The Birth of Aus Agriculture in the South-eastern Highlands of India – an Exploratory Synthesis

Away from the Ganges valley, the south-eastern highlands of India is recognized as the region of origin of upland or 'aus' rice. In this narrative, we attempt to reconstruct its origin synthesizing inklings from genetics, prehistory, and anthropology, and to find out the putative paleo-ecological, environmental, and cultural context that provided the necessary impetus to it. Genetically, we uncover a highly diverse phenotypic base with unique alleles hinting at an independent origin of 'aus' perhaps from 'Oryza nivara'. Post-LGM paleo-niche portrays more widely distributed 'O. nivara' as opposed to 'O. rufipogon'; relatively abundant 'O. nivara' could have enabled its preferential exploitation. While a dearth of archaeological study does not illuminate much on this aspect; the agricultural attributes of the ethnic inhabitants of the area, e.g., dry rice cultivation with the hoe and the axe, reveal a striking similarity with 'aus' or upland rice cultivation. Furthermore, comparative analyses with other historical anecdotes suggest that upland rice seems to be born as an adaptive landscape management by pre-agriculturist society. It was developed through a broader plant-people-landscape interaction, where rice or its ancestors were grown for subsistence with other crops as a Neolithic proto-agricultural package; in this case along the hill slopes. Summarizing, the current study casts light on some of the understudied aspects of upland rice agriculture, but it also brings out many open questions inviting future examination