What exactly is agroforestry?
Everyone knows what a forest is, but what has agroforestry got to do with forests? Agroforestry means incorporating trees into farms. As forests shrink, trees on farms become all the more important. The International Year of Forests is an opportunity to highlight the global importance of agroforestry and the impact that trees on farms can have on livelihoods and the effects of climate change.
Benefits and potential of agroforestry
Trees provide farmers with a lot of useful goods, like fruit to eat and sell, feed for their animals and compost for their soils. Over 1 billion hectares of agricultural land, almost half of the world’s farmland, have more than 10 percent of their area occupied by trees; 160 million hectares have more than 50 percent tree cover, which could mean a small forest or an even scattering across the farm. These figures do not include harvesting rubber from trees growing in forests and cultivating cocoa trees in the shade of the forest.
Trees play a crucial role in almost all land-based ecosystems and provide a range of products and services to rural and urban people. As natural vegetation is cleared for agriculture and other types of development, the benefits that trees provide are best sustained by integrating trees into agriculturally productive landscapes — the practice known as agroforestry.
Farmers have practised agroforestry for generations. Agroforestry focuses on the wide range of working trees grown on farms and in rural landscapes. Among these are fertilizer trees for land regeneration, soil health and food security; fruit trees for nutrition; fodder trees that improve smallholder livestock production; timber and fuelwood trees for shelter and energy; medicinal trees to combat disease; and trees that produce gums, resins or latex products. Many of these trees are multipurpose, providing a range of benefits.
Agroforestry provides many livelihood and environmental benefits, including:
• enriching the asset base of poor households with farm-grown trees
• enhancing soil fertility and livestock productivity on farms
• linking poor households to markets for high-value fruits, oils, cash crops and medicines
• balancing improved productivity with the sustainable management of natural resources
• maintaining or enhancing the supply of environmental services in agricultural landscapes, for water, soil health, carbon sequestration and biodiversity.
Over the next two decades, the world's population is expected to grow on average by more than 100 million people a year. More than 95 percent of that increase will occur in developing countries, where pressure on land and water is already intense. A key challenge facing the international community is, therefore, to ensure food security for present and future generations, while protecting the natural resource base on which we all depend. Research on agroforestry, which comprises varied practices integrating crops, livestock and trees, can help communities and households to meet their economic, social, cultural and environmental needs. Trees on farms will be an important part of efforts to meet those challenges, for four reasons.
Trees on farms accumulate carbon
Investments in agroforestry over the next 50 years could remove 50 billion tonnes of additional carbon dioxide from the atmosphere. Most of the deforestation in Africa, and in parts of Asia, is caused by agricultural expansion, largely by smallholder farmers. Agroforestry activities curb emissions of greenhouse gases by slowing the conversion of forest to farm land and holding carbon in the trees on the farms. Developing smallholder agroforestry on land that is not classified as forest could capture 30-40 percent of the emissions related to land-use change. Encouraging farmers to plant trees has the potential to increase farmers’ income, sequester more carbon and benefit biodiversity.
Trees on farms are global
Agroforestry is uniquely suited to help grow more food and fuel while conserving the landscape. Agroforestry technologies have traditionally been developed through ‘hands-on’ experience and transmitted through the generations. Successful agroforestry systems and practices include alley cropping, silvipasture, windbreaks, hedgerow intercropping, parklands, home gardens and relay cropping. Some have been in existence for centuries, evolving in response to needs and constraints both on and off the farm.
Trees on farms feed the hungry
Agroforestry enhances soil fertility and the productivity of animals kept on farms. Planting trees that provide natural fertilizers on farms with poor soils helps farmers restore fertility and increase yields. Gliricidia bushes fix nitrogen in their roots and act as natural green fertilizer factories, tripling yields of maize on farms in Malawi. The prunings are fed to the animals. The bushes also reduce the risk of crop failure during droughts and prevent waterlogging when it rains too much. The nitrogen-fixing tree Faidherbia increased unfertilized maize yield four times in Zambia. The trees are being grown on over 5 million hectares of crop land in Niger.
In most countries, trees grown on farms in various agroforestry systems are a source of income and, more importantly, fulfil protective functions as windbreaks and shelterbelts. Establishment of windbreaks is an integral part of farming practices in most countries. Date-palm cultivation in several Western Asian countries has turned deserts into oases. In the United Arab Emirates, extensive date plantations have improved the landscape while generating substantial income. Fruit trees are also a source of wood.
Trees on farms relieve poverty
Farmers can earn considerable sums of money from the trees they cultivate. Domesticating wild fruit trees in Cameroon has allowed smallholder farmers to earn five times as much as they did before. Thousands of farmers in Tanzania are planting Allanblackia trees and earning much-needed income by selling the oil-containing seeds to companies to make margarine. Agroforestry is currently responding to new market opportunities. Planting of trees on farms to supply wood to forest industries has increased significantly in many countries.
Trees grown on homestead farms, in woodlots and on communal lands are an important source of wood and other products. In humid-zone West African countries, such as Burundi, Rwanda and Uganda in particular, trees grown in home gardens meet most household needs for fuelwood and timber. In many cash-crop systems, trees are grown for shade and eventually provide wood – an example is Grevillea robusta in tea plantations in Kenya. In the Sudan, Acacia senegal, the source of gum arabic, is largely grown in agroforestry systems.
Throughout the International Year of Forests, the World Agroforestry Centre will be celebrating and promoting the planting and nurturing of trees, both inside and outside forests.
learn more about the World Agroforestry Centre
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