At a previous job we only had turf fields, I know rough, so we created PVC poles that had 4 step intervals taped on them. Then we'd have a "Tape Crew" put down 4 step intervals on every yardline using Blue Painters tape. We just had to be very prudent removing them after every practice. Yes it's a lot of tape in a season, but it stays in place and can't get kicked around like poker chips.