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The demand for renewable energy resources, such as Miscanthus spp., has increased significantly in temperate regions. Miscanthus spp. has the potential to mitigate GHG emissions by replacing fossil fuels and sequestering carbon in soil. However, the biomass yield and C sequestration performance of Miscanthus spp. varies by climate, soil type, management practices, and land-use history. Therefore, there is a need for site-specific research on biomass yield and C sequestration of Miscanthus × giganteus (M × g). An alternative to M × g is the seed-propagated Miscanthus sinensis which could be another option as a bioenergy crop. The objective of this study was to assess the C sequestration rates and biomass yield performance of these two Miscanthus spp. The C sequestration rates were measured in side-by-side comparison plots using the 13C natural abundance technique. The results revealed C sequestration rates of M × g and M. sinensis were 1.96 ± 0.82 and 0.99 ± 0.21 Mg C ha−1 year−1 over 6 years. The average biomass yields of M × g and M. sinensis from 2010 to 2015 were 25.6 ± 0.2 and 31.2 ± 0.5 Mg ha−1 year−1, respectively. It can be concluded that M. sinensis has a higher yield while M × g has a higher potential for immediate C sequestration in cool regions such as Northern Japan.

Background: Miscanthus × giganteus is widely recognized as a promising lignocellulosic biomass crop due to its advantages of high biomass production, low environmental impacts, and the potential to be cultivated on marginal land. However, the high costs of bioethanol production still limit the current commercialization of lignocellulosic bioethanol. The lignin in the cell wall and its by-products released in the pretreatment step is the main component inhibiting the enzymatic reactions in the saccharification and fermentation processes. Hence, genetic modification of the genes involved in lignin biosynthesis could be a feasible strategy to overcome this barrier by manipulating the lignin content and composition of M. × giganteus. For this purpose, the essential knowledge of these genes and understanding the underlying regulatory mechanisms in M. × giganteus is required. Results: In this study, MgPAL1, MgPAL5, Mg4CL1, Mg4CL3, MgHCT1, MgHCT2, MgC3′H1, MgCCoAOMT1, MgCCoAOMT3, MgCCR1, MgCCR2, MgF5H, MgCOMT, and MgCAD were identified as the major monolignol biosynthetic genes in M. × giganteus based on genetic and transcriptional evidence. Among them, 12 genes were cloned and sequenced. By combining transcription factor binding site prediction and expression correlation analysis, MYB46, MYB61, MYB63, WRKY24, WRKY35, WRKY12, ERF021, ERF058, and ERF017 were inferred to regulate the expression of these genes directly. On the basis of these results, an integrated model was summarized to depict the monolignol biosynthesis pathway and the underlying regulatory mechanism in M. × giganteus. Conclusions: This study provides a list of potential gene targets for genetic improvement of lignocellulosic biomass quality of M. × giganteus, and reveals the genetic, transcriptional, and regulatory landscape of the monolignol biosynthesis pathway in M. × giganteus. [ABSTRACT FROM AUTHOR]

The multiyear cultivation of Miscanthus × giganteus Greef et Deu (M.×giganteus) at the soils polluted by metal(loid)s were researched. The biomass parameters and concentrations of elements: Ti, Mn, Fe, Cu, Zn, As, Sr, and Mo were determined in the plant's organs at harvest. The same metal(loid)s were monitored in the plant's leaves throughout three vegetation seasons. The principal component analysis and general linear model approaches were applied for statistical evaluation followed by Box-Cox transformation. The difference in the distribution of elements in the plant, the content of elements in the soil, various regime of uptake to the plant tissues, and the year of vegetation were analyzed as driving factors of the phytoremediation. The results showed that the leading promoter was the factor of the zone, which was the most essential for Ti, Fe, and Cu and the smallest for Mn. The factor of differences in soil pollution was essential for Zn and Mo, much less for As, Sr, and Mn, limited for Fe, and was not seen for Ti and Cu. The factor of the interrelation effects of the zone and experiment reflected the different regime of uptake for the plant tissues was seen for two elements: more prominent for Cu and smaller for Ti. While analyzing the dynamic of foliar concentrations of the metal(loid)s during 3 years, two groups were defined. Firstly, Fe, Ni, Mn, and Sr showed stable curves with limited distribution of the plant life cycle. Secondly, As, Zn, Cu, and Mo showed different fluctuations in the curves, which can be attributed to essential influence of those elements to the plant life cycle. Further research will be focused on the application of M.×giganteus to the polluted soil in a bigger scale and comparison results of laboratory and field experiments. [ABSTRACT FROM AUTHOR]

Spatially explicit farm‐gate production costs and the economic potential of three types of energy crops grown on available marginal land in China for 2017 and 2040 were investigated using a spatial accounting method and construction of cost–supply curves. The average farm‐gate cost from all available marginal land was calculated as 32.9 CNY/GJ for Miscanthus Mode, 27.5 CNY/GJ for Switchgrass Mode, 32.4 CNY/GJ for Miscanthus & Switchgrass Mode, and 909 CNY/GJ for Jatropha Mode in 2017. The costs of Miscanthus and switchgrass were predicted to decrease by approximately 11%‐15%, whereas the cost of Jatropha was expected to increase by 5% in 2040. The cost of Jatropha varies significantly from 193 to 9,477 CNY/GJ across regions because of the huge differences in yield across regions. The economic potential of the marginal land was calculated as 28.7 EJ/year at a cost of less than 25 CNY/GJ for Miscanthus Mode, 4.0 EJ/year at a cost of less than 30 CNY/GJ for Switchgrass Mode, 29.6 EJ/year at a cost of less than 25 CNY/GJ for Miscanthus & Switchgrass Mode, and 0.1 EJ/year at a cost of less than 500 CNY/GJ for Jatropha Mode in 2017. It is not feasible to develop Jatropha production on marginal land based on existing technologies, given its high production costs. Therefore, the Miscanthus & Switchgrass Mode is the most economical way, because it achieves the highest economic potential compared with other modes. The sensitivity analysis showed that the farm‐gate costs of Miscanthus and switchgrass are most sensitive to uncertainties associated with yield reduction and harvesting costs, while, for Jatropha, the unpredictable yield has the greatest impact on its farm‐gate cost. This study can help policymakers and industrial stakeholders make strategic and tactical bioenergy development plans in China (exchange rate in 2017: 1€ = 7.63￥; all the joules in this paper are higher heat value). [ABSTRACT FROM AUTHOR]

