You factor levels are labelled N0, N50, N100, N150, N200, and N250. This factor enters the design as a categorical factor with 6 levels. It is therefore modeled as a nominal effect. Is it, in fact, a continuous factor N that is tested at levels 0, 50, 100, 150, 200, and 250? That would change the modeling.
Your data was stored in an Excel workbook. Did you use JMP to design the experiment? I imported the worksheet. I added some useful column properties. I re-defined replicate as Whole Plot. I added it to the model as a random effect. (It is not a block, it is a restriction on randomization - you did not use a new field each time.) I fit two models. One uses the original treatment as a categorical factor. The other uses a new factor N as a continuous effect with a non-linear component.
I attached the new JMP data table.