You may have heard the expression “sow it with salt” before. It’s most commonly associated with the incident we are reading about today, in which Abimelech destroyed the city of Shechem and sowed it with salt thereafter. Salting the earth apparently became common in the ancient Near East. Hittite and Assyrian sources both mention the practice, but none predates the Judges account.
Maybe Abimelech was a trendsetter.