ARBUSCULAR MYCORRHIZAL FUNGI AS COMPONENTS OF SUSTAINABLE SOIL-PLANT SYSTEMS

Increased pressure for food production has, in recent years, led to the development of intensive agricultural systems that use significant quantities of inorganic fertilizers and pesticides. However, there is now substantial evidence for the environmental costs of this high-input strategy and this has led to demands for agricultural systems to be modified in order to make them more sustainable. Arbuscular mycorrhizal fungi (AMF) play a key role in natural and agricultural ecosystems through major functions in the enhancement of plant phosphorus and nitrogen nutrition, nutrient and soil conservation, and the biological control of plant pathogens. They are essential to the sustainability of systems and their importance in agricultural ecosystems is likely to increase as inputs are reduced and/or rationalized. In order to maximize their benefits it is essential to ensure that management practices include minimum tillage, reduced use of inappropriate fertilizer, appropriate crop rotations with minimal fallow. and rationalized pesticide use. Furthermore, crop breeders should take full account of the symbiosis in selection. Future research should be targeted to understanding the functional ecology of AMF in agroecosystems.