive change.

I hope we are now on the brink of a new wave of tree crop domestication, one focussed on the needs of the peoples and environment of the tropics and sub-tropics.


This article developed from a series of articles on Roger Leakey’s website, also published in The ECO-Journal, the West African Bilingual Economic and Business News Journal of ECOWAS.

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About Roger Leakey

Dr Roger Leakey is the Vice Chairman of the International Tree Foundation. He has been Professor of Agroecology and Sustainable Development at James Cook University, Cairns, Australia; Director of Research at the International Centre for Research in Agroforestry, in Nairobi, Kenya and Head of Tropical Ecology at the Centre for Ecology and Hydrology in Edinburgh, Scotland. He is the author of “Living with the Trees of Life – Towards the Transformation of Tropical Agriculture” and over 300 research publications.

5 thoughts on “Trees of life for food security

  1. Dear Roger,

    A refreshing and realistic contrast to the high external input (fertlizer, pesticide, seeds) approach for small-scale African farmers being advocated – and funded – by Melinda and Bill Gates – with the best of intentions but lacking the benefit of experience of working with farmers and of understanding the importance or organic matter in soils – just a few days ago. Maybe it is time to invite M&B Gates to see for themselves in Cameroon.

  2. Thanks for your comment. I have tried several times to communicate with the Gates Foundation, but never had any impact. Apparently they do not “do” agroforestry, even though it delivers all the things they say they want to achieve. I agree, it is much more convincing when you see and hear for yourself, so it would be great to have a visit by them.

  3. Can we please have lots more of Andrew Macmillan and his experiences of Conservation Agriculture on this blogosphere.

    It would certainly be more interesting to see the way in which FARMERS can be seen to conduct on-farm projects of a CA kind……instead of reading ideas & concepts that often seem to have little relevance to real life, out there in the precious soil. G

  4. Dear Graham, I have to confess that though a great admirer of those who have pioneered CA and who are, like John Landers, still trying hard to improve it(e.g through eliminating herbicides), my only first-hand experience has been to draw on the knowledge of North Korean farmers, adopting the no-till system that they have developed to grow our subsistence crop of potatoes. It works!!
    A

  5. No-till potatoes sound an interesting article to me. Could you forward something on to me please? Practical Farm Ideas has a supplement titled Soil+ Cover Cropping International that is very much concerned with no-till techniques.

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