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Accumulation of ¹³⁷Cs after potassium fertilization in plant organs of Salix viminalis L. and in combusted ash

Rosén, K., von Fircks, Y., Vinichuk, M., Sennerby-Forsse, L.
Biomass and bioenergy 2011 v.35 no.7 pp. 2765-2772
Salix viminalis, combustion, fertilizers, field experimentation, fly ash, leaves, plant organs, potassium, roots, sandy soils, stems, wood chips
The effect of potassium (K) application at a common rate on ¹³⁷Cs uptake and distribution within basket willow (Salix viminalis L.) and ¹³⁷Cs activity in willow ash was studied in a three-year field experiment on a sandy soil. Experimental plots fertilized with 60 kg N and 48 kg K per ha were compared with a control with similar N but no K fertilization. There was no significant difference in ¹³⁷Cs activity concentrations in plants growing on plots with or without fertilizer K. Higher concentrations of ¹³⁷Cs activity were found in roots and leaves of willow than in stems and cuttings. The highest ¹³⁷Cs activity concentration was detected in the fine roots (size 0–1 mm). The transfer factor (TFg) of ¹³⁷Cs in different plant organs varied between 0.1 × 10⁻³ and 2.6 × 10⁻³ m² kg⁻¹. After combustion, ¹³⁷Cs activity concentrations in ash produced from wood chips from K-fertilized plots were significantly lower than those in ash originating from plots without K fertilization. Fly ash had higher ¹³⁷Cs concentrations than bottom ash and all ash samples had ¹³⁷Cs concentrations that were well below the 10 000 Bq kg⁻¹ Swedish limit for spreading on land.