Ársrit Ræktunarfélags Norðurlands - 01.01.1966, Page 61

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Summary.
In the summer of 1966 experiments with sulphur fertilizers were car-
ried out on three locations in the North of Iceland. All the locations
were permanent grass fields.
Increasing rates of sulphur in gypsum and potassium were applied.
In addition five different kinds of sulphur fertilizers were tried out
(Gypsum, potassium sulphate, super phosphate, „25-15“ (mixed fer-
tilizer 25% N and 15% P2Or) and magnesium sulphate). (See Table 1.)
The results of the experiments showed that the above mentioned
locations lacked sulphur. (See Table 2 and Table 3.)
Sulphur in super phosphate yielded quite considerably less first
cutting than did the same rate of sulphur in gypsum and potassium
sulphate. However, super phosphate gave a considerable yield increase
11 Hkg/ha in the second cutting compared wúth a plot to which sul-
phur fertilizers had not been applied.
Maximum yield w'as obtained from 8 kg S/ha on two out of three
locations. On the third location, however, the maximum yield was ob-
tained from 16 kg/ha.
Chemical analysis of cutting samples did not show any differences
in concentrations of Ca. Mg, Na, K and P in spite of incraesing rates
of sulphur fertilizer. (See Table 5.)
Heimildaskrá.
Árni Jónsson: Skýrslur Tilraunastöðvanna (1959—1960).
Sami: Persónulegar heimildir. 1966.
Gunnarsson O.: Svavel — ett aktuellt vaxtnaringsamne. Váxt
— Nárings — Nytt. 14. (12—) 1958.
Johansson O.: On sulplntr problems in Swedisli agriculture.
Disputats. Kungl. Lantbrugshögsk. Ann. 25. (57—) 1959.
Odelien M.: Orienterende markforsók med svævelgjpdsling.
Forskning og forspk i landbruket 17 (79—116) 1966.
Örn Þorleifsson: Persónulegar heimildir. 1966.