ABSTRACT
In agronomy and conventional agriculture, the crop plant or animal population is the center of attention. A farmer attempts to maximize the performance of this population by managing the various factors of the environmental complex. When sustainability of the entire agroecosystem becomes the primary concern, however, this narrow focus on the needs of one genetically homogenous population becomes wholly inadequate. The agroecosystem must be viewed as a collection of interacting populations of many kinds of organisms, including crop and noncrop species, plants and animals, and microorganisms.
