Mycorrhiza is the symbiosis between plant roots and fungi which has been known for a long time. The benefits of the symbiosis become more important as they are not contained in customary composts and growing media and many soils show bad conditions with no active soil life.
The symbiosis is a very close relation: in the cells of the roots nutrients, mainly phosphate and nitrate, are exchanged between plant and fungi.
The mycorrhiza hyphae grow intensively in the soil which leads to an increased water supply so that mycorrhizal plants are much better adapted to drought. Besides these advantages for the host plant, an intact mycorrhiza will also stabilise the plants resistance against phytopathogenous microorganisms.