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The agricultural production of maize (Zea mays L.) increases the risk of water erosion. Perennial crops like cup plant (Silphium perfoliatum L.) offer a sustainable alternative to produce biomass for biogas plants. The assessment of soil conservation measures requires calibrated soil erosion models that spatially identify soil erosion processes. These support decision-making by farmers and policymakers. Input parameters for the physically based soil erosion model EROSION 3D for cup plant cultivation were established in a field study. Rainfall simulation experiments were conducted to determine the model input parameter's skinfactor and surface roughness. The results showed a reduction of soil erosion and higher infiltration rates for cup plant resulting in higher skinfactors of 11.5 in June and 0.75 post-harvest (cup plant) compared to 1.2 in June and 0.21 post-harvest (maize). With the extended parameter catalogue of EROSION 3D for cup plant cultivation model simulations were conducted for a rainfall event in June (64 mm). The sediment budget would have been reduced by 92.6% through the growth of cup plant in comparison to conventionally grown maize. Perennial cup plant can, therefore, contribute to achieving the targets outlined in the European Green Deal by reducing soil erosion and enhancing soil health. [ABSTRACT FROM AUTHOR]

Silphium perfoliatum, an energy crop with a high fiber content but low concentrations of fermentable carbohydrates, presents challenges for complete fermentation in biogas production. To overcome this, a bioeconomic approach proposes the use of the fibers for paper and board production, which requires high-quality silage with minimal butyric acid, which affects the marketability of the fibers. This study aims to optimize the silaging process of Silphium perfoliatum by investigating the effects of harvest date, bacterial cultures and additives on fermentation results. Laboratory experiments were conducted to evaluate the effect of three harvest dates on fermentation acid composition, with a focus on increasing lactic acid production to inhibit butyric acid formation. Results indicate that an early harvest date (early September) is critical for achieving stable fermentation and minimizing ensiling losses. The addition of sugar-rich additives, such as syrup, was found to be essential, especially for later harvest dates. Despite these interventions, a late harvest (early November) consistently resulted in suboptimal fermentation. The results suggest that optimizing harvest timing and incorporating appropriate additives are key strategies for producing high quality silage and ensuring the suitability of Silphium perfoliatum fibers for industrial applications. [ABSTRACT FROM AUTHOR]

Comparative studies have been carried out to determine the quantities and depositions of heavy metals, macro, and microelements in the vegetative organs of Silphium perfoliatum, the efficiency for phytoremediation and the quality of the biomass as a renewable energy source for the combustion process. The field experiment was conducted on an agricultural field contaminated by the Non-Ferrous Metals Plant near Plovdiv, Bulgaria. Silphium perfoliatum is tolerant to heavy metals and can be grown on highly contaminated soils (1671.6 mg/kg Zn, 1694.8 mg/kg Pb, and 54.8 mg/kg Cd). Pb, Zn, Hg, Cu, Fe, Mn, Ca and Mg accumulated in leaves, Cd and P - in roots, and K in stems. Cup plant can be classified as a exluder plant with bioconcentration factor < 1 and can also be used in phytoremediation of contaminated soils. Silphium perfoliatum can be a significant source of good-quality raw material in producing solid biofuels. The biomass studied is of high quality (high in C and H and low in ash, N, Cl, and S) and has high energy potential. Biomass of Silphium perfoliatum from highly contaminated soils could be used as a source of energy. [ABSTRACT FROM AUTHOR]

The agricultural production of maize (Zea mays L.) increases the risk of water erosion. Perennial crops like cup plant (Silphium perfoliatum L.) offer a sustainable alternative to produce biomass for biogas plants. The assessment of soil conservation measures requires calibrated soil erosion models that spatially identify soil erosion processes. These support decision-making by farmers and policymakers. Input parameters for the physically based soil erosion model EROSION 3D for cup plant cultivation were established in a field study. Rainfall simulation experiments were conducted to determine the model input parameter’s skinfactor and surface roughness. The results showed a reduction of soil erosion and higher infiltration rates for cup plant resulting in higher skinfactors of 11.5 in June and 0.75 post-harvest (cup plant) compared to 1.2 in June and 0.21 post-harvest (maize). With the extended parameter catalogue of EROSION 3D for cup plant cultivation model simulations were conducted for a rainfall event in June (64 mm). The sediment budget would have been reduced by 92.6% through the growth of cup plant in comparison to conventionally grown maize. Perennial cup plant can, therefore, contribute to achieving the targets outlined in the European Green Deal by reducing soil erosion and enhancing soil health.

