Rit Landbúnaðardeildar : B-flokkur - 01.05.1957, Side 100

98
Experiment No. 2 is a comparison of the application of farmyard manure on cul-
tivated meadow in September (ground unfrozen), October (ground frozen), April and
May; far the best results being obtained by the September application, and the autumn ^
application has shown advantages over the one in spring (Tables V and VI).
Experiment No. 3 is parallel to No. 2, but deals mainly with the working of tbe
farmyard manure into the grass-roots, simultaneously with the spreading of the manure.
The autumn application showed definite adventages as compared with that of the
spring, confirming the results obtained in No. 2, while the effects of the working-in
of the manure were more doubtful. However, it appeared profitable to pulverize the
manure in advance in autumn (Tables VII and VIII).
Experiment No. 4 consists of 3 trials for the purpose of comparing various N-ferti-
lizers (Tables IX—XI). German calcium nitrate, 15.5 per cent N, has yielded the best
overall results, otherwise there is little difference between the various kinds of nit-
rates. On the other hand, the different kinds of ammonia-fertilizer have given in-
ferior results.
Experiment No. 5 deals with the various fertilizing periods of Nitrophoska and
calcium nitrate. Nitrophoska is a mixed fertilizer (N -)- IhO, + KaO), but phosphate
and potash were applied in combination with the calcium nitrate. Still, the portions
were not equal (Table XII, A—D). The most profitable period for the use of either
Nitrophoska or calcium nitrate appears to have been Mayl6—May 25.
Experiment No. 6 is a comparison between the results of applying N-fertilizer in
one portion, and dividing it into two portions, given at different times (Table XIII).
The division does not seem to yield better results. If anything, the contrary was the
case, especially if the overall quantity of fertilizer was small.
Experiment No. 7 is a comparison between Nitrophoska (N -j- P2O5 + IVO),
Leunaphos (N + P2O5) and calcium nitrate + superphosphate (Table XIV), Nitro-
phoska yielding results similar to calcium nitrate + superphosphate, while Leuna-
phos was markedly inferior.
Experirnents Nos. 8—11 all deal with the comparison between farmyard manure
on the one hand and fertilizers on the other, applied together or separately (Tables
XV—XVIII). The farmyard manure has in all these experiments given inferior results
compared to the fertilizers, which have given improved yields. The best results were
obtained by using farmyard manure in combination with N-fertilizer.
Experiment No. 12 is for comparison between various sorts of phosphate. The
results were nil, as the experiment showed no deficiency of phosphate in the soil du-
ring the 3 years covered by the experiment (Table XIX).
Experiment No. 13 deals with potash and phosphorus, in both of which chemicals
the soil seems to be deficient. The experiment covered only one year, and the results ►
are consequently somewhat doubtful.
Experiment No. 14 is a comparison of various kinds of greenfodder-oats (Table
XX). Although the experiment covered a period of 4 years, the results are inconclu- {
sive, as there were frequent changes of the different varieties, so that no single variety
was tested during the whole period and few together more than 2 years. A Swedish
variety, Seger-oats, seems to have yielded the best results.
Experiment No. 15, which is a comparison of different varieties of tumips for
animal consumption (Table XXI), is somewhat similar to No. 14 with the same faults.
Öster Sundom gave the best yield.
Experiment No. 17 is for the purpose of comparing some potato-varieties. The
experiment is inaccurate and does not justify any conclusions (Table XXII).