Anhydrous ammonia (NH3) is injected below the soil surface during application to limit loss to the atmosphere. Application at a shallower depth may reduce tractor power or allow greater speed, which could increase field capacity if NH3 losses are held to acceptable levels. Losses of NH3 during, and for 1 h after, field application were measured from a typical knife injector treatment operated at a 15-cm (6-in.) depth and 8-km/h (5-mph) travel speed and from a single-disc injector operated at shallower depths [5 and 10 cm (2 and 4 in.)] and a range of travel speeds [8, 12, and 16 km/h (5, 7.5, and 10 mph)]. NH3 losses during application as measured with a hood over the single-disc injector were 3% to 7% in clay loam, silty clay loam, and loam soils and 21% to 52% in a coarser-textured fine sandy loam soil. Applying with a knife injector at deeper depth resulted in losses of 1% to 2% across all soil types. NH3 losses measured during an hour after application with stationary collection over the injection trench were 1% or less for all treatments. Losses during application were 5 to 55 times greater than during the first hour after application.
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