Canada: Cover crops and precision agriculture

Some growers are taking green manure to another level. Brian and Dan Sutton of Lake County, Indiana use variable rate seedlings for corn and soybeans. They increase the rate of corn sowing on soils with high yield potential and high fertility and decrease it on lighter soils and sloping fields. For soybeans, the reverse is true: more seeds on the hills and less seeds on more productive soils. A recent Corn and Soybean Digest article summarizes how they apply this principle to cover crops. They realized that it was desirable to vary not only the seed rate, but also the species chosen. “We want to accumulate as much organic matter as possible and prevent erosion on our lighter, sloping soils,” says Brian Sutton. “That's why we use rye before growing soybeans and ryegrass before growing corn,” he adds. And we are increasing the rate of seedlings in the worst places. For more fertile soils, we use Brassica species, such as radishes and turnips, to capture nitrogen that might remain in ...