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ECHO Basic Document # 4
PRINCIPLES OF AGROFORESTRY
by Franklin W. Martin and Scott D.
Sherman
In simplest language, agroforestry is the production of trees and of non-tree crops or animals on the same piece of land. The crops can be grown together at the same time, can be grown in rotation, or can even be grown in separate plots when materials from one are used to benefit another. However, this simple definition fails to take into account the integrated concepts associated with agroforestry which makes this system of land management possibly the most self-sustaining and ecologically sound of any agricultural system.
Thus a second definition of agroforestry would be the integration of trees, plants, and animals in conservative, long-term, productive systems. Agroforestry can be considered more as an approach than as a single finished technology. Although several finished systems have been devised and tested, such technology may require adjustment for particular situations. The flexibility of the agroforestry approach is one of its advantages.
Agroforestry systems make maximum use of the land. Every part of the land is considered suitable for plants that are useful. Emphasis is placed on perennial, multiple purpose crops that are planted once but yield benefits over a long period of time. Furthermore, systems of agroforestry are designed for beneficial interactions of the crop plants, and to reduce unfavorable interactions. They are designed to reduce the risks associated with agriculture, small scale or large, and to increase the sustainability of agriculture.
Agroforestry practices normally help conserve, and even improve, the soil. Agroforestry includes a recognition of the interactions of crops, both favorable and unfavorable. The most common interaction is competition, which may be for light, water, or soil nutrients. Competition invariably reduces the growth and yield of any crop. Yet competition occurs in monoculture as well and this need not be more deleterious in agroforestry systems. Interactions may be complementary, as in the case of trees, pasture, and foraging animals, where trees provide shade and/or forage, and animals provide manure.
Agroforestry systems are designed to produce a range of benefits including food, feed, fuels, often fibers, and usually renewed soil fertility. Agroforestry systems take advantage of trees for many uses, to hold the soil, to increase fertility through nitrogen fixation, or through bringing minerals from deep in the soil and depositing them by leaf-fall, to provide shade, construction materials, foods and fuel. Agroforestry systems may be thought of as principle parts of the farm system itself, which contains many other sub-systems which together define a way of life.
Improved year-round production of food and of useful and salable
products.
Improved year-round use of labor and resources.
Protection and
improvement of soils (especially when legumes are included) and of water
sources.
Increased efficiency in use of land.
Short term food production
offsetting cost of establishment of trees.
Furnishing of shade for vegetable
or other crops that require it or tolerate it.
Medium and long term
production of fruits.
Long term production of fuel and timber.
Increase of
total production to eat or to
sell.
Agroforestry is not a system of pots on the balcony nor for the greenhouse. It is a system to manage the agricultural resource, land, for the benefits of the owner, and the long term welfare of society. While this is appropriate for all land, it is especially important in the case of hillside farming where agriculture may lead to rapid loss of soil. Normally land will be what the farmer owns (farmers that rent land may have little interest in the long term benefits of agroforestry), and thus farmers must think conservatively, how the land can be maintained over long periods of time.
In agroforestry, particular attention is placed on multiple purpose trees or perennial shrubs. The most important of these trees are the legumes because of their ability to fix nitrogen and thus make it available to other plants. The roles of trees on the small farm may include the following:
Sources of fruits, nuts, edible leaves, and other foods.
Sources of construction material, posts, lumber, branches for use as wattle (a fabrication of poles interwoven with slender branches etc.), thatching.
Sources of non-edible materials, including sap, resins, tannins, insecticides, and medicinal compounds.
Sources of fuel.
Beautification.
Shade.
Soil
conservation, especially on hillsides.
Improvement of soil fertility.
In order to plan for the use of these trees in agroforestry systems considerable knowledge of their properties is necessary. Desirable information includes the uses described above, the climatic adaptations of the species, including adaptations to various soils and stresses, the size and form of the canopy as well as the root system, and the suitability for various agroforestry practices. Some of the most common uses of trees in agroforestry systems are:
Individual trees in home gardens, around houses, paths, and public places.
Dispersed trees in cropland and pastures.
Lines of trees with
crops between (alley cropping).
Strips of vegetation along contours or water
ways.
Living fences and borderlines, boundaries.
Windbreaks.
Improved
fallows.
Terraces on hills.
Small earthworks.
Erosion control on
hillsides, gullies, channels.
Woodlots for the production of fuel and
timber.
Any crop plant can be used in agroforestry systems. The choice of crop plants in designing such systems should be based on those crops already produced in a particular region either for marketing, feeding animals, or for home consumption, or that have great promise for production in the region. In keeping with the philosophy of agroforestry, however, certain other values should be pursued in the choice of crops, including:
Crops for making money.
