Archaeobotanical evidence reveals the nature of cereal agriculture at 8th- and 9th-century ad Sedgeford, East Anglia, UK.

UNLABELLED: Sedgeford's multi-feature malting complex, dated to the 8th to 9th century ad, is the earliest known of the early medieval era in England (the approximately contemporaneous, sizeable malting kiln at Higham Ferrers not being part of a larger complex). Three complementary approaches are here used to reveal cultivation practices for cereal grains (predominantly rye and free-threshing wheat) malted at Sedgeford. Specifically, these are used to determine evidence for the three elements of the medieval 'mouldboard plough package': namely, 'extensive' cultivation, the use of a mouldboard plough and crop rotation. In terms of cultivation intensity, functional weed ecology (FWE) reveals an extensive crop husbandry regime (i.e. maintaining low levels of fertility), whilst stable nitrogen isotope analyses indicate low levels of manuring. FWE also reveals high levels of disturbance, consistent with mouldboard plough use. Finally, all three approaches are used to assess evidence for crop rotation. First, correspondence analyses of the assemblage are used to explore seasonality in crop cultivation. Results of correspondence analyses, together with those from FWE and carbon and nitrogen stable isotope analyses all provide evidence for early crop rotation in fields supplying the malting complex. In sum, evidence suggests that all three elements of the medieval 'mouldboard plough package' were present at 8th and 9th century ad Sedgeford. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00334-026-01091-w.