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Schematic diagram showing RCBD split plot design at the research site, University of Guelph, Guelph, Ontario, Canada
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Biomass yields of five commonly grown bioenergy crops, miscanthus, switchgrass, poplar (2293-19), willow (SX 67) and a mix of native grasses (polyculture) were assessed on a marginal land. When long-term yield responses were examined, miscanthus yield significantly increased from 5.96 ± 1.06 odt ha⁻¹ y⁻¹ in 2011 to 17.03 ± 8.1 odt ha⁻¹ y⁻¹ in 2014....
Citations
... Soil from the site is classified as a Gray Brown Luvisol with a fine sandy loam texture (56% sand, 34% silt, and 10% clay) (Mann, 2012). The land falls under class 4 in the Canadian Land Inventory (CLI) classification (Marsal et al., 2016) which is considered as marginal agriculture land and with minimal suitability for growing annual food crops (Marsal et al., 2016). Due to poor row crop grain yield, the site which had been under corn (zea mays L.), soybean (Glycine max L.), and wheat (Triticum vulgare L.) rotation for about 25 years prior to 2009 was converted to a biomass research station in 2009 (Marsal et al., 2016). ...
... Soil from the site is classified as a Gray Brown Luvisol with a fine sandy loam texture (56% sand, 34% silt, and 10% clay) (Mann, 2012). The land falls under class 4 in the Canadian Land Inventory (CLI) classification (Marsal et al., 2016) which is considered as marginal agriculture land and with minimal suitability for growing annual food crops (Marsal et al., 2016). Due to poor row crop grain yield, the site which had been under corn (zea mays L.), soybean (Glycine max L.), and wheat (Triticum vulgare L.) rotation for about 25 years prior to 2009 was converted to a biomass research station in 2009 (Marsal et al., 2016). ...
... The land falls under class 4 in the Canadian Land Inventory (CLI) classification (Marsal et al., 2016) which is considered as marginal agriculture land and with minimal suitability for growing annual food crops (Marsal et al., 2016). Due to poor row crop grain yield, the site which had been under corn (zea mays L.), soybean (Glycine max L.), and wheat (Triticum vulgare L.) rotation for about 25 years prior to 2009 was converted to a biomass research station in 2009 (Marsal et al., 2016). ...
Knowledge of freeze-thaw-induced carbon (C) and nitrogen (N) cycling and concomitant nitrous oxide (N 2 O) and carbon dioxide (CO 2) emissions in perennial bioenergy crops is crucial to understanding the contribution of these crops in mitigating climate change through reduced greenhouse gas (GHG) emissions. In this study, a 49-day laboratory incubation experiment was conducted to compare the impact of freeze-thaw cycles on N 2 O and CO 2 emissions in different perennial bioenergy crops [miscanthus (Miscanthus giganteus L.), switchgrass (Panicum virgatum L.), and willow (Salix miyabeana L.)] to a successional site and to understand the processes controlling the N 2 O and CO 2 emissions in these crops. The results showed that freeze-thaw cycles caused a decline in dissolved organic C (DOC) and dissolved inorganic N (DIN) concentrations but enhanced the dissolved organic N (DON) and nitrate (NO 3 −). Although, freeze-thaw decreased water stable soil aggregates in all the bioenergy crops and successional site, this did not have any significant impact on N 2 O and CO 2 emissions, suggesting that the N 2 O and CO 2 emitted during the freeze-thaw cycles may have originated mostly from cellular materials released from lysis and death of microbial biomass rather than from soil aggregate disruption. Cumulative N 2 O emissions measured over the 49-day incubation period ranged from 148 mg N 2 ON m − 2 to 17 mg N 2 ON m − 2 and were highest in miscanthus followed by willow, switchgrass, and successional site. Cumulative CO 2 on the other hand was highest in the successional site than any of the bioenergy crops and ranged from 25,262 mg CO 2-C m − 2 to 15,403 mg CO 2-C m − 2 after the 49 days. Higher N 2 O emissions in the miscanthus and willow than switchgrass and successional site were attributed to accelerated N losses as N 2 O. Results from our study indicate that managing perennial bioenergy crops on low productive agricultural lands to reduce freeze-thaw related GHG emissions and climate change mitigation is dependent on the crop species grown.
