Is this the drop spreader or broadcast spreader? I have the broadcast. I think the appilcation is dependant upon the setting plus the amount of fertilizer in the drum. Seems the fertilizer falls faster when the tub is full, the weight pushes the fertilizer out faster. I also think your speed while applying effects drop rate too. I thought the faster you walk the faster the fertilizer will drop, maintaining the correct rate. I always thought a pace O' meter with a needle that points to the good range when you are walking at the correct speed.