Interest renews as technology reduces equipment workload and newer generations better understand shelterbelt value
WARNER, Alta. — Ask a farmer what crop was planted in a certain field 20 years ago and he may not recall.
Ask a farmer when a tree or shelterbelt on his land was planted 20 years ago and he will likely recall the time of year, weather and who helped plant it.
That’s been Toso Bozic’s experience when he talks with farmers about trees and shelterbelts. As an agroforestry specialist with Alberta Agriculture and Forestry, he says those experiences illustrate the value people place in trees.
The lifespan of a tree in southern Alberta is about the same as the lifespan of a person, Bozic told those at an April 17 shelterbelt workshop in the County of Warner.
“Planting the trees, you leave a legacy,” he said. “I think the people and the farm communities are very aware of the value and the benefits of the trees.”
Many field shelterbelts have disappeared in recent decades to accommodate larger farm equipment, increase cultivated acres and improve operator convenience when navigating fields.
But Bozic said he is seeing a revival of interest in shelterbelts as technology reduces some of the workload in farm equipment and as newer generations better understand shelterbelt value.
“I’m not saying give up the convenience but be more conscious of the multi-benefits of having shelterbelts for their own properties, especially (when it) comes to biological diversity, the health of their crop area,” he said.
“The piece of the windbreaks or shelterbelts or trees on their properties provide so many beneficial things to their crop that maybe it’s worthwhile to give up a little bit of convenience.
“Having that row in the middle of the field is definitely not convenient, but in the long run of the health of the whole farm, I think it’s crucial to keep.”
About 40 people attended the workshop in Warner, posing questions about the care of old tree stands, species diversity, and disease identification and treatment.
“If you have nothing, start with caragana,” said Bozic, noting the proven hardiness and longevity of this shrub. As for pruning older stands of caragana, he advised a multi-year approach by removing the larger dead branches in the first year and then pruning further in subsequent years.
Alternatively, the stand can be cut down near the ground, using a sharp tool and clean cuts, so it can grow again from the base.
If a shelterbelt is dying, he advised planting new trees within the dying row rather than removing it. That way it can provide shelter for new trees and shrubs while they establish.
Those planting a new shelterbelt should heed three words, said Bozic: “diversify, diversify, diversify.
“There is no such thing as a perfect tree but if you diversify, there is no one bug that is going to kill all your trees.”
He also advised taking time with planting, keeping in mind that not all trees have to be planted at the same time or even in the same year.
“Plant only as many as you can care for,” he said.
He advised planting a combination of shrubs and trees after first doing homework on what species are likely to thrive in the site’s soil type, sun exposure, wind and moisture levels.
Mixing species within a row is generally better than planting a separate row of each species. If the climate is harsh, plant more densely because the risk of loss is higher.
Weed control in the first several years is crucial to tree and shrub survival. Plastic mulch can be a help, as can tillage, but avoid the latter once the trees are established to avoid damaging the roots.
Lindsay Bell, tree specialist for the City of Lethbridge, said the main killer of trees is bark damage from weed whippers and lawn mowers. The injury allows disease or insects to invade.
On urban property, Bell said trees and the yard determine 10 to 15 percent of the value of a home. Bozic said trees also add value on rural properties in a number of ways.
Shelterbelts can hold, conserve and purify water, and act as a sort of savings account, said Bozic. They also aid in trapping snow, sequestering carbon, creating habitat, controlling dust and enhancing enjoyment of property.
Starting a shelterbelt
Alberta Agriculture and Forestry agroforestry specialist Toso Bozic encourages landowners to research species and sites before planting a shelterbelt, but when that’s done he recommends some of the following types to start:
- Sea buckthorn
- Green ash
- Manitoba maple
- Assiniboine poplar
- Great Plains cottonwood
- Colorado spruce
- Scots pine
- Siberian larch