publications - Publishing academic research in more than one field

I have an important question, so please try to answer it precisely and carefully as possible.

If I want a career in one field in academia, would it be inadvisable to publish some other academic researches in other fields.

I have seen an article in a blog that suggest against it. But on the other hand I think that ability to publish research and practise this process is important for academic persons.

Nevertheless, lately I browsed Shanghai ranking and they have a rule that divides the researcher contribution by the number of departments they published in.

To expand my point,for many fields it is necessary to combine expertise from different disciplines in order to sythesis some new approaches. So frankly, I really do not understand the logics behind such an archaic approach.

So the question is, will it help publishing in more than one discipline or will it really make everything more difficult?