This article identifies marginal land technically available for the production of energy crops in China, compares three models of yield prediction for Miscanthus × giganteus, Panicum virgatum L. (switchgrass), and Jatropha, and estimates their spatially specific yields and technical potential for 2017. Geographic Information System (GIS) analysis of land use maps estimated that 185 Mha of marginal land was technically available for energy crops in China without using areas currently used for food production. Modeled yields were projected for Miscanthus × giganteus, a GIS‐based Environmental Policy Integrated Climate model for switchgrass and Global Agro‐Ecological Zone model for Jatropha. GIS analysis and MiscanFor estimated more than 120 Mha marginal land was technically available for Miscanthus with a total potential of 1,761 dry weight metric million tonne (DW Mt)/year. A total of 284 DW Mt/year of switchgrass could be obtained from 30 Mha marginal land, with an average yield of 9.5 DW t ha−1 year−1. More than 35 Mha marginal land was technically available for Jatropha, delivering 9.7 Mt/year of Jatropha seed. The total technical potential from available marginal land was calculated as 31.7 EJ/year for Miscanthus, 5.1 EJ/year for switchgrass, and 0.13 EJ/year for Jatropha. A total technical bioenergy potential of 34.4 EJ/year was calculated by identifying best suited crop for each 1 km2 grid cell based on the highest energy value among the three crops. The results indicate that the technical potential per hectare of Jatropha is unable to compete with that of the other two crops in each grid cell. This modeling study provides planners with spatial overviews that demonstrate the potential of these crops and where biomass production could be potentially distributed in China which needs field trials to test model assumptions and build experience necessary to translate into practicality. [ABSTRACT FROM AUTHOR]

Miscanthus × giganteus (Miscanthus) is a robust bioenergy crop, able to withstand the poor soil fertility found on marginal lands (e.g., anthropogenically disturbed lands). Mounting evidence suggests that this robustness is related to the ability of Miscanthus to partner with soil microorganisms to gain nutrients. Of particular interest is how Miscanthus may alter microbially-mediated nitrogen (N) cycling (e.g., N-fixation and mineralization) resulting in efficient N acquisition across a range of soil fertility levels. However, a mechanistic understanding of how Miscanthus responds to and influences soil nitrogen cycling under the variable soil properties that emerge from land disturbance is lacking. Further, it remains unclear whether these plant-growth promoting microbial functions can be bolstered by directly managing microbial community composition (i.e., biofertilization). To address these knowledge gaps, we performed a greenhouse experiment with Miscanthus grown in soil from two sites with different soil fertility levels (e.g., differences in soil texture, inorganic nitrogen, and C/N). We also tested the effect of two biofertilizers (commercially available biofertilizer or a soil transplant from a mature Miscanthus stand) on Miscanthus growth or plant-microbe interactions. We surveyed microbial community composition via community-based amplicon sequencing and quantified function by measuring the activity of prokaryotic N-fixers and nitrifiers. Initial soil fertility outweighed biofertilization in determining microbial community composition and function. Specifically, when Miscanthus was grown in low fertility soil from a highly disturbed site, rates of N fixation by free-living N-fixers increased. This increase was accompanied by increases in arbuscular mycorrhizal fungi (AMF) abundance suggesting a synergism between N fixation rates and AMF that facilitates plant nitrogen acquisition. These effects of Miscanthus on the soil microbiome composition and function were less pronounced in the high fertility soil with more nitrogen. This suggests a scenario where, under nitrogen limitation, Miscanthus trades with symbionts providing carbon to nitrogen fixing bacteria and AMF to acquire nitrogen. Alternatively, when nitrogen is more plentiful, Miscanthus may scavenge nutrients, obtaining nitrogen released from organic matter by saprotrophs. These observations aid in illuminating how Miscanthus can dynamically shape microbial functions occurring in its rhizosphere which more broadly increases our understanding of plant-microbe interactions and bioenergy agroecosystems. [Display omitted] • The altered properties of disturbed soil shape Miscanthus -microbe interactions • Soil disturbance outweighed biofertilization in altering microbial N cycling. • In highly disturbed soil, N-fixers and AMF were favored (nutrient trading). • In less disturbed soil, NH 4 +-oxidizers were bolstered (nutrient scavenging). • Miscanthus dynamically shaped N cycling based on initial soil properties. [ABSTRACT FROM AUTHOR]

The cell wall plays a crucial role in plant growth and development, including in response to environmental factors, mainly through significant biochemical and biomechanical plasticity. The involvement of the cell wall in C4 plants’ response to cold is, however, still poorly understood. Miscanthus × giganteus, a perennial grass, is generally considered cold tolerant and, in contrast to other thermophilic species such as maize or sorgo, can maintain a relatively high level of photosynthesis efficiency at low ambient temperatures. This unusual response to chilling among C4 plants makes Miscanthus an interesting study object in cold acclimation mechanism research. Using the results obtained from employing a diverse range of techniques, including analysis of plasmodesmata ultrastructure by means of transmission electron microscopy (TEM), infrared spectroscopy (FTIR), and biomechanical tests coupled with photosynthetic parameters measurements, we present evidence for the implication of the cell wall in genotype-specific responses to cold in this species. The observed reduction in the assimilation rate and disturbance of chlorophyll fluorescence parameters in the susceptible M3 genotype under cold conditions were associated with changes in the ultrastructure of the plasmodesmata, i.e., a constriction of the cytoplasmic sleeve in the central region of the microchannel at the mesophyll–bundle sheath interface. Moreover, this cold susceptible genotype was characterized by enhanced tensile stiffness, strength of leaf wall material, and a less altered biochemical profile of the cell wall, revealed by FTIR spectroscopy, compared to cold tolerant genotypes. These changes indicate that a decline in photosynthetic activity may result from a decrease in leaf CO2 conductance due to the formation of more compact and thicker cell walls and that an enhanced tolerance to cold requires biochemical wall remodelling. Thus, the well-established trade-off between photosynthetic capacity and leaf biomechanics found across multiple species in ecological research may also be a relevant factor in Miscanthus’ tolerance to cold. In this paper, we demonstrate that M. giganteus genotypes showing a high degree of genetic similarity may respond differently to cold stress if exposed at earlier growing seasons to various temperature regimes, which has implications for the cell wall modifications patterns.

