Urea vs UAN: comparing two nitrogen sources

The two forms

Urea is a solid that is 46% nitrogen, all in the urea form. UAN is a liquid blend of urea and ammonium nitrate, sold at grades from 28% to 32% nitrogen. Because UAN is part urea, the two share some of the same behavior in the field.

Compare on cost per pound of nitrogen

Divide the delivered price by the pounds of nitrogen it contains. For liquids priced per gallon, first convert using the product’s weight per gallon (ask your supplier). Illustrative delivered prices — not quoted prices:

See cost per pound of nitrogen for the full method.

Handling and nitrogen losses

These are the differences that price alone will not show:

• Urea can lose nitrogen to the air (ammonia volatilization) if it stays on the soil surface during warm weather; University of Minnesota Extension notes that incorporation by tillage or about a quarter-inch of rain greatly reduces this loss.
• UAN is only part urea, so its volatilization potential is lower than straight urea, but the nitrate portion is subject to leaching and denitrification once it is in the soil.
• Equipment. Urea is spread dry; UAN is handled and applied as a liquid. The right fit depends on the gear you already run.

Where the choice goes beyond price

Which nitrogen source and timing suit your field is an agronomic decision that depends on your soil, crop, weather, and equipment. This page compares the two on price and general handling only — it does not recommend a rate or a product.