On Oct. 1, the 80-acre cover crop was opened to grazing. “We got 17 days of grazing on 141 cow-calf pairs,” Miller reports. “The calves gained 3.1 lbs/day on the cover crop.”

Based on a 52-lb. total gain/calf at $1.09/lb. live weight, a gross profit of $111.00/acre was calculated. After subtracting $45/acre for expenses, the cover crop netted $66/acre.

For Miller, the grazing profits were only part of the story. “The next spring, when we planted corn on the three plots, and the earthworm population on the cover crop ground was three times that of the others,” he says adding that the improved soil health on the cover crop field was directly reflected in the net corn income in fall 2008.
The return on the cover crop ground was $62.27/acre, while the field with the manure application was $49.57/cre. The return on the corn grown on the bare ground was $13.77/acre.

One longstanding argument against planting cover crops is the loss of soil moisture that could negatively impact crops planted the following year. To test that theory, soil samples for available water capacity were taken in May 2008 prior to planting corn. Results showed that a field with no cover crop held 3.11 in., while the one that did had 3.07 in.

“These fields were side by side so the only difference was that a cover crop grown in one of them,” Miller says. “Four one hundredths of an inch less in the cover crop ground would hardly be considered significant.”

New varieties resolve issues

Byron Lannoye of Pulse USA is enthusiastic about the potential of cocktail cover crops. He sees the development of new varieties as critical in resolving some of the issues growers have with planting cover crops between their primary crops. He cites, as an example, the reluctance of growers to use conventional Austrian winter peas in their cocktails because of a tendency to have a higher percentage of hard seeds, which are known to delay germination in the year they are planted and emerge in subsequent years.

“Growers don’t want plants in these cover crops to come back and haunt them,” says Lannoye, adding that new varieties of peas – particularly the ones that bear white flowers – are far more consistent in their germination. “This opens the way to receive the benefits of peas in the cocktail without the risks of carryover into the next crop,” he says.