Ditto for Tetanus. I always half-heartedly got my Tetanus vaccine when it came time because why not? After learning what happens, I started marking the day on my calendar ten years in advance.
Since Clostridium tetani is anaerobic and in fact can't survive in the presence of oxygen, a lot of the things people suspect could give it to them likely can't. Unless you cut yourself while digging it's pretty unlikely you've been exposed to tetani.
And not to downplay your fears too much, but untreated tetanus is ~7% fatal versus 99.9% with rabies.
Like botulism or bacterial gangrene, tetani can survive for short periods (as can humans sans oxygen) but is unlikely to be found in sufficient quantities to cause concern.