Researchers are developing a new cropping option for farmers that could present interesting harvesting challenges because the crop is about five metres tall when ready for the combine.
Agriculture Canada and Natural Resources Canada are sponsoring a three-year study to find a fast-growing willow tree that would be well suited to the biomass industry.
Willows were selected for the project because of their ability to sprout back up after being cut to the ground.
“There are other trees that will do that but not with the vigor that the willows (have),” said John Kort, an agroforester with Agriculture Canada.
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The idea is to develop a willow that would be commercially grown on farms and harvested for use in direct heating applications or in cellulose-based ethanol projects.
Cellulose ethanol is seen by many as a superior product to grain-based fuel because it delivers better reductions in greenhouse gas emissions.
But while there are more than 100 grain-based ethanol plants operating in North America, the technology for converting fibre into fuel is still being refined.
“When the appropriate technology is there, we’ll be ready with some material that will hopefully produce the biomass needed,” Kort said.
The initial goal of the project is to find suitable germplasm and researchers have spent the first two years gathering and analyzing the agronomic performance of a multitude of different willow species.
They know which ones grow naturally on the Prairies and which ones have performed well in shelterbelt applications, but they need to find one that grows quickly and is well-adapted to Canada’s climatic conditions.
Kort said they should be able to make preliminary judgments about which are the hardy species within the next three years.
Determining yield projections will be a longer-term project because researchers have yet to harvest their first crop of willows.
Agronomy work will be greatly aided by research that has already taken place in Sweden, the United Kingdom and the state of New York, where willows are grown extensively for biomass applications.
“It is possible we’ll just take those management recommendations and use them out here,” Kort said.
One thing they hope to learn is how to harvest a five-metre-tall crop with a thick wooden base.
Swedish producers use a modified corn harvester with saw blades replacing the mower and a pusher bar mounted at the bottom of the machine to knock the trees over. The harvester pulls the felled trees into the combine, where they are fed directly into a wood chipper.
Researchers in Quebec are experimenting with saw blades attached to a round baler. The trees are cut down, partially shredded and baled.
“They are making good progress with that,” Kort said.
While willow trees aren’t expected to replace wheat or canola as one of Canada’s top crops, Kort foresees a small portion of agricultural land devoted to the production of money-producing tree crops.
They could also be grown in traditional areas such as shelterbelts and riparian zones near rivers, creeks and standing water.
