Biomass production and survival rates of selected poplar clones grown under a short-rotation on arable land

Fast-growing woody plants that can be grown under short-rotation systems offer an alternative to food production on arable land, and serve as a potential source of renewable energy. In order to establish the feasibility of future large scale production under the conditions of the Czech-Moravian highland, a high density experimental field plantation including a range of available clones of Populus sp. and Salix sp. with the total area of 1.5 ha was established in early 2001 in Domanínek (Czech Republic, 49°32'N, 16°15'E and altitude 530 m). The clone experiment of Populus sp. covered 0.3 ha in the center of the plantation and included 13 clones in total, with hardwood cuttings of only 6 clones available in numbers allowing 4-replicate experiment. The plantation was established on agricultural land and the trees were planted in a double row design with a density of 10 000 trees/ha. The trial was weeded by mechanical methods, and no irrigation, fertilization, or herbicides were applied. The experiment site was harvested at the end of 2006. It was found that the biomass yields of the tested clones of Populus sp. were in the higher range of results from national and European studies in case of hybrid clones. The satisfactory survival rate in the first year, when mortality tends to be highest, was supported by relatively wet weather conditions after plantation establishment. At the end of the first rotation, the highest yields were obtained from clones J-105 and J-104 (P. nigra × P. maximowiczii) and P-494 (P. maximowiczii × P. berolinensis) with J-105 showing a mean annual increment of dry matter close to 14 t/ha. Additional experiments seem to suggest that well managed poplar plantation might produce even better values if higher survival rates can be achieved.