Bere Barley, a "Neolithic" Grain

 

Series Title:- Orkney Riddle

22/27

Blog Title:- Bere Barley, a "Neolithic" Grain

Bere, pronounced “bear” is a six-row barley which when milled becomes Bere Meal. It is still grown and used today in Orkney to make a traditional flatbread called a Bannock. It is probably Britain’s oldest cereal in continuous commercial cultivation.

The domestication of the Bere Barley grain is likely to have begun soon after the retreat of the last ice age, when plants, animals, and humans first colonised the vast plains of the North European continental shelf, an area east, west, and north of Orkney.

The grain probably initially adapted itself to the local climatic conditions, and the process of domestication was continued when humans would collect the heads of the primitive wild barley, selecting for size to make the nutritional content of the cereal worth the effort of extracting it from the seed head.

The theory implies that the continued viability of seeds or grains as they were carried into higher latitudes required them to be adapted to environmental conditions starkly different to those under which they were first domesticated.

The plant that is created under these circumstances is known as a “landrace”, which is defined as a domesticated, locally adapted, traditional variety of a species of animal or plant that has developed over time, through adaptation to its environment and isolation from other populations of the species.

Bere Barley, Hordeum Vulgare L. , is the ancient grains that is found on the Outer Hebrides and Orkney.

“Barley (Hordeum vulgare ssp. Vulgare) was one of the first and earliest crops domesticated by humans. Currently, archaeological and genetic evidence indicates barley is a mosaic crop, developed from several populations in at least five regions: Mesopotamia, the northern and southern Levant, the Syrian desert and, 900–1,800 miles (1,500–3,000 kilometers) to the east, in the vast Tibetan Plateau.

The wild progenitor of all of the barleys is thought to be Hordeum spontaneum (L.), a winter-germinating species which is native to a very wide region of Eurasia, from the Tigris and Euphrates river system in Iraq to the western reaches of the Yangtze River in China. Based on evidence from Upper Paleolithic sites such as Ohalo II in Israel, wild barley was harvested for at least 10,000 years before it was domesticated.

Barley as a whole is well-adapted to marginal and stress-prone environments, and a more reliable plant than wheat or rice in regions which are colder or higher in altitude.”(Hirst)

Rather than an imported grain, modified by human agency, Bere Barley was probably self-adapted.

Different environmental conditions exist in Orkney, compared to those normally found over much of Eurasia.

I hesitate to call anywhere unique, but there are things that make the northern Isles different, and create a different climate, and radically different weather and seasons.

Chief among the factors that condition the climate here is its location on the planet. The gulf Stream is a constant flow of equatorial water that pushes up the Atlantic ocean towards the Arctic ocean bringing warmth to the British Isles. It also brings violent winds to Orkney.

"Searching for the Origins of Bere Barley: a GeometricMorphometric Approach to Cereal LandraceRecognition in Archaeology" by M. Wallace et al.

"The spread of agriculture beyond the regions of cereal domestication in the FertileCrescent of southwest Asia was a lengthy process crossing biogeographic boundaries.Following initial expansion through Anatolia and to Cyprus, domesticated crops reachedsoutheast Europe c.8500 yrs BP, and from there were dispersed along two main routes: a southern route along the Mediterranean, reaching the Iberian peninsula c.7500 yrs BP, anda northwards route passing through central Europe by c.7500 yrs BP and eventuallyreaching northern Scotland c.6000 yrs BP (Bocquet-Appel et al. 2009; Fort 2015). Thecontinued viability of agriculture as it spread across Europe, especially along the latternorthwards trajectory, required crops to adapt to environmental conditions starkly differentto those under which they were first domesticated (Bogucki 2000; Bonsall et al. 2002;Halstead 1989). This is exemplified by adaptations in responsiveness to daylength with thenorthwards spread of agriculture (Jones et al. 2012) and observed adaptation to specificabiotic stresses (George et al. 2014; Schmidt et al. in prep.). Adaptation in crop specieswould have come about through periods of stable cultivation on the edges of newenvironments, leading to the emergence of new, locally adapted landraces."

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"Scotland’s first farmers: new insights into early farming practices in North-west Europe"

Rosie R. Bishop, Darren R. Gröcke2 , Ian Ralston , David Clarke Daniel H.J. Lee5 , Alexandra Shepherd6, Antonia S. Thomas ,Peter A. Rowley-Conwy & Mike J. Church

Skara Brae and the Braes of Ha’Breck

The UNESCO World Heritage Site of Skara Brae on Orkney’s west Mainland, a surviving complex of stone-built structures, preserves an outstanding record of Neolithic society and economy (Clarke & Sharples 1990; Shepherd 2016). The two main phases of this settlement (Phase 1: c. 2910–2880 to 2860–2840 cal BC, Phase 2: c. 2800–2700 cal BC to 2550–2420 cal BC; Shepherd 2016) each encompassed six to eight buildings, surrounded by accumulated construction and occupation deposits, including two specific midden agglomerations (Shepherd 2016). In 1972–1973, a small cereal assemblage, predominantly of naked barley, together with some emmer wheat and hulled barley (Hordeum sp. hulled), was recovered from an early phase of occupation (Phase 0, c. 3360–3160 cal BC) underlying this main settlement (Figure 3) (Shepherd 2016; Rowley-Conwy & Bishop 2021). In addition, a large assemblage of wild seeds was recovered from the two main phases of the settlement, which post-date the Phase 0 cereal assemblage (Figures 6 & 7).

