The fertilizer is used to speed up crop growth below the connected machine frame. It requires water and energy to operate.
The effect on the blocks below is similar to applying bonemeal, although it is less potent. Additionally, it hydrates the farmland below.
Growth Boosts
Mineral Slurry fluid can be used instead of water. This will significantly increase the strength of the growth effect. Bone meal can also be inserted into the fertilizer block to increase its potency.
This machine is meant for continuous farming rather than burst growth. Water is the cheap baseline fluid, while mineral slurry is the better option when you want much higher crop throughput.
Like other gantry machines, multiple fertilizers can share a single frame and iterate over the same field.