Miscanthus Research Articles

Cover crop and biofuel crop effects on hydraulic properties for claypan soils

AbstractPerennial biofuel and cover crops systems are important for enhancing soil health and can provide numerous soil, agricultural, and environmental benefits. The study objective was to investigate the effects of cover crops and biofuel crops on soil hydraulic properties relative to traditional management for claypan soils. The study site included selected management practices: cover crop (CC) and no cover crop (NC) with corn/soybean rotation, switchgrass (SW), and miscanthus (MI). The CC mixture consisted of cereal rye, hairy vetch, and Austrian winter pea. The research site was located at Bradford Research Center in Missouri, USA, and was implemented on a Mexico silt loam. Intact soil cores (76‐mm diam. by 76‐mm long) were taken from the 0–10, 10–20, 20–30, and 30–40 cm depths with three plot replicates and two sub‐samples per plot replicate per depth. Soil hydraulic properties evaluated for each sample included: saturated hydraulic conductivity (Ksat), water retention, bulk density, and pore size distributions. Results showed with the test of Duncan's least significant differences that treatments of MI (1.18 Mg m−3) and SW (1.21 Mg m−3) had lower values of bulk density averaging across soil depth than CC (1.27 Mg m−3) and NC (1.31 Mg m−3). Management systems significantly increased Ksat with the biofuel treatments at 0–10 cm compared to NC system. The MI management showed a significant increase in macroporosity and fine mesoporosity as compared to other management systems. Slight changes have occurred in the measured soil physical properties for CC system compared to NC plots. Overall, increasing soil organic matter from more plant roots from long‐term biofuel cropping systems can improve soil water storage and crop productivity.

Effects of soil physics, chemistry, and microbiology on soil carbon sequestration in infertile red soils after long‐term cultivation of perennial grasses

AbstractDetermining the effect of perennial energy crop (PEC) cultivation on soil organic carbon (SOC) in marginal land soil is vital for carbon neutrality and bioeconomy development. However, a comprehensive and systematic evaluation of the response of SOC content to different PECs and its underlying drivers is still lacking. We used soil data collected from infertile red topsoil (0–20 cm) after 10 years of cultivation with Miscanthus (MS), Panicum virgatum (SG), and Saccharum arundinaceum (SA) to explore the changes in SOC stock induced by PEC. The roles of physical, chemical, and microbiological factors driving the increase in the SOC stock were investigated. Results revealed that SA and MS enhanced SOC stock by 87.97% and 27.52% relative to the uncultivated control. Conversely, PEC increased the percentage of soil mega‐aggregates, geometric mean diameters, soil chelate iron (Fe), and aluminum (Al) oxides, and reduced soil acidity for the infertile red soils. In addition, fungal richness and diversity for PEC soils were enhanced compared to the unplanted soil. It is possible that PEC cultivation reduced the relative abundance of copiotrophic fungi but increased the relative abundance of oligotrophic fungi. Furthermore, variance partitioning analysis revealed that chemical and microbiological factors accounted for 80.54% of the total variation for the SOC stock. The partial least squares path model showed that PEC cultivation enhanced soil carbon (C) stock via soil deacidification and increased soil bacterial function. In conclusion, this study confirms the SOC sequestration potential of PEC cultivation in marginal land and the underlying mechanism driving SOC stock. The main positive factors controlling soil C sequestration included “pH,” while the negative factors were “bacterial community,” “fungal community,” and “bacterial function.” Our research may help encourage and support decision‐makers of wasted marginal land conversion to PEC cultivation.

N2O emissions from decomposing crop residues are strongly linked to their initial soluble fraction and early C mineralization

