Premium
The Relationship between pH and Ammonia Equilibria in Soil
Author(s) -
Plessis M. C. F.,
Kroontje Wybe
Publication year - 1964
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/sssaj1964.03615995002800060022x
Subject(s) - soil water , volatilisation , chemistry , ammonia , aqueous solution , soil ph , ammonium , environmental chemistry , inorganic chemistry , soil science , geology , organic chemistry
Investigation of the relationship between pH and NH 3 equilibria in soils revealed that an increase in the concentration of NH 4 + , applied as (NH 4 ) 2 SO 4 , stimulated NH 3 losses from fine‐textured soils at pH's ranging from 4.5 to 7.1. Ammonia volatilization was directly related to the initial pH of the soil and increased with an increase in pH. It was postulated that NH 3 may be volatilized, even from acid soils, due to the equilibrium NH 4 + + OH ‐ ⇄ NH 3 + H 2 O. By using initial concentrations of NH 4 + from (NH 4 ) 2 SO 4 applied, initial pH of an aqueous suspension of the soil and a value K b = 1.80 × 10 ‐5 , values of NH 3 losses were predicted. The linear relationship found between predicted and measured amounts of NH 3 losses from acid as well as neutral soils, was interpreted as evidence of the existence of the proposed volatilization mechanism in soils.