Is our soil at risk?

Wednesday, April 3, 2013

Soil degradation is acute in China, Africa, India and parts of South America, says an Australian professor. But, say our own experts, we may also be neglecting Ontario's soil at our peril

by DANA SNELL

Prof. John Crawford of the University of Sydney in Australia made an alarming claim in a December, 2012 article in Time magazine, stating that "a rough calculation of current rates of soil degradation suggests we have about 60 years of topsoil left."

The problem is most acute in China, Africa, India and parts of South America, but the rest of the world is not immune. According to Crawford, "even the well-maintained farming land in Europe, which may look idyllic, is being lost at unsustainable rates."

And in Ontario? Adam Hayes, soil management specialist in the field crops division of the Ontario Ministry of Agriculture and Food, says that, while Ontario has a history of relatively good soil care and much of Ontario's land is farmed sustainably, "I would say that in some soils we have seen significant soil loss," adding, "There is some concern from an organic matter level perspective."

The main causes of soil organic matter loss, according to Hayes, include farming practices such as excessive tillage, shorter crop rotations and rises in certain crops like soybeans which "don't put a lot of organic matter back into the soil."

University of Guelph professor and Loblaw Chair in Sustainable Food Production Ralph Martin warns against ignoring emerging threats to soil health. "In my experience, there was more emphasis on (soil health) in the '70s and '80s and we've let it go by the way."

Martin points to the emerging market for crop residue, such as corn stover and wheat straw, as a new threat to Ontario's soil security. When crop residue stayed on the field, it protected soil and provided biomass that built up soil organic matter. According to Martin, "if we start removing that stover to burn as biomass or to use as bioproducts . . . then we have to make sure that we're doing something else to keep up soil organic matter and to keep the soil covered."

Martin goes on to point out that our tradition of well-managed soils was dependent on another farming practice that is going by the wayside: managing crops and livestock on the same farm. "In some cases, the livestock manure that is in large barns may not necessarily be close enough to be applied to cropland, so there is some cropland in Ontario that's receiving less manure than it did in the past. That I think is something we should be alert to."

Commercial-turned-organic farmer Mark Grahlman operates a 30-acre vegetable farm in Meaford. At one point, his commercial apple farm was 500 acres. About 12 years ago, he moved to organic and since has downsized to a "natural" farm that uses no pesticides, herbicides or fungicides. According to Grahlman, "managing our organic waste is probably one of the most important things we could do for our soils."

Grahlman makes his own compost, along with compost tea, some of which he sells to local lawn and garden companies. Grahlman eschews commercial compost because, in his opinion, "when it's done on an industrial scale it seems to me like it's kind of poorly made. There's not a lot of awareness of inputs or quality of product going back out that's organic matter and carbon
based."

For him, the key to good compost is variety. Grahlman keeps a small number of animals in pasture, many of them rescue animals, to provide manure for his compost. However, he acknowledges that making your own compost, especially on a commercial farm much larger than his, is "very expensive. There is no way to charge enough, at the farmer's market or locally, to recoup those costs."

As Australian professor Crawford points out: "Soil is not costed into food, which means that farmers don't have the financial capacity to invest in their soil to turn the situation around."

Martin believes that government intervention may be necessary. "I think it's getting to the time when we have to think about how governments might attenuate farm payments based on soil organic matter levels."

Hayes points to programs such as the Environmental Farm Plan (EFP), the Nutrient Management Act and the Farm Stewardship Program as ways that governments actively invest in soil health. But, according to Martin, the EFP may not be keeping pace with new threats to soil health. "I think we have to keep looking at the Environmental Farm Plan and nutrient management plan and think about how they can be upgraded from time to time to make sure that we're addressing needs."

One example would be to provide incentives for farmers to put in cover crops if the residue is going to leave the farm. But Hayes acknowledges that "with tight budgets, in the last number of years there hasn't been the funding to put into significant incentive programs."

Part of the problem may be the difficulty in accurately measuring soil organic levels. Martin has just begun a research project that would make it possible for farmers to more reliably measure their soil organic matter levels and be eligible for payments if they can show stability or increase. He estimates the project will take at least two years to show results.

In addition to incentives, Grahlman suggests setting up agreements to trade biomass for manure. This could offset the loss of organic matter from the field. However, Grahlman stresses again that quality control is key. "If the manure is coming from a place that's so big it's full of antibiotics and other things that you don't want in your compost pile and on your fields, well you have got nothing to sell me back, or nothing to trade for that forage that I'm going to give you."

Martin, Hayes and Grahlman all agree that we ignore soil at our peril. Events like the world's first Global Soil Week, held this past November in Berlin, seem to be indicators that soil is now being considered a resource at risk alongside water and forests.

But soil can easily slip under the radar since, as Crawford writes in the Time article, "soil isn't sexy." For concerned farmers like Grahlman, however, soil degradation is front page news, and "that particular article is a lot more important than the introduction of a new BlackBerry." BF