The Botany of Iceland - 01.12.1914, Blaðsíða 71

PHYSICAL GEOGRAPHY
255
Danish Streams 2 sb £ 3 'CS & « *? « W 4 'O > 5 o ö Laxá from Mývatn 0 "cí <r. O r. Z, 0) < 7 'O H 8 ..sS -33® cr. 1 tm 'SC'+m *o s O H 5 1 'O -C
Nitrogen .... 15-20 1.37 4.65 1.35 110.00 4.9-14.12 4.5- 6.5 3
Potash 10-15 13.50 11.50 11.00 15.50 12.5-17.5 11.0-15.5 140
Phosph. acid. 0.0-1.0 1.05 5.00 4.35 35.00 1.5- 3.5 5.6-19.5 157
I.ime 100-700 33.02 35.00 41.50 55.00 21-37 49-82 46
In several plaees river-water is utilized for irrigation, and ir-
rigated meadow-lands were calculated to cover an area of 28.4
square kilometres in 1909.
The only cultivated soil in Iceland is that of home-fields (tun)
around the farm-buildings. These home-fields are manured and levelled,
but generallv are not ploughed. The extent of the cultivated areas
(tunes) of the whole of Iceland was in 1909 calculated to be 187.8
square kilometres; lo this should be added 2.8 sq. km. for the cab-
bage and potato plots. There are often numerous knolls in the tunes,
which render haymaking very difficult (Fig. 17). Therefore the im-
provement of the soil consists in the levelling of these knolls, which,
however, reappear in several places after a time. The nature of the
tunes and the quality of the soil naturally differ greatly according
to cultivation and situation. The grass (tada) from the tunes con-
sists mainly of Gramineæ, and, as already mentioned, is used as
winter fodder for the cows. In 1910, 5145 tons of tun-hay (tada)
were cut. Outside the home-fields there is also a great deal of dry
grassland (harðvelli) covered with Gramineæ, wliich is chiefiy used
as pasture-land for sheep and cattle. In the soil of the tunes and
the dry grassland a larger quantity of lime and phosphoric acid is
usually found than in that of the wet meadow-tracts.1
As in other arctic and subarctic regions, “soil-flovvs” (Solifluk-
tion) are a common phenomenon in Iceland, and they exercise,
especially in mountainous regions, no slight influence upon the soil
and plant-growth. The upper layer of the soil upon slopes and
and in Búnaðarrit, XXII, 1908, pp. 205 and 206. No. 1 is by Feilberg and We-
stermann, Nos. 2, 3, 4, 5 and 8 by Iletlefsen and Mever; Nos. 6 and 7 by A.
Torfason. Nos. 5 and 8 appear somewhat doubtful.
1 P. Feilberg in Tidsskrift for I.andokonomi, 1881, pp. 8—12.