Food waste (FW), a major part of the US waste stream, causes greenhouse gases within landfills, but there is an opportunity to divert FW to anaerobic digestion (AD) facilities that produce biogas and digestate fertilizer. The composition of FW inputs to AD determines the value of these products. This study provides insight into the effect of waste composition on the quality of AD products by first characterizing the biogas and digestate quality of anaerobically digested FW from four diets (paleolithic, ketogenic, vegetarian, and omnivorous), and then estimating the difference in biogas produced from codigested FW and brewery waste (BW). Waste feedstock mixtures were incubated in lab-scale bioreactors for 21 days with live inoculum. Biogas quality was monitored for 21–30 days in four trials. Samples were analyzed using a gas chromatograph for detection of methane (CH4) and carbon dioxide (CO2). The composition of the waste inputs had a significant impact on the quality of biogas but not on the quality of the digestate, which has implications for the value of post-AD fertilizer products. Wastes with higher proportions of proteins and fats enhanced biogas quality, unlike wastes that were rich in soluble carbohydrates. Codigestion of omnivorous food waste with carbon-rich agricultural wastes (AW) improved biogas quality, but biogas produced from BW does not necessarily improve with increasing amounts of AW in codigestion.

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.

Giant miscanthus is a vigorously growing energy plant, popularly used for biofuels production. It is a grass with low soil and water requirements, although its productivity largely depends on complementary irrigation, especially in the first year of cultivation. The aim of the study was to assess the impact of the forecast climate changes, mainly air temperature increase, on the water needs of giant miscanthus during the growing season in 2021–2050 in the Kuyavia region (central Poland). The years 1981–2010 as the reference period were applied. The meteorological data was based on the regional climate change model RM5.1 with boundary conditions from the global ARPEGE model for the SRES A1B emission scenario. Crop evapotranspiration, calculated using the Penman-Monteith method and crop coefficients, was assumed as a measure of water needs. The study results showed that in view of the expected temperature changes, in the forecast period 2021–2050, the giant miscanthus water needs will increase by 10%. The highest monthly increase may occur in August (16%) and in September (23%). In the near future, the increase in water needs of giant miscanthus will necessitate the use of supplementary irrigation. Hence the results of this study may contribute to increasing the efficiency of water use, and thus to the rational management of irrigation treatments and plant energy resources in the Kuyavia region.

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.

Miscanthus × giganteus demonstrated good phytostabilization potentials in toxic element (TE) contaminated soils. However, information about its tolerance to elevated concentrations is still scarce. Therefore, an ex-situ pot experiment was launched using three cultivars (termed B, U, and A) grown in soils with a gradient Cd, Pb and Zn concentrations. Control plants were also cultivated in non-contaminated soil. Results show that the number of tillers per plant, stem diameter as well as leaf photosynthetic pigments (chlorophyll a, b and carotenoids) were negatively impacted by soil contamination. On the other hand, phenolic compounds, flavonoids, tannins, and anthocyanins levels along with the antioxidant enzymatic activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase increased in the plants grown on contaminated soils. Altogether, these data demonstrate that miscanthus is impacted by concentrations of toxic elements yet is able to tolerate high levels of soil contamination. These results may contribute to clarifying the miscanthus tolerance strategy against high contamination levels and its efficiency in phytoremediation.

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Background and Aims Miscanthus , a C4 perennial grass native to East Asia, is a promising biomass crop. Miscanthus sacchariflorus has a broad geographic range, is used to produce paper in China and is one of the parents (along with Miscanthus sinensis) of the important biomass species Miscanthus × giganteus. The largest study of M. sacchariflorus population genetics to date is reported here. Methods Collections included 764 individuals across East Asia. Samples were genotyped with 34 605 single nucleotide polymorphisms (SNPs) derived from restriction site-associated DNA sequencing (RAD-seq) and ten plastid microsatellites, and were subjected to ploidy analysis by flow cytometry. Key Results Six major genetic groups within M. sacchariflorus were identified using SNP data: three diploid groups, comprising Yangtze (M. sacchariflorus ssp. lutarioriparius), N China and Korea/NE China/Russia; and three tetraploid groups, comprising N China/Korea/Russia, S Japan and N Japan. Miscanthus sacchariflorus ssp. lutarioriparius was derived from the N China group, with a substantial bottleneck. Japanese and mainland tetraploids originated from independent polyploidization events. Hybrids between diploid M. sacchariflorus and M. sinensis were identified in Korea, but without introgression into either parent species. In contrast, tetraploid M. sacchariflorus in southern Japan and Korea exhibited substantial hybridization and introgression with local diploid M. sinensis. Conclusions Genetic data indicated that the land now under the Yellow Sea was a centre of diversity for M. sacchariflorus during the last glacial maximum, followed by a series of migrations as the climate became warmer and wetter. Overall, M. sacchariflorus has greater genetic diversity than M. sinensis , suggesting that breeding and selection within M. sacchariflorus will be important for the development of improved M. × giganteus. Ornamental M. sacchariflorus genotypes in Europe and North America represent a very narrow portion of the species' genetic diversity, and thus do not well represent the species as a whole. [ABSTRACT FROM AUTHOR]

To improve the efficiency of breeding of Miscanthus for biomass yield, there is a need to develop genomics‐assisted selection for this long‐lived perennial crop by relating genotype to phenotype and breeding value across a broad range of environments. We present the first genome‐wide association (GWA) and genomic prediction study of Miscanthus that utilizes multilocation phenotypic data. A panel of 568 Miscanthus sinensis accessions was genotyped with 46,177 single nucleotide polymorphisms (SNPs) and evaluated at one subtropical and five temperate locations over 3 years for biomass yield and 14 yield‐component traits. GWA and genomic prediction were performed separately for different years of data in order to assess reproducibility. The analyses were also performed for individual field trial locations, as well as combined phenotypic data across groups of locations. GWA analyses identified 27 significant SNPs for yield, and a total of 504 associations across 298 unique SNPs across all traits, sites, and years. For yield, the greatest number of significant SNPs was identified by combining phenotypic data across all six locations. For some of the other yield‐component traits, greater numbers of significant SNPs were obtained from single site data, although the number of significant SNPs varied greatly from site to site. Candidate genes were identified. Accounting for population structure, genomic prediction accuracies for biomass yield ranged from 0.31 to 0.35 across five northern sites and from 0.13 to 0.18 for the subtropical location, depending on the estimation method. Genomic prediction accuracies of all traits were similar for single‐location and multilocation data, suggesting that genomic selection will be useful for breeding broadly adapted M. sinensis as well as M. sinensis optimized for specific climates. All of our data, including DNA sequences flanking each SNP, are publicly available. By facilitating genomic selection in M. sinensis and Miscanthus × giganteus, our results will accelerate the breeding of these species for biomass in diverse environments. [ABSTRACT FROM AUTHOR]

