There is a vast, VAST sea of writing that is non-fiction but is still not scientific writing. I guess you can say simply "Non-fiction, non-scientific writing" but the general phrase "non-fiction" would work for you, since I -- and I'm pretty sure most people -- will not immediately assume you must mean scientific writing. Business letters, advertising, any non-fiction book, self-help books and do-it-yourself guides, text books, biographies, most types of journalism, academic essays, memoirs, op-ed pieces, argumentative essays -- all of these are non-fiction writing.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.