I wonder if it refers to this. I've recently read this book which deals with the issue of journalism and journalistic ethics, and denominates an area called "journalistics".

I think "Journalism Studies" is too broad a term. 'Periodística' is clearly a distinct sub-discipline and the text says it is 'heredera de la tradicional Redacción Periodística'. I think that means it's about journalistic writing and style.

Both Collins and Oxford give 'Periodística' as the equivalent of 'Journalese' but flag it as jargon. Another drawback is that 'journalese' is often - though not necessrily - used pejoratively.

'Reportage' may be too narrow, not including lifestyle features etc.

So on balance I think 'Journalistic Writing' is probably your safest bet, though I wouldn't discount the two other options.

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Note added at 1 hr (2009-10-09 10:44:12 GMT)
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Typo: necessarily

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Note added at 6 hrs (2009-10-09 14:56:59 GMT)
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Just to clarify: self-respecting journalists use the term journalese to refer to the clichéd style they try to avoid in their own work, but applied linguists use it to refer to the language of newspapers, magazines and other media. For them, journalese is simply a field of discourse analysis. See:

http://sites.uclouvain.be/etudes/cours/en/germ2344.pdf

Having said that, my best answer for this question remains 'Journalistic Writing'.