The emission of nitrous oxide (N2O), a strong greenhouse gas, during crop residue decomposition in the soil can offset the benefits of residue recycling. The IPCC inventory considers agricultural N2O emissions proportional to the amount of nitrogen (N) added by residues to soils. However, N2O involves several emission pathways driven directly by the form of N returned and indirectly by changes in the soil induced by decomposition. We investigated the decomposition factors related to N2O emissions under controlled conditions. Residues of sugar beet (SUB), wheat (WHT), rape seed (RAS), potato (POT), pea (PEA), mustard (MUS), red clover (RC), alfalfa (ALF), and miscanthus (MIS), varying by maturity at the time of collection, were incubated in two soils (GRI and SLU) at 15 °C with a water-filled pore space of 60%. The residues contained a wide proportion range of water-soluble components, components soluble in neutral detergent (SOL-NDS), hemicellulose, cellulose, and lignin. Their composition drastically influenced the dynamics of C mineralization and soil ammonium and nitrate and was correlated with N2O flux dynamics. The net cumulative N2O emitted after 60 days originated mostly from MUS (4828 ± 892 g N-N2O ha-1), SUB (2818 ± 314 g N-N2O ha-1) and RC (2567 ± 1245 g N-N2O ha-1); the other residue treatments had much lower emissions (<200 g N-N2O ha-1). For the first time N2O emissions could be explained only by the residue content in the SOL-NDS, according to an exponential relationship. Residues with a high SOL-NDS (>25% DM) were also non-senescent and promoted high N2O emissions (representing 1–5% of applied N), likely directly by nitrification and indirectly by denitrification in microbial hotspots. Crop residue quality appears to be valuable information for accurately predicting N2O emissions and objectively weighing their other potential benefits to agriculture and the environment.

Chlorophyll Fluorescence as a Criterion for the Diagnosis of Abiotic Environmental Stress of &lt;i&gt;Miscanthus x Giganteus&lt;/i&gt; Hybrid

Chlorophyll Fluorescence as a Criterion for the Diagnosis of Abiotic Environmental Stress of &lt;i&gt;Miscanthus x Giganteus&lt;/i&gt; Hybrid

Meta-analysis of leaf area index, canopy height and root depth of three bioenergy crops and their effects on land surface modeling

The expected large-scale expansion of biofuel production in climate change mitigation scenarios calls for improvements in the representation of bioenergy crops in land surface models. Leaf area index (LAI), canopy height (CH) and root depth (RD) are key parameters that regulate exchanges of heat and moisture between land and atmosphere. This study performs a meta-analysis combining unique data from 34 observational studies and 14 countries to estimate monthly variability in LAI, CH, and RD of three main bioenergy crops: miscanthus (MSC), switchgrass (SWG), and reed canary grass (RCG). Using the Community Land Model v.5.0 and the results from the meta-analysis, we also tested the effects that variability in parameterization of LAI and CH have on key components of the surface energy budget, relative to prescribed values. Results from the meta-analysis show a strong seasonality of LAI and CH, with mean (± one standard error) LAI values at the peak summer month of 6.05 ± 0.84, 5.56 ± 0.75, and 5.39 ± 1.15 m2/m2, and maximum CH of 246 ± 23, 147 ± 16, and 156 ± 10 cm, for MSC, SWG, and RCG, respectively. These values are typically larger than the default parameterizations in CLM. Information on RD was limited and average values are 172 ± 56, 165 ±46, and 193 ± 11 cm, for MSC, SWG, and RCG, respectively. The seasonal cycles of latent heat, sensible heat and surface albedo are primarily affected by the range of LAI values, and less sensitive to variability in CH. Relative to the default values, higher LAI values increase latent heat and decrease sensible heat, with the highest absolute changes in summer. They also decrease surface albedo in winter months due to a larger snow masking effect. Our results offer a basis to compare experimental work and modelling studies, improve parameterization in land surface models, and identify the importance of vegetation structure parameters to evaluate key climate processes in response to bioenergy crops.

Highly fluorescent graphene quantum dots from biorefinery waste for tri-channel sensitive detection of Fe3+ ions

Renewable lignocellulosic biomass can be effectively transformed to value-added products, enabling fast growth of related downstream processing. However, valorization of the by-produced cellulose-poor fraction, which is also in large volumes, is only occasionally reported regarding existing technologies. Here, a simple, general, and effective strategy for fabricating graphene quantum dots (GQDs) from the Miscanthus (MC) biorefinery waste consisting of sugars and depolymerized lignin, is developed. This process involves the fast and selective removal of most lignin and hemicellulose based on mild acid hydrotrope fractionation, with followed hydrothermal carbonization. The as-fabricated MC-derived GQDs (M-GQDs) exhibit several advantages such as few-layer graphene-like single crystalline structure, sulfur and nitrogen co-doping, bright fluorescence, excitation-dependent photoluminescence, and long fluorescence lifetime (11.95 ns). Furthermore, M-GQDs present prominent fluorescence reduction in the presence of Fe3+ with good linearity (≤0.995) and very low detection limit (≥1.41 nM). Later, it is found that the observed high sensitivity for Fe3+ is based on a dynamic quenching mechanism, which is caused by the Fe3+-induced increase in both the energy dissipation and photogenerated electron consumption. This work is anticipated to open new opportunities for promoting the integral valorization of biomass and sensitive fluorometric detection of Fe3+.

