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Estimating Ammonia Volatilization From Flooded Rice Fields by Simplified Techniques
Author(s) -
Freney J. R.,
Leuning R.,
Simpson J. R.,
Denmead O. T.,
Muirhead W. A.
Publication year - 1985
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1985.03615995004900040051x
Subject(s) - ammonia , calibration , environmental science , ammoniacal nitrogen , flux (metallurgy) , plot (graphics) , wind speed , volatilisation , soil science , calibration curve , nitrogen , ammonia volatilization from urea , fertilizer , chemistry , mathematics , meteorology , physics , statistics , detection limit , organic chemistry
Two simplified methods for assessing the emission of ammonia, from fertilized, flooded rice ( Oryza sativa L. cv. Inga) fields without affecting the plant's environment, are described and compared with an established micrometeorological method. Method A requires a circular plot of a 25‐m radius over which wind speed and atmospheric ammonia concentrations are observed at 0.8 m above the floodwater. Method B requires measurements of ammoniacal nitrogen concentration, pH and temperature in the floodwater, and wind speed at a fixed height. Method A is the more accurate technique and requires fewer measurements. It appears that one calibration curve relating vertical flux of ammonia to these measurements can be applied in widely different environments. Method B is not only less accurate than Method A but appears to require different calibration curves to determine vertical flux for different environments. However, this method may be more useful for comparing ammonia losses from several different fertilizer treatments since only small plot areas are required for each treatment. Method B can be calibrated easily for each site by one set of simultaneous measurements on one treatment plot, using Method A.