Impact of Plant Growth Regulators to Development of the Second Generation Energy Crop Miscanthus × giganteus Produced Two Years in Marginal Post-Military Soil

The impact of the plant growth regulators (PGRs) Stimpo, Regoplant, and Charkor on the production of the second-generation energy crop Miscanthus × giganteus on marginal post-military soil was investigated during two vegetation seasons. The land, previously a tank training polygon, has not been in use since 1990 and has become marginal. Biological parameters (stem, shoot, and root lengths) and dry biomass values were evaluated in relation to the applied treatments. The multivariate general linear model (M-GLM) results showed a positive influence of Charkor on M. × giganteus development; the effect was markedly higher in the second year of vegetation. The impact of Stimpo and Regoplant was less noticeable; nevertheless, certain combinations of treatments showed satisfactory results. The M-GLM approach detected the inter-influence of the main factors of the production process, i.e., PGRs, soil, and year of growing. The results showed the predominant influence of year, PGRs and combined factor PGRs × year on the biological parameters; the other studied factors and their combinations were not as effective. Further research should focus on verifying the field-scale results for the M. × giganteus plantation established in a post-military area and compare the lab and field studies.

Harvesting Technologies and Costs of Biomass Production from Energy Crops Cultivated on Farms in the Małopolska Region

This study aimed to assess biomass production costs from perennial energy crops, such as Miscanthus giganteus, Sida hermaphrodita, and coppiced willow, in selected agricultural holdings. This assessment was based on applied technologies for harvesting the biomass of the energy crops mentioned above. The scope of the study included research on ten farms located in Małopolska and establishing the possibility of biomass production from selected energy crops in these entities. Biomass production costs have been estimated using the computer application “Bioalkylation”. The result of the research was the answer to the question: what can be the cost range of biomass production from perennial energy crops for the crops Miscanthus giganteus, Sida hermaphrodita, and coppiced willow as the most popular plants? The study shows that production costs depend primarily on the harvesting technology used and the machinery used in the farm. The harvest with rotary mowers, small presses, and windrows was applied regarding Miscanthus giganteus and Sida hermaphrodita. The costs of biomass production were, on average, 424.7 EUR ha−1 for Miscanthus giganteus and 278.9 EUR ha−1 for Sida hermaphrodita. Concerning tonne, this was 37.6 EUR t−1 for Miscanthus giganteus and 30.0 EUR t−1 for Sida hermaphrodita, respectively. In the case of harvesting energy willow, in the form of whole shoots, inefficient and labour-intensive technologies using chainsaws and combustion cutters were applied. The biomass production costs were thus the highest among the assessed plants and amounted, on average, to 612.1 EUR ha−1, which in terms of tonne corresponded to a value of 30.6 EUR. The obtained results and the analysis presented in the paper may help in planning the cultivation of perennial energy crops in order to obtain biomass used for heating purposes on a farm.

Methods of Increasing Miscanthus Biomass Yield for Biofuel Production

The lignocellulosic perennial crop miscanthus, especially Miscanthus × giganteus, is particularly interesting for bioenergy production as it combines high biomass production with low environmental impact. However, there are several varieties that pose a hazard due to susceptibility to disease. This review contains links showing genotype and ecological variability of important characteristics related to yield and biomass composition of miscanthus that may be useful in plant breeding programs to increase bioenergy production. Some clones of Miscanthus × giganteus and Miscanthus sinensis are particularly interesting due to their high biomass production per hectare. Although the compositional requirements for industrial biomass have not been fully defined for the various bioenergy conversion processes, the lignin-rich species Miscanthus × giganteus and Miscanthus sacchariflorus seem to be more suitable for thermochemical conversion processes. At the same time, the species Miscanthus sinensis and some clones of Miscanthus × giganteus with low lignin content are of interest for the biochemical transformation process. The species Miscanthus sacchariflorus is suitable for various bioenergy conversion processes due to its low ash content, so this species is also interesting as a pioneer in breeding programs. Mature miscanthus crops harvested in winter are favored by industrial enterprises to improve efficiency and reduce processing costs. This study can be attributed to other monocotyledonous plants and perennial crops that can be used as feedstock for biofuels.

