SOIL MOISTURE IMPACT ON AMMONIA SOIL FLUXES WITH INPUT OF MINERAL NITROGEN

ABSTRACT

Ammonia as one of the air pollutant mostly originated from agricultural activities, such as manure and soil management. There is a need for precise and reliable quantification of ammonia emissions which is easy applicable on field or laboratory conditions. Cavity ring-down spectroscopy device Picarro G2508 measures ammonia (NH3) concentrations along greenhouse gasses, namely nitrous oxide, methane, carbon dioxide and water vapour content. The aim of the study is to develop methodology for NH3 measurements for Picarro G2508 in laboratory conditions as well as to conclude the peak concentrations of ammonia emission in time resolution of 5 days measurement period.
Measurements were done in laboratory with Picarro G2508 in closed chamber system with recirculation by using 3 types of mineral soils and 2 types of organic soils with disturbed structure dried in room temperature and sieved). Two soil moisture conditions were simulated both saturated and oversaturated. Water were added in the beginning of experiment and there were no additional water input during experiment. Urea and ammonia nitrate were used as nitrogen fertilizers and added to sample right before the first measurement was carried out.
The time of measurement have to be established before each experiment according to expected ammonia emission intensity and water vapour. During the second and third measurement day NH3 concentrations were the highest in mineral soil samples with addition of urea mineral fertilizer.

Keywords: ammonia, urea, ammonia nitrate, soil flux, ring-down spectrophotometer