Rit Landbúnaðardeildar : B-flokkur - 01.05.1946, Blaðsíða 110

104
The following examples on yields are cited:
Averages
from no. Time of Yields in pounds per acre
Kind of corn of years seeding (írains Straw
Donnes-barley ......... 14 April 20 2190 3750
Donnes-barley ......... 14 May 31 1400 4300
Nidar oats ............ 5 April 20 1940 3800
Nidar oats ............. 5 May 31 1400 5100
4. Since 1928 a little over 100 varieties of barley, oats, winter-rye, spring-rye, winter-
wlieat, spring-wheat, and field peas have been tested. Of these crops, six-row barley
and eariy oats, when early seeded, are most likely to mature.
The following barley varieties (all of whom come from Norway) are the „earliest"
ones: Donnes, Maskin, and Ornes. Nidar-oats, Tenna-oats, and Tilrum-oals (all Nor-
wegian) liave próved to Ite tlie earliest maturing, while Perlum-oats (Norwegian), Svalof
Orion oats (Swedisli), and Favorite-oats (American) are later maturing. Barley has
required from 103 to 136 days to ripen, oats from 115 to 150 days. Althougli they require
longer season, oats will mature a little more fully tlian barley in the southern part
of the country. BarJey and oats frequently yield from 1800 to 2700 Jbs of grain, and
from 3500 to 6000 Jbs of straw pcr acre.
Winter-rye (Torider-rye) matures in seasons tiiai are average or Jietter, and lias
yielded a maximum of 1960 Ibs of grain per acre.
Spring-rve seldom ripens.
In the best seasons, spring-wlieat has matured fully, I:ut it Jiardly ripens in an
average season. Winter-wheat Jias reached a fair maturity in an average season, and
is preferable to spring-wJieat.
Field-peas have matured fully in an average season.
Diseases in corn have not l>een muclr in evidence. Manganese deficiency symptoms
on oats liave been noticed; they are most likely to appear on naturally well drained
soils, especialJy if tlie first part of tlie season has l)ecn dry. Tlic oat varieties differ
in this respect: Nidar-oats frequently sliow tliese dcficiency symptoms, wliereas thcy
seldom are observed on Favorite oats. Barlcy has been attacked by rust (Puccinia) in
some years (1935, 1937, and 1940). It appcars, tliat the rust is favored by seasons, the
latter part of which is wet and cold. Loose smut (Ustilago muda), and covered smut
(Ustilagio Jiordea) often appear on plants grown from imported seed, l)ut seem to
disappear with continued cultivation from Icelandic-grown seed, altliough no preventive
measures are taken.
6. Experiments on tlie rate of seeding indicate, tl)at 160 to 180 pounds of good
seed is needed per acre when the seed is broadcast. SomewJiat Jess is required wlien
t he seed is drilled.
7. Drilling is prefcralrie to broadcasting. The former metliod has, on the average,
yielded 6% more tlian tlie Jatter.
8. Experiments on tlie dc]>tli of seeding indicate tliat IV2 to 2% inclies depth is the
safest one, particularly if tlie seeding is early and precipitation is scant. If a seeding
is made after May 15, it may prove to l>e equallv good or l)etter to secd sliallower, but
tlio seed should l)e wcll covered.
9. Fertilization.
a. Farm manure may wcll l>e used, but it contains a little too much nitrogen in re-
lation to the otlier fertilizer elements, and delays maturity somewhat. Horse manure,
at the rate of 9 tons per acre, has given good results with barlej'.
b. Potassium fertilizers are needed on drained half-bog lands. A rate of 180 pounds
of 40% potassium fertilizcr per acre have proved satisfactory. On naturally well
drained soils no potash is required in many cases. Sandy soils are likely to be
deficient in potassium.
c. Phosphate fertilization for corn is essential, and will hasten the ripening of the
grain. 270 to 360 pounds of 18% superphosphate pcr acre has been found sufficient.