Economically Optimal N Recommendations Based on Variable Grain and Fertilizer Pricing and Mitscherlich-Modeled Canola Yield Responses.

Twelve site-years of canola N response trials generated a range of Mitscherlich-modeled yield vs N supply relationships over a range of potential yields that were dictated by available water. The N supply and N fertilizer requirements were also greatly affected by residual N and N mineralization. Economically optimal N fertilizer application rates depend upon the relative crop price to N fertilizer price ratio. Various grain: N fertilizer price scenarios were evaluated using sensitivity analysis to define optimal economic N recommendations under different water regimes.