Crops for feeding the
farmer.
Crops for good nutrition.
Crops for self sufficiency.
Crops for
feeding the animals.
Crops for protecting the soil.
Thus, selection of crops requires a judgement based on knowledge of the crops, adaptations, production uses, as well as family needs, opportunities for barter, and markets. Any farm animal can be used in agroforestry systems. The choice of animal will be based on such values as:
Animals for making money.
Animals for feeding the
farmer.
Animals for supplying labor.
Animals for non-food
products.
Animals for using crop residues.
Animals for furnishing
manure.
Decide whether agroforestry systems are appropriate.
Describe family and community needs.
Find the limiting constraints in agriculture, including markets and marketing.
List the potential benefits of an agroforestry system in the region in question, and their relative importance. Then decide if it is worth the effort to develop one.
Consider whether the people of the region are willing or capable of adopting a system.
Design asystem.
Select the area.
Characterize it (describe it, its strengths, weaknesses) with respect to existing soil, water, and crops.
List the needs that could be met with an agroforestry system.
Characterize the crops desired by minimum space requirements, water and fertilizer needs, and shade tolerance.
Select the trees, shrubs, or grasses to be used.
If the system is temporary:
Plan the features of soil erosion control, earthworks, and gully maintenance first.
Plan spacing of fruit trees according to final spacing requirements.
Plan a succession of annual or short-lived perennials beginning with the most shade tolerant for the final years of intercropping.
If the system is permanent:
Plan the proportion of the permanent fruit and lumber trees on the basis of relative importance to the farmer.
Plan the spacing of long-term trees on the basis of final space requirements times 0.5.
Plan succession of annual and perennial understory crops, including crops for soil protection and enrichment.
As large permanent trees grow, adjust planting plan to place shade tolerant crops in most shady areas.
In temporary and permanent systems:
Keep all ground in crops or protective covers at all times.
Try the system on a small scale first.
Measure the inputs and outputs of the system.
Evaluate whether the benefits expected have been achieved.
Look for the desired plant materials or for suitable substitutes locally (Table 5).
Expand or extend any new system cautiously.
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Alley Cropping: |
Growing annual crops between rows of trees. |
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Beautification: |
Planting trees for ornamental purposes. |
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Boundary Plantings: |
Trees planted along boundaries or property lines to mark them well. |
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Dispersed Trees: |
Trees planted alone or in small numbers on pastures or otherwise treeless areas. |
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Earthworks: |
Constructions made of earth, usually to conserve or control water. |
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Improved Fallows: |
Areas left to grow up in selected trees as part of a trees-crop rotation system. |
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Individual Trees: |
Trees occurring alone, whether spontaneously or planted. |
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Living Fences: |
Fences in which the poles are living trees, or in which all of the fence consists of closely-spaced trees. |
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Nectar Crop: |
Trees valuable as a source of nectar for honey bees. |
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Terraces: |
Level areas constructed along the contours of hills, often but not necessarily planted with trees. |
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Vegetative Strips: |
Long, narrow areas of any type of vegetation, usually planted along contours for erosion control; may include trees. |
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Woodlot: |
An area planted to trees for fuel, or timber. |
Buck, L. 1988. Agroforestry Extension Training Sourcebook Cooperative for American Relief Everywhere. (CARE) International New York, N.Y., 540 pp.
Fernandez, Pamela G., guest ed. Sustainable Agricultural Newsletter, September 1990, dedicated to agroforestry seeds with an extensive listing of suppliers around the world. CUSO, 17 Phaholyothin, Golf Village, Phaholyothin Road, Bangkhen, Bangkok 10900 Thailand. free
Folliot, Peter F. and Thames, John L. 1983. Environmentally Sound Small-Scale Forestry Projects, Guidelines for Planning. Volunteers in Technical Assistance (VITA). Arlington, VA, 109 pp. $9.75 (see CODEL below)
Forestry/Fuelwood Research and Development Project. 1992 Growing Multipurpose Trees on Small Farms. Bangkok, Thailand: Winrock International. 195 + ix pp. (including 41 species fact cards). To order in the USA, call: 703/351-4006 and request book order no. PNABR667.
IITA (no date) Alley Cropping, A Stable Alternative to Shifting Cultivation. International Institute of Tropical Agriculture, Ibadan, Nigeria, 25 pp. (available for $1.00 from NFTA, see resources).
