Field studies to narrow down when, how to grow hemp

Hemp has been grown on the Prairies for decades but there’s been relatively little research on its agronomics.

Jan Slaski, senior researcher at InnoTech Alberta, is working to change that.

He’s conducting agronomy trials in Lethbridge, Falher and Vegre-ville, Alta., to learn more about seeding dates, fertility and the yield attributes of different varieties.

Plots in Lethbridge and other plots were to be seeded in mid-June.

In southern Alberta, hemp is usually planted in late May or early June so the plants don’t get too tall and cause harvest challenges.

Growers also concentrate on seed production because there are few markets for hemp fibre.

“Why we are studying hemp at three different locations (is) because you have to remember that hemp is a short day plant,” Slaski told those gathered for a Farming Smarter field event June 8.

Hemp starts to flower when days get shorter. When grown in areas with longer days, the crop gets taller and produces more biomass and fibre yield.

Slaski said plots in Falher receive three to 3.5 more hours of daylight than plots in Lethbridge, so the same hemp variety is typically 20 to 30 percent taller, even when given the same amount of fertilizer.

“Keep in mind, if you compare any other crops, you’re not seeing such huge, huge differences, such huge responses to daylight availability,” Slaski said.

Hemp is frost resistant and capable of responding quickly to good growing conditions. Slaski said one Vegreville area grower, whose crop was hailed out in July last year, replanted hemp July 16 and harvested hemp seed in early October.

“Keep in mind that hemp offers such plasticity. Every single bit of this plant can be used and more importantly can be sold and you can make money,” said Slaski.

Hemp grows quickly and forms a canopy that prevents weed growth, which is fortunate because few herbicides are registered for the crop.

Slaski is also testing nitrogen fertility and 14 different varieties of hemp, some primarily bred for seed and others for fibre. None have more than .3 percent THC, the psychoactive constituent in hemp’s cousin, marijuana.

Though hemp seed and hemp nuts have been the primary moneymakers in the past, “very soon you will be making money on grain, fibre and non-narcotic cannabinoids that are in leaves and flowers.”

Slaski said contracts will be offered for hemp fibre this year and next, and he is confident full-scale hemp fibre production, long promised but never delivered in Alberta, will come to fruition this year.

Plans to open a plant in Nisku, Alta., that would handle seed, fibre and nutraceuticals from the crop were recently announced by Hempco.

The company said it wants to be running by fall with the capacity to handle 5,000 tons of seed, 20,000 tons of fibre and 20 tons of low THC cannabinoids annually.

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