The side roll (sometimes called a wheel roll) system, as shown, consists of a lateral, usually a quarter mile long, mounted on wheels with the pipe acting as an axle. When the desired amount of water has been applied to this set area, a gasoline engine at the center is used to move the side roll to the next set. This type of system is not recommended for slopes greater than 5 % and should be used mainly on flat ground. Side roll systems also are adapted only to low growing crops, have medium labor requirements, moderate initial investment, medium operating pressure and generally rectangular field requirements. (Scherer 2010)