Silphium perfoliatum, an energy crop with a high fiber content but low concentrations of fermentable carbohydrates, presents challenges for complete fermentation in biogas production. To overcome this, a bioeconomic approach proposes the use of the fibers for paper and board production, which requires high-quality silage with minimal butyric acid, which affects the marketability of the fibers. This study aims to optimize the silaging process of Silphium perfoliatum by investigating the effects of harvest date, bacterial cultures and additives on fermentation results. Laboratory experiments were conducted to evaluate the effect of three harvest dates on fermentation acid composition, with a focus on increasing lactic acid production to inhibit butyric acid formation. Results indicate that an early harvest date (early September) is critical for achieving stable fermentation and minimizing ensiling losses. The addition of sugar-rich additives, such as syrup, was found to be essential, especially for later harvest dates. Despite these interventions, a late harvest (early November) consistently resulted in suboptimal fermentation. The results suggest that optimizing harvest timing and incorporating appropriate additives are key strategies for producing high quality silage and ensuring the suitability of Silphium perfoliatum fibers for industrial applications.

This research was focused on a production potential of cup plant Silphium perfoliatum L. grown in marginal heavy soils with the following intensity of mineral nutrition: (i) intensive 245.0 kg/ha NPK, (ii) semi-intensive 122.5 kg/ha NPK and (iii) untreated control 0.0 kg/ha NPK. The large-scale pilot field experiments with ÓVÁRI-ÓRIÁS cultivar were carried out on 2 sites under semi-humid to humid Central European temperate climate during 4 years. Overall, it was achieved 13.59 t/ha of dry matter yield on average and the yields varied from 2.37 t/ha to 42.56 t/ha. During the three productive years (2018 – 2020) the crop yield was affected mainly by years (F-ratio 70.67, P-value 0.00), then by nutrition (F-ratio 30.50, P-value 0.00), followed by sites (F-ratio 1.92, P-value 0.17) and finally by replications (F-ratio 0.00, P-value 1.00). In general, cup plant productivity was increasing by a higher number of utility years and similarly, by increasing of nutrition intensity. Although the effect of the sites seems to be almost negligible, the present study does not include sites with arid or semi-arid climate, where the crop productivity may be completely different, especially if the soils are easy soils with an already drying water regime. This study focused on cup plant is probably one of first original research papers published as study based on large-scale experiments conducted in Slovakia, the crop is recognized as suitable perennial crop for energy as other purposes and therefore further agronomic as follow-up studies are needed.

