As farmers’ attentions turn to the prospect of spring planting, a report released in late March has a long-term perspective on something near and dear to every farmer in Ontario, if not the world: the soil.
The report, “Investing in soils for a sustainable future,” released by Ontario’s environmental commissioner, Gord Miller, is an attempt to identify both the opportunities and challenges involved in increasing soil carbon levels.
The long-term goal behind the round-table discussion, held in 2012, is to build healthy soils. Attending the round-table session was a mix of university researchers, government extension personnel, industry consultants and farmers.
In very general terms, those attending acknowledged various best management practices such as crop rotations and cover crops that help increase or maintain soil carbon levels. However, barriers to implementing such practices include the complexity and cost of determining soil carbon levels, as well as the cost of using materials such as municipal compost. Establishing pricing and policy directives on the value of carbon sequestration and cap-and-trade measures were also part of the discussions.
On the research side, Paul Voroney of the University of Guelph, Johannes Lehmann of Cornell University and private sector consultant Doug Weatherbee, all made presentations on the science surrounding soil carbon levels.
Voroney keyed on the importance of soil carbon with respect to overall soil health, productivity and even climate change. He touched on the basics of soil-carbon sequestration and referenced some research that he’s done that indicates plant residues and other organic inputs are the only method of increasing soil carbon levels.
Weatherbee provided a breakdown of the activity of the “soil-food web” — the various microbes in healthy soils that carry out beneficial functions, including nutrient cycling, soil aggregation and even disease suppression.
And Lehmann emphasized the need for a life-cycle approach in managing the soil, and pointed to biochar as an interesting ingredient. In research from New York state, the use of biochar showed no yield increase or nitrogen uptake by plants — but it did reduce nutrient leaching and increased nitrogen retention in root zones of the plants.
From the extension side, Anne Verhallen and Adam Hayes from Ontario’s Ministry of Agriculture and Food/Ministry of Rural Affairs (MAF/MRA), reminded those in attendance that soil carbon has long been an issue in Ontario. Recently, there’s been a renewed interest in cover crops and forages, and that’s been seen as a positive move in the chase for improved soil conditions.
Of course, one of the big hurdles in carbon soil levels and sequestration is one of economics; how much does it cost and how much could it earn for farmers?
Ian Campbell of Agriculture and Agri-Food Canada cited options from other jurisdictions, including carbon taxes, cap-and-trade initiatives, offsets and some of the examples afforded by New Zealand and British Columbia, where carbon prices are $7 per tonne and $30 per tonne, respectively.
Karen Haugen-Kozyra also addressed some of the economic issues, referring to the work of the International Panel of Climate Change (IPCC) on agriculture and carbon. According to the panel’s latest report, the contribution of soil carbon to climate change mitigation could be significant, especially in developing countries.
The final presentation came from Don McCabe, a farmer from Lambton County and current vice-president of the Ontario Federation of Agriculture (OFA). In the bluntest of terms he said this issue is too important to ignore — that policies are being set internationally which will ultimately affect everyone, including those at the farm level.
McCabe stressed the need for more research but noted that such study should not be measured by any political calendar. Canadian agriculture is 10 per cent of the problem and 20 per cent of the solution. The rest of the world is moving toward carbon accounting in agriculture and Ontario can either choose to lead or choose to delay things another 10 years.
“For farmers, the challenges are always the same: profitability, money and economic return,” said McCabe. “Farmers agreed to do battle with Mother Nature, not with bad policy.”
— Ralph Pearce is a field editor for Country Guide at St. Marys, Ont.