As other posters have said, when it comes to this question, be honest and check yes.

It may hold you up a few minutes, but the individuals I've dealt with when checking yes were experts. They ask specific questions and they are looking for specific threats to US Agriculture.

In one case I had my shoes looked at and cleaned for me , in another case I had the soles of my shoes soaked in a solution of some type (this was during the foot/hoof and mouth episodide, IIRC).

It was explained to me soil and pathogens, etc, can collect on shoes and other items when one goes onto farm land outside of the US - which has the potential to endanger US agriculture if these pathogens (or even types of seeds from soil) are brought into the USA.

SDF_Traveler