Crop farming basics, then an auto farm in Minecraft
Bone Meal on a crop adds 2 to 5 stages at once, so 2 or 3 uses grow Wheat, Carrots or Potatoes from scratch.

Bone Meal is the fertilizer of the game: used on a plant, it makes it grow at once, or at least by a few stages. One bone gives three, and a full composter turns plant waste into more.
It is made with the Crafting Table from Bone (other recipes also exist).
Use it on crops such as wheat, carrots, potatoes and beetroots to speed them up, on a sapling to grow a tree on the spot, or on a grass block to make tall grass and flowers sprout around it. It also works on mushrooms, bamboo, kelp, sea pickles, moss and many other plants, though not on nether wart, sugar cane or cactus.
A Dispenser loaded with bone meal applies it to the block in front of it, the basis of many automatic farms. A Composter filled with seeds, leaves or crops gives one bone meal each time it is full, and a hopper underneath collects it.
Bone meal is also the base of White Dye. Nine of them make a Bone Block, and a bone block crafts back into nine. Fish sometimes drop a little bone meal too.
Bone → 3 × Bone Meal
Bone Block → 9 × Bone Meal
// Slots with several items cycle through every accepted option.
Bone Meal on a crop adds 2 to 5 stages at once, so 2 or 3 uses grow Wheat, Carrots or Potatoes from scratch.
Bone Meal speeds up the growth.
In Bedrock Edition sugar cane also grows from Bone Meal, which Java does not allow.
At the Crafting Table: 1 × Bone gives 3 × Bone Meal. It can be found as loot in Trial Chambers. It is dropped by Cod, Pufferfish, Salmon and Tropical Fish.
It makes crops, saplings, flowers and other plants grow instantly, and is crafted into white dye and bone blocks. It is an ingredient in 2 recipes, made at the Crafting Table; for example Bone Block and White Dye.