Establishment, growth and yield potential of the perennial grass Miscanthus x giganteus on degraded coal mine soils

BBS/E/W/10963A01Miscanthus x giganteus is a giant C4 grass native to Asia. Unlike most C4 species, it is relatively cold tolerant due to adaptations across a wide range of altitudes. These grasses are characterized by high productivity and low input requirements, making them excellent candidates for bioenergy feedstock production. The aim of this study was to investigate the potential for growing Miscanthus on extremely marginal soils, degraded by open lignite (brown coal) mining. Field experiments were established within three blocks situated on waste heaps originating from the lignite mine. Analyses were conducted over the first 3 years following Miscanthus cultivation, focusing on the effect of organic and mineral fertilization on crop growth, development and yield in this extreme environment. The following levels of fertilization were implemented between the blocks: the control plot with no fertilization (D0), a plot with sewage sludge (D1), a plot with an identical amount of sewage sludge plus one dose of mineral fertilizer (D2) and a plot with an identical amount of sewage sludge plus a double dose of mineral fertilizer (D3). Crop development and characteristics (plant height, tillering, and biomass yield [dry matter]) were measured throughout the study period and analyzed using Analysis of Variance (ANOVA). Significant differences were apparent between plant development and 3rd year biomass production over the course of the study (0.964 kg plant-1 for DO compared to 1.503 kg plant-1 for D1). Soil analyses conducted over the course of the experiment showed that organic carbon levels within the soil increased significantly following the cultivation of Miscanthus, and overall, pH decreased. With the exception of iron, macronutrient concentrations remained stable throughout. The promising yields and positive effects of Miscanthus on the degraded soil suggests that long term plantations on land otherwise unsuitable for agriculture may prove to be of great environmental and economic significancepublishersversionPeer reviewe

Gasification of Miscanthus x giganteus Pellets in a Fixed bed Pilot-scale Unit

Gasification of Miscanthus x giganteus (Mxgig), is highly promising due to the high efficiency of the process and the many advantageous properties of this crop. Pilot-scale, fixed bed gasification studies were performed utilizing this fuel at three temperatures (750, 850, and 950 degrees C) to determine the process effects of temperature on gas quality and tar yields. Simple thermodynamic equilibrium modeling was successfully applied to the pilot-scale gasification process. The Mxgig crop performed well, with best process stability reached at temperatures of 800 degrees C or higher. Average calorific values of the product gases were highest at around 850 degrees C at 5.2 MJ.m(-3). Tar yields gradually increased with increasing temperature and dropped after 900 degrees C. The presented thermodynamic equilibrium model conformed well with experimental results, deviating little in terms of O-2, CO2, H-2, and CH4 and no more than 8.1% in the case of CO. This indicates that simple modeling methods can be utilized to predict gas compositions for the pilot-scale.Web of Science6art. no. UNSP 9

Heavy Metal Uptake by Novel Miscanthus Seed-Based Hybrids Cultivated in Heavy Metal Contaminated Soil

When heavy metal contaminated soils are excluded from food production, biomass crops offer an alternative commercial opportunity. Perennial crops have potential for phytoremediation. Whilst the conditions at heavy metal contaminated sites are challenging, successful phytoremediation would bring significant economic and social benefits. Seed-based Miscanthus hybrids were tested alongside the commercial clone Miscanthus ? giganteus on arable land, contaminated with Pb, Cd and Zn near Katowice. Before the randomized experimental plots were established (25m2 plots with plant density 2/m2) ?time-zero? soil samples were taken to determine initial levels of total (aqua regia) and bioavailable (CaCl2 extraction) concentration of Pb, Cd and Zn. After the growing season plant material was sampled during autumn (October, green harvest) and winter (March, brown harvest) to determine differences in heavy metal uptake. Results after the first growing season are presented, including the plot establishment success, biomass yield and heavy metal uptakepublishersversionPeer reviewe

New Miscanthus hybrids cultivated at a polish metal-contaminated site demonstrate high stomatal regulation and reduced shoot Pb and Cd concentrations

The increased bioeconomy targets for the biomass share of renewable energy production across Europe should be met using land unsuitable for food production. Miscanthus breeding programs targeted the production of plants with a diverse range of traits allowing a wider utilization of land resources for biofuel production without competing with arable crops. These traits include increasing tolerances to drought, chilling, and to metal(loid)s excess. Two novel Miscanthus hybrids, GNT41 and GNT34, were compared against Miscanthus x giganteus (Mxg) on metal-contaminated arable land in Poland. This study aimed at evaluating their yield, biomass quality and quantifying seasonal differences in photosynthetic and transpiration parameters. A secondary objective was to identify key physiological mechanisms underlying differences in metal accumulation between the investigated plants. The new hybrids produced a similar yield to Mxg (13e15 t ha 1 yr 1), had shorter shoots, higher Leaf Area Index and stem number. Based on gas exchange measurements, GNT34 exhibited isohydric (water-conserving) behavior. The stomatal response to light of the new hybrids was at least twice as fast as that of Mxg, a trait that is often associated with increased seasonal water use efficiency. This contributed to the almost 40% reduction in shoot Pb and Cd concentrations for the new hybrids as compared to Mxg. This suggested that promoting stomatal regulation in conjunction with improved water conservation may be a target for improving plants for wider use on metals contaminated land

