Jouko Kortesharju , Eira-Maija Rantala

Sijoituslannoituksen vaikutuksesta hillaan (Rubus chamaemorus L.) ojittamattomilla soilla

Kortesharju J., Rantala E.-M. Sijoituslannoituksen vaikutuksesta hillaan (Rubus chamaemorus L.) ojittamattomilla soilla.

Tiivistelmä

The experiment was carried out in Kolari, northern Finland (67°14'N; 23°48'E). The experimental field was an open Sphagnum fuscum-bog with a dense but low-producing cloudberry stand. Phosphorus, nitrogen and potassium fertilizers were laid in the depth of either 10 or 20 centimetres. No combined fertilizers were used. The rhizomes of cloudberry in this bog are usually in the depth of 5—15 centimetres and roots go often much deeper (at least to 40 centimetres). The experimental field was fertilized in June 1975 and the observations were made 1975—1979. The effects of fertilization were slight and lasted only for about three years. Nitrogen had the clearest effect. The leaf size increased in 1975 (fig. 3—6) and probably the higher biomass production increased the number of shoots and flowers in 1976—1977 (fig. 1, 2, 7 and 8). Phosphorus had little effect on leaf size, but the number of shoots and flowers increased in some degree in 1976—1977. Potassium caused larger leaves in 1975, but later its effects were slight. No yield was got in 1975—1977 because of hard night frosts in early June. In 1978—1979 there was no difference in yield between different fertilizer treatments. Berries were exceptionally small in all treatments (mean weight 0.5 grams). The most probable reason for the weak effect of fertilization is the high water level on an unditched bog. The peat is moist almost all summer and nutrients are released only when the frozen peat is thawing in spring and early summer and later only when the peat is temporarily drying. Also the fertilizers are probably attached to the moist peat. The result is that this kind of fertilization of cloudberry on an unditched bog is by no means profitable.

Vastaanotettu 31.10.2017 Julkaistu 1.1.1980

Katselukerrat 2949

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