Balbridie, in Aberdeenshire, was home to some of Scotland's earliest farmers around 3,800 years ago. The site was excavated between 1977 and 1981, at which time, in addition to discovering a spectacular well-preserved wooden hall, a large quantity of Neolithic grain was also found.
Researchers at the University of Stavanger have now analyzed these cereal remains and found that the work of ancient Scottish farmers was a less stinky business than elsewhere, as they did not have to use manure to fertilize their fields, unlike what what was happening in the rest of the British Isles and continental Europe.
Experts have reached this conclusion after studying the proportions of carbon and nitrogen isotopes in plants, elements that are affected depending on growth conditions, as explained in an article published in the journal Antiquity.
"Stable isotope analysis revealed very low levels of nitrogen showing that the crops were not grown in composted soils," explains Dr Rosie Bishop, lead author of the study. "The large size and amount of recovered kernels suggest that during this early phase of cultivation, the soils were sufficiently productive without the need for fertilizer," she adds.
In contrast, previous examinations of early farms in England, as well as in continental Europe, have almost always found evidence that farmers farmed in composted fields. This would show, according to Norwegian archaeologists, that during the Neolithic period some parts of Scotland were very suitable for agriculture.
Not all of these early farmers, however, were able to avoid the manure tax. The University of Stavanger team also looked at the contemporary site of Dubton Farm in Angus, a council bordering Aberdeenshire, and found that manure was used there.
In fact, composting eventually became the norm in Scotland. Dr Bishop and her colleagues also studied later Neolithic farms in Orkney at the Skara Brae and Braes of Ha'Breck sites - dating to between 3300 and 2400 BC - and found that by that time they were already using manure.
The researchers further discovered that Orkney farmers were using permanent plots in a larger landscape than expected. Previous studies had suggested that Neolithic farmers in Britain farmed small transient fields, often moving their plots to new areas of land, or that they were a semi-nomadic population, not farming every year. But the latest results show that this was not the case in Scotland.
Rosie Bishop added that at one of the Orkney sites they were also able to “demonstrate that these early farmers grew their produce on a variety of different soils, which suggests that they either worked quite extensively around the territory or that different farms were storing their crops in a communal store.
Such extensive use of the field and possible pooling of resources would also have helped guard against crop failure, an ever-present threat in Orkney's harsh environment. Ancient farmers were able to develop various sustainable strategies for different conditions.
"The variability of identified farming strategies highlights the adaptability of early farming practices," says Dr Bishop. This raises the possibility, she adds, that additional research in other regions may also reveal similar diversity. "Perhaps there were many early farmers who were able to avoid the use of manure," she concludes.
