The Profitability of Repetitive Fertilization in Pine Stands on Dryish Mineral Soil in Southern Finland

1989

26 S.

10 Abb., 3 Tab., 19 Lit. Ang.

Bandaufführung

37227

The profitability of repetitive fertilization is examined purely on the basis of mathematical models. Profitability is shown to be dependent on variations of the fertilization treatment. The calculations were carried out for pine stands on dryish mineral soils in southern Finland. Urea (46,5 % N) or ammonium nitrate with lime (27,5 % N) fertilizers were employed, the amount vaying between 80-240 N kg/ha and the number of applications between 1-5 during a 12 years period. The whole investigated period was 18 years. The calculations were carried out for stands which at the time of the first fertilization were 30-, 50-, 70- and 90 years old. The mathematical models describe the development of volume, changes in saw timber and pulpwood percentages as well as changes in the mean volume of saw timber and pulpwood stems. Stumpage prices were calculated from a linear trend equations which were based on the stumpage prices actually paid in southern Finland during 1978-1988. The costs were caculated as a sum of the cost of fertilizer, planning and supervising, transportation and spreading. Profitability was measured by the real internal interest. The calculations were carried out by simulating several different fertilization treatments. Repetitive fertilization is, in every case, shown to be profitable investment.