Evaluation of variable rate applied enhanced efficiency N fertilizers on wheat and canola - field scale management zones comparison
Term: 4 years, ending March 2026
Status: Ongoing
Researcher(s): Haben Asgedom Tedla, Reynald Lemke, Jiali Shang, Kui Liu, Mohammad Khakbazan, Evan Derdall, Patrick Mooleki, Agriculture & Agri-Food Canada; Jeff Schoenau, University of Saskatchewan; Ikenna Mbakwe, Synergy AG; John Sulik, University of Guelph; Gurdeep Hehar, Premium Ag; Cory Willness, CropPro Consulting/Phantom Ag Ltd.
SaskCanola Investment: $137,393
Total Project Cost: $275,878
Funding Partners: Sask Wheat
Project Description
Nitrogen fertilizer to wheat and canola is one of the major input costs for growers and there has been continuous effort to improve N use efficiency for higher yield and seed quality. Once N fertilizers are applied, soil nitrate accumulation increases. Enhanced efficiency fertilizers like Environmental Smart Nitrogen (ESN), SuperU and eNtrench release N slowly or delay conversion of ammonium to nitrate. We’ve observed higher soil nitrate accumulation from urea compared to ESN before draw-down by crop uptake. Higher accumulation of nitrate in soils is prone to environmental losses and that may lead to lower yield and seed quality. On the other hand, enhanced efficiency fertilizers may not show agronomic advantage when soil is dry or when they are shallow applied. It is a well-established fact that soil moisture varies spatially, and the variation depends on frequency of extreme weather conditions, particularly precipitation. We expect such events to be even more often. Such, phenomena coupled with soil physical and chemical properties plays an important role in nutrient distribution and crop growth, which will determine effectiveness of N sources. Variable rate application (VR) of N enables spatial refined recommendation, thus increases protein content and yield of crops by matching crops N demand to soil N supply, spatially, across a field. This proposal further investigates relative performance of ESN, SuperU and eNtrench on contrasting management zone of fields.
Purpose
It is widely known that N fertilizer management increases wheat and canola yield and seed protein content, however, investment on N fertilizers is a major expense of wheat and canola growers and variable rate application of N fertilizers could help to optimize its usage. Precision agriculture has gained much importance over the past few years. Despite these developments, there have been few field studies that focused on assessment of wheat yield, protein, economic and other agronomic benefits of the technology. Most studies have been rather at plot level, that may overlook the effect of infield spatial variation. No current studies have combined variable rate N management with different sources of N to investigate profitability, yield and protein content of wheat and canola at the farm scale in Saskatchewan. We hypothesize that variable application of N based on digital mapping and the Advanced levels of 4R Practices (Right Source of N and Right Rate) could optimize N use, improve seed protein content, yield of wheat/canola and economic returns of growers. This project focuses on evaluation of three sources of N. These benefits can be optimized by selecting proper zone management delineation methods. Four methods of zone delineations will be compared. The N fertilizer products, and rates will be evaluated at a common intersection of the four delineation methods. Not only agronomical benefit but also an economic and risk analysis will be conducted to determine profitability of growers.
Goal
To recommend on agronomic potential of VR application and performance of EENF, evaluate management zone delineation mapping techniques and determine the economic feasibility of sources of N fertilizer and management zones.
Objectives
Evaluate agronomic potential of variable rate application of enhanced efficiency N fertilizers (EENF).
Assess relative performance of enhanced efficiency fertilizers (SuperU, ESN-Urea blend, eNtrench) vs. urea at contrasting zone.
Compare management zone delineation methods- results from objective 1 and 2 will be extrapolated to corresponding zones.
Conduct economic feasibility and risk assessment on sources of N fertilizer and management zones.