Neolithic farmers used manure on their crops - new study reveals
NewsFriday 19 July 2013
New research has discovered that Europe’s first farmers used livestock manure on their crops as far back as 8,000 years ago.
The neolithic samples, which were obtained from charred crop remains, contained the same type of nitrogen that is also abundant in manure.
These results now suggest that these farmers took a long-term approach when it came to cultivating their land, as opposed to leading a nomadic lifestyle.
New light could also be shed on what these early farmers ate.
Farming’s introduction was one of the most important cultural shifts in history, and it is this afe of agriculture that defines the Neolithic period, which is also known as the New Stone Age.
Until this recent study was revealed, it was believed that the use of manure to fertilise crops wasn’t developed until the Iron Age, which was the period before the Romans invaded Britain in AD43.
It was previously believed that neolithic farmers had maintained a nomadic lifestyle, which was perhaps a cross-over from hunter-gatherer days.
However, now researchers are suggesting that they invested in plots of land and cultivated it for future generations.
Using manure on crops is something of a long-term investment in arable land. As the dung breaks down slowly the crops benefit from the nutrients over a number of years.
Amy Bogaard, from the University of Oxford, led the team which found the stable isotope nitrogen-15 (N15), which is abundant in manure. They discovered this isotope in the charred cereal grains and pulses from 13 Neolithic sites across Europe.
"These results point to a different kind of farming where they were making fixed investments in land that they intended to hang onto and pass onto future generations," Dr Bogaard told BBC News.
This shift also had a radical social effect, as different families would have claimed plots of land and sought to hold onto those plots, she added.
"The idea that farmland could be cared for by the same family for generations seems quite an advanced notion, but rich fertile land would have been viewed as extremely valuable for the growing of crops.
"We believe that as land was viewed as a commodity to be inherited, social differences in early European farming communities started to emerge between the haves and the have-nots."
These findings may also alter the consensus on what Stone Age farmers ate. As manure is rich in N15, the crops fertilised with manure, and those who ate the crops, also had high N15 enrichment, explained Dr Bogaard.
It was previously thought that diets rich in meat were what caused human fossil remains from this time to have high values of N15. Juan Pedro Ferrio from the University de Lleida, Spain, said: "There are other possible environmental factors, such as high temperature and rain, which could increase N15."
But he added that manuring - whether accidentally or on purpose - was a likely explanation, and that it was clear Neolithic farmers were eating grain more enriched with N15 compared to the values of leaves of the same plant.
Picture: Scott Robinson