Agroforestry

Agroforestry is a land use system in which woody perennials (trees, shrubs, vines, palms, bamboo, etc.) are intentionally combined on the same land management unit with crops and sometimes animals, either in a spatial arrangement or a temporal sequence. It is based on the premise that woody perennials in the landscape can enhance the productivity and sustainability of agricultural practice. The approach is especially pertinent in tropical and subtropical areas where improper land management and intensive, continuous cropping of land have led to widespread devastation. Agroforestry recognizes the need for an alternative agricultural system that will preserve and sustain productivity. The need for both food and forest products has led to an interest in techniques that combine production of both in a manner that can halt and may even reverse the ruin caused by existing practices.

Although the term agroforestry has come into widespread use only in the last 20–25 years, environmentally sound farming methods similar to those now proposed have been known and practiced in some tropical and subtropical areas for many years. As an example, one type of intercropping found on small rubber plantations (less than 25 acres/10 ha), in Malaysia, Thailand, Nigeria, India, and Sri Lanka involves rubber plants intermixed with fruit trees, pepper, coconuts, and arable crops such as soybeans, corn, banana, and groundnut. Poultry may also be included. Unfortunately, in other areas the pressures caused by expanding human and animal populations have led to increased use of destructive farming practices. In the process, inhabitants have further reduced their ability to provide basic food, fiber, fuel, and timber needs and contributed to even more environmental degradation and loss of soil fertility.

The successful introduction of agroforestry practices in problem areas requires the cooperative efforts of experts from a variety of disciplines. Along with specialists in forestry, agriculture, meteorology , ecology , and related fields, it is often necessary to enlist the help of those familiar with local culture and heritage to explain new methods and their advantages. Usually, techniques must be adapted to local circumstances, and research and testing are required to develop viable systems for a particular setting. Intercropping combinations that work well in one location may not be appropriate for sites only a short distance away because of important meteorological or ecological differences. Despite apparent difficulties, agroforestry has great appeal as a means of arresting problems with deforestation and declining agricultural yields in warmer climates. The practice is expected to grow significantly in the next several decades. Some areas of special interest include intercropping with coconuts as the woody component, and mixing tree legumes with annual crops.

Agroforestry does not seem to lend itself to mechanization as easily as the large scale grain, soybean and vegetable cropping systems used in industrialized nations because practices for each site are individualized and usually labor-intensive. For these reasons they have had less appeal in areas like the United States and Europe. Nevertheless, temperate zone applications have been developed or are under development. Examples include small scale organic gardening and farming , mining wasteland reclamation , and biomass energy crop production on marginal land.

[Douglas C. Pratt ]

RESOURCES

BOOKS

Huxley, P. A., ed. Plant Research and Agroforestry. Edinburgh, Scotland: Pillans & Wilson, 1983.

Reifsnyder, W. S., and T. O. Darnhofer, eds. Meteorology and Agroforestry. Nairobi, Kenya: International Council for Research in Agroforestry, 1989.

Zulberti, E., ed. Professional Education in Agroforestry. Nairobi, Kenya: International Council for Research in Agroforestry, 1987.

agroforestry A recently coined name for a system of mixed arable farming and forestry that has been practised for milleniums in many parts of the tropics (e.g. in home gardens in Java), especially in rain-forest environments. Tree crops are interspersed with food-crop patches on a continuous basis, sometimes as hedges (so-called ‘alley-cropping’). The system ensures a continuous food supply, some continuous economic return, and the avoidance of soil degradation by exposure to tropical sunlight and rainfall during prolonged clearance; and it is suitable for small-scale family farmers. The trees act as ‘nutrient pumps’ and bring plant mineral nutrients from the depths up to the surface soil layers that are occupied by the roots of the crop plants.

agroforestry A system of mixed arable farming and forestry that has been practised for millenniums in many parts of the tropics (e.g. in home gardens in Java), especially in rain-forest environments. Tree crops are interspersed with food-crop patches on a continuous basis, sometimes as hedges (so-called ‘alley-cropping’). The system ensures a continuous food supply, some continuous economic return, and the avoidance of soil degradation by exposure to tropical sunlight and rainfall during prolonged clearance; and it is suitable for small-scale family farmers. The trees act as ‘nutrient pumps’ and bring plant mineral nutrients from the depths up to the surface soil layers that are occupied by the roots of the crop plants.