Principles of circular economy applied to energy plants in culture. The correlation of soil quality with the valuation potential of willow by-products

Abstract

Energy plants are used for biomass products such as wood chips ( pellets ) or working wood (OSB boards). For this purpose, you can cultivate willow (Salix alba), artichoke, elephant grass, Chinese reed, energetic hybrid poplars, canary grass, giant cane, and oil tree (source of biodiesel). The study aims, by analyzing the quality of the soil correlated with the composition of the energetic willow bark, to highlight the potential for the valorization of the by-products. In this study, the soil fertility of some Romanian energy willow crops was compared with chernozem with a high input of humus from the Natural Meadow Reserve of Slobozia Mare, Moldavia. Through the analysis of the bark (plant by-product), the determination of salicin from the dry extract, the aqueous extract, and a compressed mixture was sought. Reported to the main macronutrients and pH, the soil of the energy willow crops in Romania is qualitatively similar to Moldavia. Although willow is cultivated primarily as an energy plant (biomass for pellets, biodiesel), if the conditions of the culture area are monitored, the waste represented by the easily removable bark can be utilized because it contains salicin in concentrations that, depending on the area.