Nitrogen Use Efficiency (NUE) can be calculated as:
NUE = (lbs N/ac applied) / Bushels produced. The goal of the NOFRN is to continue to improve (lower) our NUE. This can be done through a few methods that are readily available for growers.
- Reactive N management is utilizing technology to provide in-season adjustments for our Nitrogen application.
- Predictive N management is utilizing the UNL N calculator https://cropwatch.unl.edu/nitrogen-tool/ to estimate a fixed amount of N to apply in the field.
When using either method, the 4 R's of Nitrogen management apply to all applications: Right Time, Right Source, Right Place, and Right Rate.
Check out the latest UNL Fertilizer recomendations for Irrigated Corn:
https://cropwatch.unl.edu/new-nebguide-season-nitrogen-management-irrigated-corn/
Reactive (Adaptive)
Improving Nitrogen Use Efficiency (NUE) can be done through reactive or adaptive measures. This method utilizes sensor based equipment, satellite imagery, and/or crop modeling to determine precise crop needs in-season. Nebraska On-Farm Research has conducted over 120+ trials between 2015-2024 using these measures to further refine this application method in crop fields. Attached is an example protocol that demonstrates the necessary procedures to implement a trial.
Predictive
Improving NUE can also be done via predictive measures. The UNL N Calculator allows for users to self calculate an estimated economically optimal N rate (EONR) for their current field conditions. Farmers can take this one step further by implementing trials using the UNL N Calculator and alternative rates surrounding the EONR rate for each field. Once a yield map is gathered the EONR can be found for each field, adding additional data for future fertilizer decisions. An example protocol is provided.
This work is sponsored by the Nebraska Corn Board, under the Nebraska Nitrogen Initiative.
