Producers are being urged to ‘rethink’ shelterbelts and how they preserve moisture and protect soil
Alberta farmers are being urged to “rethink” shelterbelts — and soil conservation experts agree.
Zero till hasn’t made shelterbelts obsolete and this year’s dry conditions have shown the value of having something to disrupt the flow of hot winds blowing over fields, said Toso Bozic, Alberta Agriculture’s agro-forestry specialist.
“Planting new windbreaks needs to be considered,” Bozic said in a recent Agri-News article. “They reduce the cost to our infrastructure, increase yields, and provide great environmental benefits to crops.”
That view is echoed by the vice-chair of the Soil Conservation Council of Canada.
“There’s definitely value to shelterbelts in terms of slowing the wind down as well as being able to trap additional snow over the winter,” said Tim Nerbas, who has a grain farm and a cow-calf operation just over the Saskatchewan border southeast of Lloydminster.
“There are gains in moisture even after you take into account the loss of productivity from the actual shelterbelt area itself as well as a certain distance from the shelterbelt.”
As farms got larger, and the shelterbelts were aging, many farmers took them out. The negative fallout has been especially evident in the last two years, said Nerbas.
“In the last 24 months, wind erosion has been a factor once again in the wintertime and in early spring particularly,” he said. “Some of it is because of the removal of shelterbelts.”
And there’s not even a yield gain from cropping the land that the shelterbelt once sat on because you’re losing the moisture that comes from trapping snow and reducing evaporation, he said.
“You were still netting basically the same yield on that given land base,” said Nerbas, adding shelterbelts are particularly useful at stopping wind erosion of sandy ridges and gravelly areas.
While reduced tillage has been a major plus, more farmers have been bringing out a cultivator or harrow to repair ruts from running combines, grain carts, or other equipment in wet fields.
“There’s also an adoption of high-speed tillage implements. As a result, it’s putting the soil in a state of vulnerability for wind erosion,” said Nerbas. “We have to re-educate everybody that there’s a reason we’ve reduced our tillage — it is because it leaves the soil vulnerable to erosion.”
And you never know when a fierce wind will start whipping across your farm, he added.
“You have to make sure your soil is protected all the time,” he said.
The inconvenience of operating big equipment in fields with shelterbelts is “overstated,” said Bosic.
“I have seen many older windbreaks that function well in large fields with large equipment,” he said. “Those producers say the benefits outweigh any inconvenience, and that is why they aren’t clearing windbreaks or old natural fences.”
Modern shelterbelt design also allows producers to select the benefits they most want, he added in the Agri-News article.
“Choosing particular shrubs or trees, as well as proper spacing, controls the density and height of these windbreaks,” he said. “The snow is evenly distributed through the field and spring run-off is reduced with a low-density windbreak. With higher-density planting, the snow will not accumulate evenly. Instead, the snow will be trapped on the leeway side of the windbreak. These dense windbreaks are planted to avoid snow drifting onto roads and highways, to protect livestock, and to recharge our dugouts.”
The trend today is to farm every acre, but that’s short sighted, said Nerbas.
“Sometimes we just have to remind ourselves that we’re going to have wet and dry years, and we have to have long-term plans to keep our shelterbelts healthy and protect from erosion.”