Giant miscanthus (Miscanthus × giganteus Greef and Deuter) and Amur silver grass (Miscanthus sacchariflorus Maxim./Hack) are rhizomatous grasses with a C4 photosynthetic pathway that are widely cultivated as energy crops. For those species to be successfully used in bioenergy generation, their yields have to be maintained at a high level in the long term. The biomass yield (fresh and dry matter [DM] yield) and energy efficiency (energy inputs, energy output, energy gain, and energy efficiency ratio) of giant miscanthus and Amur silver grass were compared in a field experiment conducted in 2007–2017 in North‐Eastern Poland. Both species were characterized by high above‐ground biomass yields, and the productive performance of M. × giganteus was higher in comparison with M. sacchariflorus (15.5 vs. 9.3 Mg DM ha⁻¹ year⁻¹ averaged for 1–11 years of growth). In the first year of the experiment, the energy inputs associated with the production of M. × giganteus and M. sacchariflorus were determined at 70.5 and 71.5 GJ/ha, respectively, and rhizomes accounted for around 78%–79% of total energy inputs. In the remaining years of cultivation, the total energy inputs associated with the production of both perennial rhizomatous grasses reached 13.6–15.7 (M. × giganteus) and 16.9–17.5 GJ ha⁻¹ year⁻¹ (M. sacchariflorus). Beginning from the second year of cultivation, mineral fertilizers were the predominant energy inputs in the production of M. × giganteus (78%–86%) and M. sacchariflorus (80%–82%). In years 2–11, the energy gain of M. × giganteus reached 50 (year 2) and 264–350 GJ ha⁻¹ year⁻¹ (years 3–11), and its energy efficiency ratio was determined at 4.7 (year 2) and 18.6–23.3 (years 3–11). The energy gain and the energy efficiency ratio of M. sacchariflorus biomass in the corresponding periods were determined at 87–234 GJ ha⁻¹ year⁻¹ and 6.1–14.3, respectively. Both grasses are significant and environmentally compatible sources of bioenergy, and they can be regarded as potential energy crops for Central‐Eastern Europe.

This paper presents the results of a 3-year field experiment conducted on soil with moderate levels of boron (B) in north-eastern Poland to determine the influence of foliar application of B (0, 150 and 300 g ha-1) on the yield components, yield, mineral composition, nutritional value and feed value of winter oilseed rape seeds. Foliar application of B at the beginning of bud formation in winter oilseed rape increased seed yield by 0.19 (3%) at the lower B fertilization level to 0.26 Mg ha-1 (4%) at the higher B fertilization level. The observed increase in the yield of winter oilseed rape seeds in response to foliar application of B can be attributed to this micronutrient’s positive influence on seed production in siliques. Foliar fertilization with B increased B content and decreased Zn and Fe levels in the seeds of winter oilseed rape. When B fertilizer was applied at the rate of 150–300 g ha-1, the N and Ca content of the evaluated seeds increased. The fertilizer improved the nutritional value (crude fat content, fatty acid concentrations) of seeds, but deteriorated their feed value (total protein content, acid detergent fiber concentrations, neutral detergent fiber concentrations, quantitative and qualitative composition of glucosinolates).

The aim of the study was to evaluate the content, uptake, and utilization of Al, Mn, Fe, Co, and Mo from municipal sewage sludge by the reed canary grass (RCG) and the giant miscanthus (MG). The impact of sewage sludge on the mass ratios between microelements contained in the plant biomass was analyzed as well. The long-term field experiment consisted in application of four levels of fertilization with sewage sludge: 10, 20, 40, and 60 Mg DM·ha⁻¹. A non-fertilized control object (0 Mg DM·ha⁻¹) was used as well. The miscanthus biomass was characterized by higher content of Al and Mn, whereas higher levels of Fe, Co, and Mo were determined in the reed canary grass biomass. As in the case of the element content, the giant miscanthus was characterized by highest level of Al and Mn uptake, while the highest uptake of Fe, Co, and Mo was exhibited by the reed canary grass. In the group of the analyzed microelements, the giant miscanthus showed the highest the recovery of Mo (47%) followed by Mn (39%), Fe (35%), and Co (15%), and the lowest uptake was determined in the case of Al (5%). In addition to the use of their biomass for the production of renewable energy, energy crops (reed canary grass, giant miscanthus) can be used to recover microelements from municipal sewage sludge. Energy crop biomass can therefore be a potential source of microelements in animal feed. Attention was paid to the mass ratios of Fe:Mn, Fe:Al, Fe:Co, Fe:Mo, Mn:Al, Mn:Co, Mn:Mo, and Co:Mo in the biomass yield of the species used.