Crushing

Agricultural trials open new doors for quarry business

Directors at Mt Sylvia Diatomite have been enthused by the growing market recognition of its fine diatomaceous earth product, absorbacide and the 50 per cent increase in the yield of palagonite, the company’s soil conditioner product in a trial on a ginger plot at Bauer’s Organic Farms, in south-east Queensland.

All the directors have a tertiary background in science, which fuels their desire to establish the value and utility of diatomite using evidence-based research. They recognise that, in this era of water shortage and increasing awareness of chemical pollution in industry and agriculture, diatomaceous earth and palagonite offer unique, environmentally sustainable solutions to a diverse range of problems.

The three directors – full time geological consultant and part-time grazier Martin I’Ons,  geologist, metal explorer and past organic macadamia farmer Guy Lewington, and retired associate professor of pharmacology Dr Ian Neering – say their diatomaceous earth products have a wide range of applications in agriculture.

Their company, Mt Sylvia Diatomite, evolved with the purchase of the diatomaceous earth mine more than a decade ago at Junction View, 40 kilometres south of Gatton, and focuses on the development of its diatomite products and the education of current and future clients in the uses of these products.

Lewington and Neering, the hands-on managers at Mt Sylvia Diatomite, say the company sells a variety of the highest quality diatomaceous earth products available in Australia, which are all Australian Organic Registered Farm inputs (allowed inputs 10575). The company also operates a 300,000 tonnes per annum basalt quarry at the site that supplies the Lockyer Valley in south-east Queensland with a range of Main Roads certified roadbase, aggregate and coarse rock products.

Lewington said the diatomaceous earth deposit was laid down in a fresh water lake some 20 million years ago, during a lull in a period of extensive basaltic volcanic activity.

“Mt Sylvia diatomaceous earth is a high quality product due to the low concentrations of natural impurities,” he said. “Samples analysed regularly exceed 90 per cent silicon dioxide (SiO2).

“Diatomaceous earth (DE) is composed of the siliceous skeletons of diatoms (plankton) and is amorphous (not crystalline) in nature.

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“Unlike other DE deposits that have higher iron content and/or kaolin contents, the near pure Mt Sylvia DE is transformed into a number of higher quality screened products for a large variety of applications.”

The basalt quarry component of the operation now produces a product that is new to the Australian agricultural market, called palagonite.

Neering says the basalt-derived rock mineral dust the company produces is also a superior soil amendment when compared with other quarry-sourced rock mineral dusts on the market. He said the Biodynamic Association of Australia had declared Mt Sylvia’s palagonite product its rock mineral dust of choice, replacing a product known as Minplus.

ORIGINS OF PALAGONITE

Palagonite is largely derived from devitrified basaltic volcanic glass that formed when the basalt lava above the diatomaceous horizon flowed into the fresh water lake.

Over time this volcanic glass has devitrified to form this new, largely soft yellow/brown amorphous material.

“Two diatomaceous earth products in particular are sold into the rural sector,” Neering said, “namely, molodri, which is a powder composed of molasses and fine DE, and absorbacide, our super-fine 10 micron DE product. “Molodri was originally sold to improve the taste of old fodder or to blend into livestock feed preparations. More recently it has been sought after for its use in internal parasite control.

“One sheep farmer in New England, Charlie McCowen, has had continued success over eight years in reducing the impact of barber’s pole worm in his flock. Reduced drenching programs and healthier animals have resulted. Other farmers have had similar positive results with their goats and chickens.”

Lewington said: “Absorbacide is our most valued DE product. This very fine powder has the ability to control weevils, caterpillars, mites and other insects through the action of cutting and abrading the insect’s exoskeleton or cuticle. It then absorbs the internal oils and waxes, killing the insect.

“Absorbacide is registered with the Australian Pesticides and Veterinary Medicines Authority for the control of weevils in edible grain that is commonly stored in silos, and the Queensland Department of Primary Industry also found it effective in controlling the small hive beetle that attacks bee hives.

“Recent trials involving the blending of absorbacide with the Gemstar NPV virus proved very effective in improving the mortality rate of Helicoverpa caterpillar in sweetcorn, broccoli and lettuce crops.

“In this case the absorbacide retained the moisture within the diatom skeletons that kept the virus alive for longer, resulting in much improved caterpillar mortality.

“After the DE has dried, the microscopic sharp points of the broken diatoms create an environment that is very uncomfortable for all insects, including caterpillars.

“They are unable to develop a resistance to absorbacide, unlike chemical insecticides that gradually become ineffective. The silica in absorbacide has an amorphous structure and is completely safe for human health.”

Neering says the kiln-dried DE is a powerful absorbent and can retain 150 per cent of its own weight in water (1kg of DE can retain 1.5 litres of water). Consequently, it has multiple applications in addition to those described above.

Popular absorbent uses are as pet litters (it was the original kitty litter), for the control of oil and fuel spills in fuel supply and vehicle maintenance garages, and similarly by fire brigades and emergency services.

It is used as a moisture retention ingredient in nursery products, and farmers also use DE as a silica spray when a silica deficiency is recognised in their soil, such as in the sugar industry. It is used as a flux ingredient in the steel industry. Other users of DE include hydroponic and bonsai growers.

