Do You Have To Have A Journalism Degree To Become A Reporter?

The answer is a resounding no.
In fact, in my 30-plus years as a newspaper copy-editor, I saw a marked decline in the language skills of young journalism grads. My joke became, "They know computers, but they don't know commas."
Reporters have degrees in a variety of subjects, besides journalism. Some of the best writers I've worked with studied philosophy, history, international relations, even business. But far and away the best writers had degrees in English literature.
Getting the story requires certain skills, but translating it into a coherent, well-written news story can be a very different kettle of fish.
Language skills such as a knowledge of grammar and syntax, punctuation, and telling a story in proper sequence are not taught in journalism schools. Another thing that seems to be lacking in today's j-school grads is an extensive vocabulary -- the kind attained from a broad liberal-arts education in other subjects.
Besides reporting, do not forget editing as a newsroom profession. This definitely requires a watertight knowledge of the language and its usage, plus a very wide background in many other subjects so that you can catch factual errors.
One of my favorite anecdotes is when, fresh from getting my bachelor's in English lit and already a proofreader at the school newspaper, I asked the dean of the journalism school at the University of California at Berkeley if I should pursue a journalism degree.
He told me, "You already know how to write and are working at a newspaper. Don't waste your time and money, kid." Shocked, I stammered out a thanks, walked out  -- and took his advice.