TY - JOUR
T1 - Seaweed fertilisation impacts the chemical and isotopic composition of barley
T2 - Implications for analyses of archaeological skeletal remains
AU - Blanz, Magdalena
AU - Ascough, Philippa
AU - Mainland, Ingrid
AU - Martin, Peter
AU - Taggart, Mark A.
AU - Dieterich, Burkart
AU - Wishart, John
AU - Sayle, Kerry L.
AU - Raab, Andrea
AU - Feldmann, Jörg
N1 - This research was partially funded by the European Social Fund and Scottish Funding Council as part of Developing Scotland's Workforce in the Scotland 2014–2020 European Structural and Investment Fund Programme. The contribution of staff from the University of the Highlands and Islands' Agronomy Institute and the James Hutton Institute to the field trial was supported by Rural and Environment Science and Analytical Services (RESAS) funding from the Scottish Government. GPS geolocation was performed by archaeologists of the Orkney Research Centre for Archaeology (ORCA). Stable isotope ratio measurements were performed at the Scottish Universities Environmental Research Centre (SUERC), East Kilbride, and elemental composition analysis was performed at the Trace Element Speciation Laboratory, Aberdeen (TESLA). MB would like to thank IM's family for their help collecting and storing the decomposing seaweed.
PY - 2019/4
Y1 - 2019/4
N2 -
Fertilisation with animal manure has been shown to affect crop chemical and isotopic composition, indicating that if manuring effects are not taken into account, there is a risk of overestimating consumer trophic levels in palaeodietary studies. The effect of fertilisation with seaweed, a common fertiliser in the past in coastal areas, has been the subject of several hypotheses, but until now has not been studied in this particular context. In this study the impact of fertilising bere, an ancient type of Scottish barley (Hordeum vulgare L.), with 25 t/ha and 50 t/ha seaweed, in comparison to a modern commercial mineral fertiliser and to no fertilisation, was investigated in a field trial on the Orkney Islands, Scotland. Stable isotope ratios (δ
13
C and δ
15
N) and elemental concentrations (B, Mg, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Mo, Cd and Pb) of grain, husk and straw samples were determined. Significant differences were found between treatment groups, including increases in δ
15
N values of 0.6 ± 0.5‰ (average ± 1σ for five replicate plots) in grain, and 1.1 ± 0.4‰ in straw due to seaweed fertilisation. Elevated concentrations of Sr in grain and husk samples (factors of 1.2–1.4) indicate the geographic tracer
87
Sr/
86
Sr may also be affected. Fertilisation with seaweed thus needs to be considered for archaeological interpretations of chemical and isotopic compositions of crop and skeletal material for accurate palaeodietary and provenance reconstructions, particularly in coastal areas. Further implications of these results for studies concerning the effects of sea spray, radiocarbon-dating, and for dietary reconstructions using trace elements are also identified.
AB -
Fertilisation with animal manure has been shown to affect crop chemical and isotopic composition, indicating that if manuring effects are not taken into account, there is a risk of overestimating consumer trophic levels in palaeodietary studies. The effect of fertilisation with seaweed, a common fertiliser in the past in coastal areas, has been the subject of several hypotheses, but until now has not been studied in this particular context. In this study the impact of fertilising bere, an ancient type of Scottish barley (Hordeum vulgare L.), with 25 t/ha and 50 t/ha seaweed, in comparison to a modern commercial mineral fertiliser and to no fertilisation, was investigated in a field trial on the Orkney Islands, Scotland. Stable isotope ratios (δ
13
C and δ
15
N) and elemental concentrations (B, Mg, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Mo, Cd and Pb) of grain, husk and straw samples were determined. Significant differences were found between treatment groups, including increases in δ
15
N values of 0.6 ± 0.5‰ (average ± 1σ for five replicate plots) in grain, and 1.1 ± 0.4‰ in straw due to seaweed fertilisation. Elevated concentrations of Sr in grain and husk samples (factors of 1.2–1.4) indicate the geographic tracer
87
Sr/
86
Sr may also be affected. Fertilisation with seaweed thus needs to be considered for archaeological interpretations of chemical and isotopic compositions of crop and skeletal material for accurate palaeodietary and provenance reconstructions, particularly in coastal areas. Further implications of these results for studies concerning the effects of sea spray, radiocarbon-dating, and for dietary reconstructions using trace elements are also identified.
KW - Archaeological chemistry
KW - Coastal archaeology
KW - Crop husbandry
KW - Kelp fertiliser
KW - Land management
KW - Manuring
KW - Past/prehistoric agriculture
KW - PLANT
KW - N-15
KW - TROPHIC LEVEL
KW - MESOLITHIC-NEOLITHIC CHANGE
KW - ACID DELTA-N-15 VALUES
KW - NATURAL-ABUNDANCE
KW - CEREAL GRAIN
KW - SEA SPRAY
KW - STABLE-ISOTOPE
KW - NITROGEN ISOTOPES
UR - http://www.scopus.com/inward/record.url?scp=85061642820&partnerID=8YFLogxK
U2 - 10.1016/j.jas.2019.02.003
DO - 10.1016/j.jas.2019.02.003
M3 - Article
AN - SCOPUS:85061642820
VL - 104
SP - 34
EP - 44
JO - Journal of Archaeological Science
JF - Journal of Archaeological Science
SN - 0305-4403
ER -
