How does the application of the fungal genus, Glomus, to the agricultural farm increase the farm output?

The application of Glomus to agricultural field increases the farm output by increasing the nutrient availability to the crops. Glomus develops symbiotic association with the roots of plants, called mycorrhiza. It absorbs phosphorus from the soil and passes it to the plants it associates with. In return, it derives sugars from the host plant cells for its survival.
Thus, it acts as a biofertiliser. This association has other advantages also, like
(i) Resistance to root borne pathogens
(ii) Tolerance to salinity and drought
(iii) Increase in plant growth and development