Canola 4R Nitrogen Project

Optimal Source, Placement and Application Timing of Nitrogen for Yield and Reduction of Greenhouse Gas Footprint for Canola Production on Light Texture Soils on the Canadian Prairies

Funding Program

Canola Agronomic Research Program (CARP) of the Canola Council of Canada

Funding Sources
Principal Investigator and Collaborators
  • PI: Dr. Mario Tenuta (Professor of Applied Soil Ecology, University of Manitoba)
  • Dr. Xiaopeng Gao (4R Management Strategies Research Associate, University of Manitoba)

Fertilizer nitrogen (N) is one of the greatest operational cost to producing canola and results in impressive production increases. However, it has the down side of producing two major greenhouse gases: nitrous oxide (N2O) and ammonia (NH3). The Prairies are reliant upon continued increases in export of canola grain but to be sustainable, reduction in N losses and more efficient use of fertilizer N is required.

Growers are faced with practical challenges of applying fertilizer N in the fall, though they know it is not the best means of using N. They are uncertain if newly available enhanced efficiency fertilizer products, that carry a price premium, are worth purchasing. Many growers faced with tight schedules for planting are opting to shallow band or even surface place fertilizer N though these are not current recommended practices. Some growers are experimenting with in-season fertilizer N application but don’t know if it worth the extra management consideration or what rates, application method and fertilizer source to use.

Through field trials in Southern Manitoba, this project will help address these outstanding issues for growers. It builds upon previous work using 4R Nutrient Management to optimize the rate, source, placement and timing of fertilizer N addition to canola for improved profitability and reduced greenhouse gas emissions on light texture soil, which are most prone to NH3 emissions.


This project aims to answer seven questions in order to improve nitrogen fertilizer use efficiency for canola production and inform canola growers which of the following practices perform better for yield and reduction of N losses on light texture soils:

  • Placement – How does surface application of double inhibitor granular urea (SuperU) compare to shallow banding of granular urea and the recommended placement of deep banding of urea?
  • N Source for Shallow Banding – Is there an advantage in using SuperU or controlled release granular urea (ESN blend) compared to granular urea when shallow banding?
  • Nitrification Inhibition for Deep Banding – Is there an advantage to inhibiting nitrification (eNtrench and DMPSA) when deep banding granular urea?
  • Fall & Spring Application – Can enhanced efficiency granular urea products and band placement of fall applied N match the benefit of spring application of N?
  • Split Application – Is there an advantage to adding N at planting and in-season compared to just at planting?
  • Placement of In-Season N – Does it matter if in-season N dressing of UAN is top-dressed by surface streaming or side-dressed by injection?
  • Inhibiting Ammonia Loss with Top-dressing – Is there a benefit to using the new ammonia volatilization inhibitor, Anvol, to top-dress UAN?
Benefits to the Canadian Canola Industry
  • Improved best management practices that will help to mitigate greenhouse gas emissions from canola grown on soils most prone to emissions while minimizing yield loss
  • Lowered environmental footprint for canola production in Canada
  • Reduced nitrous oxide (N2O) and ammonia (NH3) emissions from canola production will help achieve the greenhouse gas reduction goal for the Canadian agriculture sector

Welcome to the Applied Soil Ecology Lab at the University of Manitoba