Organosolv lignin aggregation behaviour of soluble lignin extract from Miscanthus x giganteus at different ethanol concentrations and its influence on the lignin esterification

Background Lignin is the second most abundant naturally occurring biopolymer from lignocellulosic biomass. While there are several lignin applications, attempts to add value to lignin are hampered by its inherent complex and heterogenous chemical structure. This work assesses the organosolv lignin aggregates behaviour of soluble lignin extract derived from Miscanthus × giganteus using different ethanol concentrations (50%, 40%, 30%, 20%, 10% and 1%). The effect of two different lignin concentrations using similar ethanol concentration on the efficacy of esterification was studied. Results Overall, particle size of lignin analysis showed that the particle size of lignin aggregates decreased with lower ethanol concentrations. 50% ethanol concentration of soluble lignin extract showed the highest particle size of lignin (3001.8 nm), while 331.7 nm of lignin particle size was recorded at 1% ethanol concentration. Such findings of particle size correlated well with the morphology of the lignin macromolecules. The lignin aggregates appeared to be disaggregated from population of large aggregates to sub-population of small aggregates when the ethanol concentration was reduced. Light microscopy images analysis by ImageJ shows that the average diameter and circularity of the corresponding lignin macromolecules differs according to different ethanol concentrations. The dispersion of lignin aggregates at low ethanol concentration resulted in high availability of hydroxyl group in the soluble lignin extract. The efficacy of the lignin modification via esterification was evidenced directly via FTIR using the similar ethanol concentration of soluble lignin extract at different lignin concentrations. Conclusion This study provided the understanding of detail analysis on particle size determination, microscopic properties and structural insights of lignin aggregates at wider ethanol concentrations. The esterified lignin derived at 5 mg/mL is suggested to expand greater lignin functionality in the preparation of lignin bio-based materials.

Exploring the Bioethanol Production Potential of Miscanthus Cultivars

Miscanthus is a fast-growing perennial grass that attracts significant attention for its potential application as a feedstock for bioethanol production. This report explores the difference in the lignocellulosic composition of various Miscanthus cultivars, including Miscanthus × giganteus cultivated at the same location (mainly Lincoln, UK). It also assesses the sugar release profiles and mineral composition profiles of five Miscanthus cultivars harvested over a growing period from November 2018 to February 2019. The results showed that Miscanthus × giganteus contains approximately 45.5% cellulose, 29.2% hemicellulose and 23.8% lignin (dry weight, w/w). Other cultivars of Miscanthus also contain high quantities of carbohydrates (cellulose 41.1–46.0%, hemicellulose 24.3–32.6% and lignin 21.4–24.9%). Pre-treatment of Miscanthus using dilute acid followed by enzymatic hydrolysis released 63.7–80.2% of the theoretical glucose content. Fermentation of a hydrolysate of Miscanthus × giganteus using Saccharomyces cerevisiae NCYC2592 produced 13.58 ± 1.11 g/L of ethanol from 35.13 ± 0.46 g/L of glucose, corresponding to a yield of 0.148 g/g dry weight Miscanthus biomass. Scanning electron microscopy was used to study the morphology of raw and hydrolysed Miscanthus samples, which provided visual proof of Miscanthus lignocellulose degradation in these processes. The sugar release profile showed that a consequence of Miscanthus plant growth is an increase in difficulty in releasing monosaccharides from the biomass. The potassium, magnesium, sodium, sulphur and phosphorus contents in various Miscanthus cultivars were analysed. The results revealed that these elements were slowly lost from the plants during the latter part of the growing season, for a specific cultivar, until February 2019.

Phosphorus availability and leaching losses in annual and perennial cropping systems in an upper US Midwest landscape

Excessive phosphorus (P) applications to croplands can contribute to eutrophication of surface waters through surface runoff and subsurface (leaching) losses. We analyzed leaching losses of total dissolved P (TDP) from no-till corn, hybrid poplar (Populus nigra X P. maximowiczii), switchgrass (Panicum virgatum), miscanthus (Miscanthus giganteus), native grasses, and restored prairie, all planted in 2008 on former cropland in Michigan, USA. All crops except corn (13 kg P ha−1 year−1) were grown without P fertilization. Biomass was harvested at the end of each growing season except for poplar. Soil water at 1.2 m depth was sampled weekly to biweekly for TDP determination during March–November 2009–2016 using tension lysimeters. Soil test P (0–25 cm depth) was measured every autumn. Soil water TDP concentrations were usually below levels where eutrophication of surface waters is frequently observed (> 0.02 mg L−1) but often higher than in deep groundwater or nearby streams and lakes. Rates of P leaching, estimated from measured concentrations and modeled drainage, did not differ statistically among cropping systems across years; 7-year cropping system means ranged from 0.035 to 0.072 kg P ha−1 year−1 with large interannual variation. Leached P was positively related to STP, which decreased over the 7 years in all systems. These results indicate that both P-fertilized and unfertilized cropping systems may leach legacy P from past cropland management.