The Impact of Nitrogen on the Yield Formation of Wall: Efficiency and Assessment of Energy Parameters.

With the increasing importance of energy crops, research on potential energy crops is carried out to identify plant species with high productivity and energy value. The field experiment with the new promising energy crop, (wormwood), was executed at the Vėžaičiai Branch of the LAMMC. The soil site was naturally acidic (pH 4.2-4.4). The species was investigated as an energy crop through the evaluation of its biomass productivity and some energetical qualities. According to the three investigation years, DM yield significantly varied depending on the growing season, cutting time and nitrogen rate. The highest average DM yield was observed in 2020-10.58 t ha. On average, the DM yield varied from 6.49 t ha (first cutting) to 11.82 t ha (third cutting). The DM yield was positively correlated with stem height and the mass of one stem. Nitrogen use efficiency (NUE) depended on the growing season, cutting time and nitrogen rate. Both N90 and N180 rates should be used for fertilization. Energy growing analysis (including direct and indirect expenses) revealed that the highest share of energy expenses are due to indirect energy expenses (particularly nitrogen application). EUE (energy utilization efficiency) tends to decrease as a result of increasing nitrogen fertilization. Overall, granules are characterized by a high calorific value.