Seasonal dynamics of dry matter accumulation and nutrients in a mature miscanthus × giganteus stand in the lower silesia region of poland

Funding: J.C.B. and P.R.H.R. were funded by the Biotechnology and Biological Sciences Research Council strategic programme grant on Resilient Crops (BBS/E/W/10963A01).Peer reviewedPublisher PD

Economic and environmental assessment of seed and rhizome propagated Miscanthus in the UK

Growth in planted areas of Miscanthus for biomass in Europe has stagnated since 2010 due to technical challenges, economic barriers and environmental concerns. These limitations need to be overcome before biomass production from Miscanthus can expand to several million hectares. In this paper we consider the economic and environmental effects of introducing seed based hybrids as an alternative to clonal M. x giganteus (Mxg). The impact of seed based propagation and novel agronomy was compared with current Mxg cultivation and used in ten commercially relevant, field scale experiments planted between 2012 and 2014 in the UK, Germany and Ukraine. Economic and greenhouse gas (GHG) emissions costs were quantified for the following production chain: propagation, establishment, harvest, transportation, storage and fuel preparation (excluding soil carbon changes). The production and utilisation efficiency of seed and rhizome propagation were compared. Results show that new hybrid seed propagation significantly reduces establishment cost to below ?900 ha-1. Calculated GHG emission costs for the seeds established via plugs, though relatively small, was higher than rhizomes because fossil fuels were assumed to heat glasshouses for raising seedling plugs (5.3 and 1.5 kg CO2 eq. C Mg (dry matter (DM))-1), respectively. Plastic mulch film reduced establishment time, improving crop economics. The breakeven yield was calculated to be 6 Mg DM ha-1 y-1, which is about half average UK yield for Mxg; with newer seeded hybrids reaching 16 Mg DM ha-1 in second year UK trials. These combined improvements will significantly increase crop profitability. The trade-offs between costs of production for the preparation of different feedstock formats show that bales are the best option for direct firing with the lowest transport costs (?0.04 Mg -1 km-1) and easy on-farm storage. However if pelleted fuel is required then chip harvesting is more economic. We show how current seed based propagation methods can increase the rate at which Miscanthus can be scaled up; ~x100 those of current rhizome propagation. These rapid ramp rates for biomass production are required to deliver a scalable and economic Miscanthus biomass fuel whose GHG emissions are ~1/20th those of natural gas per unit of heatpublishersversionPeer reviewe

Extending Miscanthus cultivation with novel germplasm at six contrasting sites

The OPTIMISC project received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 289159.Peer reviewedPublisher PD

Environmental Influences on the Growing Season Duration and Ripening of Diverse Miscanthus Germplasm Grown in Six Countries

The development of models to predict yield potential and quality of a Miscanthus crop must consider climatic limitations and the duration of growing season. As a biomass crop, yield and quality are impacted by the timing of plant developmental transitions such as flowering and senescence. Growth models are available for the commercially grown clone Miscanthus x giganteus (Mxg), but breeding programs have been working to expand the germplasm available, including development of interspecies hybrids. The aim of this study was to assess the performance of diverse germplasm beyond the range of environments considered suitable for a Miscanthus crop to be grown. To achieve this, six field sites were planted as part of the EU OPTIMISC project in 2012 in a longitudinal gradient from West to East: Wales?Aberystwyth, Netherlands?Wageningen, Stuttgart?Germany, Ukraine?Potash, Turkey?Adana, and Russia?Moscow. Each field trial contained three replicated plots of the same 15 Miscanthus germplasm types. Through the 2014 growing season, phenotypic traits were measured to determine the timing of developmental stages key to ripening; the tradeoff between growth (yield) and quality (biomass ash and moisture content). The hottest site (Adana) showed an accelerated growing season, with emergence, flowering and senescence occurring before the other sites. However, the highest yields were produced at Potash, where emergence was delayed by frost and the growing season was shortest. Flowering triggers varied with species and only in Mxg was strongly linked to accumulated thermal time. Our results show that a prolonged growing season is not essential to achieve high yields if climatic conditions are favorable and in regions where the growing season is bordered by frost, delaying harvest can improve quality of the harvested biomasspublishersversionPeer reviewe