Plant a cover crop of clover or alfalfa to fix nitrogen, or apply nitrogen fertilizer. Corn is a heavy feeder and is grown commercially in rotation with a nitrogen fixing crop such as soybean.

Crimson clover or hairy vetch will fix lots of N that will be released in early summer, when the soil warms up. In spring, just before you turn it under, you will be able to see the weak spots based on the vigor of the cover crop, and can increase fertilization accordingly for your corn.

Some folks use sorghum instead of corn for mazes, which needs less N and grows faster.

Our issue would be the deer ruining crops if it was sorghum

Crimson looks like it is good to grow from seed but when do we plant the cover crop? We plant corn in June/July so when would we need to plant this to prep for June/July? Or should we toss fertilizer over the winter to increase nitrogen.