IIRR, 1990, Agroforestry Technology Information Kit. The International Institute of Rural Reconstruction, 475 Riverside Drive, Room 1270, New York, NY 10115 ($20.00). Kits are probably available as well from their office in the Philippines: IIRR, Silang, Cavite 4118, PHILIPPINES. Nitrogen Fixing Trees for Wastelands. FAO Regional Office for Asia and the Pacific, Maliwan Mansion, Phra Atit Road, Bangkok, THAILAND.
NAIR, P.K.R. Classification of Agroforestry Systems. Agroforestry Systems 3: 97-128.
National Academy of Sciences. 1980, Firewood Crops, Shrub and Tree Species for Energy Production, Vol I, Washington, D.C., 236 pp. (available free to those actively working in development: BOSTID (JH-217D), National Research Council, 2101 Constitution Avenue, Washington, D. C. 20418, USA).
National Academy of Sciences. 1983, Firewood Crops, Shrub and Tree Species for Energy Production, Vol II, Washington, D.C., 92 pp. (see vol I).
Rockeleau, D., Weber, F. and Field-Juma, A. 1988. Agroforestry in Dryland Africa. International Centre for Research in Agroforestry (ICRAF). Nairobi, Kenya, 311 pp. $31.00
Save The Children/US, Thailand. 1992, Collection, Storage, and Treatment of Tree Seeds: A Handbook for Small, Farm Tree Planters. The FAO Regional Wood Energy Development Programme in Asia, Bangkok, Thailand.
Shankarnarayan, R. A. (Ed.) 1984. Agroforestry in Arid and Semi-arid Zones. Jodphur, India, ICAR Central Arid Zone Research Institute, 295 pp.
Teel, W.A., 1984. A Pocket Directory of Trees and Shrubs in Kenya. Kenyan Energy Non-Governmental Organization (KENGO). Nairobi, Kenya, 151 pp.
Thuvesson, D. (Ed.) Forests, Trees and People Newsletter, Swedish University of Agricultural Sciences/IRDC, Box 7005, S-750 07 Uppsala, Sweden. (Quarterly publication distributed to those interested in and/or working with community forestry activities). free
USAID 1987. Windbreak and Shelterbelt Technology for Increasing Agricultural Production. United States Agency for International Development, Washington, D. C. 219 pp.
Liegel, Leon H.; Venator, Charles R. A technical guide for forest nursery management in the Caribbean and Latin America, Gen. Tech. Rep. SO©67. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station; 1987. 156p.
von Carlowitz, P. 1986. Multipurpose Tree and Shrub Seed Directory. International Center for Research in Agroforestry, Nairobi, Kenya. 265 pp. $24.00
VSO (no date). If a Tree Falls: A VSO Guide to Raising and Planting Trees in Kenya. Voluntary Services Overseas
Wesley, S.B. (Ed.) Agroforestry Today, ICRAF. Nairobi, Kenya, quarterly. (Subscriptions for development workers and scientists are free (see ICRAF below).
ECHO Crop Production Bulletin: Coconuts Bananas & Bread Fruit ($2.00)
ECHO Technical Notes: Comments on Citrus($2.00) Honey Producing Trees Suitable for Multiple Use ($1.00)Insecticidal Properties of Neem ($1.50) Living Fences ($1.50) Moringa: It's Many Uses ($2.00)
Articles: Australian Suppliers of Tree Seed ($1.00)IFAS Citrus Publications ($1.00)Jojoba: How to Grow it ($1.00)Key to Mango Flowering ($1.00) Learn to Eat Malunggay ($3.00)Leucaena and Growing Giant Leucaena ($1.50) Paulownia: China's Wonder Tree ($1.50) Fruit Tree Seed Characteristics Table ($1.50) Sesbanias: A Treasure of Diversity ($1.50)Sloping Agricultural Land Technology ($3.00) Tagasaste ($1.00)
Agroforestry Seed Information Clearing House (Pamela Fernandez, Department of Agronomy, University of the Philippines at Los Banos, College, Laguna 3720, PHILIPPINES) Information
ATSC (Australian Tree Seed Centre, CSIRO Division of Forestry and Forest Products, PO Box 4008 Queen Victoria Terrace, Canberra, ACT 2600, AUSTRALIA) Seeds
CARE (660 First Ave., New York, NY 10016, USA) Information
Carter Seed Co (475 Mar Vista Drive, Vista CA 92083, USA) Seeds
Centro Agromomico Tropical de Investigacion y Esperanza (CATIE, Turrialba, Cartage, COSTA RICA, 56-6431/56-0169). Information & Seeds
Centro de Mejoramiento Genetico y Banco de Semillas Forestales de Nicaragua (Magaly Urbina M., Director, Km. 12 1/2 Carretera Norte, Managua, Nicaragua, phone; 505-2 31622, fax: 505-2 31623). Seeds
DANIDA (Forest Seed Centre, Krogerupvij 3A, DK-3050, Humleback, DENMARK). A project of the Danish International Development Agency offering information and library service, publications and training to countries which Denmark renders support. Information
Florida Keys Native Nursery Inc, 102 Mohawk St., Tavernier, FL 33070. Seeds Forestry Fuelwood Research and Development Project (F/FRED, Winrock International, 1611N. Kent St. Suite 600, Arlington, VA 22209, USA). Information
Forestry Support Program (International Forestry, USDA Forest Service, P.O. Box 96090, Washington, DC 20090©6090). Provides technical assistance in forestry and natural resources to USAID and U.S. Peace Corps.
