Bio Ag & Hort Ltd. Barry Davidson. ph 0800 NATRAKELP email:barryd1968@xtra.co.nz
Bio Vermis vermicast
Bio Vermis vermicast is an all purpose natural fertilizer. Compost worms are fed organic waste materials which
contains a wide variety of minerals and trace elements. The earthworms digest this material and in its' passage
through the worm, it is beneficially altered both chemically and physically. The end product is "super humus"
which is an extremely fertile top soil. Earthworm castings contain rich proportions of water soluble nutrients. This
is a primary reason for being able to provide incredible results. Vermicast allows plants to quickly and easily
absorb all essential nutrients and trace elements. This is possible because the earthworm grinds and uniformly
mixes the nutrients and trace elements in simple forms, so plants need only minimal effort to obtain them. Though
they may have many nutrients and/or higher analyses, the ability of plants to optimally use them is limited
because they are not broken down to the degree in which the earthworm is able to provide them. As well as an
abundance of available nutrients, vermicast also provides a perfect mix of nutrients that are not readily available,
but present for long term nutritional needs. Vermicast provides essential nutrients, including over 60 trace
minerals and humus. Even though castings have low NPK values, worm castings provide nature’s perfect blend of
micro and macro nutrients which are available for immediate as well as time released long lasting nutrition.100%
organic worm castings will not burn even the most delicate plants.
How does it work?
Until recently scientific documentation of the responses of plants to the application of vermicast to soil or container
media has been poor, even though anecdotal evidence has been abundant.
Over the past five years the soil ecology laboratory at the Ohio State University has developed a comprehensive
research program in vermicomposting. They have found consistently the addition of relatively small amounts of
worm castings to standard horticultural container mixes, and even commercially prepared premium quality
container media has resulted in dramatic improvements to plant growth.
A consistent and interesting trend for trials with plants grown in container media is for the best responses to occur
when worm castings constitute only 10 - 20% of the volume of the mix and with increasing proportions of castings
not always improving plant growth as well. Pasture trials have shown the same effects with as little as 20 - 40
grams of vermicast per square metre making significant improvements to grass growth.
Broad acre application of 200kg /ha of vermicast onto lucerne gave a 15% increase in yield. The low % of castings
required for a dramatic response indicate that the dramatic responses are more than simply a function of
supplying plant nutrients and that other related growth stimulants are involved.
It has now been found that vermicast increases microbial populations, and adds biologically active metabolites
such as plant growth regulators (aukins, cytokinnins and gibberellins). The addition of vermicast has consistently
improved seed germination, enhanced seedling growth and development and increased plant productivity much
more than would be possible from the mere conversion of mineral nutrients into more plant available forms.
Vermicast has also been shown to reduce the incidence of plant diseases. Research indicates that microbial
activity and the make up of the microbial communities existing in vermicast play an important role in plant growth
responses. The reason being that different microbes act on different substances from simple sugars to complex
substances. If any are missing it will inhibit growth. The diversity of microbes in vermicast allows all substrates to
be broken down.
The role of earthworm derived humic acids has also received much attention recently. Humic acids are produced
by the breakdown of organic matter by microorganisms . They are generally negatively charged so attracting
positive ions, for example calcium. Humic substances promote the conversion of a number of elements into forms
available to plants, of particular importance is phosphate. Phosphate reacts with other minerals in the soil,
(particularly iron and aluminium) and becomes locked or unavailable to plants. Humic acids help substitute iron
and aluminium with other elements e.g calcium making phosphate plant available.
Enhancing this is mycorrhizal fungi. Vermicast contains large concentrations of mycorrhizal fungi spores.
Enzymes associated with this fungi are able to unlock soil phosphate making it plant available. Mycorrhizal fungi
work mutualistically with plant roots extending the roots network throughout the soil. Mycorrhizal fungi supply the
roots with important nutrients such as phosphorous and the plant supplies the fungi with carbon. This association
is very important for plants such as clover.
Vermicast is humus rich. The break down of organic material by earth worms accelerates the humification of
organic matter. The humic and fulvic acids produced in this process have been proven to stimulate plant growth
beyond that produced by solely the mineral nutrient found in vermicast. Humic acids are large complex molecules.
Partial oxidation of humic acids allow bonding sites for plant nutrients including calcium and magnesium and other
humic like materials produced in the faeces of earthworms which exhibit auxin, gibberellin and cytokinin like
activities.
Studies of the positive effects of these humic substances on plant growth when full requirements for mineral
nutrition are met resulted consistently in positive effects on growth independent of nutrition. Humic acids have
been reported to enhance mineral uptake by plants by increasing the permeability of membranes of the root cells.
Vermicast humic acids appear to have greater effects upon the root growth of the plants than on the above ground
parts of the plant. Stimulation of root growth, increased proliferation of root hairs, and enhancement of root
initiation by humic acids has been reported commonly by several other researchers.
The best plant growth responses are when vermicast and traditional fertilisers are used together.
Application rates
Pasture and fruit crops
Apply between 250 and 500 kg’s per ha using a chain spreader.
Vermicast can be mixed with lime at application time.
Home garden
Soil conditioner
– apply 1 part Bio Vermis to 4 parts soil
Vegetable and flower beds
– 4 to 5 litres per square metre
Potting mix
– Blend 1 part Bio Vermis to 2 parts compost or potting mix