Arable land (from Latin arabilis, "able to be plowed") is, according to one definition, land capable of being ploughed and used to grow crops.[1] In Britain, it was traditionally contrasted with pasturable lands such as heaths which could be used for sheep-rearing but not farmland.
This could be bad because Canada will have less crops which would could mean less grains. This is a problem because people need crops to survive.