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 Lory, J. A. Articles by Peterson, T. A. Search for Related Content PubMed Articles by Lory, J. A. Articles by Peterson, T. A. Agricola Articles by Lory, J. A. Articles by Peterson, T. A.

A Comparison of Two Nitrogen Credit Methods: Traditional vs. Difference

USDA-ARS, 119 Keim Hall-East Campus, Univ. of Nebraska-Lincoln, Lincoln, NE 68583-0915
USDA-ARS and Dep. of Soil Science 439 Borlaug Hall, Univ. of Minnesota, St. Paul, MN 55108-6028
Dep. of Agronomy, Southeast Res. and Ext. Center, Univ. of Nebraska, Lincoln, NE 68583-0714

^* Corresponding author.

Cereals and other nonlegumes typically require less fertilizer N when grown following a legume. Nitrogen credits for a previous legume crop often are used to reduce fertilizer N recommendations in combination with other site-specific information. Researchers continue to use two methods of determining N credits, the traditional and difference techniques, which often produce unequal estimates. Our objective was to clarify when each method provides accurate N credit estimates. The traditional method compares yield of a nonfertilized nonlegume crop grown in rotation to the fertilizer N response curve of the continuously cropped nonlegume. This approach assumes that fertilizer N compensates for all benefits of rotation. The difference method compares the economic N rate of the nonlegume crop grown in rotation with that of the continuously cropped nonlegume. We use examples from the literature to demonstrate that when non-N rotation effects are present, N credit estimates from the two methods will differ. The difference method is more accurate and should be used unless it has been demonstrated that non-N rotation effects are not present.

Received for publication April 13, 1994.

This article has been cited by other articles:

				S. A. Ennin and M. D. Clegg Effect of Soybean Plant Populations in a Soybean and Maize Rotation Agron. J., March 1, 2001; 93(2): 396 - 403. [Abstract] [Full Text] [PDF]