The Thermal Release of Ammonium Nitrogen from Ammonium Chloride-Treated and Nontreated Soils1
- L. K. Porter and
- B. A. Stewart2
Comparisons were made of the thermal release of NH4+-N from soils and NH4+-saturated soils. Fixed NH4+-N was lost from untreated and NH4Cl-treated soil samples when the samples were subjected to temperatures above 400C. A treatment of 800C for 5 min generally released more than 85% of the fixed NH4+-N. However, small amounts of indigenous fixed NH4+-N, 25 to 30 ppm N, may be retained by some soils when they were subjected to a temperature treatment of 1,000C for 5 min.
Release of exchangeable NH4+-N was essentially completed when samples were subjected to a treatment of 500C for 5 min. The nontreated surface soils exhibited sharp increases, three- to sixfold, in their exchangeable NH4+-N when samples were heated at 250 or 300C for 5 min. It is suggested that these increases were derived from NH4+-N being released as soil organic matter decomposed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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