The aim of study was to determine ligno-cellulose quality and calorific value of cup plant Silphium perfoliatum L., whereas impact of nutrition, years and sites on the quality were evaluated as main effects within a huge pilot field experiment. Two complete data sets of acid-detergent fiber (ADF), acid-detergent lignin (ADL), crude cellulose (CE), hemicellulose (HEM), neutral-detergent fiber (NDF) and high heating value (HHV) were evaluated, a primary one in terms of quality content and a secondary one in terms of quality yield. Average, minimal and maximal ADF content was 43.73 – 31.32 – 48.94%, ADL 10.22 – 7.21 – 12.54%, CE 33.51 – 24.11 – 37.30%, HEM 4.17 – 2.33 – 5.75%, NDF 48.12 – 34.94 – 54.69% and HHV 15.83 – 15.21 – 16.79 MJ/kg, respectively. Adequate values of ADF yield was 5.461 – 1.021 – 20.827 t/ha, ADL 1.274 – 0.235 – 5.115 t/ha, CE 4.187 – 0.786 – 15.112 t/ha, HEM 0.569 – 0.055 – 2.447 t/ha, NDF 6.041 – 1.139 – 23.273 t/ha and HHV 195.528 – 36.481 – 704.914 GJ/ha, respectively. Ligno-cellulose quality and calorific value of cup plant vary with environment and management practices. In terms of quality content, the influence of the sites was generally the most significant (valid for ADF, ADL, CE and NDF), or alternately with the influence of the years (HEM and HHV) it was higher than a medium influence of the nutrition. In terms of quality yield the years has been confirmed the most important factor (mainly because great increasing of phytomass yield by utility year of that perennial crop), followed by nutrition and then by sites with the least impact, whereas that impact order was valid for each of parameter.

The effects of novel perennial energy crops on arthropod abundance and diversity were tested using three field trials in Bavaria. Established cup plant (Silphium perfoliatum), Virginia mallow (Sida hermaphrodita) and tall wheat grass (Thinopyrum ponticum) plots were sampled in autumn using a modified leaf blower and their arthropod faunas compared with that recorded in maize plots. At the time of sampling, maize, cup plant and Virginia mallow had already been harvested and samples from the remaining stubble were compared with those from open ground. Collembola were the most abundant group. The highest abundance and diversity of arthropods was recorded in tall wheat grass, with Hemiptera and Aranea especially benefitting from the green and taller vegetation. Post-harvest cup plant and Virginia mallow plots harboured a more diverse and more abundant arthropod assemblage than maize plots. Stubble was identified as a suitable habitat for arthropods in agricultural fields. In conclusion, the integration of perennial energy crops into existing biogas production systems could play an important role in supporting arthropods in agricultural landscapes by providing crucial structures and resources, such as the grassy vegetation of tall wheat grass in autumn and the long-lasting stubbles of cup plant and Virginia mallow.

For higher sustainability in biomass production the use of new perennial species can lead to sustainable progress in the energy production and manufacturing industry. During the last decades, two different species of Silphium were discussed for biomass production. However, some questions regarding their cultivation and different uses are still to be answered. In this study, two accessions of Silphium perfoliatum L. and Silphium integrifolium Michx. were investigated during the year of establishment, and the first generative year for the phenotypic characteristics and suitability for cultivation, under Central European field conditions. Intra- and interspecific comparisons were made with special attention to their growth kinetics. While cup plant (S. perfoliatum) is well known as a potential biomass crop in Europe, silflower (S. integrifolium) is still unknown. In intraspecific comparison, S. integrifolium shows a more uniform development than S perfoliatum. In parallel, the development of S. perfoliatum accessions is temporally shifted, so that the S. perfoliatum accessions differ in the length of their phases of generative growth and onset of senescence in comparison to S. integrifolium. To make these results applicable, an improvement proposal was made to the existing BBCH scale for S. perfoliatum. In addition, an adaptation was conducted on S. integrifolium. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central European Agriculture is the property of Journal of Central European Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Central European Agriculture is the property of Journal of Central European Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of novel perennial energy crops on arthropod abundance and diversity were tested using three field trials in Bavaria. Established cup plant (Silphium perfoliatum), Virginia mallow (Sida hermaphrodita) and tall wheat grass (Thinopyrum ponticum) plots were sampled in autumn using a modified leaf blower and their arthropod faunas compared with that recorded in maize plots. At the time of sampling, maize, cup plant and Virginia mallow had already been harvested and samples from the remaining stubble were compared with those from open ground. Collembola were the most abundant group. The highest abundance and diversity of arthropods was recorded in tall wheat grass, with Hemiptera and Aranea especially benefitting from the green and taller vegetation. Post-harvest cup plant and Virginia mallow plots harboured a more diverse and more abundant arthropod assemblage than maize plots. Stubble was identified as a suitable habitat for arthropods in agricultural fields. In conclusion, the integration of perennial energy crops into existing biogas production systems could play an important role in supporting arthropods in agricultural landscapes by providing crucial structures and resources, such as the grassy vegetation of tall wheat grass in autumn and the long-lasting stubbles of cup plant and Virginia mallow. [ABSTRACT FROM AUTHOR]

