If you're looking to plant a crop in a massive field at once, for say a build, then just run these commands.
/fill ~10 ~0 ~40 ~-40 ~-1 ~-40 wheat replace air
This first command replaces the air with wheat within a certain radius, feel free to make the radius bigger or smaller depending on how good your computer is. After running that command, you will want to enter this next one
/kill @e[type=!minecraft
layer]
This will kill every entity in loaded chunks that is not the player. If you want to spare something from this genocide, simply add it with a comma, like so. You cankeep adding commas and exceptions until you are satisfied you wont harm anything unintentionally.
/kill @e[type=!minecraftlayer, type=!other entity]
the reason for doing this is because the game will try to replace all the air blocks inside the radius with seeds, which will most likely create tremendous lag, so be quick to issue both commands.
/fill ~10 ~0 ~40 ~-40 ~-1 ~-40 wheat replace air
This first command replaces the air with wheat within a certain radius, feel free to make the radius bigger or smaller depending on how good your computer is. After running that command, you will want to enter this next one
/kill @e[type=!minecraft
layer]This will kill every entity in loaded chunks that is not the player. If you want to spare something from this genocide, simply add it with a comma, like so. You cankeep adding commas and exceptions until you are satisfied you wont harm anything unintentionally.
/kill @e[type=!minecraft
layer, type=!other entity]the reason for doing this is because the game will try to replace all the air blocks inside the radius with seeds, which will most likely create tremendous lag, so be quick to issue both commands.