Effect of Sulfur on Bio-Modified Rubberized Bitumen

This paper examines how the effect of sulfur on bio-modified rubberized bitumen depends on the bio-modifier’s chemical composition. The study was performed on rubberized bitumen modified with bio-derived compounds from castor oil (CO), corn stover (CS), miscanthus (MS), wood pellets (WP), and waste vegetable oil (WVO). The effect of sulfur on the evolution of the thermo-mechanical and chemical properties of rubberized bitumen was monitored for 60 days. The study results showed that the introduction of sulfur significantly reduced the elasticity of rubberized bitumen. However, as curing time progressed, the elasticity was regained to some extent. Each case had a different curing rate, with WVO having the overall fastest curing rate and WP having the slowest. The observed curing phenomenon was attributed to the progress of sulfur recrystallization and sulfur-bitumen interactions. Among all scenarios, bio-modified rubberized bitumen containing vegetable oils (CO and WVO) was more impacted by the introduction of sulfur, as evidenced by the highest change in elasticity, the greatest percent recovery, and the fastest curing rate. In addition, vegetable-oil-based scenarios showed a continued gain in elasticity even after 60 days. The latter was attributed to vegetable oils having the highest content of unsaturated compounds, giving rise to sulfur-bitumen reactions. As evidenced in our infrared spectroscopy results, carbon–sulfur bond indexes continuously increased and alkene decreased during the curing time. The latter was most evident in the cases of CO and WVO, with alkene reductions of 10.7% and 10.8%, respectively, during the 60-day curing. The study outcomes provide insights pertaining to the interplay between sulfur and bitumen modifiers such as bio-oils. This in turn helps asphalt producers take advantage of the synergy between modifiers to enhance sustainability in construction.

Recyclable deep eutectic solvent coupling sodium hydroxide post-treatment for boosting woody/herbaceous biomass conversion at mild condition

A novel recyclable deep eutectic solvent (DES) consisting of p-toluene sulfonic acid (p-TsOH) and choline chloride (ChCl) was developed for efficient woody poplar sawdust (PL) and herbaceous miscanthus (MC) conversion at mild condition. The extraction of leftover lignin on the surface of DES pretreated residues using NaOH solution at room temperature greatly improved the enzymatic hydrolysis efficiency. Near complete cellulose conversion of PL and MC residues were obtained with a degree of delignification and xylan removal over 90% at 100 °C within 40 min. The strong correlations between xylan (R2 = 0.95) and lignin (R2 = 0.82) removal with cellulose conversion were observed in MC as well as positive correlations (R2 > 0.77) in PL. The results demonstrated that the DES system coupling NaOH post-treatment was a promising method to achieve an economically feasible biomass conversion process, which was effective for both woody PL residues and herbaceous MC.

Synthesis of Large-Scale Supply Networks for Complete Long-term Transition from Fossil to Renewable-based Production of Energy and Bioproducts

This contribution presents the synthesis of sustainable larger-scale supply networks to produce alternative energy and bioproducts across an entire system’s lifetime. In particular, production of food, first, second and third generation of biofuels, hydrogen, and renewable electricity are considered. Corn and wheat grain are used for production of food; corn stover, wheat straw, miscanthus, forest residue, algae oil and waste cooking oil are biomass and waste sources for the manufacture of bioproducts; and solar, wind and geothermal sources for electricity production. The objective of supply network synthesis is the maximization of Sustainability Net Present Value, which is a sustainability metric composed of economic, environmental and social net present values. The dynamic mixed-integer linear programming problem is formulated as a multi-period model where i) monthly time periods are used for the manufacture of biomass and bioproducts, while ii) daily, hourly and monthly periods are used for the production of electricity. A case study of EU-27 is considered and gradual energy transition from the current energy supply to 100 % renewable-based production of fuels and electricity over a time horizon of 40 y is investigated. The results of this study indicate that long-term transition from fossil to renewable-based generation of electricity, fuels and bioproducts is possible to a large extent. The results suggest an optimal selection of types, locations and dynamics of technology installations across the EU in order to achieve energy transition in the transport and electricity sectors.

