Japanese Language usage question

[Ki no Kotori]

Okay, got a usage question and was hoping that anyone here with more practical Japanese-language skills could help me out.

The word in question is 草原 or maybe 大草原. The Onyomi (Chinese) reading is そうげん (だいそうげん） Sougen or Daisougen, while the Kunyomi (Japanese) reading is くさはら　（おおくさはら ) Kusahara or O-kusahara. It means prairie.

I'm working out the title for my next collection of poems (basically another diary, like my earlier 秋川日記　（Autumn River Diary). This would be the "Prairie Diary" 草原日記 ( but I'm not sure which pronunciation would be "correct". My sense would be to go with the kunyomi pronunciation since there was so much effort to go with the Japanese words in classical Japanese poetry, but OTOH, I honestly don't know what would sound more natural.

Any opinions?

Many thanks,

Ki no Kotori

[AJBryant]

True there were many classically Japanese–based words in waka, as there should be -- but my gut tells me that, still, the title would have been following the Chinese pronunciation as it was a literary thing, and Chinese was the literary language. (Much as, even though the guy's name was Yoshitsune, "The Chronicle of Yoshitsune" was the Gikei Ki; and even though the guy's name was Nobunaga, his bio was the Shinchô-kô Ki.)