The site at the Braes of Ha’Breck is located on Wyre, a small island (approximately 1.5 × 2.5km) north of Mainland, Orkney (Thomas & Lee 2012; Farrell et al. 2014). The settlement comprises two timber-built and three stone-built structures, with evidence for several phases of construction, an external working floor, and occupation deposits, including midden deposits (Thomas & Lee 2012). Bayesian modelling of the radiocarbon dates indicates that occupation began c. 3585–3375 cal BC and ended c. 3270–2980 cal BC (Bayliss et al. 2017). Within one of the stone-built structures was a layer of carbonised grain (dated to 3090–2920 cal BC; Garrow et al. 2017)—perhaps a store accidentally burnt in a house fire (Figure 9) (Thomas & Lee 2012; Bishop 2013). This assemblage, which comprises hundreds of thousands of grains, is one of the largest Neolithic cereal assemblages in North-west Europe (Bishop 2015). Elsewhere on site, charred cereals, almost exclusively of naked barley, together with scarce emmer wheat and hulled barley, were recovered in moderate concentrations from a range of negative features, occupation deposits and hearths (Figure 3) (Bishop 2013). Both sites produced evidence for cattle and sheep/goat husbandry, with pig also recovered in smaller quantities from Skara Brae (Clarke & Sharples 1990: 75; Thomas & Lee unpublished data).

The δ15N isotope values for the crops at Skara Brae range from 0.9 to 5.3‰ (mean: 3.2‰ ±1.1) (Figures 4 & 5) and are consistent with low-to-moderate levels of manuring (cf. Bogaard et al. 2013). At the Braes of Ha’Breck, there is considerable variation in the δ15N isotope values for the crops (mean: 3.9‰±2.3; range: 0.2‰ to 13.7‰)—greater than at any other site considered here—indicating low, moderate and high levels of manuring. The medium and high δ15N isotope values are unlikely to result from waterlogging. Though no wild seeds were recovered in association with the cereals at Skara Brae (Rowley-Conwy & Bishop 2021), the Δ13C isotope values for the crops from the site indicate relatively dry growing conditions (Figure 4), consistent with growth in the sandy soils of the area (see below). Furthermore, at the Braes of Ha’Breck, seed indicators of wet growing conditions are relatively rare (see Figures 6 & 7; Table S1).

Most of the data from both Orcadian sites fall within the ‘moderate manuring’ range (Figure 4), consistent with the dataset for early cereal agriculture across North-west Europe (Figure 8). This suggests that these crops were mainly cultivated in permanently maintained plots fertilised with nitrogen-enhanced organic material. The consumption of grain from these manured crops could partly explain the relatively high δ15N values observed in Neolithic human remains from Orkney (Schulting et al. 2010).

The very high δ15N isotope values from the Braes of Ha’Breck (8.8‰ and 13.7‰; seeTable S5) are most likely explained by the addition of nitrogen-enhanced organic matter to the soils. The alternative of cultivation directly on a midden, as has been suggested for Neolithic Orkney at Tofts Ness (Guttmann et al. 2006), is both logistically impractical due to unstable surfaces on middens and strategically undesirable because of the likely adverse effects of exploiting such high nitrogen conditions, which would have risked lodging and loss of the crop (cf. Briggs 1978: 302–308). The grains were well preserved, and the samples were reanalysed to ensure accuracy, so charring at high temperatures or analytical error is unlikely, although contamination cannot be ruled out (see OSM2). Similarly high δ15N isotope values for Neolithic naked barley were obtained from Frydenlund in Denmark (13.8‰) (Gron et al. 2021) and Oldenburg LA77 in Germany (13.9‰) (Filipovićet al. 2019), which the latter authors suggest might reflect the use of seaweed fertiliser or manure from seaweed-eating herbivores. The impact of fertilising crops with manure from herbivores with marine diets has yet to be assessed, and crop trials of hulled barley in Orkney using seaweed fertiliser have not produced δ15N crop isotope results above 5.6‰ (Blanz et al. 2019).

The latter result, however, might be explained by the seaweed and soil in this study having similar δ15N values, with recent experiments by Gröcke and colleagues (2021) demonstrating a significant increase in δ15N (up to 15‰) for beans grown in soils fertilised with seaweed and marine fish rich in nitrogen.

