Trace Adkins -- Divorce a Long Time Coming

Trace Adkins' life sounds like a country song -- a drunken fight, rehab, the death of his father and now a divorce -- and it was anything but a spur-of-the-moment decision.

Trace's wife, Rhonda, filed divorce papers this week to end their 17-year marriage ... but Trace says they're still united in a way more important way -- making sure their children come first. The kids are 16, 12 and 9.

We're told Rhonda's decision to divorce was a long time coming -- and both say they're torn up by it.

It's been nothing but bad news for Trace since January ... when he got into a drunken fight with an impersonator on a cruise ship. He entered rehab to deal with his booze problem ... then bailed on rehab two weeks later to tend to his ailing father, who died in early Feb.