For the past two decades uses of intimate associations of trees and agricultural crops have been known as agroforestry practices. These practices have been used all over the world but today they are mainly found in the tropics. Originally, systems with trees on farmland were primarily intended for food production. By the end of the 19th century foresters adapted this mixed planting concept and used temporary interplanting of forest trees with food crops as a cheap method of establishing forest plantations. Much later, in the 1970s, when degradation of natural resources became an important issue, the need was felt to develop combined production systems which would integrate forestry, crop production or animal husbandry in order to optimize tropical land-use.
In 1977 the International Council for Research in Agroforestry (ICRAF) was established in order to collect and disseminate information on existing systems and to develop new ones. This organization developed agroforestry