Contamination of soil by heavy metals is among the important environmental problems due to their toxicity and negative impact to human health and the environment. An effective method for cleaning the soil from heavy metals is phytoremediation using the second-generation bioenergy species Miscanthus × giganteus. The purpose of this research is to study the benefits of M. × giganteus cultivation at the soils taken from the mining and former military sites contaminated by As, Pb, Zn, Co, Ni, Cr, Cu, V, Mn, Sr, and U as well as at the soil artificially contaminated by Zn and Pb, to evaluate the physiological parameters of the plant, to establish peculiarities of the phytoremediation process, and to characterize the behavior of the plant in relation to the nature and concentrations of the metals in the soils. Results showed that M. × giganteus was resistant to heavy metals (tolerance index ≥ 1) and that the greatest portion of metals accumulated in the root system. The morphological parameters of the plant while grown on different soils are influenced by soil type and the content of contaminants. The stress effect while growing M. × giganteus on soil artificially contaminated by Zn and Pb was evaluated by measuring the content of pigments (chlorophylls a, b, and carotenoids) in the plant's leaves. The decrease in the total content of chlorophylls, Сa + b/Сcar and transpiration rate of water along with the increase in the water absorbing capacity were observed. The accumulation of heavy metals in different parts of the plant was determined; bioaccumulation coefficient and values of translocation factor were calculated. The obtained results showed that M. × giganteus was an excluder plant for nine highly toxic elements (As, Pb, Zn, Co, Ni, Cr, Cu, V, U) and an accumulator species for the moderately dangerous elements (Mn, Sr). Further research will be focused on the extraction of stable stimulated plant-growth–promoting rhizobacteria from the rhizosphere of M. × giganteus and formulation on that base the plant-bacterial associations as well as on the comparison of the plant physiological parameters, biochemical soil activity, and accumulation of heavy metals in the Miscanthus tissues between first and second vegetations. [ABSTRACT FROM AUTHOR]

Miscanthus × giganteus (M. × giganteus) is a perspective plant produced on marginal and contaminated lands with biomass used for energy or bioproducts. In the current study, M. × giganteus development was tested in the diesel-contaminated soils (ranged from 250 mg kg−1 to 5000 mg kg−1) and the growth dynamic, leaves quantity, plants total area, number of harvested stems and leaves, SPAD and NPQt parameters were evaluated. Results showed a remarkable M. × giganteus growth in a selected interval of diesel-contaminated soil with sufficient harvested biomass. The amendment of soil by biochar 1 (produced from wastewater sludge) and biochar 2 (produced from a mixture of wood waste and biohumus) improved the crop’s morphological and physiological parameters. Biochar 1 stimulated the increase of the stems’ biomass, while biochar 2 increased the leaves biomass. The plants growing in the uncontaminated soil decreased the content of NO3, pH (KCl), P2O5 and increased the content of NH4. Photosynthesis parameters showed that incorporating biochar 1 and biochar 2 to the diesel-contaminated soil prolonged the plants’ vegetation, which was more potent for biochar 1. M. × giganteus utilization united with biochar amendment can be recommended to remediate diesel-contaminated land in concentration range 250–5000 mg kg−1.

Lignocellulosic biomass is one of the dominant renewable energy resources suited for the production of sustainable biofuels and other energy purposes. This study was focused on weed management strategies that can improve the establishment of six lignocellulosic crops. The studied crops included: giant miscanthus, switchgrass, giant reed, cardoon, sweet sorghum, and kenaf. Delayed planting, increased planting densities, and mulching techniques can suppress weeds in giant miscanthus. Weed competition is detrimental for switchgrass establishment. Seedbed preparation and cultivar selection can determine its ability to compete with weeds. Giant reed is unlikely to get outcompeted by weeds, and any weed control operation is required only for the first growing season. Competitive cultivars and increased seeding rates maximize the competitiveness of cardoon against weeds. Several cultural practices can be used for non-chemical weed management in sweet sorghum and kenaf. For all crops, pre-emergence herbicides can be applied. The available safe post-emergence herbicides are limited. Mechanical weed control during crucial growth stages can provide solutions for sweet sorghum, kenaf, and perennial grasses. Further research is required to develop effective weed management strategies, with emphasis on cultural practices, that can improve the establishment of these prominent lignocellulosic crops.

Use of plant growth-promoting bacteria (PGPB) for cultivation of the biofuel crop Miscanthus × giganteus (Mxg) in post-military and post-mining sites is a promising approach for the bioremediation of soils contaminated by metals. In the present study, PGPB were isolated from contaminated soil and screened for tolerance against abiotic stresses caused by salinity, pH, temperature, and lead (Pb). Selected strains were further assessed and screened for plant growth-promoting attributes. The isolate showing the most potential, Bacillus altitudinis KP-14, was tested for enhancement of Mxg growth in contaminated soil under greenhouse conditions. It was found to be highly tolerant to diverse abiotic stresses, exhibiting tolerance to salinity (0–15%), pH (4–8), temperature (4–50 °C), and Pb (up to 1200 ppm). The association of B. altitudinis KP-14 with Mxg resulted in a significant (p ≤ 0.001) impact on biomass enhancement: the total shoot and dry root weights were significantly enhanced by 77.7% and 55.5%, respectively. The significant enhancement of Mxg biomass parameters by application of B. altitudinis KP-14 strongly supports the use of this strain as a biofertilizer for the improvement of plant growth in metal-contaminated soils.

