A salt on nature

Did ancient conquerors punish their enemies by sowing captured fields with salt?

Don't be stupid.

As with most things, it's all about the money. Spitefully punishing your enemies with pestilence and death is good innocent fun-- but not if you have to dump precious commodity on the ground to do it.

Consider these facts:

Cecil estimates it'd take 31 tons to ruin an acre of farmland. Salt was the bling of the Roman era and in fact the word "salary" comes from "salt". Ergo there's no way that conquering Roman soldiers would take a pay cut to teach Carthage a lesson about throwing down.