Henry Doubleday Research Association (Dr. Phil Harris, Overseas Projects Coordinator, HDRA, Ryton-on-Dunsmore, Coventry, CV8 3LG, UK). Information & seed for groups working in Africa and the Indian sub-continent, especially drought tolerant Prosopis species.
Inland & Foreign Trading Co. (Block 79A, Indus Road #04-418/420, SINGAPORE, 0316. Information & Seeds
Institute of Tropical Forestry (P.O. Box 25000, Rio Piedras, PR 00928-2500, USA). Information
International Centre for Research in Agroforestry (ICRAF, P.O. Box 30677, Nairobi, KENYA, e mail: icraf@cgnet.com) Newsletter, Information & Seeds
International Livestock Center for Africa (ILCA, P.O. Box 5689, Addis Ababa, ETHIOPIA). Information and Seeds
International Society of Tropical Foresters (ISTF, 5400 Grosvenor Lane , Bethesda, MD 20814, USA). Newsletter and Information
J.R. Palmer, IUFRO (International Union of Forest Research Organizations, A-1131, Wien-Schonbrunn, Austria KENGO (P.O. Box 48197, Nairobi, KENYA) Information
Kenya Forestry Seed Centre (Kari, P.O. Box 74, Kikuyu, KENYA). Seeds
Kimseed (Australian Revegetation Corporation Ltd., 51 King Edward Road, Osborne Park 6017, Western Australia), extensive inventory of arid land trees & shrubs and equipment for planting, harvesting etc.
Kumar International (Ajitmal 206121, Etawah (UP), INDIA). Seeds
The New Forests Project (731 Eighth Street, SE, Washington, D.C. 20003). Seeds & Information.
Nitrogen Fixing Tree Association (c/o Winrock International, Petit Jean Mountain, Morrilton, AR 72110-9537, Ph 501/727-5435, Fax 501/727-5417). Newsletter, Information
NifTAL Project (Department of Agronomy and Soil Science, University of Hawaii, P.O. Box 0, Paia, HI 96779, USA). Rhizobia
Oxford Forestry Institute, Plant Science Department, South Parks Road, Oxford OX1 3RB, UK. Seeds
Peace Corps (Information Collection and Exchange, 1990 K Street NW, Room 808 Washington, DC 20526, USA). Information
Petawawa National Forestry Institute (Chalk River, Ontario K0J 1JO). Seeds for research purposes.
Roy Danforth (Imeloko Agroforestry Project, B.P. 1377, Bangui, Central African Republic). Working to promote agroforestry as an alterative to "slash and burn" farming in Africa. Seeds (375+ species of tropical fruit trees)
RWEDP (Regional Wood Energy Development Programme in Asia, FAO/RAPA, 39 Maliwan Mansion Phra Athit Road, Bangkok 10200, THAILAND. Information
SETROPA (P.O. Box 203, 1400 AE Bussum, HOLLAND). Seeds
Shivalik Seeds Corporation (Panditwari, P.O. Prem Nagar, Dehra Dun - 248007 (UP), INDIA). Seeds
The Bharatiya Agro Industries Foundation (´Kamdhenu', Senapati Bapat Marag, Pune-411 016, INDIA). Seeds
Tree Crops Centre (PO Box 27, Subiaco, WA 6008, AUSTRALIA). Information
Tree Seed Program (Ministry of Energy & Regional Development, P.O. Box 21552, Nairobi, KENYA). Seeds
University of Hawaii at Manoa (Department of Agronomy & Soil Science, U. of H. at Manoa, 190 East-West Road, Honolulu, HI 96822, USA). Seeds
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