Farmers cut costs 60% using oats, radish cover crops

Researchers in Canada say cover crops may smooth the tricky switch from aging perennial forage stands to annual crops by keeping weeds and old plants in check. Trials in Saskatchewan found that planting a fast-growing cover like oats or radish after killing a grass-alfalfa stand cut regrowth by up to 60% and reduced weeds by about 40% in the first year. The work is still early, but it points to a simple way to avoid costly herbicide spikes or yield dips when fields move from long-lived grasses to short-lived cash crops.

The problem starts with age. Perennial forage stands—often grass-alfalfa mixes—can last a decade or more. But after year seven or eight yields slide and growers want to plant annuals like canola or wheat for better margins. The catch is that the old crop doesn’t give up easily. Its roots keep sprouting, and open soil invites weeds to move in. Farmers can spray glyphosate twice and still face a jungle of quackgrass and dandelions by planting time, adding cost and risk. Canada has around 3 million hectares of aging forage stands, so any tool that trims that headache matters to the bottom line and the next crop.

In field plots near Saskatoon, researchers tested five cover crops after glyphosate knockdown. Oats and tillage radish proved the most aggressive, producing thick mats that blocked light and slowed regrowth. Biomass from the covers topped 4 tonnes per hectare, locking up nitrogen and carbon that would otherwise be lost. Soil tests taken six weeks after termination showed 15–20 kg more available nitrogen compared with plots left bare. The team plans larger trials this year to see if the same effect holds across different soils and climates, and whether the cover crops can be rolled or crimped instead of sprayed out.

If the method scales, it could cut herbicide use by a third and save growers an estimated $50 to $80 per hectare in the first year alone. More importantly, it offers a gentler way to rotate systems that have dominated the Prairies for decades. That matters not just for farm budgets, but for soil health in a region where wheat and canola rotations are already pushing the limits of sustainability.