Journal Article

Biomass production and energy balance of Miscanthus over a period of 11 years: A case study in a large‐scale farm in Poland

Dubis, Bogdan, Załuski, Dariusz, Szempliński, Władysław, Jankowski, Krzysztof Józef, Bórawski, Piotr

2019

Overview

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. In northeastern Poland, the biomass yield of Amur silver grass was determined at 9.26 Mg DM/ha, and it was equivalent to 60% dry matter yield of giant miscanthus (average for 11 years). Giant miscanthus produced the highest biomass yield in year 5, and Amur silver grass in year 11. The average energy efficiency of giant miscanthus biomass was determined at 13.6 during the 11 year experiment, whereas the energy efficiency of Amur silver grass was 46% lower. The energy efficiency of giant miscanthus biomass was highest (23.2–23.3) in years 5 and 6, and Amur silver grass was characterized by the highest energy yield in year 11 (14.3).

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Agricultural production / Alternative energy sources / Amur silver grass / Biogas / Biomass / Biomass energy production / Corn / Crop yield / Crops / Cultivation / Dry matter / Energy balance / Energy crops / Energy efficiency / energy efficiency ratio / energy gain / energy inputs / Energy output / Experiments / Farms / Fertilizers / giant miscanthus / Grasses / Mineral fertilizers / Miscanthus / Photosynthesis / Plantations / Potential energy / Power efficiency / Raw materials / Renewable energy / Renewable resources / Rhizomes / Salinity