Swidden-fallow agroforestry, a brief explanation
The swidden-fallow process can be summarized as follows: A plot of forest is selected and surveyed – valuable, or desirable species occurring naturally in the area are identified and left in the area, all other undesirable species (of shrub, vine, tree, etc.) are removed. All biomass from felled vegetation is either left to slowly decompose providing nutrients and suppressing weeds, or it is burned for nutrients in the ash. Void spaces left by eliminated species are filled in with food, medicine, or other useful crops.
Based on growth-rate, eventual size, and overall growth habits of individual species, plantations are organized so as to mimic natural, stratified forest composition. Then the swidden site is left to fallow. In the time between a new planting and maturation of tree crops a swidden site can be intensively cultivated with annuals and perennials.
Once young trees have developed a substantial canopy, leaving the under-story with insufficient light to be cultivated with perennial crops, the site is left to mature and self-regulate and planted with shade-loving species, and harvested by humans on a regular basis. Thus an anthropogenic forest and low input agricultural system are created in synthesis.
If one is familiar with the concept of “slash and burn”, a more commonly discussed form of shifting cultivation, swidden-fallow might be understood as a similar approach, but with a greater degree of complexity, selection, and a heightened potential for longer-term, restorative agricultural.
One of the major reasons why the swidden-fallow method was developed by peoples living in various tropical regions around the world relates to the extremely poor condition of rainforest soils. Fallowing land after intensive cropping is one of the most basic and assured ways of restoring soil fertility; vegetation returns regenerating depleted nutrients.
Read more here in a portion of an essay I wrote on Agroforestry and the Built Environment…