This is a follow-up project to our first experiment.com project "How much fertilizer do we really need?" where it was difficult to find any response to phosphorus (P) or potash (K) fertilizer inputs, suggesting that, in a healthy, cover cropped soil, legacy P and K may be untapped resources, while economic nitrogen rates seemed to be lower than initially thought. Soil test P in our 40 plots is in the "High" range, so we will concentrate on the effect of nitrogen and potassium in this research.