Instinct or N-Serve with Band-Injected UAN: Does It Matter?.

INSTINCT or N-SERVE with Band-Injected UAN: Does it Matter? B. MENELAS, B. C. Joern and J. J. Camberato. Department of Agronomy, Purdue University. West Lafayette, IN 47907.

Instinct is a microencapsulated formulation of nitrapyrin designed to reduce N loss from urea-ammonium nitrate (UAN) and liquid manure. However, N-Serve is an unencapsulated formulation of nitrapyrin designed to delay N loss in anhydrous ammonia and UAN fertilizers. The purpose of this research was to quantify the retention of ammonium (NH₄⁺) from band-injected UAN with Instinct and N-Serve under optimum temperature and moisture content.  We applied Instinct (2.56 L/ha), N-Serve (2.37 L/ha)), and no inhibitor without and with UAN (196 kg N/ha) into the center of plastic containers (14 x 22 x 5 cm) packed with soils (Avonburg silt loam or a Chalmers silty clay loam) at a bulk density of 1.0 Mg m^-3. KCl-extractable NH₄⁺ and NO₃^- were measured at 7, 14, 21, 28, and 42 days. In one run of the experiment, both inhibitors equally enhanced NH₄⁺ retention by 2.5 fold in the Avonburg silt loam and 1.5 fold In the Chalmers silty clay loam compared to the control. However, for the second experiment N-Serve was significantly better (p<0.05) than Instinct.