... Where, ALLC represents annual leaf litter carbon (kg C) (Marsal et al. 2016;Bazrgar et al. 2020) ...
Riparian buffer systems (RBSs) can sequester atmospheric carbon dioxide into terrestrial carbon (C) pools. C stocks and C sequestration potential of diverse RBSs are not adequately reported. This study, therefore, quantified: (a) C stocks in various RBSs and (b) system-level C sequestration potentials (SLCSP) [SLCSP= ΔSOC + Biomass C Pools] in southern Ontario, Canada. Results showed significant differences (p < 0.05) in system-level C stocks between tree buffers (765.8 Mg C ha-1) and grass buffers (291.7 Mg C ha-1) and between natural forest buffers (935.9 Mg C ha-1) and rehabilitated buffers (595.6 Mg C ha-1), but no difference (p > 0.05) between coniferous buffers (722.4 Mg C ha-1) and deciduous buffers (809.1 Mg C ha-1) were recorded. Tree buffers had higher SLCSP (633.5 Mg C ha-1) than grass buffers (126.7 Mg C ha-1). Natural forest buffers had higher SLCSP (806.7 Mg C ha 1) than rehabilitated buffers (460.3 Mg C ha-1). There was no difference (p > 0.05) in SLCSP between coniferous buffers (615.0 Mg C ha-1) and deciduous buffers (652.1 Mg C ha-1). Results from this study confirm that the establishment of RBSs within agricultural watersheds can significantly contribute to create new terrestrial C sinks. RÉSUMÉ Les bandes riveraines boisés (BRB) peuvent séquestrer le dioxyde de carbone atmosphérique dans des réservoirs ter-restres de carbone (C). Les stocks de carbone et le potentiel de séquestration de différents BRB ne sont pas adéquatement répertoriés. Cette étude, en conséquence, a permis de quantifier : (a) les stocks de C pour différents BRB et (b) le potentiel de séquestration du carbone des bandes (PSCB) localisées dans le sud de l'Ontario au Canada. Les résultats ont démontré une différence significative (p < 0,05) au niveau des stocks de C retrouvés dans des bandes riveraines boisées (765,7 Mg C ha-1) et des bandes herbacées (291,7 Mg C ha-1), ainsi que pour des bandes riveraines naturellement boisées (935,9 Mg C ha-1) et des bandes reboisées (595,6 Mg C ha-1), mais aucune différence (p > 0,05) entre les bandes résineuses (722,4 Mg C ha-1) et les bandes feuillues (809,1 Mg C ha-1) n'a été enregistrée. Les bandes boisées ont affiché un PSCB plus élevé (633,5 Mg C ha-1) que les bandes herbacées (126,9 Mg C ha-1). Les bandes naturellement boisées ont démontré un PSCB plus élevé (806,7 Mg C ha-1) que les bandes reboisées (460,3 Mg C ha-1). Aucune différence n'a été relevée (p > 0,05) au niveau des PSCB des bandes résineuses (615,0 Mg C ha-1) et des bandes feuillues (652,0 Mg C ha-1). Les résul-tats de cette étude confirment que la création de BRB dans les écosystèmes agricoles peut contribuer significativement à la mise en place de nouveaux réservoirs terrestres de C. Mots clés : carbone de la biomasse aérienne et souterraine, agroforesterie, atténuation des changements climatiques, bandes herbacées, bandes naturellement boisées, réservoirs terrestres de carbone, séquestration du carbone par les bandes riveraines
... Where, ALLC represents annual leaf litter carbon (kg C) (Marsal et al. 2016;Bazrgar et al. 2020) ...
