Last Minute Thoughts on N For 2021

By Paul Kassel

The following are a few thoughts on nitrogen (N) management for the 2021 growing season.  Many fertilizer decisions have already been made - however a quick review of N plans is in order. However, the recent increase in corn grain prices and in-season cost of nitrogen fertilizer may warrant of review of N rates.

Farmers and dealers need to check the Corn Nitrogen Rate Calculator (CRNC) web site to confirm N rates for 2021 corn production (http://cnrc.agron.iastate.edu).  The CRNC uses Iowa based research data, current N prices and anticipated grain prices to determine profitable N rates for Iowa corn farmers.   

Some additional thoughts on N application for the spring of 2021 include ammonia application guidelines.  Spring ammonia applications should be made an angle to future corn rows to avoid ammonia injury.  Inject the ammonia at a depth of 6-7 inches – or more.  Injury to corn from spring ammonia application does occur – and is more likely in ammonia applications occur in wet soils followed by dry conditions.

Many farm operations will use liquid N products this spring.  It is recommended to incorporate the urea or UAN solutions within 24 -48 hours of application to prevent volatilization losses from these products.  Rainfall amounts of 0.25 to 0.50 inch within 24 hours of application will essentially eliminate volatilization losses.