About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in AJ

  1. Vol. 97 No. 5, p. 1380-1389
     
    Received: Oct 25, 2004
    Published: Sept, 2005


    * Corresponding author(s): hortuzar@neiker.net
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/agronj2004.0268

N-Tester Use in Soft Winter Wheat

  1. M. A. Ortuzar-Iragorri *a,
  2. A. Alonsoa,
  3. A. Castellóna,
  4. G. Besgaa,
  5. J. M. Estavillob and
  6. A. Aizpuruaa
  1. a Neiker, Berreaga 1, 48160 Derio, Spain
    b Dpto. Biología Vegetal y Ecología, UPV/EHU, Apdo. 644, 48080 Bilbao, Spain

Abstract

Chlorophyll meters can be an alternative to traditional tissue analysis as plant N nutritional diagnostic tools. In the present study, the relationships among chlorophyll meter N-Tester measurements, plant N concentration, N uptake at different growth stages (GS-32, GS-37), and grain yield were studied to evaluate the N-Tester as a tool to diagnose the N status of soft red winter wheat (Triticum aestivum L. cv. Soissons) and predict yield. Ten experiments were conducted in the years 2001, 2002, and 2003 where 0, 100, 140, 180, and 220 kg N ha−1 were applied. N-Tester values ranged between average values of 382 and 608 at GS-32 for 0 and 220 kg N ha−1, respectively, and between 408 and 649 at GS-37 for 0 and 220 kg N ha−1 correspondingly. The normalization of N-Tester values in relation to a non-N-limited plot (i.e., ≥220 kg N ha−1) enabled the prediction of plant N concentration (R 2 = 0.64) of Soissons soft red winter wheat at GS-32 and N uptake at both at GS-32 and GS-37 (R 2 > 0.6) in contrast to absolute N-Tester values (R 2 < 0.4). However, when excluding the N-Tester values corresponding to control treatments (0 kg N ha−1), the robust correlations diminished as to invalidate comparison of normalized N-Tester readings for N concentration and N uptake across different sites and years for rates in the 100 to 220 kg N ha−1 range. Normalized N-Tester values could discriminate between grain yields from non-N-fertilized and fertilized plots but could not distinguish grain yields among plots fertilized in the 100 to 220 kg N ha−1 range.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2005. American Society of AgronomyAmerican Society of Agronomy