Field hockey is played on grass, so moving the ball from one side of the field is much harder than moving an ice hockey puck across an ice rink. The reason for this is due to a force called friction.
Friction: the resistance to motion of two moving objects or surfaces that touch.
There is more friction on a coarse, grassy surface than on the slick icy surface of an icehockey rink due to the amount of resistance. Consequently, a field hockey player is required to hit the ball with a great amount of force to send it across the field, compared to ice hockey players who can easily send a puck gliding across the rink.