Tuesday, December 04, 2012

Mycorhizal Inoculant

I've been reading up on the soil "world wide web" of fungal mycelia. These organisms benefit plants and trees in many ways, and connect plants to one another. They transfer nutrition between plants and trees, bring nutrition from otherwise unavailable sources in the soil, improve root growth, stimulate top growth, improve drought resistance, and improve disease resistance. Apparently, disturbance of soil can reduce or eliminate some mycorrhizal mycelial webs, which take a long time to regenerate. Those disturbance include plowing, tilling, soil compaction, fertilizing, and pesticides. The marketing argument for inoculants is, they replenish the mycelial web at the place where it is most needed, the plant root. Technically, once inoculum is added, it should not be needed again.
Plant Success mycorrhizal inoculant list of species. I bought via Amazon.  The advantage is the variety of species.  Different plants benefit from different fungal species, with a lot of overlap.  By providing a variety of species, the thinking is that the ones that can become symbionts with the particular garden plant, will grow, and the others wont hurt anything.  Some plants can use multiple species.  Some mycorrhiza associate with certain plants and not others.

In order to apply at the roots, inoculant is best used at time of planting.  The granules are sprinkled on the plant roots, or in the soil that is then applied to the plant roots.   The alternative is to dig small holes around the plant and sprinkle inoculant into the holes, with the expectation that once against the roots, the mycelium will spread from root to root.
Mykos mycorrhizal inoculant.  I did not see a list of species.  I also could not find that on the website.  From other sites on the internet, it looks like Mykos is one species, Globus intraradices TRI 801, 80 spores per gram.  Reading on mycorhiza, Globus intraradices  is not so likely to benefit woody trees like this hazelnut.  I should have used Plant Success for this.  A lot of other plants should be happy with the G. intraradices so I will use up the package for them.  The main issue is that G. intraradices is an "endo" mycorrhiza, which lives within the root.  Many plants benefit from endo, but apparently a lot of woody trees benefit from "ecto" myorrhiza, which live surrounding the root.
Mushrooms.  I am not adventurous enough to eat them.  This part of the yard has a number of old, nearly decomposed, tree stumps.  There are mushrooms throughout the yard.  There appear to be multiple varieties.

Mushrooms are the fruiting structures of a mature mycorrhizal mycelium, responding to weather or other stimuli to grow and produce spores.  There are thousands of species.
This is one mushroom, near a spruce tree.  There are more of the same type, near other spruce trees.  Which leads me to suspect some species specificity.  Big mushroom.

Seeing mushrooms around the yard, makes me wonder if adding mycorrhizal inoculant is like taking coals to Newcastle.  Maybe.  The raised beds are, by definition, highly disturbed soils.  The first two were filled largely with granular soil from the hundreds of molehills that had baked in the sun.  That was easy to handle and they needed to be removed so mowing would not cause big dust-bowl quality clouds of soil.  So no active mycelia, I'm sure, but maybe lots of spores.   Even though about 1/4 of the volume of those beds was compost, I don't know the mycorrhizal content of the compost.  I suspect this compost's population is mainly bacterial and actinomycete, not mycorrhizal fungi.  No way for me to know, and I don't think anything is hurt by adding some inoculant.

Another argument could be made that the most adapted, most likely to survive and flourish, mycorhiza are the ones that were already growing here.  Valid argument.  I view adding inoculant as a boost for newly planted trees, shrubs, and garden plants.  Since I use lots of mulch and add lots of organic matter, this will be a "one time" effort.

I suspect that some (much?) of the market for mycorrhizal inoculant is in the home production of certain herbal products that I have no interest in growing and don't want to know about.   All I want from it is better trees, shrubs, flowers, and vegetables.

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