A plough (UK) or plow is a tool or farm implement used in farming for initial cultivation of soil in preparation for sowing seed or planting to loosen or turn the soil.
Ploughs were traditionally drawn by working animals such as oxen and horses, but in modern times are mostly drawn by tractors. A plough may be made of wood, iron, or steel frame with an attached blade or stick used to cut the soil and loosen it. It has been a basic instrument for most of recorded history, although despite archeological evidence for its use written references to the plough do not appear in the English language before c. 1100, after which point it is referenced frequently.
The plough represents one of the major agricultural inventions in human history. The earliest ploughs were wheelless, and the Romans used a wheelless plough called the aratrum, but Celtic peoples began using wheeled ploughs during the Roman era.
The primary purpose of ploughing is to turn over the upper layer of the soil, bringing fresh nutrients to the surface,
while burying weeds and the remains of previous crops and allowing them to break down.
As the plough is drawn through the soil it creates long trenches of fertile soil called furrows.
In modern use, a ploughed field is typically left to dry out, and is then harrowed before planting.
Ploughing and cultivating a soil homogenises and modifies the upper 12 to 25 centimetres (5 to 10 in) of the soil to form a plough layer. In many soils, the majority of fine plant feeder roots can be found in the topsoil or plough layer.
