The benefits of mycorrhiza have been identified and studied since 1885. The name literally means "fungus-root," and researchers have been learning ever since that the relationship between this type of fungi and plant roots is the norm. Very few plant species exist without it on some level.
Mycorrhizal fungi, in exchange for carbon from the plant, help plants make phosphorus soluble. They also aid in the plant's absorption of water, nitrogen and other needed micronutrients.
Like other fungi, the action of mycorrhizae aids in the decomposition of organic matter, converting it to more digestible forms for other species, such as earthworms. Plant hormone levels are also increased as a result of the relationship of mycorrhizal fungi.