Mycorrhizae & Worm Castings
Mycorrhizae
With the astronomical rise in world nutrient prices in
the past year Australian primary producers are keen to source alternative
sources of nitrogen at affordable prices. The clear standout in this field is to
rely on adding mycorrhizae to your soil or potting media.
So what are mycorrhizae? Mycorrhizae are generally spoken of in the plural
(rather than the singular mycorrhiza) since they comprise vast colonies are very
small micro-organisms found naturally in the top profile of undisturbed soils.
Visually they resemble the fine white root like growths that you see when you
pull up a mushroom. That’s not surprising because what looks like mushroom roots
are mycorrhizae that are fine fungal filaments.
| There are literally tens of thousand of different types or species and some enter the roots of host plants to aid the collection of nutrients and even assist their host to turn atmospheric nitrogen into organic nitrogen that a plant can use to aid its growth. This type is called endomycorrhizae. Another group of these tiny organisms termed the exomycorrhizae stay on the outside of the plant such as the mushroom and pine tree roots and turn soil nutrients into forms of nutrient that are more readily available to the host plant. Both types are soil born organisms that do not retard or destroy the host plant but on poor soils greatly improve the plant’s ability to survive on poor soils. |
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When a cereal farmer plants a crop of wheat for instance
they frequently inject soluble nitrogen as urea (that is 42% nitrogen in the
form of a salt), but on very alkaline soils of say pH 9, such as those soils in
the Murray Mallee of SA and Victoria the soil alkalinity locks up much of the
nitrogen. This in effect means the farmer(s) paid for nutrients that their
plants cannot access. They are sitting on reserves of soil nutrients and not
just nitrogen that can be released with the aid of the tiny catalytic soil
organisms, the noble mycorrhizae.
Fortunately these tiny mycorrhizae are plentiful in worm castings and although
there are commercial sources of mycorrhizae rich compounds being sold by farm
supply companies, the richest and cheapest source is in inoculated worm
castings. The importance of inoculated castings is that the composted slurry of
feedstock that worms are feed in cultivation farms is added to the pure castings
just before they are despatched so that the buyer is buying a live organism and
not dead or dormant media. Most organic pellets on the market have been
sterilized by steam or ultraviolet rays in their manufacture to reduce
contamination and health risks, so that they only become an active source of
micro-organisms when added to a rich soil. Added to a sterile potting media, the
value of organic pellets is limited to the chemical nutrients that have been
added, rather than any live nutrient-scouring organisms such as mycorrhizae that
exist in the product supplied. For instance blood and bone products contain
average just 5% nitrogen and seldom more than 40% or any organic material. In
NSW that can even be canola meal (no blood meal & no bone meal). The 60% balance
called ‘FM’ or filling matter is sand, gypsum or sewerage effluent that is
loaded with heavy metals, such as mercury and cadmium, which plants cannot use.
Inoculated worm castings are sold nationally as Wormswork™ in retail packs to 25
litres or in bulk.
For more information phone (08) 8354 1088 Or phone Craig on 04296 77728 - E-mail
craig@wormswork.com.au