Arbuscular mycorrhiza

Arbuscular mycorrhiza (AM) are fungi that can enter into symbiosis with about 80% of all plant species. In doing so, the fungi grow in and around the roots and supply the crop with nutrients and water in exchange for sugars. The larger the mycelium (network of fungal threads or hyphae) around the roots of a crop is, the more nutrients, such as nitrate and phosphate, the plant can absorb.

Crops that do not engage in symbiosis with arbuscular mycorrhiza, if at all, are crops from the Cruciferae (cruciferous plants, e.g., cole crops) and Chenopodiaceae (goosefoot plants, e.g., spinach, beet) families.