The fertlization of fields in Gaul (500 BCE-500 CE), approached by the biogeochemistry of cereal remains.
Résumé
The dynamic demography and economy of Gallic societies in the Second Iron Age and
the Roman period is based on the efficiency of the agricultural system. One of the
parameters that increased the potential of crops, and which was studied in a recently
defended thesis, was the management of soil fertility. Archaeologists have often dealt
with this issue from disparate sources (Latin agronomists, stall and latrine studies, offsite
furniture, weed ecology), but which often only attest to the capacity to produce
manure. Recent methodological developments in biogeochemistry applied to
archaeobotany have made it possible to renew our knowledge of a territory that has
been little studied.
These isotope analyses (δ15N), applied to cereal remains from 68 archaeological sites,
have shown that the use of manure was widespread throughout the northern half of
France throughout the Second Iron Age and the Roman period. In some areas, it was
shown that farmers used less fertiliser, probably due to geological constraints limiting
agriculture. A second contribution of this study was to highlight the specific treatment of
certain cereal species, in particular bare wheat, which benefited from fertilisation in a
greater number of cases.