In this work, the costs for machinery and all means for site preparation of forest clearings for afforestation with intensive poplar plantations were studied by applying various technological schemes. For this purpose, three technological schemes (TS 1 , TS 2 and TS 3 ), applying in Bulgaria, were studied. By applying the respective technological scheme, the site preparation was performed entirely with a milling aggregate PT-400, equipped with multifunctional forest tiller FAE-300/S. The

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... es of shredding stumps, mulching clearing debris and bushes, and primary tillage of the soil up to depth of 50 cm were examined. The survey was conducted in poplar clearings along the river Danube, over alluvial moderately moist soil. A new categorization of the poplar clearings is proposed depending on the operating conditions. The performance of the milling unit and the relative costs for labor, machinery and means for site preparation per unit area were defined. Depending on the category of poplar clearings, total cost for site preparation applying the studied technology vary between 27.6 h/ha and 29.3 h/ha, which at current prices of 53.5 €/h for the operation of PT-400 with FAE 300/S is between €1,478/ha and €1,569/ha. To conduct comparative analysis of the new technology and the old technologies under similar operating conditions, the relatively costs for site preparation of the previously applied technologies which use rotary and tooth uprooter machines are defined. According to the applied technological scheme and used machines in different categories, clearings costs for land preparation vary between €1,230/ha and €3,300/ha. Based on comparative analysis, it is designed a new technological scheme for afforestation with poplar plantations in riverside clearings, where by ensuring high quality work, the costs for site preparation become lower (24.2-25.9 h/ha) and thus cost from €993/ha to €1,084/ha is achieved.