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 Google Scholar Google Scholar Articles by Broadbent, F. E. Articles by Stojanovic, B. F. Search for Related Content PubMed Articles by Broadbent, F. E. Articles by Stojanovic, B. F. Agricola Articles by Broadbent, F. E. Articles by Stojanovic, B. F.

The Effect of Partial Pressure of Oxygen on Some Soil Nitrogen Transformations¹

ABSTRACT

Two New York soils were incubated under conditions permitting control of the partial pressure of oxygen in a stream of gas passing continuously through the soil sample. Ammonium and nitrate salts and organic materials were added in various amounts and combinations and distribution of inorganic nitrogen determined at the end of each experiment. In two experiments the N¹⁵ tracer was used to determine accurately the fate of added nitrate.

Immobilization of added inorganic nitrogen occurred whether or not ample nitrogen was available to the soil population, probably due to preferential assimilation. Reduction of nitrate to ammonia was almost negligible at all oxygen concentrations, though slightly higher under anaerobic conditions than otherwise. Denitrification of added nitrate was inversely related to partial pressure of oxygen, but was of appreciable magnitude even under fully aerobic conditions. No evidence of nitrogen loss from the soil was obtained when ammonium salts were added.

The experimental findings are compatible with the theory that nitrous oxide in the earth's atmosphere arises from the soil, and that denitrification is of major importance in the nitrogen cycle.

¹ Contribution from the Department of Agronomy, Cornell University.