The chemical composition and efficiency of biogas production in the methane fermentation process of silages of wild and cultivated varieties of reed canary grass were compared. An attempt was made to answer the question on how the habitat and the way of utilization of plants affect chemical composition and biogas yield. Physicochemical properties such as dry matter, organic dry matter, protein, fat, crude fiber fraction, macro- and microelements content were considered. The anaerobic digestion process and FTIR analysis were also carried out. The results showed that the two varieties differ essentially in their physical and chemical properties. The cultivated variety was characterized by higher biogas yield (406Ndm(3)kg(-1) VS) than the wild one (120Ndm(3)kg(-1) VS). This was probably related to the chemical composition of plants, especially the high content of indigestible crude fiber fractions and ash. These components could reduce biogas quantity and quality.

The present pilot study examined the potential of tobacco (Nicotiana tabacum L.) as an energy source. The fresh matter of whole tobacco plants, the yield of dry matter of stems and leaves, as well as the higher heating value and methane production potential from tobacco biomass were determined. The yield of tobacco leaves was on average 4.69 Mg ha⁻¹ (dry matter) and 76.90 GJ ha⁻¹ yr⁻¹ (biomass energy yield). Tobacco stems yielded on average 8.55 Mg ha⁻¹ and 150.69 GJ ha⁻¹ yr⁻¹, while yields of whole tobacco crops were (on average) 13.24 Mg ha⁻¹ and 227.59 GJ ha⁻¹ yr⁻¹. Methane potential of tobacco plants was (on average) 248 Nm³ Mg⁻¹ VS (volatile solids). The tobacco plants tested in the study could be used as energy crops as their dry matter and energy yields are similar to those of the most popular energy crops being currently used in biomass production in Poland and the European Union. Nevertheless, further studies to choose the Nicotiana species and varieties most suitable for energy production and to assess the cost-effectiveness of tobacco biomass production are needed.

The cultivation of perennial energy crops is a new agricultural system and so there is limited information available on its effects on biodiversity. The aim of this study was to assess the impact of the cultivation of energy crops on the diversity of weed flora and to compare this diversity with that found in crop production systems on arable land. The best habitats for weed flora were created by willow (Salix viminalis), poplar (Populus sp.), false acacia (Robinia pseudoacacia), and perennial grasses (25–30 species), with the exception of reed canary grass (Phalaris arundinacea) (20 species). The lowest diversity and abundance of weed flora were observed on plantations of Virginia mallow (Sida hermaphrodita) and Jerusalem artichoke (Helianthus tuberosus). Weed communities in energy crops included more perennial species (by 11%), ruderal species (by 10%), and those typical for grassland (by 7%) and forests (by 4%), in comparison to arable land. The plantations of energy plants promoted an increase in the density of the invasive species Solidago gigantea (from 1.9 to 6.3 plants m⁻² over six years). The introduction of perennial energy crops into an agricultural landscape causes quantitative and qualitative changes in weed flora communities and, therefore, control of the spread of some non-native and invasive species is needed.

In response to the growth in the global population and climate change concerns, questions remain regarding the adaptation of production systems to meet increasing food and energy demands. The aim of the paper is to present the production potential and biometric features of 11 willow varieties bred and cultivated mainly in Europe. The experiment was set up on marginal soil. The research was conducted in 2016–2020 and concerned 11 varieties of willow harvested in a three-year cycle. The dry matter yield of the examined willow varieties ranged from 6.5 to 13.8 Mg ha⁻¹ year⁻¹. Varieties Tur, Sven, Olof, Torhild, and Tordis were characterized by a relatively low level of yield (7.2–8.2 Mg ha⁻¹ year⁻¹). The highest dry matter yield was obtained for the varieties Ekotur and Żubr, respectively, of 11.5 and 13.8 Mg ha⁻¹ year⁻¹. The assessed varieties differed in both the level of obtained dry matter yield and biometric features. The Żubr variety produced the smallest number of shoots (three), but with the greatest height (4.8 m) and diameter (29.6 mm). Varieties with high production potential develop fewer shoots, but are taller and have a larger diameter than other varieties.

A growing interest in the cultivation of non-food crops on marginal lands has been observed in recent years in Poland. Marginal lands are a refuge of agroecosystems biodiversity. The impact of the cultivation of perennial industrial plants on the biodiversity of weeds and arthropods have been assessed in this study. The biodiversity monitoring study, carried out for three years, included five perennial crops: miscanthus Miscanthus × giganteus, cup plant Silphium perfoliatum, black locust Robinia pseudoacacia, poplar Populus × maximowiczii, and willow Salix viminalis. As a control area, uncultivated fallow land was chosen. The experiment was set up in eastern Poland. A decrease in plant diversity was found for miscanthus and black locust. The diversity of arthropods was the lowest for the cup plant. No decrease in the number of melliferous plants and pollinators was observed, except for the miscanthus. The biodiversity of plants and arthropods was affected by the intensity of mechanical treatments, the fertilization dose, and the use of herbicides. The biodiversity also decreased with the age of plantation.