A Look into the Past: Tracing Ancient Sustainable Manuring Practices by Thorough P Speciation of Northern European

Abstract

Regionally restricted, hums-rich topsoils in Southwest Norway and the Baltic Sea region of Germany and Denmark were formed by inputs of various amendments (combustion residues and marine biomass) and, therefore, were classified as Anthrosols. For a deeper insight into the ancient management practices, we investigated the elemental and P-composition in the upper and underlying horizons from 12 soil profiles in the Jæren region, at the islands of Karmøy and Feøy (Norway), at the island of Fehmarn and the peninsula of Wagrien (Germany), and at the islands of Poel (Germany) and Sjaelland (Denmark). We used aqua regia digestion and the complementary methods of sequential P fractionation, phosphorus K-edge X-ray absorption near edge structure (P-XANES) spectroscopy, and 31P nuclear magnetic resonance (31P-NMR) spectroscopy. Results were compared with the composition of differently amended and/or un-amended soils from other studies. In addition, archaeological literature was used to confirm possible inputs of specific P-containing amendments in ancient agriculture. The P composition from SF of the Anthrosols in Norway (44% NaOH-Pi >1 8% NaOH-Po > 14% NaHCO3-Pi, 12% H2SO4-P > 7% NaHCO3-Po > 3% residual-P = 3% resin-P) and complementary archaeological literature provided strong indication for the use of peat, sheep manure, compost, and human excreta. The Anthrosols in the Jæren region have been formed from peat, which had been used as alternative bedding material and had been mixed with sheep and/or cattle manure. The P-composition in the Anthrosols at the island of Fehmarn and at the peninsula of Wagrien (42% H2SO4-P > 25% residual-P > 10% NaOH-Po, 8% NaOH-Pi: > 6% NaHCO3-Pi and NaHCO3-Po, 4% resin-P) resulted from the application of domestic cattle manure. This was strongly supported by archaeological findings of cattle bones in this region, as well as high proportions of Ca-P, as confirmed by P-XANES. The predominance of Po in the Anthrosols at the island of Poel and Sjaelland (31% NaOH-Po > 23% NaHCO3-Po, 21% H2SO4-P > 11% NaOH-Pi > 8% NaHCO3-Pi > 4% residual-P, 3% resin-P, in agreement with results from 31P-NMR) indicated low ancient inputs of various excrement or manure. This was supported by low livestock history at the island of Poel. In conclusion, these agricultural techniques can be considered as sustainable P recycling and soil amendment since they improved soil fertility for many generations.

Contrasting Effects of Long-Term Nitrogen Deposition on Plant Phosphorus in a Northern Boreal Forest

“…Most of the P present in spruce needles are presumably organically bound as phosphate monoesters anddiesters (Koukola et al, 2006) and would thus contribute to an accumulation of organic P. More recent research also suggests that P mineralization can be driven by the decomposers' need for C (Spohn and Kuzyakov, 2013), so the overall lower rate of decomposition in N2 may thus potentially contribute to an accumulation of organic P, not only in the litter, but also in the Ohorizon. While the Hedley fractionation, that we used, does not provide any detailed information on P species, a recent study by Acksel et al (2019) found a relatively good agreement between NaHCO 3 and NaOH extractable Po and organic O determined with 31 P Nuclear Magnetic Resonance (NMR) spectroscopy. The here obtained proportions between inorganic and organic P also agrees well with O-horizon soils in similar boreal forests in this region of Sweden when 31 P NMR has been used: The proportion of organic P relative to total NaOH extractable P using 31 P NMR was 76% (Vincent et al, 2012) and ranged from 53 to 85% in the region (Vincent et al, 2012(Vincent et al, , 2013.…”

Bioturbation by black soldier fly larvae—Rapid soil formation with burial of ceramic artifacts

“…Anthrosols are soils that have been transformed, influenced, or created by human activities [1]. These soils are found in different places around the world [2][3][4]. Special attention has been paid to Amazonian Anthrosols in the past decades [5], which occur in and around ancient tropical settlements [6].…”