Feature Articles

New life for soil science

March 23, 2007:

Academics on the front lines of soil science research say the discipline is far from a mature field of study

Many long established soil science departments in Canadian universities have been swallowed up by renewable resource or environmental studies departments. But soil scientists across the country say that's not because soil conservation is seen as losing relevance, rather because its focus has changed, especially on the Prairies.

It's been said that it can take a generation for farmers to adopt a new technology. That has been the case with reduced tillage practices in Western Canada, which have been credited with drastically reducing the number and degree of damage of dust storms of decades past. But researchers say that while wind erosion has decreased, it's only one piece of the soil conservation pie.

"There are still many environmental issues that involve soils," says Dr. Dan Pennock, a professor of soil science with the University of Saskatchewan. "Areas such as soil organic matter, contamination by petroleum exploration or the role of soils in the greenhouse gas equation are major fields of study. So even with well established soil conservation techniques, there are many questions that need to be answered."

Tweaking established practices

In the West, traditional soil conservation research has had to find a new focus. The risk of wind erosion is being managed on much of the farm land, but there are still challenges. Scientists continue to look at rehabilitating degraded soil even under reduced or no-tillage systems.

Peter Gamache, team leader with Reduced Tillages Linkages, says that there's no doubt that in general, Western Canadian farmers have bought the conservation message in low disturbance farming. He says that tough times have proven what researchers have claimed and farmers have seen just how important no-tillage is for soil conservation. But he says there are research areas that still need work.

"We are doing a great job at slowing erosion, especially wind erosion," he says. "With direct seeding soils develop better structure and are covered most of the year so the soil is better able to handle more of what nature throws at them. But there are still issues that need more research. For example, we need to continue to look at soil conservation in irrigation systems."

He would also like to see long-term soil research plots continue so we can track the impact of the technological changes that farmers have adopted over the past 30 years. He sees studies such as this coming from government or extension researchers.

Dr. Gary Parkin, an associate professor with the University of Guelph says that much of their research looks away from soil erosion research and into water budgets and transport in soil. It's also looking at the science behind established on-farm practices, to make sure they will work in the long-term.

"You can look at science as basic or applied," he says. "Applied is directed at solving today's issues. Basic looks at future issues. We want to keep the basic science going, and this knowledge gathering can be used in applied research and new technology."

Nutrient management

Much of the fertility work in agriculture is considered mature, with little in the way of new frontiers being explored with well established technology in use. But there are still nutrient-related areas that soil scientists can examine.

Dr. Brian Amiro, Chair of the Bachelor of Science Program in Agroecology with the University of Manitoba says that nutrient management is actually a key area for soil science research at his school. He says an important area of research is on losses of nutrients into the ground and surface water bodies.

"Nutrient management is related to the greater agricultural ecosystem which uses things like disposing of animal manure onto fields and concerns of nutrient overloading into the ecosystem," he says. "Soil is the reservoir and much of the solution to deal with environmental contamination really resides with how we treat that input of nutrients into the soil."

Scientists in Eastern Canada have focused on the issues of soil erosion into water. Nutrient management and the prevention of runoff have been in the forefront of those research efforts. In Eastern Canada growers have dramatically reduced soil erosion into water through voluntary measures such as terraces and grassed waterways, as well as through measures such as nutrient management planning.

"We also need to look closely at fertility in direct seeding operations," adds Gamache. "The soil test data available today in Western Canada is 20 years old and was done in such a different tillage regime. We take soil health for granted because the uptake of direct seeding has been so high."

Gamache says that a better understanding of soil biology presents a clearer picture of the benefits of direct seeding. He says that researchers can look to biologicals for an enhancement of nitrogen fixation. He'd like to see more research on how building back fertilization into the land affects the biological processes and the quality of the soil.

Focus on the environment

Much of the current research on soils falls under the environmental sciences umbrella. "There still is a strong linkage to agriculture," says Pennock. "A lot of work is being done on the effects of agriculture on the environment, but research is not so much completed directly in support of producers, rather it looks at the effects of ranching and farming on the overall environment."

Pennock says that 20 years ago, the majority of the research in soils science was, in fact, in direct support of agriculture whereas a fundamental shift in soils sciences thinking has reduced that figure to about a quarter of all research currently underway.

He also talks about the treatment of agro-forestry as an agricultural crop, which wasn't even talked about 15 years ago. He says by looking at forests as a crop, they can look at how to maintain healthy soil, how get better 'yields' in terms of a healthy, fast growing forest, and how to capture carbon in the earth.

"The ability of the ecosystem to take up carbon really is a soil science issue," says Amiro. "Carbon that's taken up by plants doesn't have any permanence; it's lost as soon as you harvest it. It's the amount that goes into the soil that is the permanent sink – it's where we want to sequester it, so soil conservation is at the center of the carbon debate."

Schools of thought

Today most agriculture and environmental science undergrads don't begin their careers looking for a future in soil science. Their interest grows as they see there remains a need to look at soil as the basis for everything that grows. For example, the University of Manitoba offers a minor in soil science to allow for a broad based degree with a specialization that makes students more marketable.

Amiro says that he feels that the research pendulum is swinging once again back to soil science and conservation efforts. "It's an area that's been reborn because of new issues on the land," he says. "The demand is out there, so a lot of young and energetic scientists are tackling environmental issues from a soils science perspective."