Rit Mógilsár - 2000, Blaðsíða 3

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2 SUMMARY

Oskarsson, H. 2000. The effect of timing of ferilization on survival
and growth. Implimentation and results after three growth periods.
IFRS report, 1/2000. 28 pp.

In 1998 a trial was established, where the effects of different timing
of fertilizer application were tested. The aim of the trial was follow-
ing: 1) which timing of application gives the best survival and
growth?;
a) fertilization at time of planting (in June),
b) in the middle of July,
c) late August or
d) one year after planting.
2) Do the four tree species; downy birch (Betula pubescens Ehrh.),
Sitka spruce (Picea sitchensis (Bong.) Carr.), Russian larch (Larix
sukaczewii Dylis.) and lodgepole pine (Pinus contorta Dougl. ex.
Loud.), show different responses to the timing of application?
The trial was established on three locations in June 1998, two in
S-Iceland and one in N-Iceland. Due to high mortality in pine and
problems caused by water-logged soils on the site in northern Ice-
land, only the results from birch and spruce at Markarfljótsaurar and
Kollabær were used.
There was no statistical significant difference between treat-
ments, i.e. timing of application, as regards the survival of seed-
lings. Seedlings that received fertilizer at time of planting were
taller, had greater diameter and larger annual growth increment
than those receiving fertilizer at other times. This difference was
pronounced with birch but less obvious with spruce. Results for
birch show that no fertilization at all gives poorer growth and diame-
ter than any of the other treatments that were tested in the trial.
Birch gave much larger growth response than spruce.

Key words: timing of fertilization, afforestation, growth, ground-
level-diameter, crown diameter, survival, Iceland, Betula pubes-
cens, Picea sitchensis.