Riparian buffer systems (RBSs) can sequester atmospheric carbon dioxide into terrestrial carbon (C) pools. C stocks and C sequestration potential of diverse RBSs are not adequately reported. This study, therefore, quantified: (a) C stocks in various RBSs and (b) system-level C sequestration potentials (SLCSP) [SLCSP= ΔSOC + Biomass C Pools] in southern Ontario, Canada. Results showed significant differences (p < 0.05) in system-level C stocks between tree buffers (765.8 Mg C ha ⁻¹ ) and grass buffers (291.7 Mg C ha ⁻¹ ) and between natural forest buffers (935.9 Mg C ha ⁻¹ ) and rehabilitated buffers (595.6 Mg C ha ⁻¹ ), but no difference (p > 0.05) between coniferous buffers (722.4 Mg C ha ⁻¹ ) and deciduous buffers (809.1 Mg C ha ⁻¹ ) were recorded. Tree buffers had higher SLCSP (633.5 Mg C ha ⁻¹ ) than grass buffers (126.7 Mg C ha ⁻¹ ). Natural forest buffers had higher SLCSP (806.7 Mg C ha ¹ ) than rehabilitated buffers (460.3 Mg C ha ⁻¹ ). There was no difference (p > 0.05) in SLCSP between coniferous buffers (615.0 Mg C ha ⁻¹ ) and deciduous buffers (652.1 Mg C ha ⁻¹ ). Results from this study confirm that the establishment of RBSs within agricultural watersheds can significantly contribute to create new terrestrial C sinks.
... Among LCM, Paulownia is a deciduous tree (Akyldiz and Kol, 2010) with a low demand of water, despite not growing in barren zones (Caparrós et al., 2008). Paulownia is a fast growing tree that has a high biomass production and resprouting potential (up to 50 t /ha·year) (Domínguez et al., 2017), generating higher biomass in one year than other species (such as poplar, switchgrass, miscanthus or willow) (Marsal et al., 2016). These characteristics make Paulownia a suitable feedstock to produce bioethanol. ...
In this work, valorization of Paulownia wood (PW) was proposed following several process configurations for biofuels and value-added compounds production. Firstly, autohydrolysis and ethanol-organosolv strategies were assessed separately for the fractionation of PW to enhance the enzymatic digestibility of cellulose. A third strategy focused on a sequential process (autohydrolysis and organosolv) was explored. Two temperatures were selected for the first stage of the combined process. High concentration of oligosaccharides (26.29 g/L) and high concentration of degradation products (17.21 g/L) were obtained at 210 and 230°C, respectively. The solids obtained from both pretreatments were subjected to organosolv delignification (200°C, 3h and 50% ethanol) achieving delignification of 58 and 30% for the autohydrolyzed biomass at 210°C and 230°C, respectively. The combined process resulted in susceptible biomass able to produce 64 g/L of ethanol. Therefore, the strategies explored in this work open the possibility to build a refinery around Paulownia wood.
... The belowground biomass C is usually represented by fine roots, mostly in herbaceous cropping systems [23]. Fine roots turnover (FRT) in this study was estimated at 50% of the annual litterfall C input in woody crops [8,36,37]. For example, the value for DCr was derived as (1 − 0.74 [decomposition rate]) = 0.26 (gain, after loss factor (microbial decomposition) that we used to multiply the belowground C stock of the roots), similarly, DCl (1 − 0.71) = 0.29, and DCfr (1 − 0.8) = 0.20. ...
... This is mainly due to significantly (p < 0.05) higher aboveground biomass C (Table 4) and numerically higher belowground biomass C (Table 4) compared to other tested biomass crops. Willow has the ability to coppice more vigorously after each harvest than poplar and also adapts itself better than other biomass crops on low-productive or marginal lands [37]. The total C pool values reported in this study are within the previously reported range of values, 12-175 Mg C ha −1 [36,47,48]. ...
