An education department review has recommended a significant extension of the school year in remote Aboriginal lands to tackle widespread truancy.
Under the proposal, schools would open for 48 weeks a year in a bid to boost student attendance.
Assessing school attendance rates was a recommendation in an inquiry by the late Supreme Court judge Ted Mullighan into abuse on the state's APY Lands.
At the start of last year, it was revealed that no children at all turned up for first term at some schools on the lands.
Welfare agencies warned that, on any given day, approximately one in three students was absent.
The Education Union says it has concerns about how the plan would affect teachers.
The union's South Australian vice-president David Smith says he wants to see more detail on how teachers would be rostered over the year and how the curriculum would be delivered to students.
"Are they going to be learning the same curriculum but have that spread out over 48 weeks? We don't know that," he said.
"Are they going to have some perhaps cultural awareness programs or some other programs that might be more associated [with] out-of-school-hours care programs? We're not sure at all about that.
"Not only are our members concerned about the speed with which this is being introduced, namely that it should be starting next year, but also some of the members of the communities, with whom we are in contact, are concerned that they haven't had it really very clearly explained to them, nor have they had enough time to think about whether it's something they would like to support."
Education Minister Jennifer Rankine says she is yet to receive the final report.