I agree with John. Just glue it without biscuits or dowels. An edge grain joint will be stronger than the wood around it. For edge grain joints, I consider biscuits and dowels to be alignment aids, not strength builders. For joints as short as yours, you shouldn't have alignment problems anyway. End grain is a different story. I use biscuits or dowels on end grain to add strength because the end grain doesn't glue well.
“We should be careful to get out of an experience only the wisdom that is in it and stop there lest we be like the cat that sits down on a hot stove lid. She will never sit down on a hot stove lid again and that is well but also she will never sit down on a cold one anymore.” - Mark Twain