Measuring Nitrous Oxide Emission

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Showcasing technology demonstrations at Innovation Farms

EMILI, University of Manitoba

As part of Manitoba 4R Day 2023, Dr. Mario Tenuta and a team of University of Manitoba researchers conducted a study at Innovation Farms measuring Nitrous Oxide (N2O) emissions from two different Nitrogen (N) fertilizers applied using three placement methods in canola.

Objective

This research aims to determine which sources and placement of N show consistent reductions in N2O emissions. This will help farmers guide management practices that reduce N2O emissions per unit of crop produced without reducing yield. Practices that reduce N2O emissions have an added benefit since they also tend to increase nitrogen use efficiency.

Project details

Urea and eNtrench NXTGEN (urea treated with Nitraphyrin) were either broadcast, shallow banded, or deep banded during seeding (Figure 1). Gas collection chambers were inserted 5 cm into the soil between seed rows a day before the first sampling and left in place from seeding through soil freeze-up to capture representative emissions of the fertilized and unfertilized bands. Gas samples were collected one to three times per week, sampling more frequently after N application. Concentrations of N2O were determined using a gas chromatograph equipped with an electron capture detector.

Figure 1. Plot map detailing the types of fertilizer and placement methods in the canola field.

Figure 1: Plot map detailing the types of fertilizer and placement methods in the canola field.

What we learned

We found a consistent reduction in N2O emissions from canola production through use of the eNtrench NXTGEN nitrification inhibitor compared to urea alone, but a variable response to placement. Banding of urea decreased emissions in drier years, but increased them in wetter years. Shallow sub-surface banding of urea tended to produce higher emissions than deep. Nitrogen placement did not alter the ability of eNtrench to reduce emissions.

Learn more about EMILI's 2023 Collaborations at Innovation Farms.