Total nonsense. I mean really total nonsense.
"They", meaning NFL owners, will only even think about attempting to maintain....you do not have to "grow grass".....and in fact NO grass fields are the result of "growing grass"....they ALL get sod that is grown somewhere else and most grass field have their sod replaced at least once a year if not several times (In FACT, the grass field for the Super Bowl was NEW SOD that was installed weeks before the game....which is exactly what happened in Arizona for last year's SB....the issue with the bad field last year was it was not cared for properly after it was installed)....
....grass fields inside a dome WHEN THEY ARE FORCED TO DO SO!!!!!
When they are FORCED TO DO SO, they will find a way by many of the solutions that I have outlined and are eminently feasible TODAY. There is NO NEED to do so until the NFL (with pressure from the NFLPA) REQUIRES ALL NFL games to be played on grass fields.