Ammonia volatilization from five nitrogen compounds used as fertilizers following surface application to soils

Abstract

SUMMARY Measurements were made of the volatilization of ammonia from mono‐ammonium phosphate (MAP), di‐ammonium phosphate (DAP), ammonium sulphate (AS), ammonium nitrate (AN) and urea, applied to the surface of five contrasting soils. The compounds were applied as solids, at a rate equivalent to 100 kg N ha−1, to samples of moist soil packed into columns (48 mm diameter) and placed individually in jars through which a stream of air was passed for a period of 8 d. Volatilization ranged from nil to 53% of the N applied, with both the nature of the compound and soil type having large effects. Taking all combinations into account, there was a close relationship between the extent of volatilization, expressed as a percentage of the ammonium or urea N, and the pH attained after 24 h by the corresponding mixtures of soil and compound. Using the results of these and other experiments, the proportion of fertilizer N volatilized as ammonia is estimated to be about 3.4% over the UK as a whole.

A review of emissions of methane, ammonia, and nitrous oxide from animal excreta deposition and farm effluent application in grazed pastures

“…For example, Selvarajah et al (1989) obtained an inverse relationship between NH 3 volatilisation and the CEC of a number of soils, which they attributed to increased retention of NH 4 + onto the cation exchange sites. Whitehead & Raistrick (1990) also obtained an inverse relationship between NH 3 loss and CEC, but the relationship was stronger for urine than for urea; this was attributed to greater contact between soil and urine-derived than urea-derived NH 4 + ions. Similarly, Singh et al (2003) noticed higher levels of NH 3 loss from surface-applied urea granules than from urine application.…”

“…It has often been shown that NH 3 volatilisation increases with soil pH. For example, Whitehead & Raistrick (1990) obtained a strong exponential relationship between NH 3 volatilisation from surface-applied N fertilisers and cattle urine and the pH of the soils. Although higher NH 3 volatilisation losses are expected from calcareous soils that are high in pH, the extent of NH 3 volatilisation depends on the carbonate concentration in the soil solution, which in turn is affected by the solubility of the calcium salts formed by the anion added through the NH 3 source.…”

Technical note: Laboratory evaluation of a tunable diode laser system for eddy covariance measurements of ammonia flux

“…Agriculture is the major source of gaseous ammonia (NH 3 ), producing emissions through animal waste volatilization (Whitehead and Raistrick, 1990), fertilizer and manure application (Sommer et al, 1991;Hansen et al, 1998) and livestock grazing (Denmead et al, 1974;Jarvis and Pain, 1990). Natural and semi-natural systems were for a long time believed to be significant and continual sinks of atmospheric NH 3 (Sutton et al, 1993).…”

Ammonia: emission, atmospheric transport and deposition

“…The situation is different, however, when the soil surface, or a covering layer of leaf litter, is a large source of NH $ emission. Soil-surface NH $ emissions are most closely associated with the application of mineral fertilizers (Whitehead & Raistrick, 1990 ; a ; van der Weerden & Jarvis, 1997), especially following urea application. Decomposition of leaf litter is also a ground source of NH $ emission and its importance needs further investigation.…”