Cultivation and Potential for Biomass Production for Energy and Seed Purposes of Tall Wheatgrass (Agropyron elongatum (Host) Beauv.) Under Sandy Soil and Temperate Climate Conditions

An experiment was conducted to analyse the potential for obtaining biomass for energy purposes and tall wheatgrass (TWG) seeds grown under conditions of varying pre-sowing fertilisation with compost and mineral fertilisation with nitrogen on sandy soils. Field trials were conducted between 2012 and 2015. The study factors were compost from municipal green areas with I-doses of 0, 10 and 20 Mg∙ha−1 added before sowing and nitrogen II-doses of 0, 40, 80 and 120 kg∙ha−1 added each year in the form of ammonium nitrate. During the experiment conducted on sandy soils, a favourable effect of fertilisation on the morphological parameters of above-ground vegetative and generative parts was found. The experiment resulted in high dry matter yields (DMYs) in the range of 9.08–31.38 Mg∙ha−1 and high seed yields (SYs) (635 kg∙ha−1 to as much as 2397 kg∙ha−1), which depended on the applied fertilisation variant. The applied levels of compost fertilisation had a positive effect on the obtained dry matter yields (DMYs) and SY. Analysing the effect of the applied doses of mineral nitrogen fertilisation (40, 80 and 120 kg∙ha−1) on the dry matter yield of TWG under sandy soil conditions, it should be noted that this factor significantly increased the DMY and SY in all years of the study. At the same time, the response of plants to this factor of the study over the years varied and depended on weather conditions. The high energy yield (192.50 GJ∙ha−1–408.93 GJ∙ha−1) closely related to the high DMY indicates the high suitability of TWG as a new grass species under temperate climate conditions grown for biomass energy production and the possibility to harvest seeds when adequately cultivated.