Assertion: soil | /r/HasProperty | cropped with maize
Facets:
value: for at least 12 years
type: TEMPORAL
Source sentences:
text: The soils had been cropped with maize for at least 12 years which provided a continuous input of C with a C isotope signature (δ13C) −13.1, distinct from the δ13C of soil organic carbon (−27.4 ‰) and charcoal (−25.7 ‰) collected in the surrounding area.