Background: The sustainability of bioenergy is strongly affected by direct field‐derived greenhouse gas (GHG) emissions and indirect emissions form land‐use change. Marginal land in low mountain ranges is suitable for feedstock production due to small impact on indirect land‐use change. However, these sites are vulnerable to high N2O emissions because of their fine soil texture and hydrology. Aims: The perennial cup plant (Silphium perfoliatum L.) might outperform silage maize (Zea mays L.) on cold, wet low mountain ranges sites regarding yield and ecosystem services. The aim of this study was to assess whether the cultivation of cup plant also provides GHG mitigation potential compared to the cultivation of maize. Methods: A t‐year field experiment was conducted in a low mountain range region in western Germany to compare area and yield‐scaled GHG emissions from cup plant and maize fields. GHG emissions were quantified using the closed chamber method. Results: Cup plant fields emitted an average of 3.6 ± 4.3 kg N2O‐N ha–1 year–1 (–85%) less than maize fields. This corresponded to 74.0 ± 94.1 g CO2‐eq kWh–1 (–78%) less emissions per produced electrical power. However, cup plant had a significantly lower productivity per hectare (–34%) and per unit of applied nitrogen (–32%) than maize. Conclusion: Cup plant as a feedstock reduces direct field‐derived GHG emissions compared to maize but, due to lower yields cup plant, likely increases emissions associated with land‐use changes. Therefore, the increased sustainability of bioenergy from biogas by replacing maize with cup plant is heavily dependent on the performance of maize at these sites and on the ecosystem services of cup plant in addition to GHG savings. [ABSTRACT FROM AUTHOR]

European policy recommends that biomass production occur on marginal land, such as poorly draining Stagnosols. Compared to annual cropping, perennial crops may better mitigate N2O emissions at such sites, through more complete denitrification. To test that hypothesis, we compared N2 and N2O fluxes from the soils of a perennial crop (cup plant, Silphium perfoliatum L.) and an annual crop (silage maize, Zea mays L.). Intact soil columns (35 cm height, 14.4 cm diameter) were incubated for 37 days. The soils were fertilized with 60 or 120 kg N ha−1 and exposed to successive phases of waterlogging: free drainage, waterlogging of 1/3-, and waterlogging of 2/3- of the column. Source-specific N2O and N2 fluxes were measured using the 15 N gas flux method. Denitrification was higher in cup plant than maize soil and total N losses from denitrification were dominated by emissions from the third phase. Cup plant soil emitted 33.6 ± 78.1 mg N m−2 and 95.8 ± 64.4 mg N m−2 more N2O than maize soil in the low and high N treatments, respectively. The product ratio of denitrification (N2Oi = N2O/(N2 + N2O)) increased with waterlogging in maize soil, while remaining stable in cup plant soil. Emissions from the top 10 cm dominated the N2Oi rather than N2 fluxes from the saturated soil. This study did not show N2O mitigation in cup plant soil, instead highlighting the complexity of plant-soil effects on denitrification. We clearly showed that the application of a general N2Oi for agricultural soils across annual and perennial cropping is not recommended. [ABSTRACT FROM AUTHOR]

