Roller

The roller is an agricultural tool used for flattening land or breaking up large clumps of soil, especially after ploughing. Typically, rollers are pulled by tractors or, prior to mechanisation, a team of animals such as horses or oxen. Flatter land makes subsequent weed control and harvesting easier, and rolling can help to reduce moisture loss from cultivated soil. On grassland, rolling levels the land for mowing and compacts the soil surface. For many uses a heavy roller is used, and rollers may be weighted in different ways. Heavy rollers may consist of one or more cylinders made of thick steel, a thinner steel cylinder filled with concrete, or a cylinder filled with water. A water filled roller has the advantage that the water may be drained out for lighter use or for transport. In frost prone areas a water filled roller must be drained for winter storage to avoid breakage due to the expansion for water as it turns to ice.