Agroforestry comes of age in Orlando

In his village in Chipata North, eastern Zambia, Harrison Chongwe is known as 'the Professor'. The title was first coined by a former director in the agricultural service on the strength of Chongwe's innovative farming methods. Recently, working in partnership with researchers from the World Agroforestry Centre, the 'Professor' has been experimenting with uses of Gliricidia sepium, a tree originating from the lowlands of Central America, whose nitrogen-rich leaves now serve as fertiliser in his maize field and vegetable garden. With subsidies on chemical fertilisers withdrawn in Zambia in the early 1990s, and local suppliers unable to guarantee fertiliser stocks even for those farmers who can afford them, it does not need a professor to realise that growing fertiliser trees makes sense.

Agroforestry, according to the Nairobi-based World Agroforestry Centre, is a science at a crossroads. Whilst the growing of trees on farms is an ancient practice, understanding and developing the relationship between trees, crops and farm livelihoods has been the subject of scientific study for only the last quarter century. Yet even in that short time, agroforesters' understanding of the potential of their science has changed dramatically. The First World Congress of Agroforestry, held in Orlando, Florida in July was an opportunity for practitioners from both North and South to share their research findings, but it also prompted a plea for greater recognition. Agroforestry techniques, it was argued, could provide solutions, or at least part-solutions, to many of the world's intractable problems: rural poverty and disease, global warming, loss of biodiversity and environmental degradation. Dennis Garrity, Director General of the World Agroforestry Centre, believes that the young science is now looking beyond individual farms to the transformation of landscapes, watersheds and communities.

Technologies for the North...
Among modern sciences, agroforestry has had an unusual evolution. Developed largely in the South, it was only in the 1990s that it gained recognition as offering potentially useful technologies for the developed world. Participants at the Orlando conference were invited to see several such technologies: high value floral, herb and fern crops grown under trees; integration of livestock, timber production, hunting and ecotourism; and use of short rotation woody species for production of fuel, used in firing power stations. Growing more trees on farms as a form of carbon sequestration is also under study, and Garrity speculates that in future agroforestry could become an alternative focus for farm subsidies. While crop production subsidies decline, subsidies on trees could support developed world farmers, with added ecological and landscape benefits.

...and the South
For farmers in the South, trees on farms can serve as a more immediate mitigation of climate change. At one level, trees can diversify sources of farm income, with many species providing fruit, medicines, fodder, poles and fuel that can be sold. But trees also help to protect farmland from the elements, from wind and water erosion and excessive sun. Many species used in agroforestry have nitrogen-rich foliage, ideal for making compost or mulch, and thereby reducing soil temperatures, conserving soil moisture, controlling weeds and boosting nutrient levels. Using leaves as fertiliser may be labour intensive, but for most farmers it is an affordable technology, and once the plants are established farmers are no longer dependent on external suppliers.

While species such as Gliricidia sepium are proving their value far from their countries of origin, another branch of agroforestry is building on the potential of local species. Many indigenous fruits, for example, are more nutritious than their exotic rivals, despite being undervalued in some areas, as 'famine food'. In Cameroon, trees such as the African plum (Dacryodes edulis) and the bush mango (Irvingia gabonensis) provide fruit rich in proteins and oil, and have an important function in rural diets, particularly at times when cultivated foods are scarce (see also Cultivating Cinderella trees Developments 01-3). Domestication and cultivation of indigenous fruit trees around the homestead are a time saving and potentially profitable venture, with research in Cameroon suggesting that a significant market for indigenous fruit exists in urban areas (see also Focus on agroforestry).

Links with livestock
The importance of livestock as a source of income for poor families has been widely recognised, and the integration of agroforestry with livestock keeping is a third area believed to have great potential. The nutrient-rich leaves of shrubs such as Leucaena leucocephala and Grevillea robusta are particularly valuable in filling the feed gap that occurs during long dry periods, and can save farmers from having to buy expensive alternatives such as groundnut hay. Other species, such as the thorny Acacia laeta, are being promoted for use as live fencing, used to protect vegetable plots or to pen livestock.

Raising awareness among policy makers, natural resource professionals and farmers about the potential of agroforestry technologies such as these is now seen as a vital need, one expressed by participants at the First World Congress of Agroforestry in the Orlando Declaration. From an environmental perspective, such technologies, it is argued, could have a major role in helping countries to meet their commitments to international conventions on climate change, biodiversity and desertification. Widespread adoption could also contribute substantially to the achievement of the Millennium Development Goals, increasing household income through farm diversification, improving health through fruit and medicinal species, and promoting environmental sustainability. What is needed, say the Orlando participants, is the integration of agroforestry into broader natural resource and watershed management efforts. But creating the infrastructure, such as tree seedling nurseries, that will be needed for a broad adoption of these methods, and communicating the agroforestry message to rural communities will require substantial donor commitment. Without it, the benefits of these ancient but newly formalised technologies will continue to be practised by just the innovative few.