This was a visitation of God for the people’s sins.- I'd use a stronger word- wrath/retribution/punishment, etc
She died by the visitation of God. 'Died by' doesn't work here for me. I'd use something like the visitation.../it was the visitation... that killed her.
This soil will not grow fruit trees.- 'Fruit trees won't grow in this soil' is more natural to me.