• One of the concerns with green chopping would be the potential for nitrates, particularly if the layby or side-dress nitrogen application already has been made.
• You need to leave 12 to 15 inches worth of stubble height if you’re going to green-chop.
When drought becomes severe, the decision sometimes must be made to salvage the value from a corn crop by cutting it as forage. When this time comes, there are several options for producers, says Dennis Hancock, University of Georgia Extension forage specialist.
“We can look at, for example, trying to green-chop a field, where you actually chop it in the field and feed it to the animals,” says Hancock.
One of the concerns with that would be the potential for nitrates, particularly if the layby or side-dress nitrogen application already has been made, he says. “You need to leave 12 to 15 inches worth of stubble height if you’re going to green-chop. In some of these plants, more nitrates are concentrated in the lower part of the stem. So we want reduce the overall nitrate concentration by increasing the stubble height. We’ll cut it higher than we normally would, say for a corn silage field,” he says.
A second option is to make a hay crop from the field, says Hancock. “Again, we have the same restriction regarding nitrates. Nitrates will not dissipate in the hay. We need to increase the cutting height so that we’re reducing the total nitrate concentration. But with hay production, the cattle actually do pick through the hay more. They generally select more leaf material out of the hay. As a result, their actual intake of nitrates will be lower, and as a consequence, we can lower our cutting height, making it easier. Still, we need to leave about 8 to 12 inches of stubble. That’s a lot if we’re trying to make hay,” he says.
One of the strategies for dealing with that situation, says Hancock, is to windrow the crop as you’re cutting it with a mower conditioner.