* When a plant has its maximum of fruits, it needs less fertilizer. As the fruits spoil after some time, leaving the plant in a non-full state for some time, these numbers are rather theoretical maximums.
For optimal production put 3 stacks of keratin, 9 stacks of Spoiled Meat, 7.5 stacks of hide, and 9 stacks of charcoal in a handmill. These numbers will fill up the allowed slots in the handmill to maximum efficiency (29/30). This will make 300 bonemeal fertilizer.