... The findings show that the woody systems may have an advantage over herbaceous biomass systems based on the numerical SLCG values. It will be interesting to monitor as to how these systems will differ in their C sequestration numbers into the future as both, woody and herbaceous systems, are considered to be productive for up to 22 years [37]. ...
Enhancement of terrestrial carbon (C) sequestration on marginal lands in Canada using bioenergy crops has been proposed. However, factors influencing system-level C gain (SLCG) potentials of maturing bioenergy cropping systems, including belowground biomass C and soil organic carbon (SOC) accumulation, are not well documented. This study, therefore, quantified the long-term C sequestration potentials at the system-level in nine-year-old (2009–2018) woody (poplar clone 2293–29 (Populus spp.), hybrid willow clone SX-67 (Salix miyabeana)), and herbaceous (miscanthus (Miscanthus giganteus var. Nagara), switchgrass (Panicum virgatum)) bioenergy crop production systems on marginal lands in Southern Ontario, Canada. Results showed that woody cropping systems had significantly higher aboveground biomass C stock of 10.02 compared to 7.65 Mg C ha−1 in herbaceous cropping systems, although their belowground biomass C was not significantly different. Woody crops and switchgrass were able to increase SOC significantly over the tested period. However, when long term soil organic carbon (∆SOC) gains were compared, woody and herbaceous biomass crops gained 11.0 and 9.8 Mg C ha−1, respectively, which were not statistically different. Results also indicate a significantly higher total C pool [aboveground + belowground + soil organic carbon] in the willow (103 Mg ha−1) biomass system compared to other bioenergy crops. In the nine-year study period, woody crops had only 1.35 Mg C ha−1 more SLCG, suggesting that the influence of woody and herbaceous biomass crops on SLCG and ∆SOC sequestrations were similar. Further, among all tested biomass crops, willow had the highest annual SLCG of 1.66 Mg C ha−1 y−1.
... The most common Ontario biomass crops include perennial warm-season grasses such as switchgrass (Panicum virgatum) and miscanthus (Miscanthus spp.). While woody species such as hybrid willow (Salix spp.) and poplar (Populus spp.) are also grown in Ontario (Marsal et al. 2016), herbaceous biomass species have garnered the most attention. Perennial warm-season grasses are of interest due to their high yields, low nutrient requirements, a broad range of environmental tolerances and environmental benefits in comparison to common Ontario field crops such as corn (Zea mays), soybean (Glycine max) and wheat (Triticum aestivum). ...
Nineteen farms growing herbaceous biomass crops, switchgrass (Panicum virgatum) and miscanthus (Miscanthus spp.), were sampled for soil organic carbon (SOC) across Ontario, Canada in 2016. Switchgrass and miscanthus fields were sampled in addition to nearby agricultural fields and woodlots to compare SOC in herbaceous biomass systems relative to alternative land-uses. The mean SOC concentration of the woodlots was 4.26 ± 0.29% and was significantly higher (p < 0.05) than in any other types of land-use. The mean SOC concentration in agricultural fields was 2.21 ± 0.31%, while switchgrass and miscanthus had a mean SOC concentration of 2.50 ± 0.29 and 2.50 ± 0.36%, respectively. The mean SOC stock (0–30 cm) was highest in woodlots at 103.55 ± 7.40 Mg C ha⁻¹. This was significantly higher than stocks quantified in agricultural and miscanthus land-uses, which contained 80.51 ± 7.74 and 83.36 ± 8.97 Mg C ha⁻¹, respectively. The mean SOC stock calculated for switchgrass was 85.30 ± 7.14 Mg C ha⁻¹ and was not significantly different (p > 0.05) when compared with the SOC stocks quantified for the woodlot. The study recorded numerically higher SOC concentrations and stocks in biomass fields compared to agricultural fields. Therefore, biomass systems contribute to higher SOC sequestration. However, challenges associated with this study such as accurate bulk density measures and lack of baseline data need to be resolved in order to improve quantification of SOC sequestration.
