The profitability of PK and NPK fertilization in Scots pine stands on ditched peatlands was investigated. The aim was to determine the private profitability of a single and repeated fertilization separately. The data (site and stand parameters) was collected from 8 fertilization experiments established during the 1960's and 1970's in northern Ostrobothnia. In thick- peated sites self-financed PK treatment turned out to be rather profitable both in the first and the second fertilization. The real internal rate of return was 6-7 % at the end of the calculation period (11 years). It was not possible to determine the optimal duration for the self-financed fertilization investment within the calculation period. The maximum net present value with the 3 % interest rate was 450 FIM/ha. The use of nitrogen (NPK treatment) increased the stand growth response, but the increment was not big enough to cover the higher cost. In thin-peated sites the first fertilization was not profitable when self-financed because of the poor increment. The state forest improvement subsidies increased considerably the private profitability of all the fertilization treatments. Real internal rates of return increased by 10.6 % on the average consequently shortening the optimal duration for investment. Profitability of the NPK treatments increased most. The first fertilization on thin-peated sites was not profitable even if subsidized. Reasonable changes in ther fertilization costs and stump prices did not significantly increase the risk of running a loss, especially if the investment was financed with the state forest improvement subsidies.
237.4 (Verwendung von Düngemitteln z.B. Klärschlamm, Kompost oder Bodenimpfung [Unterteilung wie 232.322.4]) 114.444 (Torfböden, Moorböden [siehe auch 232.23 Moorwaldbewirtschaftung]) 651.79 (Verschiedenes) 56 (Zuwachs (Meßmethoden und Ergebnisse); Wachstumsgang und Struktur der Bestände) 174.7 (Coniferae [Siehe Anhang D]) [480] (Finnland)