N-(n-Butyl)thiophosphoric triamide

N-(n-Butyl)thiophosphoric triamide (NBPT) is the organophosphorus compound with the formula SP(NH2)2(NHC4H9). It is an amide of thiophosphoric acid. A white solid, NBPT is an "enhanced efficiency fertilizer", intended to limit the release of nitrogen-containing gases following fertilization. Regarding its chemical structure, the molecule features tetrahedral phosphorus bonded to sulfur and three amido groups.

Use
NBPT functions as an inhibitor of the enzyme urease. Urease, pervasive in soil microorganisms, converts urea into ammonia, which is susceptible to volatilization if produced faster than it can be utilized by plants. Approximately 0.5% by weight NBPT is mixed with the urea.