Una wrote:

In places with high salt content in the soil already, soil amendments that
are high in salts can be bad news.

I take it salt in soil is a sign of poor drainage and/or insufficient
rainfall. When Rome finally took out Carthage they plowed salt into the
soil. Carthage never came back from that and the place is still desert
today, but the soil is no longer salty. Even in a desert there's been
enough rain and drainage to leach it all away centuries ago.

One of the long term problems with pumping well water and other
irrigation for crops is it tends to build minerals in the soil faster
than natural drainage. The soil moves towards desert over a period of
centuries. There are vast deserts in the world that were once lush
agricultural lands. The desert of Iraq was one of the birthplaces of
agriculture and there was a History Channel show this week on a Sahara
site that was once a grain farming community.