... Although economically feasible production of giant Miscanthus production with low N inputs have been observed in eastern Canada, dry matter production responded positively (up to 50 Mg ha −1 yr −1 in established, mature stands) with increasing N fertilizer application (Tubeileh et al. 2015). Marsal et al. (2016) reported that M. giganteus 'Nagara' yields increased from 13.2 to 23.8 Mg ha −1 in response to N-P-K fertilization (at 75-42-62 kg ha −1 , respectively) on marginal land in southern Ontario. Although the identification and development of dedicated lignocellulose feedstocks have made significant progress, a high-yielding, ideal production system on marginal lands is yet to be identified. ...
Sustainable production of biomass crops is important in the development of feedstocks for the production of biofuels and other bioproducts. This study investigates the use of nine beneficial soil microbes and a plant biostimulant (i.e., Ascophyllum nodosum seaweed extract) to increase the growth of two giant Miscanthus (Miscanthus × giganteus) cultivars, ‘Amuri’ and ‘Nagara’, under greenhouse conditions and in the field on poor-quality, marginal land. Greenhouse trials indicated increases in shoot dry weight (DW) in ‘Amuri’ in treatments with Gluconacetobacter diazotrophicus PAL5T LsdB ⁺⁺ , Gluconacetobacter johannae UAP-Cf-76, and Variovorax paradoxus JM67 by 15%–24% compared with untreated controls. In ‘Nagara’, shoot DW was increased in the treatments with Penicillium bilaiae by 11% and the seaweed extract by 10%. The nutrient content of shoot tissues increased in the same treatments in which biomass was increased. Despite a lack of treatment effects on shoot DW in ‘Amuri’ in the field, several treatments increased Fe and Zn content in shoots by up to 1.9×. In ‘Nagara’ in the field, treatment with G. johannae UAP-Cf-76 and the seaweed extract resulted in increases in shoot DW by 16% and 23%, respectively, and several treatments resulted in increases in shoot Fe and Zn concentrations. The productivity enhancements in giant Miscanthus by beneficial soil microbes and the seaweed extract may be associated with increasing access to limited soil nutrients. These findings suggest that the use of beneficial soil microbes and plant biostimulants may aid in the sustainable production of giant Miscanthus on marginal lands.
... Previous studies found similar results that energy crops had Z. Cui et al. Field Crops Research 223 (2018) 41-47 potential biomass yields and associated yields which could reach the maximum production as early as three years after establishment (Lewandowski et al., 2003;Engbers, 2012;Marsal et al., 2016). Therefore, growing energy crops may be beneficial for carbon sequestration and soil erosion control in semi-arid areas (Galati et al., 2016;Mekonnen et al., 2017). ...
Large-scale vegetation construction has generally led to soil desiccation in arid and semi-arid regions. Energy crops with high biomass and water use efficiency are generally beneficial to agriculture and the environment. It is necessary to understand how to maintain the dynamic balance of soil moisture and biomass production on herbaceous energy croplands. In this study, soil moisture data at different depths of soil were obtained from long-term field observations for two energy crops, i.e., Panicum virgatum and Miscanthus sinensis, and a forage crop-Medicago sativa. Relative aridity of the soil and plant biomass were compared among different vegetation types, transects, and cultivation years. Medicago sativa soil was severely, even extremely, desiccative with increasing cultivation years, whereas there was nearly no desiccation in the soil of energy crops. The values of compared soil water storage compensation indexes in deep soil layers were higher than those in shallow soil layers, with the evaluated soil water storage compensation index being the smallest in the 40-80 cm layer. Energy crops had significantly higher aboveground biomass, mostly exhibiting more than 2.6 kg m −2 , while the aboveground biomass of M. sativa was only above 0.5 kg m −2. Furthermore, the water use efficiencies of energy crops were obviously higher than that of M. sativa (P < 0.05). Our results indicated that deep soil moisture conditions were mainly determined by field crop types. Energy crops may be suitable candidates for compensating soil water storage and maintaining high biomass production in semi-arid regions.
