SUDBURY, Ont. – Remains from a volcanic deposit near Sudbury, Ont., are being spread on North American farmland as a mineral-rich soil amendment.
Agricultural Mineral Prospectors Inc. plans to sell 15,000 tonnes of Spanish River carbonatite this year to farmers in Ontario and the United States.
Miners-turned-farmers John Slack and Chris Caron say that will go a long way to recouping the $2 million the company has invested in the project since 1992.
The product, rich in calcium, is sold in Ontario for $140 per tonne.
“Our goal is to increase the level of sales to more or less keep pace with the rate organic agriculture is growing,”Slack said.
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There has been interest in the product from Western Canada, Slack added, including at least two Saskatchewan farmers.
AMP is looking to organic agriculture for the bulk of its sales. However, Slack said he and his partners think conventional farmers can also benefit from their product, especially if their soil is deficient in calcium. The rising cost of conventional fertilizer is prompting farmers of all stripes to look at alternatives, he added.
“Conventional farmers are looking at a lot of things that 10 years ago would have been unheard of.”
Spanish River carbonatite consists of calcite (calcium limestone,) apatite (rock phosphate,) and biotite (a source of potassium.) There are also significant levels of iron and sulfur and trace amounts of manganese, zinc, copper, cobalt, molybdenum and boron.
Slack said the product’s reactivity makes it unique. Nutrients quickly become available to crops when applied in a ground or powdered form. Slack said it’s also affordable compared to other organic amendments. Soft rock phosphate from Florida can cost $380 for a short ton, he said.
“What we’ve done is marry two disciplines â farming and mining,”said Slack, who farms organically near Erin, Ont.
“We’re interested in providing a balanced mineral product directly to the microbes in the soil, liberating nutrients for the plants.”
A thousand tonnes were marketed last year and several field trials were conducted in Ontario. Slack said trial results are promising and additional research is being conducted, including research at the University of Laurentian, in Sudbury. Trials with tomatoes, barley and alfalfa suggest the product increases plant protein, calcium, phosphorus and potassium levels, and generally improves plant health and vigor.
George Kerr, who farms near Chatham, Ont., applied Spanish River carbonatite to parts of his asparagus field last year that had tested low for calcium.
He said an application of 400 pounds per acre cost him less than $24 per acre and resulted in a substantial boost in soil calcium levels. That was a marked improvement from Kerr’s previous “liming” of his field using a different product.
“Three years ago we limed those spots and took some follow-up soil samples and the calcium level wasn’t changing that fast.”
Kerr, who farms more than 1,700 acres, doesn’t have anecdotal observations about improvements to his asparagus crop, but he plans to apply more Spanish River carbonatite to problem areas – the knolls in his field.
He also plans to apply it to alfalfa ground and pasture land this spring and will compare treated areas to untreated areas.
Still, Kerr is cautious.
“There aren’t any magic bullets in terms of soil fertility,” he said.
“To say you’re going to get a very different result with one single (product) doesn’t happen too often … I think it would be great if someone at the University of Guelph became interested in this and laid out some research.”
The Spanish River deposit is composed of igneous or primary rock. It’s a rare formation. Slack said if all such deposits around the world were put in one place, they would only cover 200 sq. miles.
Rock at the Spanish River deposit is quarried with a skid-steer loader. It’s processed in a small screening plant and shipped south.
Spanish River carbonatite is approved by the Organic Crop Producers and Processors Association for certified organic use. It has also passed tests by the Ontario and British Columbia agriculture departments for use as a compost additive and soil amendment.
