Food & agriculture · c. 800 CE
Three-field rotation
Rotating winter grain, spring crops and fallow raised the share of land in use from half to two-thirds.
Carolingian estates in Frankia increasingly split land three ways instead of two. Spring legumes such as peas and beans replenished nitrogen, improved diets and fed horses, supporting Europe's medieval expansion.
What it built on 2
What it led to 1
Related measurements
The dashed line marks when it first worked.
Cereal yields in England/UK since 1275 Latest: Wheat: 7.28 t/ha (2024) Source: Our World in Data
World population over a million years Latest: 6.27k million people (2000) Source: DeLong 1998, table 'Total World Population' (Kremer series); Kremer 1993, Population Growth and Technological Change: One Million B.C. to 1990, QJE 108(3)
Cereal yield Latest: 4.21 t/ha (2024) Source: Our World in Data