G01_P03

Radiocarbon concentration of wheat (Triticum aestivum L.) and soybean seeds (Glycine max (L.) Merr.) grown during the bomb spike.

Huels M¹, Hamann C¹, Börner A²

¹Christian-albrechts-university, Kiel, Germany, Kiel, Germany, ²2)            Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, OT Gatersleben, Germany

Here we report radiocarbon measurements made on soybean seeds (Glycine max (L.) Merr.), grown and harvested on the experimental fields of the IPK in Gatersleben, Saxony-Anhalt, Germany, between 2000-2021, complementing the ¹⁴C measurements from wheat seeds over the bomb-spike (Hüls et al 2021).

Soy is sown around mid May and harvested by the end of September / beginning of October, forming its main bean tissue between July and October. The results give an overview of ¹⁴C  in agricultural grown plant tissue during the growth-period between April to September. The combined wheat and soybean seed radiocarbon record is compared to known pre- and post-bomb radiocarbon records (e.g. atmospheric Jungfraujoch, Schauinsland, and NH₁ datasets).

The Gatersleben plant tissue radiocarbon concentration indicates incorporation of fossil carbon of about 1% with respect to the high alpine, clean-air CO₂ of the Jungfraujoch station between 1987 and 2019. As shown previously with wheat seed (Hüls et al 2021), recent (i.e. 2021) grown plant-tissue give apparent ¹⁴C concentrations slightly below the 1950 reference level (i.e., -5.3±2 ‰ for wheat, -6.9±3‰ for soybean, respectively).

We suggest to use the pre- and post-bomb radiocarbon record of Gatersleben seeds as a reference in forensic investigations, such as the age estimation of paper by analyzing starch used in paper manufacture. A further advantage of the dataset reported here lies in its comparably simple extensibility by adding new analyses from future harvests.