The three-field system is a regime of crop rotation in which a field is planted with one set of crops one year, a different set in the second year, and left fallow in the third year. A set of crops is ''rotated'' from one field to another. The technique was first used in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

in the Eastern Zhou period, and was adopted in Europe in the medieval period. Three Field System

The three-field system let farmers plant more crops and therefore increase production. 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 Rye (''Secale cereale'') is a grass grown extensively as a grain, a cover crop and a forage crop. It is a member of the wheat tribe (Triticeae) and is closely related to both wheat (''Triticum'') and barley (genus ''Hordeum''). Rye grain is u ...

; the second field was planted with other crops such as

pea The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...

s, lentils, or

bean A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes th ...

s; and the third was left fallow (unplanted).

Cereal A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...

crops deplete the ground of nitrogen, but

legumes A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock fo ...

can fix nitrogen and so fertilize the soil. The fallow fields were soon overgrown with weeds and used for grazing farm animals. Their excrement fertilized that field's soil to regain its nutrients. Crop assignments were rotated every year, so each field segment would be planted for two out of every three years. Previously a

two-field system Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. It reduces reliance on one set of nutrients, pest and weed pressure, and the probability of developing resistant ...

had been in place, with half the land being left fallow. With more crops available to sell and agriculture dominating the economy at the time, the three-field system created a significant surplus and increased economic prosperity. The three-field system needed more plowing of land and its introduction coincided with the adoption of the moldboard plow. These parallel developments complemented each other and increased agricultural productivity. The legume crop needed summer rain to succeed, and so the three-field system was less successful around the Mediterranean. Oats for horse food could also be planted in the spring, which, combined with the adoption of horse collars and

horseshoe A horseshoe is a fabricated product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toen ...

s, led to replacement of oxen by horses for many farming tasks, with an associated increase in agricultural productivity and the nutrition available to the population. In his 1769 work ''Lehre vom Gyps als vorzueglich guten Dung zu allen Erd-Gewaechsen auf Aeckern und Wiesen, Hopfen- und Weinbergen'',Roeber, A. G. (1998). ''Palatines, Liberty, and Property: German Lutherans in Colonial German America''. p. 58. Johann Friedrich Mayer was one of the first Germans to advocate for new ways of expanding beyond the medieval three-field system.

References

Bibliography

* {{Authority control Agricultural soil science History of Europe Sustainable agriculture Medieval agriculture Early Modern economics