Well, if it didn't go off from crashing into the ground at high speed, in the first hour or so
Then it's unlikely to go off at all, smoking won't set it off.. nor will sitting on it.
Maybe schwacking the tip with a hammer might.
To us in Flanders , our farmers pick up way more dangerous 100 year old shells, they plow em up and put em on a pile . and then EOD will eventually come pick it up.
This is the cage for shells they find, at my buddies farm.. That cage is 15 feet from the main house on the farm..