The research into forest improvement in stands on transitional bogs
1994
Pikk, J. | Valk, U.
Using the similar measures of forest improvement in different stands on a transitional bog does not give identical results. The efficiency of drainage and fertilization mainly depends on the fertility of surface peat, composition of tree species in stands and suitable combinations of fertilizers. In the pine stand drained 21 years ago and fertilized 16 years ago on a relatively fertile peat soil, the timber productivity was increased only due to drainage during the 16 years by 3,5 times and the quality class was improved by one class. The application of PK+NP- and NPK-fertilizers was not efficient. The fertilizers should be applied only in that case when at least 20 years have passed since drainage and so the nutrients made available for use in tree have been exhausted. Good results were obtained by the application of fertilizers to the white birch stand drained 22 years ago and fertilized 16 years ago. The stand is on the peat soil with a low fertility where the deficit of phosphorus and potassium occurs. On transitional bogs drained and fertilized with PK the conditions for a rise in natural regeneration of pine, spruce and birch are improved. On a drained bog in white birch stands the role of coniferous trees is increased by fertilization. The fertilization of birch stands on a bog is justified only in case of their refertilization and a proper maintenance of ditches.
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