Of mustard and manure
On prehistoric seasoning & fertilization
The fourth in a series of posts by Dr Mark McKerracher on the origins of agriculture.
Every now and again agricultural archaeology and related disciplines hit the headlines. This latest post was inspired by a couple of pieces of new research, which the BBC flagged a couple of years ago, and which indicate a hitherto unexpected sophisication of farming and diet in prehistory. And, better yet, the original research article (Saul et al. 2013)is open access so you can see it for yourself here. The results are from ‘The Baltic Foragers and Early Farmers Ceramic Research Project’, in which Mesolithic and Neolithic pottery from modern Denmark and northern Germany were examined for food residues. Now, I’d heard of lipid residue analysis before, but in this case the evidence comes from phytoliths preserved in charred residues on the pottery. Literally, phytolith translates as something like ‘plant-stone’: they are the remains of an insoluble silica that gets deposited amongst cells in the living plant, and survives even once the plant itself has been burned away. Usefully for us, they can often be identified to family, genus or even species level, allowing us some insight into plant use and ecology (see Cappers & Neef 2012 p.130 for a good brief summary). In this case, the phytoliths point to Alliaria petiolata (M. Bieb) Cavara & Grande – more commonly known as garlic mustard. The context suggests culinary use; the plant gives a strong taste but has negligible nutritional value; hence, those prehistoric chaps and chapesses were apparently spicing their food, simply for the delectable taste. Yum.
And why not, after all? Why shouldn’t hunter-gatherers and early farmers have been concerned to eat something tastier than hulled wheat, hazelnuts and crab apples? For me, though, this raises the question of gathering vs. cultivation – i.e. were they deliberately growing spices, in a kind of herb garden set-up? This might sound fanciful for the Neolithic but, again, if you can invent agriculture, why not herb gardens?
And talking of Neolithic inventiveness, here’s the second piece of news that interested me: “Neolithic farmers used manure on crops”. This one strikes rather closer to home, not just because it came shortly after Dung Awareness Day, but because the work was led by my colleagues, elders and betters at Oxford University. The School of Archaeology even issued its own press release. Neolithic plant remains from across Europe were subjected to stable isotope analysis, and the results indicate that certain crops were manured – a means of fertilisation whose usage wasn’t previously known as early as this.
The ‘certain crops’ bit is highly significant, since it implies that the Neolithic farmers were selecting those crops that they thought would benefit the most from manuring, leaving the hardier types to fend for themselves. The lead researcher Dr Amy Bogaard, quoting to the BBC, draws out the wider significance of these findings:
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 on to future generations…
This is cutting-edge stuff, and excitingly we can expect more good things to come, because Dr Bogaard is running an impressive ERC-funded four-year project investigating “The Agricultural Origins of Urban Civilization”, which now has its own website that is well worth keeping an eye on.
The paper has now been published – it’s one of those where the number of authors exceeds the number of pages, demonstrating the wealth of expertise behind these results: Bogaard et al. 2013.
So, the moral of the story – if any – is that you should never underestimate prehistoric farmers.
Bogaard, A., Fraser, R., Heaton, T.H.E. et al. (2013). ‘Crop manuring and intensive land management by Europe’s first farmers’, Proceedings of the Natural Academy of Sciences 110 (31), pp.12589-12594.
Cappers, R.T.J. & Neef, R. (2012). Handbook of Plant Palaeoecology, Groningen/Barkhuis.
Saul H, Madella M, Fischer A, Glykou A, Hartz S, et al. (2013). ‘Phytoliths in Pottery Reveal the Use of Spice in European Prehistoric Cuisine’.
Image credit: ‘Garlic Mustard (Alliaria petiolata)’, BiteYourBum.com. Creative Commons license.