Farming is the foundation of modern civilization, but because of its importance, the proper use of farming can mean the difference between a baby-boom or a mass famine. Minecraft however never has to worry. Unless your enemy raids your crops and home, you can maintain an absurd surplus of food. If a Steve (player) devotes their occupation to farming, including underground farming or a well protected greenhouse, then they can fuel an entire town all by themselves. Minecraft also has relatively stable climate; no tornadoes, volcanic eruptions, earthquakes, tsunamis or hurricanes (at least in the current patch). Famine, the leading cause of genocide, will be eliminated (at least initially) since anyone can be a farmer, mastering agriculture in minutes.
Now I am aware that a Minecraft day is absurdly fast, but I think that's because if you were to realistically farm, it would be extremely slow; so the game's days is fast to not make the game slow and boring. So throughout this entire blog, for the sake of argument; a Minecraft day and Steve's speed is what it is ingame.
Considering that a Minecraft day is 20 minutes and that you can farm 4 blocks a second; this means 4800 blocks of crops can be fielded in a day. Assuming it takes 3 carrots a day to resist hunger for a normal Steve (that is not doing any labor intensive work), and assuming that each block of carrots produces 3 carrots (which is the average), then one Farmer Steve could feed a town of about 4799 other Steves (not including himself). If Farmer Steve spends half his time replanting then the yield is about 2399. Considering that this is excluding tractor technology; this crop yield is absolutely absurd. Food (at least initially) would be literally dirt cheap.
This does mean that Minecraft is going to be dangerously overpopulated, even compared to our current day world: almost every issue associated with overpopulation is going to max out. Eventually Minecraft will reach its peak and go only downhill from there. Without population control, virtually all accessible dirt-blocks will be used in some way, shape or form; even if society used 3d or underground farming techniques. What makes this worse is that dirt blocks can be destroyed yet cannot be created, it is a plentiful yet non-renewable resource; especially since feces and decomposition doesn't exist to make new supplies of dirt. This will clearly lead to a war, which I will mention in a later chapter.
In these times of famine or overpopulation; a theoretical Zombie plague could spread rapidly if an overpopulated community is infected from Zombie bites or if those famished and desperate start eating rotten-flesh. However since Zombies are so easy to defeat and die in sunlight; such an outbreak would only work if an underground society was somehow completely defenseless.
Some foods will be relatively luxurious; like fish, apples or cake.
And while it's technically not food; I do want to mention sugar-cane due to paper. With paper, Written Books and fully detailed maps (at least above ground) can be mass produced. This is revolutionary; culture within Minecraft would be diverse from the very start thanks to books spreading novels, philosophies and religions across the world. The use of Maps will also make it easy for the entire world to be recorded, potentially within only a few months. The Americas, Sub-Saharan Africa and Australia would have far more interaction with the empires of the Old World. The Silk Road and other highways would remain intact throughout most of history. It is an exchange of culture and politics our Ancient World would only dream about. And repressing or censoring this would be difficult due to underground tunneling and the ease of copying texts.