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Temperature Quotients of Ammonia Emission of Different Nitrogen Sources Applied to Four Agricultural Soils
Author(s) -
Liu G. D.,
Li Y. C.,
Alva A. K.
Publication year - 2007
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/sssaj2006.0221
Subject(s) - loam , soil water , volatilisation , nitrogen , ammonia , chemistry , ammonia volatilization from urea , silt , environmental chemistry , environmental science , soil science , geology , paleontology , organic chemistry
Emission of N as NH 3 is the primary gaseous loss of N from N sources applied to soils. Knowledge of NH 3 volatilization, however, in relation to temperature is incomplete. Soils used in this study were a Biscayne marl soil (BMS) and Krome gravelly loam (KGL) from Florida, and Quincy fine sand (QFS) and Warden silt loam (WSL) soils from Washington. These soils were amended with either KNO 3 , NH 4 NO 3 , (NH 4 ) 2 SO 4 , or urea, and incubated at 11, 20, or 29°C under 20 or 80% field capacity (FC) soil water regimes. A change in the rate of NH 3 emission corresponding to a 9°C change in temperature is expressed as the temperature quotient ( Q 9 ), which describes the temperature effect on rates of NH 3 volatilization. At 20°C, the cumulative NH 3 emission at 20% FC was up to 8.1‐fold greater than that at 80% FC. The Q 9 values of NH 3 emission from the WSL soil were up to 10‐fold greater than those from the other three soils amended with either (NH 4 ) 2 SO 4 or NH 4 NO 3 The Arrhenius activation energy ( E a ) was about 188 J mol −1 for the WSL soil but ≤42 J mol −1 for the other soils. Volatilization from the WSL soil was highly temperature dependent. These results indicate that Q 9 and E a could be used as indices for N management for crop production to minimize NH 3 emissions. Further research is needed, however, to verify the above relationships across a wide range of soils and agroclimatic regions.