July 15, 2013

Early European farmers used manure

PNAS doi: 10.1073/pnas.1305918110

Crop manuring and intensive land management by Europe’s first farmers

Amy Bogaard et al.

The spread of farming from western Asia to Europe had profound long-term social and ecological impacts, but identification of the specific nature of Neolithic land management practices and the dietary contribution of early crops has been problematic. Here, we present previously undescribed stable isotope determinations of charred cereals and pulses from 13 Neolithic sites across Europe (dating ca. 5900–2400 cal B.C.), which show that early farmers used livestock manure and water management to enhance crop yields. Intensive manuring inextricably linked plant cultivation and animal herding and contributed to the remarkable resilience of these combined practices across diverse climatic zones. Critically, our findings suggest that commonly applied paleodietary interpretations of human and herbivore δ15N values have systematically underestimated the contribution of crop-derived protein to early farmer diets.



andrew said...

Presumably, this means that the hypothesis that early farmers had much lower caloric intake than late hunter-gatherers and pastoralists may have been skewed. N15 levels may have caused people who were actually manure fed farmers to be misclassified as pastoralists or hunter-gathers based on their diets.

Such a reclassification would make the Neolithic revolution, which seemingly entailed a transition to a less prosperous life style make more sense.

Black Taylor said...

Are you sure you don't have this backwards? I read the abstract and the related news reports as indicating early farmers had a LESS diverse diet than the isotopic signatures were originally thought to represent. That is, before the identification of the use of manure the observed nitrogen values were thought to stem from rich sources of protein like meat and milk, and now they know this was an illusion, and the people were in fact eating proportionally even more (relatively nutrient poor) cereals.