Fertilizer
Fertilizer is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients.
Nitrogen Fertilizer
From Urea
Urea can be used as a source of nitrogen for plants, however, it will quickly break down into unusable ammonia gas. Urinary urine concentration ranges from 9 to 23 g/L.[1]
Urease inhibitors can slow the breakdown of urea so that it can be more efficiently used as a fertilizer. The most widely use compound is N-(n-Butyl)thiophosphoric_triamide.[2]