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 Harper, J. E. Articles by Cooper, R. L. Search for Related Content PubMed Articles by Harper, J. E. Articles by Cooper, R. L. Agricola Articles by Harper, J. E. Articles by Cooper, R. L.

Nodulation Response of Soybeans (Glycine max L. Merr.) to Application Rate and Placement of Combined Nitrogen¹

Uniform incorporation of ammonium nitrate (dispersed throughout a 30.5 cm soil column) impaired nodular development of soybeans (Glycine max L. Merr.) more than deep application (lower 10 cm of soil column) when ammonium nitrate was applied at a rate of 150 ppm N in growth chamber studies. Nodule fresh weight and haemoglobin content were decreased by nitrogen application, while nodule number was not as markedly affected, indicating an effect on nodule development rather than on root infection or nodule initiation. Greater nitrate content of roots and tops under dispersed nitrogen application, compared with deep application at the same rate, suggested that internal nitrate may be influencing nodulation. However, deep placement of 150 ppm combined nitrogen allowed greater root nitrate uptake than uniform incorporation of 50 ppm N, without concomitant inhibitory effects on nodulation. Nodulation response was not, therefore, strictly dependent upon internal nitrate content of the roots, indicating that application site may provide a means of partially alleviating the detrimental effect of combined nitrogen on nodulation.

Key Words: Haemoglobin • Kjeldahl nitrogen • Nitrate reductase • Nitrate

² Research Plant Physiologist and Research Agronomist, respectively, Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Urbana, Illinois 61801.

Received for publication November 21, 1970.

This article has been cited by other articles:

				J. R. Freeborn, D. L. Holshouser, M. M. Alley, N. L. Powell, and D. M. Orcutt Soybean Yield Response to Reproductive Stage Soil-Applied Nitrogen and Foliar-Applied Boron Agron. J., November 1, 2001; 93(6): 1200 - 1209. [Abstract] [Full Text] [PDF]