Biological control as a means of enhancing the sustainability of crop/land management systems

Biological control can contribute to the sustainability of crop/land management systems by reducing the inputs currently derived from non-renewable fossil energy sources. Biologically based technology will have to be developed and gradually integrated into management systems that will include sorne chemicals for a long time to come. A researchable paradigm is presented: using "weed-suppressive soils" for biological Control of weeds in crops. This example requires extensive knowledge of the ecology of soil microflora and how various populations are affected by management strategies. These management strategies are structured to foster microbial populations in soils that will provide timely suppression of early flushes of annual weeds. Biological seed treatments using microbial antagonists will have to be developed to "safen" the crop against the active biological factors in the "weed-suppressive soils". As these and other biological alternatives are adopted, the concept of "sustainability" will move closer to reality. (C) 2002 Elsevier Science B.V. All rights reserved.