It was 45 years ago that “Soil at Risk,” a Senate report on soil erosion, pushed soil conservation to the forefront of research and helped change farming on Canada’s Prairies. Zero till and minimum till have made made great strides in reducing the erosion of previous decades, but now our soils are threatened by “developers.”
It’s time for people outside agriculture to see that farmland is not vacant or idle, says Alberta Agriculture agronomy research scientist Dr. Ross McKenzie.
He surprised many at the Southern Alberta Conservation Association conference when he used his time at the podium to highlight the precarious state of Alberta’s soil resources. He’s spent his whole career developing ways farmers can work with the soil to produce better crops, but now sees Alberta’s soils and water, essential for food and life itself, in jeopardy as everything is valued by its price.
Urban sprawl is destroying huge areas, especially around cities such as Calgary and Edmonton and the Highway 2 corridor. The land that’s being destroyed is Alberta’s best, most productive land most needed to produce food for increasing populations.
“The best farmland we have in Alberta is being destroyed as we watch”
Every city in Alberta is expanding. As each new subdivision is “developed,” about 10 inches of topsoil is stripped off and taken away. Calgary already covers 500 square kilo-metres. If Calgary expands at three per cent a year over the next 40 years it will cover 1,800 sq km by 2050.
The city has actually been growing at 4.5 per cent a year, meaning that it could cover 3,800 sq km or 2,891 square miles or 1.86 million acres. The neighbouring municipalities of Rockyview, Wheatland and Foothills will become almost completely urban.
Edmonton is similar, and other cities are growing as well. As the topsoil is scraped away for yet-another subdivision, another section of farmland is lost forever. Our farmlands look endless, but our eyes deceive us. Alberta has 40 million acres of agricultural land, but 14 million is in permanent pastures and about two million acres in summerfallow each year, leaving 24 million acres for annual crops. That is only 16 per cent of Alberta’s land base.
BEST FARMLAND THREATENED
None of Alberta’s land is Class 1, the best agricultural soil according to Canada’s soil classification system. There is a small amount of Class 2 land, mainly around Edmonton, Calgary and the corridor between them.
“The best farmland we have in Alberta is being destroyed as we watch,” said McKenzie. “We must tell our politicians that agricultural land must be protected before we lose all our Class 2 land. It’s our best farmland.”
Around the cities, “rural residential developments,” are also increasing. These developments take large amounts of land out of agricultural production by fragmenting the land, limiting farm activities.
Energy developments also degrade agr icul tural land. “Alberta’s hydrocarbon reserves have brought huge wealth to the province, but it has used up or degraded a significant amount of agricultural land,” said McKenzie.
“Over 155,000 gas wells, and probably as many oil wells have been abandoned and over 100,000 km of pipelines have been buried throughout Alberta.
That land cannot be reclaimed to its original production potential.”
Alberta Environment only requires reclamation of land disturbed by oil and gas activity to 80 per cent of its original productivity, McKenzie said.
“That regulation must be enforced to protect our prime agricultural land and protect sensitive lands from degradation. Even after eight or 10 years, production on many pipeline routes is less than half that of the original land.”
Green energy doesn’t avoid land destruction, either. Wind farms and the road and transmission systems needed to service them take land out of production. Roads invite erosion and soil degradation. Disturbance and vehicles bring in weeds that can destroy native pastures.
AGRICULTURE NOT WITHOUT BLAME
Farmers don’t completely escape McKenzie’s ire. In the first 60 or 80 years of farming the Prairies, we lost half the soil’s organic matter. Direct seeding and varied rotations have significantly improved soil organic matter in southern Alberta, with most of the increase in the light-fraction carbon, which is a very important form of organic matter.
But wind and water erosion still happen, especially under irrigation, or on sloping land that gets heavy rain.
Confined feeding operations can have a negative effect on soil and the environment if manure is frequently applied at excessive rates.
“Under Alberta’s old Codes of Practice, we’ve been overapplying P and K,” says McKenzie. “It’s become a huge issue over 20 or 30 years of applying manure to meet crops’ N needs. In some fields soil P levels are over 700 lb. P/acre. At that level of concentration, P can run off and contaminate surface water.”
Salinity is an old problem that hasn’t gone away. According to PFRA, salinity is the biggest restriction to farm income across the prairies. It’s still spreading. “It takes special expertise to identify discharge and recharge areas,” says McKenzie. “In southern Alberta, soil salinity is still spreading at a rate of three to six per cent per year, but farmers don’t have any professional or technical support to combat this serious soil degradation problem.”