Arbuscular Mycorrhizal Fungi (AMF) colonize 80% of crops. Their effect on plant growth can be positive, neutral or negative. It depends on many factors including the crop species and genotype, the species of AMF, and the characteristics of the soil. A low pH favors colonization of the plant by AMF while application of chemical fertilizers, especially phosphate, inhibits colonization by AMF. In the absence of chemical fertilizers and in the presence of low levels of pH, AMF provides the plant with phosphorous. AMF can extract P from rocks so it can get P from soil that tests low for P.
AMF can dramatically increase plant yield and resistance to pathogens and drought, as well as decrease irrigation needs and sensitivity to salinity. Thus, AMF can be of great assistance in transitioning from conventional to sustainable/regenerative agricultural. There are now many suppliers of AMF but there is no guarantee that any one product will be optimal for your crop and your soil.
The new microBIOMETER® test, which estimates fungal to bacterial ratios in soil, can help you decide which AMF works best with your plant and soil because it can detect colonization of rhizosphere soil for fungi within a month of AMF application.
Leifheit, E. F., Veresoglou, S. D., Lehmann, A., Morris, E. K., & Rillig, M. C. (2014). Multiple factors influence the role of arbuscular mycorrhizal fungi in soil aggregation—a meta-analysis. Plant and Soil, 374(1-2), 523-537.