UAN fertilizer is made up of a liquid mix, that one prepares from urea and ammonium nitrate settled in water. Today it belongs to the most used liquid nitrogen fertilizer. To produce it one mixes warm solution of urea with warm solution of ammonium nitrate, to form a clear and stable liquid.

The nitrogen amount splits equally between the parts of urea and ammonium nitrate in the mix.

What is UAN fertilizer and how to use it

UAN usually stores from 28 to 32 percent of nitrogen. It is sold under the names UAN-28 and UAN-32, where those figures point to the nitrogen share. Both variants are the same products, only with different levels of nitrogen.

The mix from urea and ammonium nitrate has very low critical relative humidity, so it works only for use as liquid fertilizer, not for dry form.

An interesting feature of UAN is that it has three differnet kinds of nitrogen. Both UAN-28 and UAN-32 carry 25 percent of nitrate nitrogen, 25 percent of ammonia nitrogen and 50 percent of urea nitrogen. Those three kinds ensure gradual delivery of nutrients to the crops.

That happens, because each kind becomes available for the plants at a different speed.

One can apply UAN more evenly then non-liquid fertilizer. Liquid fertilizer is handled safely, mixes easily with other nutrients and chemicals, and is applied simply. Thanks to their flexibility in handling and use, liquid fertilizer helps farmers in efficient management of nutrients.

UAN works well for drip systems, leaf feedings and fertigation.

Compared to urea and anhydrous ammonia, UAN gives similar results as urea, but both are much more simple in use than ammonia. Urea is sold widely as a dry granular product, that one applies during plowing. If one lays urea bare, it is not immediately available for the plants.

First it must convert in the ground by means of the urease enzyme into usable ammonium. UAN delivers the needed nitrogen for healthy growth of crops directly in the soil.

Urea, anhydrous ammonia and UAN rank between the three main sources of nitrogen fertilizer by sold amount in regions like Minnesota. One gallon of UAN weighs around 11 pounds, with about 3.52 pounds of nitrogen per gallon. There are some risks of leaf burn, if UAN touches the leaves of plants and does not get washed away quickly enough.

Commonly one injects shallow or side applications in the ground, to avoid contact with the plants. UAN is also used on meadows, where special mixes are meant forspring startup and summer feeding during the year.