On catching out the material to determine pattern accuracy, you really need to make sure you overlap is set correctly as well. For example if your running 80' track lines, you'd run ideally down your edge, then center and then finish with your far edge pass. This process described here only gives you an idea on how wide to run. Also this process should be repeated for different materials and different rates. It is crucially important to conduct these calibrations at the speed you hope to apply at, as the fertilizer flow changes as your ground speed changes thus changing your pattern. Spinner machines can be highly accurate if set correctly.
