Fróðskaparrit - 01.01.1996, Side 87

CLIMATIC CHANGES AND FAROESE AGRICULTURE
91
toes, carrots, cale and cabbages can give ac-
ceptable yields, as they can germinate and
grow under present climate, although not
maximal yields (Andersen, 1961).
Factors limiting crop and
animal production
Precipitation and light intensity is fully suf-
ficient for production of most agricultural
crops in the Faroes. The low temperature is
the main limiting factor (sometimes to-
gether with excessive precipitation).
The annual meat production from 75.000
mother sheep is depending on the tempera-
ture (and growth of the grasses) during
there season, and, may vary by up to 25%
(Helgi í Brekkunum, pers. comm.).
Most crops need above 5-6 °C for
growth (Andersen, 1961) and thus a varia-
tion in midsummer temperature between 9
and 11 °C has a large influence on total pro-
duction, as two summer months with 9 deg.
give 240, - and two months with 11 deg.
give 360 degree-days for growth (above 5
°C).
The year 1993 had a low sum, and 1988
high mid-summer degree-sum, above 5 °C
degree the difference being more than 40%.
Agricultural applications
Comparison of growth and yield in re-
search trials from different years can be
compared when adjustments are made for
the climate of the years.