The role of arbuscular mycorrhizas in reducing soil nutrient loss

• AM are one of the most widespread symbioses on earth.
• AM can reduce nutrient loss from soils.
• Reductions in nutrient loss by AM have been a largely overlooked ecosystem service.
• Maintaining high levels of AM may enhance the nutrient use efficiency of ecosystems.

Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular mycorrhizas (AM), associations of plant roots with fungi that acquire soil nutrients. There is emerging evidence that AM have the ability to reduce nutrient loss from soils by enlarging the nutrient interception zone and preventing nutrient loss after rain-induced leaching events. Until recently, this important ecosystem service of AM had been largely overlooked. Here we review the role of AM in reducing nutrient loss and conclude that this role cannot be ignored if we are to increase global food production in an environmentally sustainable manner.