... For instance, Mann (2012) did not find any difference in biomass yield during the first two growing seasons of poplar and switchgrass in southern Ontario. Later, similar results were reported for the fifth growing season for the same crops on the same site by Marsal et al. (2016). Amaducci et al. (2017) compared the yield of six biomass crops including poplar and switchgrass and found that switchgrass biomass yield was significantly higher than poplar. ...
... The 2-yr poplar stem biomass yield ranges between 7.0 and 15.5 t ha −1 , with significant differences between the two studied clones. This yield range is consistent with poplar biomass yield reported in many studies (Aylott et al. 2008;Dillen et al. 2013;Marsal et al. 2016). Similarly, switchgrass harvestable biomass yield (stem and leaves) ranged from 1.6 t ha −1 (SGN) to 2.6 t ha −1 (SGC), which can be compared with the average yield of 3.5 t ha −1 yr −1 reported in other studies on marginal lands (Qin et al. 2015;Marsal et al. 2016). ...
... This yield range is consistent with poplar biomass yield reported in many studies (Aylott et al. 2008;Dillen et al. 2013;Marsal et al. 2016). Similarly, switchgrass harvestable biomass yield (stem and leaves) ranged from 1.6 t ha −1 (SGN) to 2.6 t ha −1 (SGC), which can be compared with the average yield of 3.5 t ha −1 yr −1 reported in other studies on marginal lands (Qin et al. 2015;Marsal et al. 2016). However, relatively lower SGC yields in this study can be attributed mainly to the following establishment issues at the Kemptville site: crop failure due to early frost during the establishment year (2014) and uncontrolled weeds during subsequent years. ...
The sustainability of purpose-grown biomass production on marginal lands in Canada is uncertain. In this study, an assessment of biomass yield and sustainability was performed for two poplar clones (Poplus deltoides × P. nigra, DN-34—PDN, and P. nigra × P. maximowiczii, NM-6—PNM) and two switchgrass cultivars (Panicum virgatum ‘Cave-in-Rock’—SGC, and P. virgatum ‘Nebraska’—SGN) on three marginal lands in Guelph (ON), Kemptville (ON), and Nappan (NS) in Canada. The differences in stem biomass across sites were not significant; however, differences in stem biomass among plants were statistically significant between poplar and switchgrass (p < 0.0001) and between poplar clones (p < 0.0001). The 2-yr stem biomass yield in PNM (15.27 ± 1.28 t ha⁻¹) was significantly higher than those in PDN (7.02 ± 0.54 t ha⁻¹), SGC (2.57 ± 0.28 t ha⁻¹), and SGN (1.45 ± 0.22 t ha⁻¹). Two sustainability indices based on macronutrients (MBSI) and nitrogen (NBSI), were developed to assess sustainability. Both indices show that the biomass production system of high-yielding poplar clone PNM depicts nutrient loss and may require external nutrient inputs via fertilization during the establishment phase. Higher index values for switchgrass SGC (1.47 ± 0.22, 1.11 ± 0.15) and SGN (1.37 ± 0.16, 1.17 ± 0.12) for MBSI and NBSI, respectively, indicate that despite low stem biomass yields, switchgrass biomass production is sustainable. These findings suggest that, from a nutrient perspective, sustainable biomass production systems can be established on marginal lands in Canada; however, there is a trade-off between high yield and long-term sustainability in purpose-grown biomass production systems.
... In addition, perennial grasses have a higher water use efficiency ( Podlaski et al. 2017) and achieve higher biomass yields than woody perennials ( Marsal et al. 2016;Amaducci et al. 2017). Further advantages are that the harvest is possible with more conventional harvesting technologies, the period until the first harvest is shorter and the harvest then takes place on an annual basis, which results in a more regular cash flow ( Styles et al. 2008). ...
