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

Abstract

This study aims at finding out the effects of fertilisation and drainage intensity on the needle 134 Cs and 137 Cs 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 134 Cs were 821 in the control, 442 in the single fertilisation and 485 Bq kg-1 in the repeated fertilisation treatment, and the 137 Cs 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.