Possible Clues:

• Capable of being debated
• Open to dispute
• Arabian film star engages university in dispute
• Not quite self-evident
• Good university to be sited in type of farmland -- that's contentious
• Chap briefly invested in farmland? That’s open to debate
• Ace grub with ale? Could be contentious!
• Not necessarily so
• Tenable (theory); dubious