Pro-Mix MP Organik with Mycorrhizae provides the perfect solution for growers in need of an organic-certified, growing medium that delivers well balanced air/water qualities. OMRI-Listed, this formulation is ideal for a variety of growing uses and is designed to meet crop requirements for certified organic growers. Enriched with mycorrhizae, this growing medium will not only improve the overall growth and yields of your crops, it will also increase your plants’ resistance to environmental stresses. 3.8 cubic foot compressed bale.