Near-complete enzymatic hydrolysis efficiency of Miscanthus using hydrotropic fractionation at atmospheric pressure

Enhanced enzymatic saccharification of Miscanthus (MC) biomass, based on a novel benzenesulfonic acid (BA)-induced fractionation at mild condition as the pretreatment, gives a good example for the efficient transformation of energy crops into value-added products with minimal environmental impact. The results indicated that BA could facilitate the rapid and high solubilization of both lignin and hemicellulose, approximately 90.8 % of lignin and 75.5 % of hemicellulose were removed at 80 °C within 20 min. Consequently, the subsequent enzymatic hydrolysis efficiency was greatly enhanced to obtain an improved enzymatic digestibility with a high glucose yield of 97.9 %. Our study opens up an innovative avenue for the efficient valorization of the recalcitrant energy crops as MC.

Lignin-based resins for kraft paper applications

We investigated miscanthus (MS) and willow (W) lignin-furfural based resins as potential reinforcement agents on softwood and hardwood kraft paper. These resins might be sustainable alternatives to the commercial phenol-formaldehyde (PF) resins. Phenol is a petrochemical product and formaldehyde has been classified as a carcinogen by the U.S. Environmental Protection Agency. The lignin used in this study was derived from hot water extraction (160ºC, 2 h) of MS and W biomass, and may be considered sulfur-free. These biorefinery lignins were characterized for their chemical composition and inherent properties via wet chemistry and instrumental techniques. The resin blends (MS-resin and W-resin) were characterized for their molecular weight, thermal behavior, and mechanical properties. Mechanical properties were measured by the resin’s ability to reinforce softwood and hardwood kraft papers. The effect of adding hexamethylenetetramine (HMTA), a curing agent, to the resin was also examined. Mixtures of PF and lignin-based resins were investigated to further explore ways to reduce use of nonrenewables, phenol, and carcinogenic formaldehyde. The results show that lignin-based resins have the potential to replace PF resins in kraft paper applications. For softwood paper, the highest strength was achieved using W-resin, without HMTA (2.5 times greater than PF with HMTA). For hardwood paper, MS-resin with HMTA gave the highest strength (2.3 times higher than PF with HMTA). The lignin-based resins, without HMTA, also yielded mechanical properties comparable to PF with HMTA.

Production of Liquid Compounds by Co-Pyrolysis of Different Pre-Treated Biomasses Mixed With Plastic Wastes

As an innovation to conventional biomass pyrolysis to produce liquid biofuels, different types of biomass wastes were pre-treated by autohydrolysis, prior to pyrolysis. Eucalyptus forestry waste, corn cobs agricultural residue, and miscanthus (an energy crop) were autohydrolysed. Autohydrolysis led to valuable sugar-rich stream that may be used in fermentation and to solids rich in lignin that were pyrolysed. Pyrolysis of autohydrolysed eucalyptus led to an increase in liquids yields of 24 % in relation to untreated eucalyptus, as autohydrolysis weakened initial macromolecular structure and thus helped chemical bonds breakdown during pyrolysis. However, similar pyrolysis liquid yields were obtained by autohydrolysed or untreated corn cobs and miscanthus, thus feedstock composition is an important issue. Nevertheless, the production of added value products by autohydrolysis may still justify this pre-treatment. Otherwise, more severe pre-treatments of these biomasses might improve co-pyrolysis as it happened with eucalyptus. As polyethylene (PE) is easier to pyrolyse than biomass and greatly favours the production of liquid hydrocarbons, autohydrolysed and untreated biomass was mixed with PE wastes to be used in co-pyrolysis. The rise of PE content in the blend clearly favoured the production of liquid products of pre-treated and untreated biomass. 75 %wt. of PE in the blend led to liquid yields of 72 %wt. for untreated eucalyptus and of 82 %wt. for autohydrolysed eucalyptus.