In a developing bioeconomy, the demand for biomass for industrial purposes is expected to increase significantly. This demand needs to be met in a sustainable way and without compromising food security. With this goal in mind, resource-efficient lignocellulosic crops, such as perennial energy grasses, are often cited as a biomass source with low negative impacts on the environment. Under European conditions, miscanthus is the leading perennial energy grass because of its high biomass and energy yield potential. It is a C4 plant, which achieves dry matter biomass yields of up to 20 Mg haâ1 yrâ1 when harvested in later winter, and up to 30 Mg haâ1 yrâ1 when harvested green in October. Currently the main utilization route of miscanthus is direct combustion for heat generation, but the biomass can also be used for various other applications, such as biofuels and insulation material. Several studies have analysed the environmental performance of perennial crop-based value chains, but most of these only assessed the Global Warming Potential (GWP). However, the GWP alone is not an adequate indicator for the holistic assessment of the environmental performance of such value chains. In addition, these studies often used generic data and applied varying assumptions, which makes a comparison of different value chains difficult. The main goal of this thesis is to draw up recommendations for future assessments of the environmental performance of perennial crop-based value chains. For this purpose, five research objectives were formulated: 1) to identify the key parameters influencing the environmental performance of perennial crop-based value chains; 2) to analyse which impact categories are most relevant when assessing the environmental performance; 3) to assess the differences between various perennial-crop based value chains; 4) to assess the environmental performance of the utilization of marginal land to grow perennial crops for industrial purposes; and 5) to analyse and compare the environmental performance of annual and perennial crops in the example value chain biogas production. To achieve these research objectives, the environmental performance of several perennial crop-based value chains was analysed in various impact categories applying the same underlying assumptions and using field data obtained under ceteris paribus conditions. The analysis was carried out using the globally recognised Life Cycle Assessment (LCA) methodology, which is standardized by two ISO norms (14040/44). The results revealed that biomass yield is one of the most important parameters influencing the environmental performance of perennial crop-based value chains. An increase in yield of 50%, for instance, leads to an increase in carbon mitigation potential in a comparable range (46%). Furthermore, the marked influence on the environmental impact mitigation potential of both fertilizer-induced emissions and selection of the reference system was demonstrated. For example, if the reference system is changed from light fuel oil to natural gas, the substituting by heat generated from the combustion of miscanthus biomass increases the net impact in the category particulate matter formation by 220%. The relevance of different impact categories was analysed for various perennial crop-based value chains using a normalisation approach. The results clearly indicated that a holistic assessment of the environmental performance of perennial crop-based value chains should at least include the impact categories marine ecotoxicity, human toxicity, agricultural land occupation, freshwater eutrophication and freshwater ecotoxicity. In future assessments, it is recommended to include the impacts of land-use on both biodiversity (using species richness as an indicator) and soil quality (using SOM as an indicator). The comparison of the environmental performance of different perennial crop-based value chains revealed clear environmental advantages of the cascade use of biomass. An example is the production of miscanthus-based insulation material, which is first used as a building material and then incinerated to generate heat and electricity. The results also demonstrate that, despite low biomass yield on marginal land, miscanthus-based value chains have a substantial environmental impact mitigation potential when substituting a fossil-based reference system. Furthermore, the comparison of annual and perennials crops as biogas substrates showed that perennial crops, and in particular miscanthus, have a considerably better environmental performance in the impact categories climate change (up to -73%), fossil fuel depletion (up to -79%), freshwater eutrophication (up to -69%), marine eutrophication (up to -67%), and terrestrial acidification (up to -26%). In all four studies included in this thesis, it was observed that the data used for the biomass cultivation in particular, such as yield and fertilizer-induced emissions, have a considerable influence on the environmental performance. This data is highly site- and crop-specific and is strongly dependent on the agricultural management system applied. Based on the results of this thesis, the common practice of using generic data in assessments of the environmental performance of perennial crop-based value chains should be rejected. In order to obtain realistic results, the use of site- and crop-specific data is highly recommended.
