Don't ever practice short field landings involving a touch and go on a short gravel strip!!!!
Always do a full stop, back track, do your checks and do a short field takeoff.
That almost killed me when the Cessna Flap Switch decided it was not going to raise flaps during the touch and go. The mighty C150 does not climb out of ground effect with Forty degrees of flap, probably doesn't with Thirty either.
Needless to say, the problem could not be duplicated on the ground.