Ploughing a field. Ploughing is the act of digging up and turning over the topsoil in a field, to expose the underlying soil and bring nutrients to the surface, as well as to aerate the soil. This improves the efficiency of sowing a new crop, allowing the plants to embed and grow more easily in the ploughed soil. The plough in use here (upper left) is being pulled by a tractor (not seen). An alternative plough type (not in use) is at right.