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 Sabey, B. R. Articles by Bartholomew, W. V. Search for Related Content PubMed Articles by Sabey, B. R. Articles by Bartholomew, W. V. Agricola Articles by Sabey, B. R. Articles by Bartholomew, W. V.

The Formation of Nitrate from Ammonium Nitrogen in Soils: III Influence of Temperature and Initial Population of Nitrifying Organisms on the Maximum Rate and Delay Period¹

ABSTRACT

A number of soils of varying properties were incubated at several temperatures and rates of inoculation of nitrifying organisms to determine the influence of these factors on nitrification. The time-nitrification curve generally exhibited a "delay" phase and a "maximum rate" phase followed by a phase in which the rate of nitrification declined as the substrate was exhausted and the end product concentration increased. Each phase must be measured and characterized before difference in nitrification in soils can be fully understood and described.

In soils incubated at field capacity, the maximum nitrification rates increased from immeasurably low values to as great as 900 ppm. per week in some soils and the delay periods decreased from about 32 weeks to < 1 day, as temperatures increased from 0 to 25° C. Increase in initial population of nitrifying organisms caused decreases in delay periods but did not appreciably affect the maximum rate above 10° C. The influence of temperature and nitrifying population on delay periods and maximum rates varied greatly among soils indicating that other factors inherent in the soils also affect nitrification.

¹ Journal Paper No. J-3648 of the Iowa Agr. and Home Econ. Exp. Sta., Ames. Project No. 1378. Contribution from the Department of Agronomy (Soils). Supported in part by a grant from Phillips Petroleum Company. Presented before Ind. & Agr. Div., Society of American Bacteriologists, Chicago, Ill., April 28, 1958.

² Instructor, Associate Professor, and Professor of Agronomy (Soils), respectively. The authors are now with the Agronomy Depts. of the Universities of Illinois, Iowa State College, and North Carolina State College, respectively.

Received for publication May 11, 1959. Accepted for publication July 7, 1959.

This article has been cited by other articles:

				P. M. Vitousek, J. R. Gosz, C. C. Grier, J. M. Melillo, W. A. Reiners, and R. L. Todd Nitrate Losses from Disturbed Ecosystems Science, May 4, 1979; 204(4392): 469 - 474. [Abstract] [PDF]