The three-field system is a regime of

crop rotation 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 ...

in which a field is planted with one set of crops one year, a different set in the second year, and left

fallow Fallow is a farming technique in which arable land is left without sowing for one or more vegetative cycles. The goal of fallowing is to allow the land to recover and store Organic compound, organic matter while retaining moisture and disrupting ...

in the third year. A set of crops is ''rotated'' from one field to another. The technique was first used in China in the

Eastern Zhou The Eastern Zhou (; zh, c=, p=Dōngzhōu, w=Tung1-chou1, t= ; 771–256 BC) was a royal dynasty of China and the second half of the Zhou dynasty. It was divided into two periods: the Spring and Autumn and the Warring States. History In 770 ...

period, and was adopted in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

in the

medieval period In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire an ...

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 Winter is the coldest season of the year in Polar regions of Earth, polar and temperate climates. It occurs after autumn and before spring (season), spring. The tilt of Axial tilt#Earth, Earth's axis causes seasons; winter occurs when a Hemi ...

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeolog ...

or rye; the second field was planted with other crops such as peas,

lentil The lentil (''Lens culinaris'' or ''Lens esculenta'') is an edible legume. It is an annual plant known for its lens-shaped seeds. It is about tall, and the seeds grow in pods, usually with two seeds in each. As a food crop, the largest pro ...

s, 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 t ...

s; and the third was left

(unplanted).

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

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 A plough or plow ( US; both ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses, but in modern farms are drawn by tractors. A plough may have a wooden, iron or ...

. 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 The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human co ...

for horse food could also be planted in the spring, which, combined with the adoption of

horse collar A horse collar is a part of a horse harness that is used to distribute the load around a horse's neck and shoulders when pulling a wagon or plough. The collar often supports and pads a pair of curved metal or wooden pieces, called hames, to wh ...

s 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 ...

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