My favorite tip for land turtles, is when they come out of winter and won't eat. To get them to eat, you set a pan in the sink, and pour V-8 in it.
Plop the turtle right in it (make sure that it's not too deep for the turtle's size.), and watch until he drinks. They will drink.
Because it's not water, but blended vegetables, it gets their digestive system going, and perhaps even whets their appetite for food. Repeat daily until they will take regular food. :-)
Love All Life, Thank You For Posting! :)