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Due to the salt-character of the substance the calculation of a fugacity model is not appropriate. Based on the physico-chemical properties of ammonium sulfate, water is expected to be the main target compartment.

Zhu et al (1989) investigated losses of nitrogen after application of ammonium bicarbonate to flooded rice at transplanting. Total loss of fertilizer nitrogen (N) was measured by 15N balance. All the loss appeared to be in gaseous forms, since there was no evidence of leaching and runoff was prevented. The difference between N loss and NH3 loss was thus assumed to be denitrification loss. Both NH3 volatilization and denitrification losses were large, being 39 % and 33 %, respectively, of the ammonium bicarbonate. Ammonia fluxes from the field fertilized were very high for two days, and then declined very rapidly as the NH3 source in the floodwater diminished.

The ammonium cation is relatively immobile in soils, because it is adsorbed on the negatively-charged clay colloids present in all soils. Ammonia may be lost from soils by volatilization, especially after the application of ammonia fertilizers, sewage, or manures, and by uptake of ammonium ions into root systems. However, the most likely fate of ammonium ions in soils is conversion to nitrate by nitrification. Nitrate is, in turn, lost from soils by: leaching, which occurs readily, since it is repulsed by the clay particles; denitrification, which occurs rapidly within a few days or weeks in warm, moist soils; and by uptake by the plant root system. Ammonia in soil is largely fixed (EHC, 1986).

Reference:

OECD (2006). SIDS Ammonium bicarbonate CAS: 1066-33-7, Draft 2006

WHO (1986). EHC 54, Ammonia.