ARBUSCULAR MYCORRHIZAL FUNGI AS COMPONENTS OF SUSTAINABLE SOIL-PLANT SYSTEMS

Increased pressure for food production has, in recent years, led to th e development of intensive agricultural systems that use significant q uantities of inorganic fertilizers and pesticides. However, there is n ow substantial evidence for the environmental costs of this high-input strategy and this has led to demands for agricultural systems to be m odified in order to make them more sustainable. Arbuscular mycorrhizal fungi (AMF) play a key role in natural and agricultural ecosystems th rough major functions in the enhancement of plant phosphorus and nitro gen nutrition, nutrient and soil conservation, and the biological cont rol of plant pathogens. They are essential to the sustainability of sy stems and their importance in agricultural ecosystems is likely to inc rease as inputs are reduced and/or rationalized. In order to maximize their benefits it is essential to ensure that management practices inc lude minimum tillage, reduced use of inappropriate fertilizer, appropr iate crop rotations with minimal fallow. and rationalized pesticide us e. Furthermore, crop breeders should take full account of the symbiosi s in selection. Future research should be targeted to understanding th e functional ecology of AMF in agroecosystems.