Ferti lizers effect on growth and development of norway spruce ten years after application

This publication evaluates results of last three years of ten-years lasting trial with slow release fertilizers conducted in the Ore Mountains in the administration unit Horní Blatná. The contribution aims to illustrate the possible effects of slow-release fertilizers on growth and development of young plantations of Norway spruce. The first stage of the trial was established in 2001. Seven different fertilizers were selected to be tested. Five testing blocks were prepared at four locations. Each block contained eight plots. Fertilizers were applied to young seedlings planted at testing blocks. One plot was left without fertilizer as a control. Three selected fertilizers were applied to the trial plots again in 2005 to test the effect in a later stage of the tree development. Quantitative tree features were measured to demonstrate the effect of fertilizers. The best results were observed couple years after the application. The effect of fertilizers applied during the second stage was partially evident as well. However, the overall effect of fertilizers is not considerable when the trees get older. The use of fertilizers could be recommended to shorten the time needed for securing the plantations and support forest regeneration at locations with extreme conditions and at degraded sites