"Drengen spiser brune ris i august og september."
Translation:The boy eats brown rice in August and September.
I'm guessing that for the rest of the year han spiser æbler - everyone else seems to...
Looks like the word is used in plural (same form as singular: ris, -en, -, -risene) when talking about rice as a "collection of rice grains", i.e. usually when talking about rice in recipes or eating rice.