In previous studies, the regeneration rates of Miscanthus × giganteus J.M.Greef, Deuter ex Hodk., Renvoize from callus tissue cultured on semi-solid media significantly declined after 4 mo of culture, which presents problems with germplasm conservation and use as an alternative propagation system. Due to the species' lignocellulosic nature, it was hypothesized that the accumulation of phenolic compounds in the callus may be responsible for inhibiting regeneration. The current study aimed to optimize regeneration of M. × giganteus callus by culturing the callus tissue in the presence of 2-aminoindan-2-phosphonic acid (AIP), a competitive inhibitor of phenylalanine ammonia lyase (PAL), to reduce the biosynthesis of phenolics. Embryogenic callus was cultured on media supplemented with 9.0- or 11.3-μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 0-, 1-, 10-, 100-, or 1000-μM AIP. Every 28 d for 7 mo, the callus tissue was visually classified based on morphology and regeneration rate. Over the duration of the study, regeneration of shoots was consistently highest in callus cultured on 11.3-μM 2,4-D supplemented with 10- and 100-μM AIP (13-58.3%), and in vitro plantlet development from callus cultured on all concentrations of AIP demonstrated tillering and rooting. Total soluble phenolic content of the callus decreased in a dose-dependent manner from 2242.34-μg g−1 dry weight in the control to 1569.71-μg g−1 dry weight in AIP-treated callus. These data indicate that inhibiting PAL in M. × giganteus cultures increased the percentage of calluses exhibiting regeneration over time. [ABSTRACT FROM AUTHOR]

Abstract: The weight share of the pith, nodes and internodes in the stalks of Miscanthus, as well as the types of cells in these anatomical parts, were examined. Studies have shown that the pith contains mainly parenchyma cells, nodes—short fibres and palisade parenchyma cells, while internodes contains mainly fibres, which are accompanied by a certain amount of vessels and parenchyma cells. Then the whole stalks of Miscanthus were subjected to pulping using the kraft and soda pulping methods. These studies have shown that hard, regular, soft and very soft kraft pulps can be obtained using a lower amount of active alkali, with comparable or higher screened yield of pulp than is the case of pulping of birch. Furthermore, it was found that the content of knots and shives was lower in the digester hard and regular kraft pulps from Miscanthus compared to birch kraft pulp. Of the two pulping methods studied, kraft pulping gives better results than soda pulping concerning the considerably higher yield of pulp.Graphical abstract: [ABSTRACT FROM AUTHOR]

Miscanthus  ×  giganteus and Zea mays , closely-related C 4 grasses, originated from warm climates react differently to low temperature. To investigate the response to cold (12–14 °C) in these species, the photosynthetic and anatomical parameters as well as biochemical properties of the cell wall were studied. The research was performed using M. giganteus (MG) and two Z. mays lines differentiated for chilling-sensitivity: chilling-tolerant (Zm-T) and chilling-sensitive (Zm-S). The chilled plants of Zm-S line demonstrated strong inhibition of net CO 2 assimilation and a clear decrease in F’ v /F’ m , F v /F m and ɸ PSII, while in MG and Zm-T plants these parameters were almost unchanged. The anatomical studies revealed that MG plants had thinner leaves, epidermis and mesophyll cell layer as well as thicker cell walls in the comparison to both maize lines. Cold led to an increase in leaf thickness and mesophyll cell layer thickness in the Zm-T maize line, while the opposite response was observed in Zm-S. In turn, in chilled plants of MG and Zm-T lines, some anatomical parameters associated with bundle sheath cells were higher. In addition, Zm-S line showed the strong increase in the cell wall thickness at cold for mesophyll and bundle sheath cells. Chilling-treatment induced the changes in the cell wall biochemistry of tested species, mainly in the content of glucuronoarabinoxylan, uronic acid, β-glucan and phenolic compounds. This work presents a new approach in searching of mechanism(s) of tolerance/sensitivity to low temperature in two thermophilic plants: Miscanthus and maize. [ABSTRACT FROM AUTHOR]

The demand for renewable energy resources, such as Miscanthus spp., has increased significantly in temperate regions. Miscanthus spp. has the potential to mitigate GHG emissions by replacing fossil fuels and sequestering carbon in soil. However, the biomass yield and C sequestration performance of Miscanthus spp. varies by climate, soil type, management practices, and land-use history. Therefore, there is a need for site-specific research on biomass yield and C sequestration of Miscanthus × giganteus (M × g). An alternative to M × g is the seed-propagated Miscanthus sinensis which could be another option as a bioenergy crop. The objective of this study was to assess the C sequestration rates and biomass yield performance of these two Miscanthus spp. The C sequestration rates were measured in side-by-side comparison plots using the 13C natural abundance technique. The results revealed C sequestration rates of M × g and M. sinensis were 1.96 ± 0.82 and 0.99 ± 0.21 Mg C ha−1 year−1 over 6 years. The average biomass yields of M × g and M. sinensis from 2010 to 2015 were 25.6 ± 0.2 and 31.2 ± 0.5 Mg ha−1 year−1, respectively. It can be concluded that M. sinensis has a higher yield while M × g has a higher potential for immediate C sequestration in cool regions such as Northern Japan. [ABSTRACT FROM AUTHOR]

Soil health is the capacity of soil to function as a living ecosystem that sustains plants, animals, and humans. Healthy soils support the optimal crop yields and also plays a crucial role in protecting water quality and other aspects of environmental stewardship. Meanwhile, the agricultural damage by the earthquake causes serious crop productivity degradation in Japan. Thus, there is a need for research on crop productivity, especially land under the earthquake disaster. In addition, the global demand for renewable energy resources such as Miscanthus spp., mainly the triploid interspecific hybrid Miscanthus × giganteus (M × g), has increased substantially. Because it has the potential to have a high yield, sequester the carbon into the soils, and improve the soil health. Therefore, the objective of this study was to demonstrate soil health index assessment at Miscanthus spp. fields. We investigated (1) to quantify the impact on land use changes including Miscanthus, pasture, and arable land on soil health index. T soil under M × g increases the over-all SHI value to compare another land use. Therefore, it can be concluded that M × g is the better land use management option in the cool climate regions such as Northern Japan. [ABSTRACT FROM AUTHOR]

