Effect of an Experimental Urease Inhibitor on Ammonia Volatilization of Surface Applied Urea.

The effect of ammonia volatilization on crop growth and productivity from surface applied urea and UAN is well documented. The urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) has been thoroughly researched and commercially marketed for more than 15. It has been shown to dramatically reduce ammonia volatilization and improve crop yield. Recently, Koch Agronomic Services, LLC. discovered and patented a new urease inhibitor that demonstrates improved performance in lab and field trials when compared to AGROTAIN® ADVANCED 1.0 (the leading commercial urease inhibitor). Laboratory volatilization chamber studies conducted in 2016 and 2017, using several soils from across the US, compared untreated urea and urea treated with AGROTAIN® ADVANCED 1.0 or the experimental inhibitor. In addition, field trials were conducted at 4 and 20 locations in 2016 and 2017, respectively. Field studies consisted of N treatments ranging from 0-268 kg N ha^-1 in 67 kg N ha^-1 increments with urea and the two inhibitors with (13 treatments with 4 replications). Crops studied include corn, wheat, and rice. Results of available field and laboratory studies will be reported.