Desperate to save his famous family farm, a proud cowboy tries to win $50,000 at the state rodeo, only to find out that his biggest rival is the college-indebted woman who stole his heart. (My idea with this logline is that the cowboy has a problem to lose against a woman in the first place. But he actually loves her. This tension drives the characters and the story forward.)

Why does it matter if his love interest is "college-indebted?"

The protag is the cowboy, the logline only needs to focus on him, and why is his family farm in trouble if his family is famous?

Calling him a proud cowboy comes off as redundant, as cowboys inherently give off a vibe of pride/machismo.

The farm is a good motivator, but it needs more significance for the MC.

I seem to remember this concept fro a few months ago, can't remember what the principle comments were in the thread though.

It seems like he needs to NEED to save the farm, in other words, what can you add that will raise the stakes for him to keep the farm - not sure sentimentality alone will do it.
Could his family be berried there, or maybe he recently discovered oil on his land?

I think it creates more dramatic tension if he desperately needs the money rather than merely wants it. ?It makes him a more sympathetic character if he's ?competing for a selfless purpose -- to save the family farm -- rather than a selfish one, to win the money for himself while inflating his ego.

I also think he should have to compete against a rival for her affections.

Then drop the money, farm blah blah.

A "never lose to a woman" rodeo rider fails for a female competitor who is just as desperate for the prize money as he is.

Needs work. But you correctly identified the story. It's not the farm. He could need the money for his kid sister's operation, the story would be basically unchanged.

Stole his heart or broke his heart?

What is the status of their relationship at the time both sign up for the rodeo?