In spring, 2022, Agriculture and Agri-Food Canada published a discussion paper outlining why and how it proposes to reduce nitrous oxide (N2O) emissions from the application of nitrogen (N) fertilizer in Canada by 30% by 2030. The discussion paper is here. Comments were invited on/before August 31, 2022. For those interested, here are the comments I have submitted.

I have grain farmed near Guelph for 50 years, now growing corn and soybeans with minimal or no tillage, using split nitrogen (N) applications, urease and nitrification inhibitors and variable rate technologies for more efficient N usage. I believe that it is possible to reduce N2O emissions with N fertilizer usage while not reducing yields. Indeed, I think I am achieving this myself using the technologies listed above. Despite this, I believe there are some critical flaws in the proposed federal strategy as described in the discussion document released in spring 2022. These include:

1. The Canadian annual N2O emission, defined as 12.75 Mt CO2e in the discussion document, comes directly from the National Inventory Report (NIR) submitted to the UNFCCC in April 2021. The current document uses this number to calculate that a reduction of about 4 Mt CO2e is necessary to meet its objective of a 30% reduction in N2O emissions from use of N fertilizer. However, some of the most effective methods for reducing N2O emissions from N fertilizer application come from practices that are not accounted for in Canadian NIR accounting. These include the use of urease and nitrification inhibitors and split-applications of nitrogen fertilizer. Both can be expected to reduce N2O emitted per kg of N applied (though not necessarily total kg applied). Even if thousands of farmers did this, it would not show up in Canadian NIR calculations of N2O emissions in Canadian agriculture.

The discussion document does devote three paragraphs to discussion of the need to correct this flaw and Minister Bibeau made the briefest reference to the same in a recent interview (https://www.producer.com/news/ag-minister-insists-fertilizer-use-reduction-not-on-the-table/). However, neither really addresses how difficult this adjustment will be, given the current rules and procedures for NIR reporting. Indeed, Environment and Climate Change Canada (ECCC) updated its methodology for calculating N2O emissions from fertilizer usage in the 2022 NIR submission, and did not include adjustments for inhibitor usage or for times of application. The reason would seem to be that this was not presently possible using the Tier 2 ecodistrict approach used by Canada, with the accuracy needed for NIR reporting.

Making the adjustment needed to account for the benefit to be provided by the two practices identified above will be very difficult. That is not acknowledged in the discussion document. But without that, changes in practices to reduce N2O emissions in a way that shows up in annual reporting, without affecting agricultural (i.e., food-producing) capacity, will be very difficult – likely impossible. The Government of Canada needs to develop a different accounting method, somewhat independent of NIR, to measure the extent and speed by which Canada approaches a goal of 30% reduction in N2O emissions with fertilizer N usage – or whatever the final reduction goal turns out to be.

2. The fact that ECCC updated its calculation methodology for the 2022 NIR is a positive. It shows willingness to make changes as new information becomes available. But the magnitude of the changes made with the 2022 reporting, and related discussion in Annex 3.4.5 of Part 2 National Inventory Report 1990 –2020: Greenhouse Gas Sources and Sinks in Canada shows the uncertainty that still exists in N2O calculations for agricultural soils and fertilization procedures. As but one example, the new calculation factors mean a lower N2O estimation when the same quantity of N is provided by manure application rather than by inorganic N fertilizer ingredients. That’s probably correct when manure is applied at about the same time as crop planting and is incorporated immediately, according to published literature. But when manure is applied months earlier – for example, after cereal grain harvest in summer or early autumn to provide fertilizer to be used by a corn crop planted the following spring (a very common practice in Ontario), the N-use efficiency is substantially lower (See http://www.gocorn.net/v2006/Manure/Ontario_Manure_Nutrients_Calculator_2013_ver1_2.xls ).

The point is that calculation procedures for N2O emissions linked to N fertilizer usage are still very crude, and AAFC needs to be very cautious in attempting to make calculations for regulatory purposes. The document states that this is not the intent as of August 2022. But what’s voluntary now can change very quickly by regulatory decision.

3. Mention should be made, also, of the confusion created when the Government of Canada decided to place emission reductions with N fertilizer usage in a “Nature-Based Solutions” section of its 2030 Emission Reduction Plan (https://www.canada.ca/content/dam/eccc/documents/pdf/climate-change/erp/Canada-2030-Emissions-Reduction-Plan-eng.pdf)  rather than in the agriculture section. This means that any reduction in GHG emission achieved through fertilizer-use management will not show up as a decrease in agricultural emissions as presented by Canada. This decision by Canada adds to the confusion. (I’ve discussed this further at https://tdaynard.com/2022/04/11/trying-to-make-sense-of-canadas-greenhouse-gas-reduction-plans-for-agriculture/ ).
4. The discussion document makes reference to the economic analysis done for, and released by, Farmers for Climate Change (accessible at link, https://farmersforclimatesolutions.ca/budget-2021-recommendation/#programs). That analysis shows an expected cost of about $47/t of CO2e for emission reductions largely based on three practices, N2O emission reduction, cover-crop usage and pasture management. However when Agriculture and AgriFood Canada (AAFC) announced its new Agriculture Climate Solutions On-Farm Climate Action Fund, in February 2022, the news release stated an expected cost of equivalent to about $90/t of CO2e reduction. That’s almost a 100% increase over the cost calculated by the expert panel of the Farmers for Climate Change. AAFC has made no attempt to explain the large discrepancy; until that occurs, use of the calculations from Farmers for Climate Solutions to justify costs sketched in the current discussion document is not justified, in my opinion.

In summary, most importantly for the reason described above in point #1, but also for also for issues raised in #2, #3 and #4 above, AAFC should not finalize its plan to reduce N2O emissions from N fertilizer usage until a proper and credible accounting protocol is also provided.