HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Foster, N. W. Articles by Corke, C. T. Search for Related Content PubMed Articles by Foster, N. W. Articles by Corke, C. T. Agricola Articles by Foster, N. W. Articles by Corke, C. T.

Immobilization of Nitrogen-15-Labelled Urea in a Jack Pine Forest Floor¹

ABSTRACT

Urea labelled with ¹⁵N was applied at 200 kg N ha^–1 in the spring to a 45-yr-old natural jack pine (Pinus banksiana Lamb.) forest near Chapleau, ON. Fertilizer recovery in the L and F horizons was determined 32, 64 and 96 d after fertilization. Three months after fertilization, 25% of the added N had been immobilized in the forest floor and was recovered as organic N. The possibility that chemical reactions contribute to fertilizer N immobilization was investigated by applying urea to sterilized, mixed L and F horizon materials in an 8-d laboratory incubation study. The amount of N fixed chemically in urea-treated forest floor materials exceeded the amount of N immobilized in microbial tissue. The nature of the chemical reaction was investigated in a second incubation study. Urea did not react with L + F horizon materials either at the natural soil pH (4.5) or at the higher pH (8.0) resulting from the addition of KOH. Since urea was applied at a rate sufficient to raise soil pH to the alkaline range, immobilization may be explained by reaction between NH₃ and soil organic matter.

¹ Contribution from the Government of Canada, Canadian Forestry Service, Great Lakes Forest Research Centre, Sault Ste. Marie, ON. From a thesis submitted by the senior author in partial fulfillment of the requirements for the Ph.D. degree at the Univ. of Guelph. Presented before Div. S-7, at the American Society of Agronomy meeting, Anaheim, CA, on 1 December 1982.

² Research Scientist (Great Lakes Forest Research Centre), Professor, and Professor (retired), Univ. of Guelph, respectively.

Received for publication February 21, 1982. Accepted for publication October 10, 1984.

This article has been cited by other articles:

				F. Accoe, P. Boeckx, X. Videla, I. Pino, G. Hofman, and O. Van Cleemput Estimation of Gross Nitrogen Transformations and Nitrogen Retention in Grassland Soils Using FLUAZ Soil Sci. Soc. Am. J., October 27, 2005; 69(6): 1967 - 1976. [Abstract] [Full Text] [PDF]

				D.W. Johnson, W. Cheng, and I.C. Burke Biotic and Abiotic Nitrogen Retention in a Variety of Forest Soils Soil Sci. Soc. Am. J., July 1, 2000; 64(4): 1503 - 1514. [Abstract] [Full Text]