Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/14/2005
Publication Date: 7/20/2005
Citation: Hanna, H.M., Boyd, P.M., Baker, J.L., Colvin, T.S. 2005. Anhydrous ammonia application losses using single-disc and knife fertilizer injector. Applied Engineering in Agriculture. Paper No. 051060.
Interpretive Summary: Anhydrous ammonia is applied as a major source of nitrogen for corn production in the USA. High fuel use can result from placing the ammonia deep enough (6-8 inches) to prevent vapor losses during application with injection knives. This project was an investigation of an alternate method of application with a single-disc opener which might speed application and reduce fuel costs compared to the knife. Losses of ammonia were measured during application and for one hour after application for the currently used knife and the proposed single-disc opener. Ammonia losses during application were 3-7% in clay loam, silty clay loam and loam soils but rose to 21-52% for a coarser-textured fine sandy loam soil for the single-disc. In contrast, the knife has losses of 1-2% across all soils. Losses for the hour after application were in the range of 1% for both methods of application. Development of a successful alternative to the traditional knife might allow a doubling in speed of the application process and a major reduction in fuel use for application. Farmers will directly benefit from the increased speed of application and decrease in fuel use which will translate into reduced costs for crop production. All of the USA will benefit from lower crop production costs as the country is in a global economy for all farm products including corn.
Technical Abstract: 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 horsepower or allow greater speed which could increase field capacity if NH3 losses are held to acceptable levels. Losses of NH3 during, and for one hour after, field application were measured from a typical knife injector treatment operated at a 15-cm (6-in.) depth and 8 km/h (5 mi/h) 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 mi/h)). 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 1-2% 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 5-55 times greater than during the first hour after application.