Question

wh do we plough the field

Answer 1

Plowing fields can also turn organic matter into soil to increase decomposition and add nutrients from the organic matter to the soil. Many farmers spread manure from cattle and swine onto their fields. This manure is rich in nitrogen which is essential for plant growth
hope it helps ....

Answer 2

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.

Ploughs were initially human-powered, but the process became considerably more efficient once animals were pressed into service. The first animal-powered ploughs were undoubtedly pulled by oxen and later in many areas by horses (generally draft houses) and miles, although various animals have been used for this purpose. In industrialised countries, the first mechanical means of pulling a plough were steam-powered (ploughing engine or steam tractor), but these were gradually superseded by internal-combustion-powered tractor.

Modern competitions take place for ploughing enthusiasts like the National Ploughing Championship in Ireland. Use of the plough has decreased in some areas, often those significantly threatened by soil damage and erosion, in favour of shallower ploughing and other less-invasive conservation village techniques.