Can mycorrhizal fungi fix farming? Benefits and limitations of applying them to agroecosystems

Abstract

The intensification of agriculture over the past decades has helped increase crop yields but has also led to various environmental issues, potentially undermining future productivity. One of the options considered for increasing the sustainability of agriculture is the stimulation or enhancement of microorganisms that associate with plants and help them acquire more nutrients from the soil leading to benefits such as increased growth. One key player considered are arbuscular mycorrhizal fungi (AMF), a group of below-ground fungi that form symbiotic relationships with the vast majority of land plants. However, evidence from lab and field trials suggests that not all plants respond equally to colonization by these fungi, and research is on-going to better understand the context-dependency of the symbiosis. Moreover, introducing AMF to agricultural fields through the application of commercial inoculants that contain fungal spores and hyphae has been inconsistent in their desired effects of boosting crop yield and quality. Recently, a quality framework has been put forward to try and increase the reliability of these inocula so farmers can make better use of them. Although further research on the fundamental and applied aspects of plant–arbuscular mycorrhizal associations is required, agricultural practices that favour these fungi should be encouraged as they are likely to lead to wider benefits and ultimately contribute to a more sustainable agricultural system.