INFLUENCE OF PLANTING SEASON ON SIBERIAN ELM YIELD AND ECONOMIC PROSPECTS

Siberianelm (Ulmuspumila L.) isrecognized as a promising short rotationwoodycrop (SRC) tobegrownunderharshenvironmentalconditions. Crop establishment of SRC is usually a crucial stage, e.g. the planting date has an effect onthe establishment of the crop and on the economic viability of the first crop rotation. The twofold objective of the present workis: (i) to study the effect of the planting season on the biomass production of Siberian elm in the second vegetative period when it is grown as SRC in Oropesa, Toledo (central Spain), and(ii) to estimate the production costs of Siberian elm biomass and the economic prospects. The yield obtained in the summerestablished plantation was more than twice (8.64 t dm.ha(-1)) the winter-established plantation (3.73 t dm.ha(-1)) with a sparse density at6,666 trees ha(-1). Plant height and stem diameter were also significantly higher. Biomass production costs were estimated at 61.9 (sic).t fm(-1)and 88.2 (sic).t fm(-1) for the summer and winter-established plantation, respectively. Economic analysis showed that the breakeven point of growing Siberian elm is reached when the production costs are below 38.3 (sic).t fm(-1), which could be achieved from yields over 7.5 t dm.ha(-1).year(-1).