Lasse Aro , Seppo Kaunisto

Jatkolannoituksen ja kasvatustiheyden vaikutus nuorten mäntymetsiköiden ravinnetilaan sekä puuston ja juuriston kehitykseen paksuturpeisella suonpohjalla

Aro L., Kaunisto S. Jatkolannoituksen ja kasvatustiheyden vaikutus nuorten mäntymetsiköiden ravinnetilaan sekä puuston ja juuriston kehitykseen paksuturpeisella suonpohjalla.

Tiivistelmä

The effects of refertilisation and growing density on the soil and tree nutrition, root penetration and growth of Scots pine stands were studied in a cutaway peatland area with deep peat layers. The fertilisation treatments were control, N1975+PKB1985 and PK1975+PKB1996 refertilisations and those of the growing density <1 300, 1 654 and 1 954 trees ha-1. The maximum root penetration varied between 26 and 34 cm independently of the treatments. The N/P ratios in pine needles were quite high even on the refertilised plots (11.6-15.7). The duration of P fertilisation seems to be shorter (about 15 years) on cutaway peatlands with deep peat layers than on drained peatland forests. The greatest yield without natural removal (239 m3 ha-1, on an average) in 35-years-old stands was measured on plots, which had the highest growing density and had been repeatedly fertilised with PK. The results show that quite a high yield of Scots pine can be reached on cutaway peatlands. However, pine has to be fertilised with PK at the afforestation stage and at least once later if the remaining peat layer is 40-60 cm, and possibly several broadcast fertilisations are needed on peat layers deeper than 60 cm. It seems that growing tree stands on cutaway peatlands in higher densities than in conventional forestry may improve nutrient cycling in stands and hence decrease leaching of nutrients from the site.

Avainsanat
afforestation; root penetration; Pinus sylvestris; nutrition; Fertilisation; cutaway peatlands; N/P ratio

Vastaanotettu 31.10.2017 Julkaistu 1.1.2003

Katselukerrat 515

Saatavilla http://suo.fi/article/9826 | Lataa PDF