Comparison of the Effect of Perennial Energy Crops and Arable Crops on Earthworm Populations

The purpose of the study was to compare earthworm communities under winter wheat in different crop production systems on arable land—organic (ORG), integrated (INT), conventional (CON), monoculture (MON)—and under perennial crops cultivated for energy purposes—willow (WIL), Virginia mallow (VIR), and miscanthus (MIS). Earthworm abundance, biomass, and species composition were assessed each spring and autumn in the years 2014–2016 using the method of soil blocks. The mean species number of earthworms was ordered in the following way: ORG &gt; VIR &gt; WIL &gt; CON &gt; INT &gt; MIS &gt; MON. Mean abundance of earthworms decreased in the following order: ORG &gt; WIL &gt; CON &gt; VIR &gt; INT &gt; MIS &gt; MON. There were significantly more species under winter wheat cultivated organically than under the integrated system (p = 0.045), miscanthus (p = 0.039), and wheat monoculture (p = 0.002). Earthworm abundance was significantly higher in the organic system compared to wheat monoculture (p = 0.001) and to miscanthus (p = 0.008). Among the tested energy crops, Virginia mallow created the best habitat for species richness and biomass due to the high amount of crop residues suitable for earthworms and was similar to the organic system. Differences in the composition of earthworm species in the soil under the compared agricultural systems were proven. Energy crops, except miscanthus, have been found to increase earthworm diversity, as they are good crops for landscape diversification.

Advanced strategy to produce insecticidal destruxins from lignocellulosic biomass Miscanthus

BackgroundBiorefineries are widely recognized as the most feasible solution to the problem of achieving environmental sustainability along with economic growth. Furthermore, pine wilt disease has caused severe environmental and economic damage worldwide to date. Herein, a highly efficient, advanced process for producing destruxins (DTXs) from Miscanthus (MCT) is reported, along with an application strategy.ResultsThe acetic acid–sodium chlorite pretreatment of MCT (AASC-MCT) is found to improve the monosaccharide production. Through biocatalytic conversion processes (simultaneous saccharification and cultivation), Metarhizium anisopliae JEF-279 can efficiently produce DTXs from 1% (w/v) AASC-MCT, i.e., DTX E (334.8 mg/L), A (288.8 mg/L), and B (48.6 mg/L). Monochamus alternatus (MA, Japanese pine sawyer) is known to act as a mediator transferring Bursaphelenchus xylophilus to pinewood. As B. xylophilus is associated with the occurrence of pine wilt disease, biological control of MA is a major strategy or controlling this disease. In this study, upon the application of a mixture of DTXs and protease-containing culture filtrate (PCF), complete mortality of MA is observed after a 5-day incubation. The MA immune system response is believed to cause an overexpression of actin and tropomyosin as a defense mechanism against the flaccid paralysis induced by the DTXs and PCF treatment.ConclusionsThese results suggest that MCT can be used as a major feedstock in the biorefinery industry and that DTXs can be applied as an insecticide for biological control of pine wilt disease via MA termination.

Production of Agri-Energy Crop Miscanthus gigantheus on Land Degraded by Power Industry: SWOT Analysis

Production of Agri-Energy Crop Miscanthus gigantheus on Land Degraded by Power Industry: SWOT Analysis

Pelletization of wood and alternative residual biomass blends for producing industrial quality pellets

Pellets for industrial use were produced from blends of pine sawdust (PIN) and alternative residual biomasses in a pilot-scale pelletizer. The effect of the pelletization temperature (T = 50–80 °C) and biomass moisture content (MC = 14–20%) on pine sawdust pellet quality was studied by using response surface methodology (RSM). Pelletization performance was evaluated on the basis of the durability, bulk density, moisture content, lower heating value (LHV), energy density, diameter, length and density of the pellets. From the RSM analysis, a maximum durability value of 99.4% was obtained at T = 80 °C and MC = 16.6%. Under these conditions, all the parameters showed values within the required range of industrial pellet qualities, i.e., a bulk density of 616 kg/m3, a pellet moisture content of 7.6%, a lower heating value (as received) of 18 MJ/kg, a diameter of 6.2 mm and a length of 23.4 mm. Blends of pine sawdust with eleven unconventional biomass samples were then pelletized under the optimum conditions to obtain pellets for industrial use according to the categories of quality defined by ISO 17225-2. Blends of pine sawdust with almond shells (AS) and olive stones (OS) contents of up to 30 wt%, as well as with pine cone leafs (PCL) contents of up to 15 wt%, produced I1 pellets. Blends of pine sawdust with coffee dregs (CD), coffee husks (CH) and grape pomace (GP) proportions of up to 10 wt%, as well as with hazelnut shells (HS), miscanthus (MIS), pine kernel shells (PKS) and switchgrass (SG) contents of up to 15 wt%, and also with a PCL content of between 15 and 30 wt%, generated I3 class pellets. Classification was not possible for cocoa shells (CS) mixed with pine sawdust due to the low bulk density of the pellets. Energy consumption resulting from the pelletization of the blends was evaluated with values ranging from 0.09 to 0.33 kWh/kg, while the pelletization of pine sawdust required 0.18 kWh/kg. The addition of alternative biomass feedstocks to pine sawdust may therefore serve to reduce energy consumption in industrial pelletization.

