6675 Highway 15
Seeleys Bay, ON K0H 2N0

Month: June 2016

Wollastonite: A win-win for sustainable phosphorus management

In the summers of 2014 and 2015, massive algal blooms in Lake Erie made headlines across North America, particularly in 2014 when toxins produced by microcysts in the blue-green algae shut down Toledo’s water works, leaving hundreds of thousands of people without access to safe drinking water. The problem affects lake and rivers across the continent, threatening human health, wildlife populations, recreational opportunities, and commercial fisheries. With the warmer summers associated with climate change, the problem is only expected to get worse.

Phosphorus run-off from point sources like factories and sewage treatment plants and non-point sources like lawns and farm fields is the primary culprit behind these harmful outbreaks. Numerous efforts are underway to reduce the amount of phosphorus finding its way into our waterways. A growing body of research indicates that wollastonite is effective at capturing phosphorus from water in a number of applications.

Several studies demonstrate that wollastonite can be very effective at removing phosphorus from municipal wastewater treatments systems, particularly in constructed wetlands. Ongoing research in Ontario also suggests that wollastonite will adsorb significant amounts of phosphorus from greenhouse nutrient solutions. These point sources tend to have relatively high concentrations of phosphorus.

Recent research demonstrates that wollastonite powder is the most effective option for adsorbing phosphorus from water that has a relatively low concentration of phosphate but is still prone to algal blooms. While other substances were less effective at adsorbing phosphate as the phosphorus concentration in the solution decreased, wollastonite powder remained effective. It removed more phosphorus, a higher percentage of total phosphorus, and worked faster at all concentrations tested. This is likely due to the particle size of the powdered wollastonite, the porosity of the material, and the chemistry of the substance.

While some substances remove phosphorus by precipitation, which renders it practically immobile, phosphates adsorbed onto wollastonite molecules are less tightly bound and can re-enter the phosphorus cycle when environmental conditions are appropriate. This means that the wollastonite used to remove phosphorus from water sources where it isn’t needed or wanted can be re-used as a fertilizer source of calcium, magnesium, silicon, and phosphorus. Recycling phosphorus in this way not only protects waterways: it helps preserve dwindling phosphate deposits used for agricultural fertilizers –  a win-win for sustainability!

Re-Blog: Silica – The Hidden Cost of Chemicals

Interest in the role of silicon in crop production and protection has been growing around the world for several years now. Some might say that North America is a bit behind the curve! We recently came across a comprehensive article from 2010 on the website of an Australian agricultural consulting company. It begins:

A major mineral is missing in many soils and most soil tests do not even monitor its presence. This mineral can increase stress resistance, boost photosynthesis and chlorophyll content, improve drought resistance, salt tolerance and soil fertility and prevent lodging. It can also reduce insect pressure, frost damage and destructive disease while lowering irrigation rates, neutralising heavy metal toxicity and countering the negative effects of excess sodium. If I were to tell you that this same missing mineral can increase root growth, boost yield and enhance crop quality, you could well ask, “how could we have overlooked something so important?” and you would be correct. It has been a serious oversight. The mineral in question is silicon, and science is rapidly revealing the scope and scale of our silicon neglect.

The article goes on to describe the role of silicon in cell wall resilience, photosynthesis and mineral uptake, abiotic and biotic stress management, plant immune response, and even human health! It concludes:

Proactivity is the essence of the biological approach. If you understand how plants protect themselves, then you provide the necessary components to maximise that process and minimise the need for chemical intervention. In this context, silicon is an essential pre-requisite for proactive pest and stress management and should be an integral part of every good nutrition program.

Click here to read the complete article.

Wollastonite from Canadian Wollastonite is a natural, mined calcium silicate with the demonstrated ability to increase levels of silicon in plants when used as a soil amendment.

A Natural Solution to Control Grub Damage?

Last summer, an interesting thing happened on a field of turf north of Toronto. The grower was testing a new soil amendment as a source of calcium, magnesium, and plant-available silicon. Research indicated it could lead to healthier, more disease-resistant grass. Sure enough, the grass on the test area grew better –  so much better that the grower had to dig deeper to find out what was going on. To their surprise, the soil under the treated area was free of the white grubs that were feeding on the roots of nearby grass, stunting its growth.

White grubs are the larval stage of a number of species of beetles. Although grass roots are their preferred food source, grubs feed on the roots of a number of plants, including corn, soybeans, legumes, and cereals. Depending on the species, grubs remain in the soil for one to three years. At elevated populations, grubs stunt, weaken, and delay plant growth and can even kill young seedlings or plants experiencing other stresses (i.e. drought). 

“Could it be the soil amendment?” they wondered. Collecting some grubs, they exposed them directly to the material. Within minutes, something about the mineral literally made the grubs curl up and die.

The mineral was wollastonite from Canadian Wollastonite, a newly opened mine in Kingston, Ontario.

Repeated trials last summer and research over the past few months has started to confirm what was happening to those grubs. In technical terms, wollastonite has an acicular crystal structure at the microscopic level. Acicular means “shaped like a needle.” When grubs come into contact with wollastonite, its needle-like crystals pierce and lacerate their soft bodies, leading to dessication (drying out) and death.

Electron microscope images show the needle-like crystals of wollastonite and its effect on larva.

This type of pest control action is well-known in the case of diatomaceous earth (DE), which is used to control insects on plants and in stored grains. However, DE also absorbs water quickly, which softens its edges and makes it less effective. Wollastonite stays “sharp” in moist conditions, making it an ideal addition to soils.

More turf managers and homeowners are starting to experiment with wollastonite. It’s beginning to appear that the wollastonite crystals even discourage the digging activity of raccoons and skunks who are well-known for tearing up lawns in search of grubs.

With increasing concerns about the impact of pesticides on our environment and on pollinators in particular, everyone from farmers to homeowners are looking for more natural, less risky ways to keep their fields and lawns healthy and productive. Stay tuned for more research and reports on the potential for Canadian Wollastonite to help reach these goals.