Effect of fertilisation and drainage intensity on the foliar radiocaesium and potassium concentrations of Scots pine on a drained peatland

¹ Finnish Forest Research Institute, METLA, Parkano Research Station, 39700 Pankano, Finland
² Radiation and Nuclear Safety Authority, STUK, P.O. Box 14, 00881 Helsinki, Finland

Abstract

This study aims at finding out the effects of fertilisation and drainage intensity on the needle ¹³⁴Cs and ¹³⁷Cs activity in Pinus sylvestris on a pine mire in Finland. The fertilisation treatments were as follows : a control, fertilised once in 1965 or fertilised twice in 1965 and 1977, with N, P and K. The potassium concentrations of the current year needles in 1990 showed severe potassium deficiency on the controls (K 3.6 mg g^-1) and slight deficiency on the plots fertilised only once (K 4.2 mg g^-1) but no deficiency on the plots fertilised twice (K 4.8 mg g^-1). Fertilisation decreased the radiocaesium concentrations and amounts in the needles. The concentrations of ¹³⁴Cs were 821 in the control, 442 in the single fertilisation and 485 Bq kg^-1 in the repeated fertilisation treatment, and the ¹³⁷Cs concentrations 5378, 2734 and 2104 Bq kg^-1, respectively. Drainage intensity (10-100 m) had no significant effect on the needle K concentration or radiocaesium activity.