Here are six tips to help you build your nitrogen program and boost yields:
1. Assess the environment for every field; that is crucial in building a nitrogen program. Know your risk of nitrogen loss from leaching, denitrification and/or volatility.
2. Pick the right nitrogen sources, timing and placement. Doing those three things is much more important than trying to pick the right rate.
3. Assess the carbon penalty potential based on the amount and type of carbon left from your previous crop. Don’t forget to assess a carbon penalty for grass cover crops.
4. Consider that split applications and nitrogen inhibitors might be part of the balance of your nitrogen plan.
5. If corn greens up right after a sidedress applocation, it is telling you that the crop was waiting for the nitrogen and it was giving up yield potential during the process.
6. Season-long scouting is the only way to get a handle on nitrogen needs and management. Knowing when you run short is more important than knowing how much you ran short. As Ferrie emphasizes, “Scout, scout, scout and then make a plan.”
(Source – http://www.agweb.com/farmjournal/article/six_nitrogen_tips_to_boost_yields_NAA_AgWebcom_Editors/)