Detecting long-term valley fill evolution and rice paddy land use: Ageoarcheological investigation of the Baeksuk valley and the Bronze Age settlement, South Korea

- We reconstruct paleo-pedosequence based on a set of soil analyses.
- Valley fill evolution by natural processes and anthropogenic impact
- A buried horizon of assumed ancient cultivated field was examined.
- Characteristics of cumulic soil by long-term paddy rice agriculture
- Empirical dataset of altered soil by incipient and advanced rice agriculture

This study investigates paleoenvironmental changes over time and ancient land use related to agriculture at the Bronze Age settlement of Baeksuk, Cheonan, South Korea. Geoarcheological analytic methods including soil micromorphological, physical and multi-element analyses were employed to examine the alluvial valley fill between hills occupied by a large-scale Bronze Age settlement with abundant crop remains including rice, but which was scarcely inhabited in later periods. The location of the cultivation fields remains as yet undetermined despite a full excavation. This research reveals that there were four phases in the build-up of the valley fill from wetland to periodically dry wetland and, eventually, to the present day rice paddy, forming a cumulic A horizon. In particular, the lower buried horizon may have served as the earliest location for growing rice with surface disturbance noted by textural pedofeature formation, while the upper part of the soil profile exhibits features typical of paddysol with high iron and manganese accumulations. The analyses of the valley soil profile suggest plausible interactions between human agricultural activities and environment through rice paddy cultivation.