An Ecological Approach to Reducing External Inputs Through the Use of Intercropping

Abstract

Resources that promote plant growth in agroecosystems, such as light, water, and nutrients, contribute to the formation of biomass, a part of which eventually leaves the system in the form of harvest yields. A major concern of agriculture has been how to maximize this output of biomass, with much research focusing on the development of optimal crop densities, which promote the most efficient uptake and conversion of these resources into profit-producing yields. In conventional agriculture, though, this focus has used primarily single-crop plantings, where it is possible to maintain optimum fertilizer levels, water availability, and light capture, as well as keep other factors at levels that are of benefit to the crop output. With additional inputs for weed, disease, and insect control, sole-crop planting systems can achieve substantial yields and profit. But as awareness of the combined ecological and economic costs of maintaining yields in these monoculture systems has grown, the search for alternatives that rely less on fossil-fuel based energy and material inputs has begun to intensify (Altieri, 1987; Stinner and House, 1988). One of these alternatives is intercropping (Francis, 1986).