ESN is a controlled-release nitrogen fertilizer. ESN encapsulates the nitrogen and controls all N losses by regulating the exposure of N to the environment while it gradually feeds the crop. Nitrogen in ESN remains encapsulated and releases N over a period of about 50-80 days protecting that N during the periods of generally greatest losses. Agrotain and other “look-a-like” urease inhibitors are chemical additives, called stabilizers, added to urea to reduce volatilization only and are effective for about 7-14 days after application. Urea treated with these additives is immediately water soluble.