%0 Research Notes
%T Refertilization on meso-trophic pine swamps in northern Finland
%A Penttilä, Timo
%D 1984
%J Suo - Mires and peat
%V 35
%N 4-5
%U http://suo.fi/article/9592
%X The paper deals with the effects of refertilization on the growth response of pine growing on drained nitrogen-rich swamps in northern Finland. The results of five replicated factorial experiments are presented. Primary fertilization, mainly with PK, was carried out 10—13 years before refertilization with the following treatments: N, P, K and in three experiments also a micronutrient mixture (H). Growth responses were measured 4—6 years after refertilization.
Of the single factors, N had a positive effect in a shallow-peated experiment and the micronutrient mixture in a deep-peated one. The effect of P and K was not significant in any of the experiments. However, the treatment means showed a clear positive effect with NK or NKH, except in the northernmost experiment. The effect of PK strengthened towards the end of the study period. The results imply that primary fer-tilization, especially with P, still had an effect at the time of refertilization. Final conclusions concerning PK fertilization and also the effect of nitrogen should be based on a longer period of observation.