Silphium perfoliatum L. and Helianthus salicifolius A. Dietr are perennial herbaceous crops (PHC) that have recently attracted much attention. This study aimed to determine the energy input, the yield energy value, and the biomass production energy efficiency for the two prospective PHC species depending on the type of fertilizer (liquid digestate and mineral fertilizers) and the nitrogen fertilization level (0, 85 and 170 kg ha−1 N) in three consecutive growing years (2019–2021). S. perfoliatum produced a 14.1 % higher biomass yield energy value (142.3 GJ ha−1 y−1 on average) than H. salicifolius. However, the production of S. perfoliatum also required 22.8 % higher mean energy input (11.3 GJ ha−1 y−1) compared to H. salicifolius. As a result, the mean energy ratio for H. salicifolius (15.2) was 8.6 % higher than for S. perfoliatum. The highest energy ratios for H. salicifolius and S. perfoliatum were 29.7 and 22.8, respectively. Liquid digestate and mineral fertilization resulted in an increase in the yield energy value compared to plots with no fertilization, but at the same time, it increased the energy input. Therefore, the energy ratio in control plots was higher compared to the variants with fertilization. • The Silphium perfoliatum gave a 14.1 % higher biomass yield energy value than Helianthus salicifolius. • Digestate and mineral fertilization resulted in an increase the biomass yield energy value. • The S. perfoliatum production required 22.8 % higher energy input than H. salicifolius. • The mean energy ratio for H. salicifolius was 8.6 % higher than S. perfoliatum. • The energy ratio in control plots was higher than in the variants with fertilization. [ABSTRACT FROM AUTHOR]

Cup plant cultivation as feedstock for anaerobic digestion has become an emerging topic in European Agriculture. Although there is a gap in methane yields between cup plant and the benchmark crop silage maize, cup plant as a perennial crop provides several ecological advantages. Amongst others, studies have proven its potential for carbon sequestration. With the present study, we addressed the gap in knowledge about biomass partitioning above- and belowground as well as recycling of organic matter and nutrients for cup plant and compared the results to silage maize. Therefore, a 2 year field experiment was conducted under practical conditions on rather shallow soil conditions in a low mountain landscape in Western Germany. Relevant plant fractions like litterfall, yield biomass and stubbles were collected continuously and analyzed for their nutrient contents. Results show that the cup plant is characterized by more than 2000 kg ha− 1 a− 1 of pre-harvest losses with a high palatability. In sum, only 77% of the grown cup plant biomass can be harvested in contrast to 96% of silage maize. Thus, an intense, element-specific nutrient recycling takes place in cup plant whereas this is negligible in silage maize. Furthermore, clearly different, element-specific nutrient exports with yield were highlighted. In cup plant, exports were distinctly lower for nitrogen but several times higher for calcium compared to silage maize. Cup plant also showed 36% more roots with higher root masses particularly in the subsoil. [ABSTRACT FROM AUTHOR]

Abstract Sustainability of biogas production is strongly dependent on soil‐borne greenhouse gas (GHG) emissions during feedstock cultivation. Maize (Zea mays) is the most common feedstock for biogas production in Europe. Since it is an annual crop requiring high fertilizer input, maize cropping can cause high GHG emissions on sites that, due to their hydrology, have high N2O emission potential. On such sites, cultivation of cup plant (Silphium perfoliatum) as a perennial crop could be a more environmentally friendly alternative offering versatile ecosystem services. To evaluate the possible benefits of perennial cup plant cropping on GHG emissions and nitrogen losses, an incubation study was conducted with intact soil cores from a maize field and a cup plant field. The 15N gas flux method was used to quantify N source‐specific N2 and N2O fluxes. Cumulated N2O emissions and N2+N2O emissions did not differ significantly between maize and cup plant soils, but tended to be higher in maize soil. Soils from both systems exhibited relatively high and similar N2O/(N2+N2O) ratios (N2Oi). N2O emissions originating from sources other than the 15N‐labelled NO3 pool were low, but were the only fluxes exhibiting a significant difference between the maize and cup plant soils. Missing differences in fluxes derived from the 15N pool indicate that under the experimental conditions with high moisture and NO3‐ level, and without plants, the cropping system had little effect on N fluxes related to denitrification. Lower soil pH and higher bulk density in the cup plant soil are likely to have reduced the mitigation potential of perennial biomass cropping.

