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Ammonia Volatilization from Surface‐Applied Urea: Effect of Hydrogen Ion Buffering Capacity
Author(s) -
Ferguson R. B.,
Kissel D. E.,
Koelliker J. K.,
Basel Wes
Publication year - 1984
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/sssaj1984.03615995004800030022x
Subject(s) - ammonia volatilization from urea , cation exchange capacity , chemistry , alkalinity , soil water , urea , soil ph , ammonia , volatilisation , soil acidification , environmental chemistry , fertilizer , alkali soil , inorganic chemistry , urease , soil science , environmental science , organic chemistry
The influence of soil pH and soil cation exchange capacity on ammonia volatilization from surface applied ammoniacal nitrogen has been reported in previous studies. Since the hydrolysis of ureacontaining N fertilizers causes an increase in alkalinity, a soil's inherent H + buffering capacity (defined as the soil's total acidity, comprised of exchangeable acidity plus non‐exchangeable, titratable acidity), should exert a dominant influence on the maximum soil pH at the site of urea fertilizer application. The objective of this study was to demonstrate the importance of a soil's H + buffering capacity in affecting NH 3 volatilization from surface‐applied urea. The H + buffering capacity of two soils was increased by adding hydroxy‐Al polymers to one soil, and weak and strong acid cation exchange resins to the other soil. Care was taken to keep cation exchange capacity and initial pH close to the same on amended and unamended (control) soils. Urea was surface‐applied to amended and unamended soils and ammonia volatilization and soil surface pH were measured. The increase of H + buffering capacity of soils was found to reduce soil surface pH and NH 3 volatilization after application of urea. It is concluded from this work that H + buffering capacity of a soil is a better indicator of NH 3 loss potential than a soil's initial pH.