That's what we have done for many years now. It's pretty common in the NE IL area. Broadcast amounts of liquid N, either 28 or 32% UAN, most often mixed with pre-emerge weed chemicals. Our personal rates are usually 12-20 gpa since we sidedress the balance of N needs. However, 50 gpa rates (150 N units of 28) are used by many also. Then incorporated with a field cultivator or soil finisher type tool ahead of planter. Sometimes applied days ahead of planting, sometimes minutes ahead.

No problem that I've heard of about burning seedlings with those amounts broadcast.