Before using novel energy crops to produce bioenergy, feasibility studies should be completed to determine their effect on net greenhouse gas emissions. The current study developed a model to study the greenhouse gas emissions associated with the cultivation of two novel bioenergy crops: Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L., using Intergovernmental Panel on Climate Change (IPCC) guidelines. The establishment and cultivation of Sida hermaphrodita and Silphium perfoliatum were compared with an arable rotation, short rotation coppice (SRC) and Miscanthus. Under the assumptions specified in the current study, including annual fertilisation and a high root: shoot ratio for Sida, the cultivation of Sida hermaphrodita and Silphium perfoliatum resulted in a mean net emission of 3.0 Mg CO2eq ha−1y−1 and mean net sequestration of 0.6 Mg CO2eq ha−1y−1 respectively over a 16 year rotation. This compared to predicted mean net emissions of 4.2 Mg CO2eq ha−1y−1 for an arable rotation, and intermediate values for the SRC and Miscanthus crop (1.0 and 2.2 Mg CO2eq ha− 1y− 1, respectively).

Abstract Perennial energy crop (PEC) fields need to be reintegrated into the farm's crop rotation when yield performance declines after years of use or when the farm operation requires it. In this study, 8‐year‐old stands of cup plant (Silphium perfoliatum L.) and lucerne grass followed by field grass were converted to arable cropping, while continuous silage maize (Zea mays L.) grown over the same period served as a control. The study aimed to assess changes in the weed flora, control of cup plant regrowth, pre‐crop value of PECs for subsequently grown maize and N release through mineralization of crop litter and soil organic matter in the first year after converting the PECs. The previously practiced cropping systems resulted in widely divergent maize weed populations. About 90% of the cup plant volunteers were successfully eliminated by two treatments of herbicides containing clopyralid. Maize following cup plant exhibited a faster soil cover, earlier male and female flowering, taller plants and a 10.6% and 13.6% higher aboveground biomass yield than former field grass and maize respectively. The N release by mineralization of 222 and 238 kg N ha−1 following cup plant and field grass conversion, respectively, clearly exceeded the 129 kg N ha−1 observed in the maize control. The residual mineral nitrogen in the 90 cm soil profile after the maize harvest was also significantly higher in the former field grass and cup plant plots than in the maize control. The excess N in the first year after reverting to annual cropping runs the risk of N leaching. Given that N fertilization is substantially reduced after cup plant and field grass conversion, maize appears to be a well‐suited follow‐up crop due to its good suppression of cup plant volunteers and high N uptake capacity which helps minimize nutrient losses to the environment.

For higher sustainability in biomass production the use of new perennial species can lead to sustainable progress in the energy production and manufacturing industry. During the last decades, two different species of Silphium were discussed for biomass production. However, some questions regarding their cultivation and different uses are still to be answered. In this study, two accessions of Silphium perfoliatum L. and Silphium integrifolium Michx. were investigated during the year of establishment, and the first generative year for the phenotypic characteristics and suitability for cultivation, under Central European field conditions. Intra- and interspecific comparisons were made with special attention to their growth kinetics. While cup plant (S. perfoliatum) is well known as a potential biomass crop in Europe, silflower (S. integrifolium) is still unknown. In intraspecific comparison, S. integrifolium shows a more uniform development than S perfoliatum. In parallel, the development of S. perfoliatum accessions is temporally shifted, so that the S. perfoliatum accessions differ in the length of their phases of generative growth and onset of senescence in comparison to S. integrifolium. To make these results applicable, an improvement proposal was made to the existing BBCH scale for S. perfoliatum. In addition, an adaptation was conducted on S. integrifolium.

