This paper integrates archaeological, environmental and isotopic data from Roman Iron Age

(1–400 AD) settlements in Lithuania to present an updated framework for understanding the

development of farming and agricultural landscapes during this period. The study dates the introduction

of new crop species, such as rye and oats, to around 100–200 cal AD. Notably, rye

quickly became one of the most economically important crops, coinciding with the adoption

of the infield-outfield cultivation system. This system combined intensively farmed fields in

open, well-irrigated areas near settlements with more distant swiddens used for extensive farming.

Archaeobotanical analysis, along with δ15N and δ13C isotopic measurements of charred crop

assemblages, reveals a high level of diversification in both species composition and cultivation

strategies. These findings suggest that Roman Iron Age farmers employed complex farming methods

aimed at increasing agricultural productivity and expansion while maintaining adaptability

and resilience in response to environmental challenges.