Because of its high persistence in soils, t 1/2 = 30 years, chlordecone (CLD) was classified as a persistent organic pollutant (POP) by the Stockholm Convention in 2009.The distribution of CLD over time has been heterogeneous, ranging from banana plantations to watersheds, and contaminating all environmental compartments. The aims of this study were to (i) evaluate the potential of Miscanthus species to extract chlordecone from contaminated soils, (ii) identify the growth parameters that influence the transfer of CLD from the soil to aboveground plant parts. CLD uptake was investigated in two species of Miscanthus , C4 plants adapted to tropical climates. M . sinensis and M . × giganteus were transplanted in a soil spiked with [ 14 C]CLD at environmental concentrations (1 mg kg − 1 ) under controlled conditions. Root-shoot transfer of CLD was compared in the two species after two growing periods (2 then 6 months) after transplantation. CLD was found in all plant organs, roots, rhizomes, stems, leaves, and even flower spikes. The highest concentration of CLD was in the roots, 5398 ± 1636 ( M . × giganteus ) and 14842 ± 3210 ng g − 1 DW ( M . sinensis ), whereas the concentration in shoots was lower, 152 ± 28 ( M . × giganteus ) and 266 ± 70 ng g − 1 DW ( M . sinensis ) in soil contaminated at 1 mg kg − 1 . CLD translocation led to an acropetal gradient from the bottom to the top of the plants. CLD concentrations were also monitored over two complete growing periods (10 months) in M . sinensis grown in 8.05 mg kg − 1 CLD contaminated soils. Concentrations decreased in M . sinensis shoots after the second growth period due to the increase in organic matters in the vicinity of the roots. Results showed that, owing to their respective biomass production, the two species were equally efficient at phytoextraction of CLD. [ABSTRACT FROM AUTHOR]

Giant miscanthus (Miscanthus × giganteus Greef et Deu.) is a perennial rhizomatous grass with C4 type photosynthesis, which is distinctive by its resistance to cold temperatures when maintaining a sufficient photosynthesis rate. We revised potential of Miscanhus for use in soil bioremediation, especially from biological point of view. Translocation rate from roots to aerial part is low in general, but Miscanthus is able to grow even on highly contaminated soils without artificial fertilization. We also discussed the role of root exudates in pollutant immobilization, chelation and uptake. Commetabolism of polycyclic aromatic hydrocarbons with assistance of soil microbes shows promising results and significant reduction of tetracyclic PAHs in soil. Miscanthus is therefore suitable for immobilization of inorganic pollutants in soil and removal of organic pollutants, which makes it suitable to create buffer zones for surface waterway protection, stabilization of heavily contaminated substrates (e.g. reclaimed burrows of mining industry and sedimentation pools). According to low content of pollutants in aerial biomass the harvested plant material is deemed safe for further agricultural or industrial use.

A correction to the article "Temperature Response of Mesophyll Conductance in Three C4 Species Calculated With Two Methods: 18O Discrimination and In Vitro Vpmax" by N. Ubierna and colleagues is presented.

In experimental research plots in Kolíňany (SW Slovakia), ecological and socio-economic characteristics of weed vegetation were evaluated in the energy stands of Miscanthus × giganteus during three vegetation seasons (2010–2012). The spontaneous vegetation in the Miscanthus stand was dominated by annual therophytes (55.5 to 62%) and geophytes (17.2 to 22.2%). We identified two categories of herbaceous undergrowth in Miscanthus plantation: with potential positive (e.g. presence of medicinal plants and plants with melliferous potential) and potential negative impacts (e.g. invasive and toxic plants). Based on our observations, we can conclude that the species composition of spontaneous herbaceous vegetation is comparable with weed vegetation found on arable land.

Miscanthus species are important energy crops, due to their high yield of biomass, used for combustion, biofuel fabrication and as a feedstock for various products. They can be also utilised for phytoremediation and other ecological programmes. Extensive needs require considerable amounts of planting material, which can be provided by in vitro micropropagation. A new effective and simple regeneration system of M. sinensis , M. × giganteus and M. sacchariflorus was developed, which comprises just two media supplemented exclusively with growth regulators and lasts for 5 months. Significant differences in regeneration capacity were observed between species, genotypes, and initial explants, and also in the effects of media and growth regulators. Embryogenic callus was induced on explants excised from whole immature inflorescences for M. sinensis and M. × giganteus , or inflorescence axes for M. sacchariflorus , implanted on C17 medium with 90 g l −1 maltose, 5.0 mg l −1 2,4-D and 0.5 mg l −1 BAP. Plant regeneration, tillering, and rooting were conducted on 190-2 medium with 30 g l −1 sucrose, 0.5 mg l −1 KIN and 0.5 mg l −1 NAA. The system produces about 7–20 plantlets per a single explant depending on responsiveness of a genotype of M. sinensis , M. × giganteus and M. sacchariflorus . This indicates the potential scale of direct production at 1500–2000 plantlets from a donor clump. The presented system may provide a large number of plants for field trials and physiological research, as well as facilitate the application of biotechnological methods to improve utility traits of bioenergy crops. [ABSTRACT FROM AUTHOR]

Giant reed, miscanthus, and switchgrass are considered prominent lignocellulosic feedstocks to obtain fermentable sugars for biofuel production. The bioconversion into sugars requires a delignifying pre-treatment step followed by hydrolysis with cellulase and other accessory enzymes like xylanase, especially in the case of alkali pre-treatments, which retain the hemicellulose fraction. Blends richer in accessory enzymes than commercial mix can be obtained growing fungi on feedstock-based substrates, thus ten selected Trichoderma isolates, including the hypercellulolytic strain Trichoderma reesei Rut-C30, were grown on giant reed, miscanthus, or switchgrass-based substrates. The produced enzymes were used to saccharify the corresponding feedstocks, compared to a commercial enzymatic mix (6 FPU/g). Feedstocks were acid (HSO 0.2-2%, w/ v) or alkali (NaOH 0.02-0.2%, w/ v) pre-treated. A microplate-based approach was chosen for most of the experimental steps due to the large number of samples. The highest bioconversion was generally obtained with Trichoderma harzianum Or4/99 enzymes (78, 89, and 94% final sugar yields at 48 h for giant reed, miscanthus, and switchgrass, respectively), with significant increases compared to the commercial mix, especially with alkaline pre-treatments. The differences in bioconversion yields were only partially caused by xylanases (maximum R = 0.5), indicating a role for other accessory enzymes. [ABSTRACT FROM AUTHOR]

