Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: September 30, 2003
Publication Date: November 3, 2003
Citation: Meisinger, J.J., Jokela, W.E. 2003. Analysis and interpretation of manure ammonium-n for nutrient management [abstract]. American Society of Agronomy Meetings. Agronomy Abstracts 2003 CDROM S08-meisinger799620.
Analyzing and interpreting the ammonium-N (NH4-N) content of manure is essential in nutrient management planning because NH4-N is the largest fraction of immediately available N. The analysis of manure NH4-N can be readily accomplished, e.g. analysis based on the Bertholet colorimetric reaction between NH4-N with salicylate and hypochlorite, or the distillation of ammonia (NH3) under mildly alkaline conditions (MgO). All of the NH4-N is usually considered to be potentially available for plant uptake, with the quantity estimated from the application rate and the NH4-N concentration. However, after manure application NH3 volatilization can remove 5-70% of the NH4-N. The major factors influencing NH3 losses are: manure composition (dry matter content), environmental factors (temperature, wind, rainfall), and application method (surface vs. incorporation). Volatilization from surface applied liquid cattle slurries can amount to 30-70% of the NH4-N within two days, while dry cattle manure can lose somewhat higher percentages. Poultry litter commonly losses 10-45% of the NH4-N over a period of 7 to 14 days. Soil incorporation or injection greatly reduces NH3 losses. Improved estimates of NH3 volatilization for a range of manures, weather conditions, and soils will improve estimates of plant available manure NH4-N for nutrient managers.