Three-field system

The three-field system is a regime of crop rotation in use in medieval and early-modern Europe from around the time of Charlemagne. Under this system, the arable land of an estate or village was divided into three large fields: one was planted in the autumn with winter wheat or rye; the second field was planted with other crops such as peas, lentils, or beans; and the third was left fallow, in order to allow the soil of that field to regain its nutrients. With each rotation, the field would be used differently, so that a field would be planted for two out of the three years used, whilst one year it 'rested'. This allowed farmers to plant more crops and therefore to increase production. With more crops available to sell, this also helped the economy in general to thrive. The introduction of the three-field system and the adoption of the moldboard plow were parallel developments which worked hand in hand to increase the productivity of the land.