DHM How To: Kill Alfalfa The Right Way

DHM How To: Kill Alfalfa the Right Way
Cover crop photos from IL Corn College 2014 ( Rhonda Brooks )

We’re coming to that time of year when you have to make a decision about which alfalfa fields you’re going to rotate into another crop next spring. Even thought you might still get another cutting off those fields, now is the time to make a plan for killing those fields the right way.

The first decision that has to be made has to do with whether you want to kill the fields in the fall or the spring. 

“If you know you’re going to kill off fields in the fall, those fields are good candidates for late summer manure application,” says Dennis Frame, owner of Timber Ridge Consulting. “Those fields might not need it, but you’re going to tie up the nitrogen and get phosphorus and potassium benefits. It’s a great place to start spreading manure early.”

The problem with fall-killed alfalfa fields, Frame says, is there isn’t much cover to keep the soil in place once the plant dies. To prevent soil erosion, he says to make sure that a cover crop gets planted as soon as the field is killed so it can get established and hold the soil in place. 

The best option is to wait until next spring, but Frame says farmers are worried about a yield loss if they wait for the alfalfa to green up, then spray it, then plant corn. 

“We’ve seen farmers here in Wisconsin plant corn into alfalfa fields and then spray the alfalfa once the corn is in the ground,” Frame says. “You’re not going to hurt the corn unless it’s up above the crown.”  

For more detail, watch the video where Frame explains fall alfalfa management in greater detail.