Current nitrogen recommendations are based on research conducted 20 years ago. Yield potential has changed significantly since then through changes in production practices including better genetics (varieties), fungicides, and growth regulators. As producers pursue higher wheat yields using these improved management techniques, current N recommendations may not be sufficient. This study evaluates the Maximum Economic Rate of Nitrogen (MER-N) under current management regimes.
Multiple nitrogen rates were applied to generate nitrogen response curves and determine MER-N. Additional treatments were included at selected sites to evaluate the impact of fall nitrogen on wheat yield and economic return. Post harvest soil nitrate tests were collected to determine if higher N rates increased fall residual soil-N, which could be an environmental concern if not managed properly.