Effects of Some Urease Inhibitors on Urea Hydrolysis in Soils

Abstract Studies reported showed that, of eight urease inhibitors tested (2,5‐dimethyl‐ p ‐benzoquinone, catechol, p ‐benzoquinone, hydroquinone, phenylmercuric acetate, N‐ethylmaleimide, sodium p ‐chloromercuribenzoate, and acetohydroxamic acid), 2,5‐dimethyl‐ p ‐benzoquinone had the greatest ability to retard urea hydrolysis in soils and reduce gaseous loss of urea N as ammonia. Gaseous loss of urea N as ammonia from a urea‐treated sandy soil incubated at 20C for 14 days was reduced from 61.1% to 0.3% by addition of 2,5‐dimethyl‐p benzoquinone (2.3 parts/100 parts of urea).