Effect of Meteorological Parameters on Ammonia Loss from Manure in the Field

TLDR

Volatilization from liquid manure is mainly governed by the drying rate and the partial pressure of NH₃. The study aimed to correlate observed NH₃ volatilization rates with individual meteorological parameters such as windspeed, temperature, and net radiation. Micrometeorological flux measurements were conducted on surface‑applied swine and dairy manure during precipitation‑free June to October conditions. The study found that while windspeed and net radiation correlated strongly, the interdependence of meteorological variables made single‑parameter correlations inconclusive; however, a linear relationship between applied nitrogen and NH₃ flux was observed, and the hay drying index emerged as the most promising single indicator of high volatilization.

Abstract

Abstract A micrometeorological flux measuring technique was used to determine ammonia (NH 3 ) volatilization from surface‐applied swine ( Sus scrofa ) and dairy ( Bos taurus ) manure under precipitation‐free June to October weather conditions. An attempt to correlate observed volatilization rates of NH 3 to single meteorological parameters such as windspeed, temperature, net radiation, etc. was inconclusive insofar as these variables are not independent under field conditions; correlations with windspeed and net radiation appeared generally high. An approximate linear relationship was obtained, however, between applied total N or ammoniacal‐N and NH 3 flux within the meteorological conditions encountered during the experiments. This is consistent with the assumption that volatilization from liquid manure is primarily determined by the drying rate of the manure insofar as partial pressure of NH 3 is the primary parameter determining volatilization. A derived meteorological variable such as the hay drying index already used in some network agrometeorological forecasts may thus be the most suitable single indicator of high‐volatilization weather conditions.