Confederate conscription laws included loophole provisions. under what circumstances was a southern male citizen within the conscription age range exempt from military service?

Owning 20 or more slaves--It allowed very wealthy men a way out of the war and became very controversial in the South.

Southern men who were not exempt from the war found this exemption insulting. The war was coined as a "rich man's war" being the war was being fought for a states' rights to allow slavery and then the slave holders were allowed to exempt fighting. Economically, this helped keep product for sale and bring money into the Confederacy. 

The amendment process.