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The impact of extreme drought and heat stress that occurred in the Midwestern U.S. in 2012 on evapotranspiration ( ET), net ecosystem productivity ( NEP), and water-use efficiency ( WUE) of three perennial ecosystems (switchgrass, miscanthus, prairie) and a maize/soybean agroecosystem was studied as part of a long-term experiment. Miscanthus had a slower initial response but an eventually drastic ET as drought intensified, which resulted in the largest water deficit among the crops. The substantially higher ET at peak drought was likely supplied by access to deep soil water, but suggests that stomatal conductance of miscanthus during the drought may respond differently than the other ecosystems, consistent with an anisohydric strategy. While there was a discrepancy in the water consumption of maize and switchgrass/prairie in the early time of drought, all these ecosystems followed a water-saving strategy when drought intensified. The gross primary production ( GPP) of miscanthus dropped, but was reversible, when temperature reached 40 °C and still provided the largest total GPP among the ecosystems. Increased ET for miscanthus during 2012 resulted a large decline in ecosystem WUE compared to what was observed in other years. The biophysical responses of miscanthus measured during an extreme, historic drought suggest that this species can maintain high productivity longer than other ecosystems during a drought at the expense of water use. While miscanthus maintained productivity during drought, recovery lagged associated with depleted soil moisture. The enhanced ET of miscanthus may intensify droughts through increase supply of deep soil moisture to the atmosphere. [ABSTRACT FROM AUTHOR]

Little is known about the degradation and environmental impacts of carbon (C) amendments such as hydrochar and biochar in soil under the influence of disturbance events such as wetting, freeze-thaw cycles, manual stirring, and glucose additions. Thus, we assessed the degradation and greenhouse gas (GHG) emissions of Miscanthus x giganteus biochar (from pyrolysis), hydrochar (from steam and water hydrothermal carbonization, HTCs and HTCw), the uncarbonized feedstock material in a sandy and a loamy soil, compared to a control, with four replicates per treatment. The C amendments were mixed with soil at a rate of ∼20 t/ha wt% and incubated at 30 °C over the period of 441 days. Over the whole incubation period, the soil mixtures were exposed consecutively to different disturbance events, with the intention to simulate a worst-case scenario for C degradation and GHG emissions. The degradation kinetics were quantified by source partitioning of the headspace 13 C-CO 2 and the application of an isotope two-component mixing model. Additionally, microbial biomass and composition were quantified and characterized at the end of the experimental period by chloroform fumigation extraction and phospholipid fatty acid analysis. The molecular composition and structural properties of the C amendments obtained by elemental analysis and NMR spectroscopy proved to be suitable indicators for the CO 2 emissions which mostly followed the sequence feedstock > HTCs > HTCw > biochar over the experimental duration. The addition of glucose triggered a short-lived, temporary co-mineralization of the otherwise recalcitrant materials HTCw and biochar. Among all C amendments, biochar proved most recalcitrant against decomposition and disturbance in both soils with a calculated recovery rate of 95–99% of the initially added biochar-C. Additionally, biochar amendment led to a decreased decomposition of soil organic C, especially in sandy soil. [ABSTRACT FROM AUTHOR]

Grasses such as Miscanthus × giganteus and Panicum virgatum (switchgrass) can potentially be used to produce bioenergy on a large scale in the Midwestern USA. The biomass productivity of these warm-season perennial grasses, particularly M. × giganteus, can be substantial, even when grown with limited inputs. The literature, however, varies regarding the nitrogen requirements for M. × giganteus biomass production. In addition, there is a lack of information that identifies the yield-component(s) (including total tiller number, tiller weight, total tiller diameter, total tiller height, phytomer number, reproductive tiller number, vegetative tiller number, reproductive tiller height, vegetative tiller height, reproductive tiller diameter, vegetative tiller diameter, and reproductive tiller phytomer number) that contributes to M. × giganteus biomass yields. Thus, the objective of this study was to examine the effects of fertilization on biomass yield and individual M. × giganteus plant-yield components. Plots of M. × giganteus were planted in 2008 in Urbana, IL, USA and received annual applications of 0, 60, or 120 kg N ha-1. M. × giganteus productivity increased when nitrogen was applied; between 2011 and 2014, nitrogen applications of 60 or 120 kg N ha-1 produced average annual yields of 22.0 dry Mg ha-1 compared to 11.8 dry Mg ha-1 for unfertilized M. × giganteus. Both the total number of tillers per m2 and the tiller weight also increased as N-application rates increased. Our results indicate that increased reproductive tiller density and tiller weight with increased N fertilization increased M. × giganteus biomass yield. [ABSTRACT FROM AUTHOR]

Mesophyll conductance ( gm) is an important factor limiting rates of C3 photosynthesis. However, its role in C4 photosynthesis is poorly understood because it has been historically difficult to estimate., We use two methods to derive the temperature responses of gm in C4 species. The first (Δ18O) combines measurements of gas exchange with models and measurements of 18O discrimination. The second method ( in vitro Vpmax) derives gm by retrofitting models of C4 photosynthesis and 13C discrimination with gas exchange, kinetic constants and in vitro Vpmax measurements., The two methods produced similar gm for Setaria viridis and Zea mays. Additionally, we present the first temperature response (10-40°C) of C4 gm in S. viridis, Z. mays and Miscanthus × giganteus. Values for gm at 25°C ranged from 2.90 to 7.85 μmol m−2 s−1 Pa−1., Our study demonstrated that: the two described methods are suitable to calculate gm in C4 species; gm values in C4 are similar to high-end values reported for C3 species; and gm increases with temperature analogous to reports for C3 species and the response is species specific. These results improve our mechanistic understanding of C4 photosynthesis. [ABSTRACT FROM AUTHOR]

