Kacey Musgraves has opened up about her divorce from Ruston Kelly for the first time, admitting their marriage "simply didn't work out".

The Follow Your Arrow star filed for divorce from Ruston in July last year, after almost three years of marriage, citing irreconcilable differences. She had remained silent about the reasons behind the split, but has now spoken candidly in a new interview with Rolling Stone magazine.

"(It) just simply didn't work out," she said. "It's nothing more than that. It's two people who love each other so much, but for so many reasons, it just didn't work. I mean, seasons change. Our season changed."

The Grammy Award-winning singer added that since the breakdown of her relationship, she has started to question the entire concept of marriage.

"Part of me questions marriage as a whole, in general," she mused. "I mean, I was open to it when it came into my life. I embraced it. I just have to tell myself I was brave to follow through on those feelings. But look at Goldie Hawn and Kurt Russell. They're doing something right... I think I live best by myself. I think it's OK to realise that."

Kacey also admitted her new songs could be inspired by the breakdown of the relationship, though she promised to "honour" the love they had for each other.

Since their split, Kacey and singer-songwriter Ruston have done their best to remain friends, and frequently comment on each other's social media posts.

Announcing the end of their marriage last year, they said in a joint statement: "The love we have for each other goes far beyond the relationship we've shared as husband and wife. It's a soul connection that can never be erased. Though we are parting ways in marriage, we will remain true friends for the rest of our lives."