Spring wheat agronomic and quality responses to a genotype × environment × N source and management systems approach
Wang, Z., S. Strydhorst, X. Hao, G.H. Ramirez, G. Semach, C. Holzapfel, J. Enns, L. Thompson and B. L. Beres. 2024.
Abstract
Yield and quality improvements in Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) are increasingly difficult
to attain, which behooves a systems approach to unlock genotype (G) × environment (E) × management (M) synergies. This 25
site-year study was designed to assess a G × E × M systems approach to improve CWRS agronomics, quality, and N use efficiency
(NUE). The investigation consisted of genetics (AAC Viewfield vs. AC Stettler), N source (untreated urea; urea urease inhibitor,
N-(n-butyl) thiophosphoric triamide (NBPT); urea nitrification inhibitor, nitrapyrin; urea dual-inhibitor (NBPT dicyan-
diamide); and polymer-coated) and N timing/placement (all-banded at planting, two-split applications and three-split applica-
tions), deployed across diverse soil zones in western Canada. Differential yield responses were observed between cultivars as
AAC Viewfield produced superior yield over AC Stettler ( 4.3%) in black and grey soils, while yield attainment was similar in
dark brown soils. Genetic improvement over AC Stettler seemed most apparent in water abundant environments; however,
AC Stettler was often superior in drier conditions. All N sources produced comparable outcomes for yield, quality, NUE, and
net returns. In black and grey soils, adopting either all-banded or two-splits improved grain yield due to augmented seedling
vigor, heads per plant, and N recovery. The timing of split-applications introduces more risk to yield and is likely attributed to a
poorly developed source:sink relationship in the critical growth period if applied late to optimize grain protein. This highlights
the complexity of the system and balance needed to harness the potential synergy between G, E, and M components.
Key Words
Canada Western Red Spring wheat, soil, grain yield, quality, enhanced efficiency fertilizer, nitrogen N use efficiency