The purpose of this research was to fill the identified gap on financial data of Sida hermaphrodita (L.) Rusby (Sida) and Silphium perfoliatum L. (Silphium), two perennial bioenergy crops that potentially provide a more sustainable alternative/complement to other bioenergy crops. Using discounted cash flow analysis, the Net Present Values of Sida and Silphium were compared to a rotation of other arable crops including maize, and the two energy crops of short rotation coppice and Miscanthus. The analysis was completed using the SidaTim analysis tool for the UK, Italy, Germany and Poland, producing a total of four independent models. The results showed that with no subsidies, cultivating Sida was unattractive in all four countries relative to other crop options. However, Silphium, was an economically viable option in each country. Both Sida and Silphium can offer greater environmental benefits than other arable crops, and the profitability of each crop would be further enhanced if additional payments for such public services were made to farmers, and if there were secure markets for the sale of the biomass. This study is the first comparative economic analysis in West and Central Europe of the two novel energy crops in comparison to more common energy crops and an arable rotation.

The life history of the cup plant leaf miner, Microrhopala laetula LeConte, in eastern South Dakota is briefly described, and the species is reported from the state for the first time. A confounding taxonomic history with M. vittata (Fabricius) restricted recognition of host plant specialization and beetle identity. Adult M. laetula overwinter and become active with mating and oviposition occurring with host plant emergence. Eggs are deposited abaxially and adaxially on leaf tips. Larvae are miners, forming a large blotch style mine, with all mesophyllic and vascular tissues consumed, resulting in most to all of a leaf dying. Pupation occurs within the leaf mine. The larva and pupa of M. laetula are compared to that of M. vittata including an ANOVA test based on morphological measurements,supporting a heuristic inference of three larval instars in M. laetula. The beetle's phytophagous impact on its host cup plant, Silphium perfoliatum (L.), can significantly reduce photosynthetic potential and biomass production through leaf loss in its first 4-6 weeks of growth. [ABSTRACT FROM AUTHOR]

Abstract Agricultural production of biogas maize (Zea mays L.) causes hazards to aquatic ecosystems through high levels of nitrogen (N) inputs. Newly introduced and already established perennial crops such as the cup plant (Silphium perfoliatum L.) and perennial grass mixtures offer the possibility of more environmentally friendly agricultural bioenergy production. The objectives of this field study were to quantify and compare soil mineral N, water infiltration, water runoff, soil erosion and N leaching under maize, permanent cup plant, and a perennial grass mixture. The study was conducted from October 2016 to March 2019 in Braunschweig, Germany. Plots with cup plant and grass mixture exhibited lower mineral N contents than maize, especially between 30 and 90 cm soil depth. Soil water infiltration was significantly different between the three crops. The grass mixture had the highest infiltration rates (6.2 mm/min averaged across 3 years), followed by cup plant (3.6 mm/min) and maize (0.9 mm/min). During wet periods, higher N leaching was found for maize (up to 42 kg N ha−1 year−1) than for cup plant (up to 5 kg N ha−1 year−1) or the grass mixture (up to 11 kg N ha−1 year−1). While runoff and erosion for cup plant and the grass mixture were negligible during the study period, considerable amounts of runoff water and eroded sediment of up to 1.5 Mg ha−1 year−1 were collected from the maize plots despite the near flat terrain of the experimental field. Overall, permanent cup plant proved suitable as a component for energy cropping systems to reduce the risk of N leaching and soil erosion, which is particularly important for the preventive flood protection in view of the more frequent occurrence of high intensity rainfall under climate change conditions.

