Mikko Moilanen , Timo Penttilä, Jorma Issakainen

Lannoituksen vaikutus kuusikoiden kasvuun ja ravinnetilaan ojitetuilla turvemailla Pohjois-Suomessa

Moilanen M., Penttilä T., Issakainen J. Lannoituksen vaikutus kuusikoiden kasvuun ja ravinnetilaan ojitetuilla turvemailla Pohjois-Suomessa.

Tiivistelmä

Abstract: The stand-level responses to fertilization and refertilization were studied in seven factorial field experiments established in 1974-1976. The factors were nitrogen fertilization (N) and phosphorus-potassium fertilization (PK). The factorial treatments were applied at two levels: (i) control and (ii) fertilized with a dosage following the currently used Finnish forest fertilization guide-lines. The spruce-dominated stands were selected from areas drained according to normal forestry practises between 1932 and 1969. The sites covered fairly well the trophic variation that occurs on spruce-dominated peatlands in the mid-boreal zone in Finland. Tree growth was monitored during two periods of five to seven years. The second period followed the refertilization in 1985. At the end of the second period, one-year-old sun-exposed needles were sampled from the four southernmost stands for nutrient analyses. The effects of fertilization on tree growth were generally fairly weak and insignificant, especially during the first study period. After refertilization, the effect of N was positive in three stands on mesotrophic sites. The foliar nutrient analyses of unfertilized spruces showed low concentrations of N, P and Cu. PK-fertilization increased foliar P concentrations and, in some cases, also K concentrations. Since the PK-fertilizer included some borate, it also increased foliar B concentrations. N-fertilization did not affect foliar N, P or K concentrations but it decreased foliar concentrations of Ca, Zn, and B in some cases. Both the growth responses and the foliar nutrient analyses indicated that nitrogen was the most deficient macro-nutrient. Key words: foliar nutrients, growth responses, mires, nitrogen, phosphorus, Picea abies, potassium

Avainsanat
nitrogen; phosphorus; potassium; Foliar nutrients; growth responses; mires; Picea abies

Vastaanotettu 31.10.2017 Julkaistu 1.1.1996

Katselukerrat 1692

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