Proper Management Needed to Gain Nitrogen From Cover Crops
Some cover crops are better than others when it comes to providing nitrogen (N) benefits in a corn-soybean cover crop rotation. If you’re using cover crops to gain N, you should evaluate your production practices to make sure they align with your cover crop selection.
“We’re trying to understand how the cover crop may influence our N management system,” says Kent Shannon, University of Missouri Extension natural resource engineer.
Shannon uses mounted sensors on a baby stroller to measure light reflection or absorption by corn plants in the research plots. He ties the results to the amount of N present.
“We did see some benefit from a legume such as crimson clover giving some nitrogen credit to the corn, so we didn’t have to apply as much side-dressed N,” Shannon says.
Not all cover crops will provide N benefits
Shannon’s earlier research indicated corn planted after cereal rye actually needed more nitrogen. However, he says they were late killing out the cereal rye, which likely influenced the results. If you’re using cereal rye, have a plan for terminating it.
Later research showed no N deficit when cereal rye was killed at the appropriate time.
Shannon says to gain an N benefit through the use of cover crops requires altering crop-management techniques.
“It is going to depend on management and weather,” Shannon says. “But with the technology, at least we can get a handle on how much extra N we’re going to need and be more efficient.”
Source: University of Missouri Extension News