Time a key challenge to building back damaged soil
Indian Head, Sask., April 24, 2007:
Building back the health of badly damaged soil is a process that takes time, say two long-time proponents of soil conservation practices. The question, however, is how much time.
A new feature story, available on the Soil Conservation Council of Canada (SCCC) Web site at www.soilcc.ca, explores this question by highlighting the perspectives of two leaders in the field of soil conservation. The article is part of a series of features available on the SCCC Web site explaining the state of soil conservation in Canada today.
"Remediating soil phosphorous levels can be a slow process," says Elena Bennett, a professor with McGill University in Montreal and an authority on the study of inland water. "It's the slowest factor in the ecosystem to recover and it can take hundreds of years to build it back from the effects of wind and water erosion, loss of organic matter, contamination and salinization. On top of that, runoff from overfertilized soil presents a water contamination threat."
Meanwhile, Jim Halford, a soil conservation pioneer and developer of Conserva Pak zero-tillage technology, believes that practices such as zero-till have changed the rules of fixing badly damaged soil and can, in fact, build soil back to reach or even exceed peak nutrient levels over a relatively short period of time. "Building back soil is a process that takes time, but not as much time as was generally thought in the past," he says.
"When I was going to university, it was commonly thought that it takes hundreds of years to reclaim soil nitrogen," says Halford. "But I have evidence on my own farm and those of customers which shows that soil, when properly managed, can be built back in a fraction of that time, possibly within a couple of decades.
"For example, there was soil on our land that lost about a third of its original organic material over the course of about 100 years. After I had been using zero-tillage for about 20 years, it was back to a little over 90 percent of its original content of organic material."
Looking at soil from a water quality and conservation context has given Bennett a long-term perspective on the effects of soil erosion and the opinion that soil badly damaged from overfertilization can take many decades to reclaim. Nutrient runoff, which pollutes lakes, rivers and other watercourses, is one consequence of overfertilization.
Soil conservation practices such as zero-till, however, can play an important role in both soil reclamation and limiting nutrient runoff, she says. Although zero-till practices generally require a high degree of fertilization, she says these practices, depending on the layout of the land and general management factors, often help minimize runoff into water bodies.
"Ultimately, the question we need to ask ourselves is how we can feed people without ruining the soil while considering water quality at the same time. It's a tricky balance."
For the full story, "No fast fixes to soil concerns: two views from two leaders," visit the SCCC Web site at www.soilcc.ca. SCCC is the face and voice of soil conservation in Canada. A national, non-governmental, independent organization, it was formed in 1987 to provide a non-partisan public forum at the national level for soil conservation.
Using a grassroots approach combined with the scientific, technical and practical experience of its members, it works with government and private industry, individuals and non-government organizations to address soil degradation and facilitate exchange of information across Canada.
For more information, contact:
Doug McKell, Executive Director
Soil Conservation Council of Canada
Indian Head, SK
Ph.: (306) 695-4212
Jean-Louis Daigle, Executive Director/Directeur général
Eastern Canada Soil and Water Conservation Centre/
Centre de conservation des sols et de l'eau de l'Est du Canada
Saint-André (Grand Falls), NB
Ph.: (506) 475-4040