Corn Science Cluster – Nitrogen

Cross-Canada Agronomic and Environmental Benefit of Advanced 4R Nitrogen Management of Corn

Funding Program

Canadian Agriculture Partnership AgriScience Program – Corn Science Cluster led by the Canadian Field Crop Research Alliance (CFCRA)

Funding Sources
Principal Investigator and Collaborators
  • PI: Dr. Mario Tenuta (Professor of Applied Soil Ecology, University of Manitoba)
  • Dr. Craig Drury (Lead, Soil Biochemistry & Soil Management Research Scientist, AAFC – Harrow)
  • Dr. Joann Whalen (Professor of Soil Ecology, McGill University)
  • Dr. David Hooker (Associate Professor of Field Crop Agronomy, University of Guelph)
  • Gaetan Parent (Senior Soil & Agronomy Specialist, AAFC – Quebec)
  • Curtis Cavers (Agronomist, AAFC – Portage la Prairie)
  • Dr. Don Flaten (Professor of Soil Fertility, University of Manitoba)
  • Dr. Lori Phillips (Microbial Ecology & Soil Biology Research Scientist, AAFC – Harrow)
  • Dr. Xueming Yang (Soil Organic Carbon Dynamics & Quality Research Scientist, AAFC – Harrow)
  • Dr. Dan Reynolds (Soil Physics & Soil Physical Quality Research Scientist, AAFC – Harrow)
Summer students install static-vented chambers for sampling greenhouse gas emissions immediately after the 2019 field site near Carman, Manitoba was fertilized and planted ©Brad Sparling

This project meets an important need to increase the use efficiency of nitrogen fertilizers to hold or reduce nitrogen fertilizer rates in grain corn without decreasing yields. The project also aims to meet both key priorities given in The Calgary Statement of reducing greenhouse gas emissions and nitrogen losses from agriculture and enhancing knowledge transfer to farmers and industry. The project advances on previous work done by our team and others on corn across Canada on agronomic and environmental benefit of 4R nitrogen management practices.

Greenhouse gas emissions from soil are monitored using two methods at the 2018 field site near Carman, Manitoba: (1) static-vented chambers (white) collect emissions which are collected and analysed for nitrous oxide, and (2) passive dosimeter tubes that measure ammonia emissions (blue) ©Megan Westphal

The project is organized into two activities. Activity 1 deals with the agro-environmental aspects. Replicated plot trials, one per year for each of 3 years will be conducted near Montreal QC, Ridgetown ON and Carman MB for total of 9 site years. Treatments for those sites in QC, ON and MB will be similar. For all locations, increasing sophistication of 4R practice suites will be examined. A key novelty of the study designs is layering rates of N application to all treatments to allow determination of rate adjustment benefits of the practices examined. One trial site at Woodslee ON will be reserved to address for the first time to our knowledge, whether application of two injection bands rather than one injection band at side-dress reduces ammonia N losses and increases yields. We hypothesize that N losses are reduced with 2 bands as the fertilizer solution would not be as concentrated and pH increases reduced as compared to the standard injection practice of applying all of the fertilizer N at sidedress in 1 band. Two bands also enables us to place the sidedress N closer to the roots as compared to a band in the center of the corn rows. Agronomic (yield, ROI) and environmental measures of efficiency (reduction in N losses as N2O, NH3 & leaching) will be determined.

Technician Krista uses an active reflectance sensor (Crop Circle ACS-470) to quickly and non-destructively measure crop nitrogen status in real-time ©Mario Tenuta

Activity 2 specifically advances the development of tools for growers to establish in-season corn N application rates. Current spectral reflectance sensors and the novel near infrared (NIR) approach will be calibrated using replicated plot trials of in-season rates and timings of N additions in QC near Quebec City and MB near Portage la Prairie for each of 3 years. Sensor calibrations and comparisons will be used to advance the Nitrogen Nutrient Index (NNI) method as a decision tool for growers.

Overall, the aim is to provide evidence for adjusting N rates for profitability and environmental stewardship depending on 4R management intensity and development of tools for growers to tune in-season N application rates.


Our field studies will be used to address the following questions:

  • Does advanced 4R N management for Quebec, Ontario and Manitoba conditions change the most economical rate of nitrogen and improve grower return on investment?
  • Does advanced 4R N management for Quebec, Ontario and Manitoba conditions reduce N losses to the environment?
  • Will a novel practice of single vs double injection bands in combination with depth placement and N source reduce N losses and increase corn grain yield in Ontario?

This research project will also advance grower tools for in-season nitrogen rate determination.

Dr. Paul Bullock and Applied Soil Ecology Lab summer students collect corn biomass samples from the 2018 field site near Carman, Manitoba. ©Krista Hanis-Gervais
Benefits to the Canadian Corn Industry

The anticipated benefits of this project are that growers will know:

  • What advanced 4R practices suites are best for their area,
  • If N application rates should be changed when moving to advanced 4R practices,
  • If advanced 4R practice suites can keep N rates in check but increase yield,
  • If yield increases are expected when moving to advanced 4R N practices,
  • If investing (time, equipment, products, learning) in advanced 4R practices pays off,
  • What in-season N status methods best to use,
  • Are double injection bands at side-dress better than one injection band?,
  • If NNI in corn production improves N fertilizer use efficiency and profitability,
  • The most optimal sensor or device for in-season crop N and NNI assessment,
  • If N available to the next crop is affected by advanced 4R practices,
  • What to expect for C credits with advanced 4R N practice use.

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