Characterizing Variation in Nitrogen Use Efficiency in Wheat Genotypes Using Proximal Canopy Sensing for Sustainable Wheat Production

Authors

Mohammed A. Naser, Al-Muthanna University & University of Nebraska-LincolnFollow
Raj Khosla, Colorado State University, Fort CollinsFollow
Louis Longchamps, Agriculture and Agri-Food CanadaFollow
Subash Dahal, Colorado State University, Fort CollinsFollow

ORCID IDs

https://orcid.org/0000-0001-5122-1071

https://orcid.org/0000-0002-0548-9103

Date of this Version

5-29-2020

Citation

2020 by the authors.

Comments

Agronomy 2020, 10, 773; doi:10.3390/agronomy10060773 www.mdpi.com/journal/agronomy

Abstract

Global nitrogen use efficiency (NUE) for cereal production is marginal and is estimated to be about 33%. Remote sensing tools have tremendous potential for improving NUE in crops through efficient nitrogen management as well as the identification of high-NUE genotypes. The objectives of this study were (i) to identify and quantify the variation in NUE across 24 winter wheat genotypes (Triticum aestivum L.) and (ii) to determine if the normalized difference vegetation index (NDVI) could characterize the variability in NUE across wheat genotypes. This study was conducted in 2010 and 2011 in the semi-arid climate of Northeastern Colorado across dryland and irrigated conditions. Our results indicate significant variation in the NUE among genotypes across two irrigation conditions. We observed a strong relationship between the NDVI and NUE—as PFP (partial factor productivity) and PNB (partial nitrogen balance)—across the 24 wheat genotypes under dryland conditions (average R2 for PFP and PNB = 0.84) at Feekes growth stage 11.1, for site year II. However, poor association was observed under irrigated conditions (average R2 for PFP and PNB = 0.29) at Feekes growth stage 3 to 4 for site year II. This study demonstrates the potential and limitations of active canopy sensing to successfully characterize the variability in NUE across wheat genotypes.