STRONG GROWTH

Lewington and Neering say Mount Sylvia Diatomite’s quarry and palagonite businesses are growing strongly.

Following floods in the Lockyer Valley in the past few years, the quarry products have been much sought after for the repair of roads and creek crossings.

“The farming community and backyard gardeners are also becoming more aware of the availability and value of palagonite, particularly since Minplus is no longer produced,” said Lewington.

“There are currently no other high quality mineral dusts available for soil reconditioning.

“As outlined above, palagonite is derived from devitrified basaltic volcanic glass. Although there are extensive basalt lava flows in eastern Australia and many quarries exploit these rocks, there are very few occurrences where these lavas flowed into freshwater lakes.

“This makes the Mt Sylvia quarry unique. Our palagonite constitutes approximately 20 per cent of the basalt above the DE horizon and has the same bulk composition as basalt. It has a wide spectrum of major and trace elements, but in a more plant available structure.

”The cation exchange level (35meq/100g) of palagonite (a measure of the fertility of the product) is moderate to high (quarry crusher dusts are normally in the range of 5-10meq/100g), largely due to the presence of a low expansion smectite clay in palagonite.

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“When it is wet it still drains well and does not become sticky, thereby promoting aeration to the root zone when added to heavy clay soils.

“Mixing palagonite with compost on a one-to-one weight ratio produces a balanced blend of macro and trace elements along with beneficial soil fungi and bacteria.”

Neering said: “For those growers looking for a paramagnetic component the recorded levels in palagonite have ranged from 600 to 1300 c/g/s.

“While the significance of high paramagnetism values remains controversial, there are many successful farmers who promote the benefits of this feature in their soil. An increased paramagnetic level is believed to result in better water retention (palagonite has a water holding capacity of >60 per cent). Higher levels of paramagnetism may lead to higher microbial activity.”

In a trial undertaken by Anthony Bauer, of Bauer’s Organic Farms, the largest organic vegetable grower in Queensland, palagonite was blended on a one-to-one by weight ratio with composted chicken manure and turned into the soil at 12 tonnes per hectare. The initial trial was on carrots and potatoes and a follow-up trial was on a ginger crop in which 50 per cent increases in yield were achieved.

Bauer was pleasantly surprised at the results. Apart from the significant improvement in yield, he was most impressed with the obvious improvement in taste as well as increased shelf life and uniformity of the product. While this is somewhat anecdotal, and more concrete evidence is required through scientific study, Bauer’s comments are nevertheless significant.

Mt Sylvia Diatomite has also initiated research to investigate the applicability of combining palagonite with ag-lime in the treatment of acidic soils.

Each tonne of ag-lime produces 400kg of carbon dioxide (CO2) when neutralised, and most of the calcium is lost through leaching. This is not an efficient outcome. Including palagonite – which has a pH of eight – in this process could result in longer lasting improvements in soil chemistry, microbiological activity and nutrient retention.

Mt Sylvia Diatomite sells minus 2.5mm screened standard palagonite to farmers in bulk from the quarry stockpile. It also sells a minus 1.25mm fine palagonite either in one tonne bulk bags or in 20kg bags under the name “soil support”.

“At Mt Sylvia Diatomite we believe we have exceptional products that will become increasingly important for the current generation of environmentally conscious farmers and backyard gardeners,” Lewington said.

“Absorbacide on its own and in combination with products such as Gemstar NPV virus provides a non-chemical insecticide, producing a high degree of safety and high efficacy.

“Palagonite on its own improves many soil characteristics and, importantly, offers an alternative to NPK fertilisers when blended with the appropriate composts.

“Palagonite is potentially a product for our times and the directors believe that it could be part of a solution to the contamination/pollution issues currently affecting many of the country’s waterways and coastal environments including the Great Barrier Reef.

“Leeching of excess nitrogen and phosphorous into our waterways is an increasing environmental issue in Australia and also represents a waste of natural resources, particularly with respect to phosphorous.”

Since the initial palagonite trial, Mt Sylvia Diatomite has worked with Vital Soils, which provides the compost for Bauer’s Organic Farms, to blend the palagonite with chicken manure compost. This could enable Mt Sylvia Diatomite to supply palagonite directly into the chicken house.

“As part of the floor mix with the current wood chip, we could produce a very good complete compost blend once the chickens have done their business,” Lewington said. “The potential additional benefit that may be afforded is a reduction in ammonia (bad smells) coming from the chicken houses because of the absorption of ammonia by the smectite clay in palagonite.”

Another potential avenue for development of Mt Sylvia Diatomite’s palagonite has been with Regen Ag, a family company that assists farmers with initiatives that will regenerate farmland through a series of educational, training and consultancy opportunities. They promote biological fertilisers using processes developed in Central and South America .
“We have formed a close working relationship with this company and palagonite is Regen Ag’s preferred product of choice in the biological soil process,” Lewington said. 

For more information about Mt Sylvia Diatomite, visit www.mtsylviadiatomite.com.au

This article is based on a story that originally appeared in ACRES Australia, the national paper of sustainable agriculture, and is reprinted in Quarry with kind permission. For more information about ACRES Australia, visit www.acresaustralia.com.au

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