The very earliest plow was the simple…

The very earliest plow was the simple scratch-plow, or ard, which consists of a frame holding a vertical wooden stick that was dragged through the topsoil (still used in many parts of the world).

It breaks up a strip of land directly along the plowed path, which can then be planted.

Because this form of plow leaves a strip of undisturbed earth between the rows, fields are often cross-plowed at ninety degree angles, and this tends to lead to squarish fields.

In the archaeology of northern Europe, such squarish fields are referred to as "Celtic fields.’

Farmers in the lower Danube region begin using cattle as plow animals by about 4500, at which time central and eastern European cultures begin to practice rich burial patterns.