Researchers have claimed that a Swedish Stone Age community may have used fertilisers.
University of Gothenburg researchers have spent many years studying the remains of a Stone Age community in Karleby outside the town of Falkoping, Sweden.
The two researchers and archaeologists Tony Axelsson and Karl-Goran Sjogren using remains of grains and other plants and some highly advanced analysis techniques, have been able to identify parts of the diet of their Stone Age ancestors.
"Our first task was to find so-called macrofossils, such as old weed seeds or pieces of grain," Axelsson said.
The results of the first grain analyses have now been presented, and point to elevated levels of the isotope N15 (nitrogen 15).
The elevated levels may indicate that the fertilisers were used in the area of Karleby already 5,000 years ago.
'We will continue our analyses both in the field and in the lab, and are hoping to find more macrofossils," Axelsson said.
"Hopefully we'll find some weed seeds, as they may help confirm that fertilisers were indeed used since the type of weeds found in a field can signal whether fertilisers or some other method was used," he added.