Mesophyll conductance ( gm) is an important factor limiting rates of C3 photosynthesis. However, its role in C4 photosynthesis is poorly understood because it has been historically difficult to estimate., We use two methods to derive the temperature responses of gm in C4 species. The first (Δ18O) combines measurements of gas exchange with models and measurements of 18O discrimination. The second method ( in vitro Vpmax) derives gm by retrofitting models of C4 photosynthesis and 13C discrimination with gas exchange, kinetic constants and in vitro Vpmax measurements., The two methods produced similar gm for Setaria viridis and Zea mays. Additionally, we present the first temperature response (10-40°C) of C4 gm in S. viridis, Z. mays and Miscanthus × giganteus. Values for gm at 25°C ranged from 2.90 to 7.85 μmol m−2 s−1 Pa−1., Our study demonstrated that: the two described methods are suitable to calculate gm in C4 species; gm values in C4 are similar to high-end values reported for C3 species; and gm increases with temperature analogous to reports for C3 species and the response is species specific. These results improve our mechanistic understanding of C4 photosynthesis. [ABSTRACT FROM AUTHOR]

Cropping practices of Miscanthus × giganteus, a promising energy crop, can influence C and N cycles and therefore potentially affect NO emissions. They may vary in harvesting date, either early (EH) or late harvest (LH), and the fertiliser form (NH or NO). In this study, we combined a long-term field experiment and simulations with the STICS model to investigate the effect of these practices on soil parameters, NO emissions and the contribution of nitrification and denitrification. Daily NO fluxes and soil parameters were measured during the 4-month period following fertilisation in 2014 and 2015. Mean cumulative NO emissions were markedly higher in LH than EH (4.21 vs. 0.89 kg NO-N ha year) but did not differ significantly between fertiliser forms or years. The difference was mainly attributed to the higher soil water-filled pore space (WFPS) observed in LH (80 vs. 56 % in EH) which resulted itself from the leaf mulch present in LH and not in EH. WFPS explained 67 % of the variance of NO emissions. The large decrease in pH observed after NH fertilisation stimulated NO emissions probably through less-efficient reduction of NO to N as simulated by STICS. Model outputs suggest a large contribution of nitrification in EH and a dominant contribution of denitrification in LH. Our study highlights the crucial impact of management practises on NO emissions in Miscanthus crops through changes in physico-chemical parameters and soil processes on the short and long term and brings knowledge required to maximise the benefits of bioenergy crops. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the composition of sugars and organic acids in root exudates of Miscanthus × Giganteus and to find out if microorganisms of the rhizospheric soil are limited by mi­ne­ral nutrients. The following sugars and organic acids were determined in root exudates of this plant: glucose, saccharose, and acids such as succinic, propionic, citric, tartaric, malic, oxalic, ascorbic, acetic and fumaric. Respiration of soil from rhizosphere of Miscanthus × Giganteus was found to be limited by N, K and Ca. Respiration rate after application of mineral compounds increased in following orther: nitrate > calcium > potassium > ammonium, giving approx. 165, 99, 52 and 31 % increase compared to control. Further research is necessary to determine the role of plant nutrients from the point of their limitations for rhizosphere microorganisms, to broader very rare knowledges in this topic, especially for polluted soils to stimulate efficiency of phytoremediations.

Rate of root exudation and identification of selected compounds in root exudates of Miscanthus × Giganteus in the autumnal period of growth was performed. Total organic carbon of root exudates was formed from 7.8 % by carbohydrates and from 1.5 % by proteins. Aspartic acid, arginine, alanine and glutamic acid were exuded with the highest rate of all amino acids. This work brings new basic know­led­ge which can be used for phytoremediations.

A wealth of data and information on the cultivation of perennial biomass crops has been collected, but direct comparisons between herbaceous and woody crops are rare. The main objective of this research was to compare the biomass yield, the energy balance and the biomass quality of six perennial bioenergy crops: Populus spp., Robinia pseudoacacia, Salix spp., Arundo donax, Miscanthus × giganteus, and Panicum virgatum, grown in two marginal environments. For giant reed and switchgrass, two levels of nitrogen fertilization were applied annually (0-100 kg ha−1). Nitrogen fertilization did not affect biomass or energy production of giant reed; thus, it significantly reduced the energy return on investment ( EROI) (from 73 to 27). In switchgrass, nitrogen fertilization significantly increased biomass production and the capacity of this crop to respond to water availability, making it a favorable option when only biomass production is a target. Net energy gain ( NEG) was higher for herbaceous crops than for woody crops. In Casale, EROI calculated for poplar and willow (7, on average) was significantly lower than that of the other crops (14, on average). In Gariga, the highest EROI was calculated for miscanthus (98), followed by nonfertilized giant reed and switchgrass (82 and 73, respectively). Growing degree days10 during the cropping season had no effect on biomass production in any of the studied species, although water availability from May to August was a major factor affecting biomass yield in herbaceous crops. Overall, herbaceous crops had the highest ranking for bioenergy production due to their high biomass yield, high net energy gain ( NEG), and biomass quality that renders them suitable to both biochemical and thermochemical conversion. Miscanthus in particular had the highest EROI in both locations (16 and 98, in Casale and Gariga), while giant reed had the highest NEG on the silty-loam soil of Gariga. [ABSTRACT FROM AUTHOR]

High salinity land may provide an alternative resource for the cultivation of dedicated biomass crops for renewable energy and chemicals, thus avoiding competition for land use with food crops. The commercial perennial grass Miscanthus × giganteus is a leading biomass crop; however, its response to salt stress is largely unknown. Miscanthus × giganteus was grown in pots irrigated with nine different NaCl concentrations (0, 2.86, 5.44, 7.96, 10.65, 14.68, 17.5, 19.97 and 22.4 dS m−1). Biomass yield was reduced by 50% at 10.65 dS m−1 NaCl. Root dry matter inhibition occurred at the highest salt concentration tested, while rhizome dry weight and the ratios of root/rhizome and below-/above-ground dry matter were not affected by elevated salinity. The accumulative effect of increasing salinity reduced stem height and elongation, while photosynthesis was reduced to a smaller extent. The duration and strength of salinity exacerbated the reduction. Water use efficiency (WUE) was maintained except at the highest salinity and plants maintained stomatal conductance ( gs) and leaf water content at low to moderate salinity. Miscanthus × giganteus showed strong induction of the osmoprotectant, proline and no significant increase in malondialdehyde content under increasing salinity. The ash content in leaves, increased, reducing the biomass quality at high salinity concentrations. The effects of salinity on the yield and the availability of land area in European geographical area for agriculture were investigated. Understanding the potential for growth of the C4 biomass crop Miscanthus on underutilized or abandoned land may offer a new range of targets for improved economics, crop management and breeding. [ABSTRACT FROM AUTHOR]