subject: The Importance of Mycorrhizal Fungi in your soil [print this page] The Importance of Mycorrhizal Fungi in your soil
The Importance of Mycorrhizal Fungi in your soil
Such fungi colonize plant or tree roots, extending the root system into the surrounding soil, via an extensive network of fungal filaments (up to 60 feet in a teaspoon of soil). These thread-like filaments extract nutrients and water from a large soil volume and exchange them for carbon from the plant. This secondary root system, when established, links the root systems of adjacent plants or trees and helps share, more efficiently, nutrient resources throughout the plant community.
The three major types of mycorrhizae differ in structural details but have many functions in common. The fungus colonizes the cortex of the host root and grows its filaments (hyphae) into surrounding soil from an inch to yards or more. The hyphae absorb nutrients and water and transport them to host roots. The fungi thus tap far greater volumes of soil at a relatively lower energy cost than the roots could on their own. Moreover, many, if not all, mycorrhizal fungi produce extracellular enzymes and organic acids that release immobile elements such as phosphorus and zinc from clay particles, or phosphorus and nitrogen bound in organic matter. The fungi are far more physiologically capable in extracting or recycling nutrients in this way than the rootlets themselves.
The major types are ectomycorrhizae, vesicular-arbuscular mycorrhizae, and ericoid mycorrhizae. Ectomycorrhizae are the most readily observed type. Ectomycorrhizal hosts strongly depend on mycorrhizae to survive. Relatively few in number of species, they nonetheless dominate most forests outside the tropics. Vesicular-arbuscular mycorrhizae (sometimes simply termed arbuscular mycorrhizae) form with the great majority of terrestrial herbaceous plant species plus nearly all woody perennials that are not ectomycorrhizal. Vesicular-arbuscular mycorrhizal hosts range from strongly mycorrhiza-dependent, especially the woody perennials, to facultative, as are many grasses.
Ericoid mycorrhizae are restricted to the Ericales, the heath order. The hosts are strongly mycorrhiza-dependent. However, relatively few in number, heath species dominate large areas around the world and are common understory plants in many forests. Other mycorrhiza types include those special for the Orchidaceae (orchids) and Gentianaceae (gentians). See also Ascomycota; Ericales; Zygomycotina.
Sugar-Water/Mineral exchange
This mutualistic association provides the fungus with relatively constant and direct access to carbohydrates, such as glucose and sucrose supplied by the plant. The carbohydrates are Trans located from their source (usually leaves) to root tissue and on to fungal partners. In return, the plant gains the benefits of the mycelium's higher absorptive capacity for water and mineral nutrients (due to comparatively large surface area of mycelium: root ratio), thus improving the plant's mineral absorption capabilities.
Mycorrhizal fungi:
Have a higher absorptive capacity for water and mineral nutrients.
Boost a plant's immune system, making them resistant to soil-borne pathogens.
Some are especially proficient at releasing nutrients bound in organic matter
Some produce more effective antibiotics or growth regulators
Some are more active in cool, hot, wet or dry times of year. They remain dormant in the soil until needed conditions exist.
Mechanisms
The mechanisms of increased absorption are both physical and chemical. Mycorrhizal mycelia are much smaller in diameter than the smallest root, and thus can explore a greater volume of soil, providing a larger surface area for absorption. Also, the cell membrane chemistry of fungi is different from that of plants (including organic acid excretion which aids in ion displacement). Mycorrhizas are especially beneficial for the plant partner in nutrient-poor soils.
Disease and drought resistance
Mycorrhizal plants are often more resistant to diseases, such as those caused by microbial soil-borne pathogens, and are more resistant to the effects of drought.
Resistance to toxicity
Fungi have been found to have a protective role for plants rooted in soils with high metal concentrations, such as acidic and contaminated soils.
Decades of chemical fertilizers, insecticides, and herbicides have greatly reduced these beneficial fungi.
Remedies
Bio-enhanced Aerify effectively aerates your soil while at the same time replenishing Mycorrhizal Fungi. Super Compost Tea replenishes and aids the growth of essential fungi. Nature's Magic detoxifies your soil.
