Soil N Dynamics As Affected by Band-Injected UAN with and without Instinct™ Nitrogen Stabilizer.

Nitrification is the leading pathway toward losses of anthropogenic or soil N as it is the precursor of leaching and denitrification. Laboratory studies were conducted with three soil types differing in texture and organic matter content to quantify the effectiveness of a newly developed nitrification inhibitor (Instinct™) in delaying nitrification. The treatments included no UAN (control) and UAN with and without Instinct were injected into the center of each container with a syringe. The containers were replicated three times, arranged in a randomized complete block design in the growth chamber, and incubated in the dark for 63 days at a temperature regime that mimics spring temperatures in west central Indiana (2 weeks at 12 ^oC, 2 weeks at 17 ^oC, and 5 weeks at 22 ^oC). Soil samples were obtained from three different concentric zones around the injection point at 14, 28, 42, 56, and 63 days after treatment application. The effect of Instinct™ on the concentration gradient of ammonium and nitrate across soil types, concentric zones and time will be discussed.