On July 26, 2021, N.C. Cooperative Extension of Pamlico and Craven Counties hosted a field event for local growers to discuss current on-farm research and demonstration projects.  These projects included a corn variety demonstration, a corn nitrogen rate demonstration, and an NC State Extension root enhancement research trial. The goal of presenting these on-farm Extension projects is to help growers maximize their profitability to ensure they can sustain their production through ever-changing climatic and economic challenges.  This is an example of one of the projects that were shared during this event.

Corn Nitrogen Rates and Realistic Yield Expectations

Of the sixteen essential elements needed for plant growth, nitrogen is one of the most important, composing about 1.7% of a plant’s mass (carbon, oxygen, and hydrogen have higher percentages, but are derived from water and air).  However, determining how much nitrogen a corn crop needs is difficult due to complex interactions between soil, weather, management practices, and plant varieties.

One of our on-farm demonstration projects focused on this subject, offering growers an opportunity to compare three different nitrogen rates during 2021.  Utilizing our cooperating grower’s standard nitrogen rate (150 lb. N), we applied this rate along with two rates being 25% above and below that amount (113, 188 lb. N).  Following harvest, we will compare the total bushels of corn produced between these rates to determine which rate produced the most grain per unit of nitrogen.

Current NC State Extension recommendations for corn nitrogen encourages the use of the Realistic Yield Expectations (RYE) database, which matches soil types within North Carolina counties with the expected yield and nitrogen rate to produce that crop (grain corn in this situation) . RYE recommendations have been updated over the past several years and reflect a reduced rate of nitrogen for corn production. Utilizing the data collected from this project, we will compare the yields and nitrogen rates to the Realistic Yield Expectations for this field.  Our goal from this project is to show that in some situations, local growers have the potential to reduce the amount of nitrogen they apply to their corn crop and that the RYE database provides a good baseline from which to begin their nitrogen fertility program.

Future research projects will continue to focus on quantifying the fertility needs of crops and adjusting recommendations to maximize crop efficiency and profitability.  This is the nature of on-farm research conducted by N.C. Cooperative Extension with the growers of North Carolina.

If you would like to learn more about these topics, please contact Daniel Simpson at 252-745-4121 or daniel_simpson@ncsu.edu.