Mycorrhiza

Definition

Mycorrhiza is a partnership between plant roots and certain soil fungi, in which the fungus extends the root's reach for water and nutrients such as phosphorus in exchange for sugars from the plant. The fungal threads also help bind soil particles into aggregates. The partnership is disturbed by heavy tillage, long bare fallows and some soil conditions, which is one reason keeping living roots in the ground is a recommended practice. See also: Aggregate, Soil organic matter, Cover crop, and the guide "Nutrient Depletion, Organic Matter Loss and the Decline of Soil Life".