Effects of fertilisation on development and nutrient uptake of black locust saplings grown in pots

Currently, black locust is the most important tree species in Hungary with significant economic value. Intensification of its cultivation and the improvement of the timber quality should include the use of highly productive clones and reasonable fertilization. Nutrition management should be based on reliable data from exact experiments. In our trial, nutrition intake of Turbo Obelisk OBE01 clone saplings was examined during a four-month period. Osmocote Pro (18:9:10 + 2Mg) was used as fertilizer at a dose of 2.5 and 5 kg m−3 mixed to a peat-based substrate. At the end of the growing period, saplings reached a height of 260-280 cm and a stem diameter of 16-18 mm. Nutrient intake order was found to be the following: Ca (3.3-4.2 g) > N (3.1-3.6 g) > K (2.1-2.9 g) > Mg (0.35-0.5 g) = P (0.3-0.5 g). Based on our results, a lower N:P and N:K rate fertilizer is recommended, especially if a non-peat based substrate and longer growing period is planned with a higher rate of nitrogen fixation. Considering nitrogen resource, a dose of 5 kg m−3 was proved to be less effective than a concentration of 2.5 kg m−3. However, the higher concentration of phosphorous, potassium and magnesium were well-utilized by the plants.