Assertion: buckwheat | /r/HasProperty | common crop
Facets:
value: worldwide
type: LOCATION
value: in the 18th and 19th centuries
type: TEMPORAL
value: in the northeastern united states
type: LOCATION
Source sentences:
text: In the northeastern United States, buckwheat was a common crop in the 18th and 19th centuries.
text: It was a common crop worldwide until nitrogen fertilizer was introduced in the 20th century, which increased the production of corn and wheat.