Urea

What is urea? Urea is a water-soluble organic compound containing 45 to 46% nitrogen. It is a natural chemical found in urine. In soil, urea almost immediately decomposes to ammonium nitrogen and carbon dioxide.

Does urea leave an acid residue? Yes, but only a slight amount of acidity is left - about a third as much as would be left from a similar amount of nitrogen from sulfate of ammonia.