It's better for the environment, of course. But did you know that legume-based cover crops have an important, added benefit that is often overlooked?

 

Growing your own nitrogen instead of buying the synthetic version reduces the risk of losing piles of money, according to a study by researchers at the University of Manitoba.

 

Using yield data from Manitoba Ag Services Corporation (MASC), fertilizer costs from Statistics Canada, and data gleaned from field trials  the researchers found that over the long term, the reduced risk from using black lentils as a cover crop to conserve and provide nitrogen paid off in computer simulations repeated thousands of times.

 

Based on the risk analysis of net revenue from a quarter section of land, the simulation compared standard rotations such as wheat-canola-wheat with a cover-crop consisting of winter wheat-black lentils-spring oats-canola, and another using peas as an in-season rotation crop.

 

What they found was that the typical cereal oilseed rotation was a recipe for the boom-or-bust returns that farmers have become all-too-familiar with over the years.

 

“As  yields, costs, and fertilizer prices change, what's likely to happen and what will the variations be?”said co-author and University of Manitoba associate professor Jared Carlberg in a presentation at Manitoba Ag Days Tuesday.

 

“In the cereal-oilseed rotation, if things went horribly awry, you could lose a lot of money. Some of the losses were huge — as high as $700,000.” 

 

Despite the extra costs of seeding the black lentil cover crop, it paid for itself in the form of more predictable returns over the long haul, he said. That rotation lost money just 12 per cent of the time, compared to 20 per cent for the cereal-oilseed rotation. The rotation containing field peas lost money 43 per cent of the time, added Carlberg.

 

“Will it work on your farm? I don't know,” he said. “But hopefully, it's food for thought.”

Jeff Moyer, farm director of the Rodale Institute, said cover crops are key to marrying the benefits of zero-tillage with organic farming practices. While no-till techniques do a good job of keeping the soil intact, they fall short when it comes building the soil.

Meanwhile organic farmers, need methods that reduce their reliance on tillage, because it increases the risk of erosion and turns up more weeds. But although early results are promising, making cover crops into a viable option for farmers will require an investment in research, Moyer said.

"We need cover crops that fit into our system, not try to take something off the shelf to make it fit," he said.