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

This Article Figures Only Full Text 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 Tiessen, K. H. D. Articles by Entz, M. H. Search for Related Content PubMed Articles by Tiessen, K. H. D. Articles by Entz, M. H. Agricola Articles by Tiessen, K. H. D. Articles by Entz, M. H. Related Collections Nitrogen Plant Nutrition Soil Fertility and Productivity

NITROGEN MANAGEMENT

Interactive Effects of Landscape Position and Time of Application on the Response of Spring Wheat to Fall-Banded Urea

^a Dep. of Soil Science, University of Manitoba, 362 Ellis Bldg, Winnipeg, MB, Canada, R3T 2N2
^b Agriculture and Agri-Food Canada, P.O. Box 1000A, RR #3, Brandon, MB, Canada, R7A 5Y3
^c Western Co-operative Fertilizers Limited, P.O. Box 2500, Calgary, AB, Canada, T2P 2N1
^d Dep. of Plant Science, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2

^* Corresponding author (Don_Flaten{at}umanitoba.ca).

The objective of this experiment was to quantify the effect of landscape position and time of application on the agronomic efficiency of fall-banded urea [CO(NH₂)₂] for spring wheat (Triticum aestivum L.) grown in the eastern prairie region of Canada. Landscape positions in this experiment were defined as high and low based on their relative elevations to one another within the field. Fertilizer treatments included urea banded at three different times in the fall (early, mid-, and late fall), in the spring at planting, plus a control with no fertilizer N added. In the low landscape positions, grain yield, total crop N uptake, grain yield increases (GYI), and crop nitrogen use efficiency (NUE) for fall-banded urea (all relative to spring-banded urea) increased linearly with delayed application dates and declining soil temperatures on date of application. However, only crop N uptake and NUE were related to cumulative soil heat units (SHU) from date of fertilizer application until freeze-up, and no measure of crop response to N was related to cumulative nitrification heat units (NHU). In the high landscape positions, the performance of fall-banded urea was not related to any measures of time and/or soil temperature. These results can be used to predict the increase in crop response to fall-banded N as a result of delaying application in low areas of the landscape. Our study also shows that date of application and soil temperature are robust and practical indicators for determining the appropriate time to fall-band urea fertilizer in these areas.

Abbreviations: GYI, grain yield increases • NHU, nitrification heat units • NUE, nitrogen use efficiency • SHU, soil heat units

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.

Received for publication August 4, 2006.