It's so prevalent that Wikipedia has dedicated pages for specifically American, [0] Indian, [1] and Canadian [2] farmer suicides. In the US, farmer suicide rates are 3.5* the general population. The rate for the general population is between 2-4%, so for farmers it'd be 7%-14%, comparable to the rate for anesthesiologists, at 7%-17%. For physicians, it's just over 1%.

[0]: https://en.wikipedia.org/wiki/Farmers%27_suicides_in_the_Uni... [1]: https://en.wikipedia.org/wiki/Farmers%27_suicides_in_India [2]: https://en.wikipedia.org/wiki/Farmers%27_suicides_in_Canada