The Δ13C values at Skara Brae (14.6–17.9‰; mean: 16.2±0.9) are notably lower than at the Braes of Ha’Breck (16.1–19.8‰; mean: 17.8±0.8) and the other sites considered here (Figures 4 & 5). This probably reflects the relatively low water-retention capacity of the calcareous windblown sands at Skara Brae (Simpson et al. 2006; Scotland’s Soils n.d.) and/or the higher soil salinity resulting from salt spray—both factors that lower Δ13C values (see OSM1). In contrast, Wyre lacks the windblown sand deposits of west Mainland, Orkney, and today the Braes of Ha’Breck is located within an area of non-calcareous gleys, which are a less well-drained soil type (Scotland’s Soils n.d.). Other factors, such as increased openness of the landscape (Heaton 1999), are an unlikely cause of the lower Δ13C values at SkaraBrae, since pollen evidence suggests that both sites were located in relatively open conditions (Fyfe et al. 2013). Drier soils, and hence lower Δ13C values, have also been linked to more steeply sloping topography in semi-arid regions, where water-stress was potentially an issue (Bogaard et al. 2016). Here, however, altitude/slope is unlikely to have been a significant factor, given Scotland’s relatively wet climate (see also Gröcke 1998: 3). Nevertheless, lower rainfall at Skara Brae as a result of changing climate remains a possibility, as the date ranges for the two crop assemblages do not quite overlap. The relatively higher Δ13C values for Balbridie and Dubton Farm—both located inland and well away from saline environments— might reflect greater levels of shading by vegetation, since woodland was more extensive on mainland Scotland than Orkney (Fyfe et al. 2013; Farrell et al. 2014).

The grain from the Orkney sites tends to be smaller than that from the mainland sites (Figure 5). Significantly, there is no correlation between grain size and δ15N or Δ13C isotope values (Figure S1), so these size differences do not reflect manuring rates or the availability of water (Figure 5). Recent studies support this, suggesting that barley grain morphology and size are influenced more by landrace type than growing conditions (e.g. Wallace et al. 2019). The size differences could therefore reflect adaptations to the local conditions (e.g. rainfall, exposure, soil type), perhaps representing the development of separate landraces for Orkney and mainland Scotland. As the Orcadian assemblages are several centuries later in date than Balbridie and Dubton Phase 1, it is also possible that there was size reduction over time.

The range in δ15N values for the available data suggests that the Skara Brae cereals were all grown under the same conditions (individual crop ranges all <5‰), whereas the Braes of Ha’Breck crops were not (individual crop ranges >5‰; Table S3). Caution should be exercised here, however, as this apparent difference may be due to the comparatively low number of grains recovered and the relatively low isotope sample size from Skara Brae. Nonetheless, the range in crop δ13C values for both sites is greater than might be expected if all the grain had been grown together (individual crop ranges all >1.5‰; Table S3). The variable carbon stable isotope values from Skara Brae probably reflect the mixing of different harvests within the deposits. It is likely that animal manure was intentionally spread on fields by people rather than directly by animals grazing on fallow cereal plots; Neolithic domestic herbivore δ15N values for Orkney are typically between 6 and 7‰ (and for Skara Brae the mean sheep δ15N value is 6.5‰), which are comparable to those obtained for wild herbivores in the region (δ15N typically approximately 6‰; Jones & Mulville 2016: 672). This suggests that cattle/sheep consumed little cereal chaff from manured crops.

Notably, the nitrogen and carbon stable isotope values for crops from the conflagration deposit at the Braes of Ha’Breck are just as variable as the values from the other contexts (Table S4), suggesting that the deposit contains multiple stored harvests, or grain grown in different microenvironments. The variable manuring of different harvests, however, does not fully account for the variation in δ15N values. Experiments have shown that after manuring ceases, δ15N values for crops grown on previously manured soils can take many decades (approximately 70 years) to return to unmanured levels (Fraser et al. 2011: 2796). The wide range of values recorded here therefore suggests that crops were grown in a range of locations in the surrounding landscape. This fits with the initial analysis of the potential arable weeds, which suggests cultivation on soils with variable levels of fertility (Bishop 2013). It isimportant to consider the small size of the island, which may have provided relatively restricted locations for optimal cultivation and limited options for wild plant collection. It is possible that crops were therefore grown extensively across the island to buffer against crop failure. Similarly, hazelnut shells are exceptionally rare in the assemblage, suggesting that the gathering of wild plants was not integral to the economy of this site (Bishop 2013). Alternatively, the conflagration deposit may represent a communal store for different households, perhaps including communities on neighbouring islands that had access to different amounts of animal manure and/or land with different levels of fertility. Although no other Neolithic settlements have been discovered on Wyre, the neighbouring island of Rousay features the Skara Brae-style settlement of Rinyo, in addition to a dense concentration of Early Neolithic chambered cairns (Davidson & Henshall 1989), suggesting a relatively wellpopulated landscape.

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All views and opinions expressed are my own, but it remains a work-in-progress for which positive criticism and comment is welcomed.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

Jiffynorm@yahoo.co.uk