The benefits of mycorrhizae
Improved nutrient and water uptake
Improved root growth
Improved plant growth and yield
Reduced transplant shock
Reduced drought stress
Q) What do they do for plants?
A) Mycorrhizal fungi increase the surface area absorbing area of roots 100 to a 1,000 times, thereby greatly improving the ability of the plant to access soil resources. Several miles of fungal filaments can be present in a thimble of soil. Mycorrhizal fungi increase nutrient uptake not only by increasing the surface absorbing area of the roots, but also release powerful enzymes into the soil that dissolve hard-to-capture nutrients, such as organic nitrogen, phosphorus, iron and other "tightly bound" soil nutrients. This extraction process is particularly important in plant nutrition and explains why non-mycorrhizal fungi form an intricate web that captures and assimilates nutrients, conserving the nutrient capital in soils.
Q) What are Mycorrhizal Fungi?
A) "Mycor" - "rhiza" literally means "fungus" - "root" and defines the mutually beneficial relationship between the plant root and fungus. These specialized fungi colonize plant roots and extend far into the soil resource. Mycorrhizal fungal filaments in the soil are truly extensions of root systems and more effective in nutrient and water absorption than the roots themselves.
Q) How hardy are mycorrhizae?
A) Shelf life ofour standard products are 2 years with a 10% decrease in viability every years thereafter. Cold temperature, even freezing, does not affect the viability of mycorrhizal propagules that are most commonly used as inoculum. High temperatures, above 140 degrees F, damage mycorrhizal propagules and should be avoided.
Once the propagules are mixed with the soil , they remain in a dormant state until there is root activity. Mycorrhizal propagules germinate in the presence of certain root exudates. Once the spores germinate and attach to the root system, the mycorrhizae will remain with the plant for the life cycle of the plant. Plants growing on stressed sites or frequently disturbed sites may require several inoculations.
Q) What plants form specialized roots with mycorrhizal fungi?
A) 90% of the world's plant species form mycorrhizae and require the association for maximum performance in non-artificial conditions.
Here is a list of some commercially important plants that form mycorrhizae.
Q) How do mycorrhizal fungi increase nutrient uptake?
A) These fungi increase the surface absorbing area of roots 10 to 100x thereby greatly improving the ability of the plants to utilize the soil resource. Estimates of amounts of mycorrhizal filaments present in soil associated with plants are astonishing. Several miles of fungal filaments can be present in less than a thimbleful of soil! But mycorrhizal fungi increase nutrient uptake not only by increase the surface absorbing area of roots, they also release powerful chemicals into the soil that dissolve hard to capture nutrients such as phosphorous , iron and other "tightly bound" soil nutrients. This extraction process is particularly important in plant nutrition and explains why non-mycorrhizal plants require high levels of fertility to maintain their health. Mycorrhizal fungi form an intricate web that captures and assimilates nutrients, thus conserving the nutrient capital in soils. In non mycorrhizal conditions much of this fertility is wasted or lost from the system.
Q) What other activities do mycorrhizal fungi do?
A) Mycorrhzial fungi are involved with a wide variety of other activities that benefit plant establishment and growth. The same extensive network of fungal filaments important to nutrient uptake is also important in water uptake and storage. In non-irrigated conditions, mycorrhizal plants are under far less drought stress compared to non-mycorrhizal plants.
Mycorrhizal fungi also improve soil structure. Mycorrhizal filaments produce humic compounds and organic "glues" (extracellular polysaccharides) that bind soils into aggregates and improves soil porosity. Soil porosity and soil structure positively influence the growth of plants by promoting aeration, water movement into soil, root growth, and distribution. In sandy or compacted soils the ability of mycorrhizal fungi to promote soil structure may be more important than the seeking out of nutrients.
Q) Don't soils already contain mycorrhizal fungi?
A) Undisturbed soils are full of beneficial soil organisms including mycorrhizal fungi. Research indicates, however, many common practices can degrade the mycorrhiza-forming potential of soil. Tillage, fertilization, removal of topsoil, erosion, site preparation, road and home construction, fumigation, invasion of non-native plants, and leaving soils bare are some of the activities that can reduce or eliminate these beneficial soil fungi. Reintroducing mycorrhizal fungi in areas where they have been depleted can dramatically improve plant establishment and growth.
Many routine nursery practices, such as fumigation and dousing with high levels of water and nutrients, produce non-mycorrhizal plants. When high levels of fertilizer and water are provided for non-mycorrhizal plants, they can thrive in this artificial growing media, but they are ill prepared to survive the eventual outplanted condition.
Q) How do you apply these mycorrhizal fungi?
A) Mycorrhizal application is easy and requires no special equipment. The goal is to create physical contact between the mycorrhizal inoculant and the plant root. Mycorrhizal inoculant can be sprinkled onto roots during transplanting, worked into seed beds, blended into potting soil, "watered in" via existing irrigation systems, applied as a root dip gel or probed into the root zone of existing plants. The type of application depends upon the conditions and needs of the applicator.
Q) Is mycorrhizal inoculation expensive?
A) Mycorrhizal inoculation is inexpensive. Typically for small plants the cost ranges from less than a penny to a few cents per seedling. For larger plants, more inoculum is needed and costs are higher.