Mycorrhizal Fungi, Nature's Key to Plant Survival and Success

Summary

Mycorrhizal fungal filaments (mycelia) radiate into the soil from mycorrhizae-colonized root tips, extending the capacity of the plant’s root system to absorb water and nutrients Over 460 million years ago, plants and mycorrhizal fungi formed a beneficial relationship below the soil surface that nurtured and protected plants while feeding the fungi and other organisms in the root zone of the plants.1 That relationship exists today for over ninety percent of terrestrial species in natural settings, allowing plants to survive harsh conditions of drought, diseases, temperature extremes, poor soil, and competition.2 They are the dominant microbial life form in undisturbed soils, accounting for sixty to eighty percent of the microbial mass of the soil. Without them, for instance, large oaks, which use hundreds of gallons of water per day in the summer heat, would not thrive or grow to mature size on the dry hills of California. Although the root-fungus association has been known since classical Greek times, when Theophrastus traced the mycelium of a mushroom back to oak tree roots, it has only been in the last ten years that this relationship has been utilized for agriculture, forestry, golf course management, and ornamental horticulture. Commercial production of mycorrhizal fungi has been available to the green industry for a decade, but only recently in small quantities for home gardeners. This article is intended to educate the home gardeners and landscape contractors, who can make use of this essential resource to bring long term health and beauty to their gardens, while weaning their properties of unsustainable practices dependent upon the use of chemical fertilizers, pesticides, and herbicides. What are Mycorrhizae, and How Do They Work? The word “mycorrhizae” comes from the Greek words for fungus and root, and refers to the symbiotic relationship that exists between plant roots and certain fungi. In natural settings, these mycorrhizal fungi are present in the soil...