ProCrop

Understanding Urea

Like most other types of fertilizer, urea has unique characteristics that affect the war it is applied and used. Volatilization (evaporation to the air) can be a problem when urea is spread on soil surfaces because of the soil enzyme urease that breaks urea into carbon dioxide and free ammonia. The free ammonia, if not covered by soil can escape into the air.

You can reduce the amount of ammonia lost from urea applications by these practices: Do not leave urea on the soil surface but incorporate it on all soils within 2-3 days if possible of soils are warm. When weather is cool and winds calm, urea can stay on the surface for up to 5 days without significant losses. Adding a urease inhibitor such as NBPT (Agrotain) can lengthen urea incorporation delay by up to 10 day additional days. If surface applied, you need one half inch rain to wash the urea into the soil where the ammonium ions can be held.

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