Physicochemical Characteristics of Biochars Derived From Corn, Hardwood, Miscanthus, and Horse Manure Biomasses

ABSTRACTBiochar, a carbon-rich by-product of biomass pyrolysis, is widely recognized as a potential ingredient for soil amendment, fertility, and carbon sequestration owing to its favorable physicochemical properties. The objective of this study was to investigate the chemical and physical properties of biochars produced through pyrolysis at 450°C from agricultural residues available in Northwest Missouri, namely hardwood (HW), corn stover (CR), miscanthus (MS), and horse manure (HM). These properties were assessed through the analysis of pyrolysis yield, pH, volatile matter, fixed carbon, ash and carbon (C), hydrogen (H), sulfur (S), nitrogen (N) contents, trace metal concentrations, surface morphology, surface functional groups, bulk density, and water holding capacity. The biochars derived from HW, MS and CR materials showed high volatile-matter (33–42%), high fixed carbon contents (42–47%), very low ash contents (6–15%), and low bulk density (0.14–0.28 g cm−3) as compared to that of HM. A wide range of trace elements was observed in biochar samples with significant differences in concentrations. In addition, CR, HW and MS biochars displayed a disordered graphitic-like structure with well-developed pores and surface areas of 23, 70 and 90 m2/g respectively, and high water-holding capacity up to 750%, indicating their potential application as a soil amendment.

Changes in Miscanthus sacchariflorus Growth and Heading Rate Influenced by Water Stress Treatment at Reproductive Growth Stage

Changes in Miscanthus sacchariflorus Growth and Heading Rate Influenced by Water Stress Treatment at Reproductive Growth Stage

Cellulose nanocrystals from Miscanthus fibers: insights into rheological, physico-chemical properties and polymer reinforcing ability

Cellulose nanocrystals (CNC) were extracted from Miscanthus (MST) fibers using a sulfuric acid hydrolysis process. The results showed that the obtained CNC exhibit a needle-like shape with an average aspect ratio of 37. The surface charge density was measured at 1.99 sulfate groups per 100 anhydroglucose units while the zeta potential value was found to be -38 mV. The crystallinity of the extracted CNC was 76%, and the cellulose I type crystal structure was predominant. Due to its high importance for potential application of CNC in aqueous systems, the rheological behavior of CNC aqueous suspensions at various CNC concentrations was determined. The CNC suspensions showed gel-like behavior at very low CNC concentrations ranging from 0.1 wt% up to 0.6 wt%, as confirmed by the steady shear viscosity measurements and the oscillatory dynamic tests. The dynamic rheological parameters of CNC suspensions were slightly affected by the temperature profile. At high temperature up to 80 °C a stronger CNC network is formed by increasing the relative motion resistance of CNC macromolecules and the entanglement. In order to identify the reinforcing ability of the newly extracted CNC, starch-based nanocomposite films were produced with various CNC contents (1, 3, 5 and 8 wt%) and their tensile properties were investigated. It was found that the addition 8 wt% CNC within starch matrix increased the Young’s modulus by 150% and the tensile strength by 118%, resulting in mechanically strong and eco-friendly nanocomposite materials.

Seedling Plug and Cutting Method for Multi-propagation of Ornamental Miscanthus Spp.

억새(Miscanthus spp.)는 경관성이 우수하고 환경친화적이며 저관리가 가능한 종 들로 알려져 있다. 플러그묘를 통한 대량번식을 위해 4가지 품종의 억새(M. sinensis 'Andersson', 'Strictus', 'Gracillimus', 'Variegatus')와 삽목번식을 위한 3가지 품종의 억새(M. sinensis 'Gracillimus', M. xgiganteus, M. saccharif...