A multi-year nitrogen recommendation analysis can be a powerful tool in understanding how specific nitrogen management practices have performed historically under different actual weather conditions of a field.
After configuring, activating, and running a recommendation, you have the ability to run a multi-year analysis with the current field configuration for any set of seasons in the previous 10 years. Click Create Multi-Year Analysis in the field recommendation page to begin.
You will then need to select a simulation date and which previous years you would like to run in the analysis. This analysis is available in both training mode and live, billable mode. In training mode activations, the current year will not be available. In all cases when including the current year, simulation dates only through "yesterday" are available.
The multi-year analysis will then use your current field configuration to compare the recommendation for the most recent season selection (only as recent as the previous season if generated in training mode) to the other selected growing seasons. The analysis will include the N recommendation, N loss, N mineralization, and rainfall totals for each season. This allows you to more accurately evaluate the current nitrogen management for that field and understand why recommendations change from year to year.
In this example, we see an analysis for June 1st. This field received 100 lbs of fall anhydrous ammonia. On June 1, 2018 Adapt-N called for an average of 67 lbs of additional nitrogen for a total of 10,363 lbs of additional N across the field. As of June 1st, the field had received 9.7" of rainfall contributing to an average of 27 lbs of N loss. There was also an average of 22 lbs of N mineralized.
For comparison, on June 1, 2012 Adapt-N called for an average of 53 lbs of additional nitrogen for a total of 8,155 lbs of additional N across the field. A 21% decrease compared to the recommendation for 2018.
However, on June 1, 2016 there was a 147% increase in the amount of additional N needed compared to 2018. Taking a look at the total rainfall of 25.3", you can see there was a substantial increase in the amount of rainfall compared to the 9.7" in 2018. These wet conditions contributed to an average of 126 lbs of N loss.
In this example, the 100 lbs of anhydrous ammonia in the fall worked okay for the grower in 2018 and 2012 but resulted in substantial nitrogen losses in 2016. Using this analysis helps illustrate how an adaptive nitrogen approach could pay dividends for this grower by planning for and reacting to changing weather conditions in their field.