Ammonium produced by urea can be absorbed by roots or it can

Ammonium produced by urea can be absorbed by roots or it can Change to nitrate.
Urea is a stable colourless and odorless solid at room temperature that will melt at 135°C. It is highly water-soluble, and will slowly hydrolyze in the presence of water, to give ammonium carbamate which slowly decomposes to ammonia and carbon dioxide.
Ammonium is converted to nitrate (NO₃^-) via nitrification. Nitrate is the form that can be moved out of the soil profile by leaching or lost by denitrification. The conversion of ammonium to nitrate and the conversion of nitrate to N gases are both microbial processes.