Did you notice that your COMET Planner practice “Improved N Fertilizer Management…Reduce Fertilizer Application Rate by 15%” shows an increase in total emissions?
There is assumption in the modeling that the baseline involves an over-fertilization and the CPS590 would improve overall efficiency, reducing the application rate. However, the only data we have on nitrogen rates is from USDA ERS that gives average nitrogen rates by crop. We are uncertain if this is an over-fertilization or not; therefore, we might actually be reducing too much. To read further about the COMET-Planner modeling in relation to this practice, please refer to the COMET-Planner Report. One page summaries are available for each practice when users select the "i" button next to a practice in Step 4.
We recommend noting that, typically, this increase in GHG emissions is quite negligible. In the screenshot above, for example, an increase of 0.24 over 12 acres accounts for just 0.02 metric tonnes per acre.