Soil is a unique indispensable natural resource which is the solar energy storage, the basis of life for plants, animals and humans, as well as a natural indicator of environmental pollution. Contamination of soil with heavy metals is of global interest in modern science in connection with the increase of man-made impact on the environment. The danger of heavy metals is determined by the fact that, unlike organic pollutants, they are not destroyed, but transfer from one form to another, in particular, they are included in the salts, oxides, organometallic compounds. The purpose of our study was to determine the content of mobile heavy metal compounds in soil while growing energy crops on the radioactively contaminated territory. The findings of the study showed that the content of toxicants in soil under conditions of radioactive contamination was considerably below the MAC. Lead concentration in the studied sites of energy crops varied within 0.72–0.87 mg/kg. The greatest difference between the variants was found while cultivating cup plant and oriental bunias (10.9 and 11.8 %), and the smallest was observed while growing miscanthus and sorghum perennial (7.5 and 9.7 %, respectively). It was found out that the highest concentration of cadmium was observed in the soil when using mineral fertilizers (N50P50K50); the content was at the level of 0.040–0.044 mg/kg. Chemical elements such as copper and zinc were in minimal quantities. The levels of copper availability varied from 0.078 to 0.091 mg/kg, and zinc from 1.83 to 2.45 mg/kg. It should be noted that the lowest concentration of heavy metals was observed while cultivating all energy crops without the use of fertilizers. Prospects for further study will be aimed at establishing patterns of distribution of heavy metals in soil layers while cultivating energy crops.

Sustainability of biogas production is strongly dependent on soil‐borne greenhouse gas (GHG) emissions during feedstock cultivation. Maize (Zea mays) is the most common feedstock for biogas production in Europe. Since it is an annual crop requiring high fertilizer input, maize cropping can cause high GHG emissions on sites that, due to their hydrology, have high N2O emission potential. On such sites, cultivation of cup plant (Silphium perfoliatum) as a perennial crop could be a more environmentally friendly alternative offering versatile ecosystem services. To evaluate the possible benefits of perennial cup plant cropping on GHG emissions and nitrogen losses, an incubation study was conducted with intact soil cores from a maize field and a cup plant field. The 15N gas flux method was used to quantify N source‐specific N2 and N2O fluxes. Cumulated N2O emissions and N2+N2O emissions did not differ significantly between maize and cup plant soils, but tended to be higher in maize soil. Soils from both systems exhibited relatively high and similar N2O/(N2+N2O) ratios (N2Oi). N2O emissions originating from sources other than the 15N‐labelled NO3 pool were low, but were the only fluxes exhibiting a significant difference between the maize and cup plant soils. Missing differences in fluxes derived from the 15N pool indicate that under the experimental conditions with high moisture and NO3‐ level, and without plants, the cropping system had little effect on N fluxes related to denitrification. Lower soil pH and higher bulk density in the cup plant soil are likely to have reduced the mitigation potential of perennial biomass cropping. [ABSTRACT FROM AUTHOR]

The aim of the present study was to generate a consistent data set for biorefinery intermediates from novel energy crop Silphium perfoliatum compared with Fagus sylvatica, including process streams from liquid hot water pretreatment, enzymatic hydrolysis, and fermentation with Bacillus licheniformis. The consistency of the data set was further supported by the application of a consistent analytical method based on high performance anion exchange chromatography with pulsed amperometric detection and validated for process intermediates, which renders the technique a versatile analytical tool also for alcoholic compounds. For the first time, Silphium perfoliatum was used for liquid hot water pretreatment which resulted in a maximal absolute glucose recovery after enzymatic hydrolysis for feedstock pretreated with 200 °C, 20 min, 20% solid loading. Under these conditions, 68% glucose were recovered for Silphium perfoliatum and 62% for Fagus sylvatica. Further, enzymatic hydrolyzates of both feedstocks were successfully used as single carbon sources for 2,3-butanediol fermentation with Bacillus licheniformis resulting in a 2,3-butanediol yield of 39% and 31% of the theoretical yield for Silphium perfoliatum and Fagus sylvatica, respectively. Thus, the technical suitability of Silphium perfoliatum as feedstock for a liquid hot water–based biorefinery process was comprehensively demonstrated and successfully bore the comparison with Fagus sylvatica. [ABSTRACT FROM AUTHOR]

Models describe our beliefs about how the world functions. In mathematical modelling, we translate those beliefs into the language of mathematics. Mathematical models can yield prognose on the base of applied fertiliser dose. In this work results of finding yield mathematical model according to fertiliser (nitrogen) dose for perennials (willowleaf sunflower Helianthus salicifolious, cup plant Silphium perfoliatum and Jerusalem artichoke Helianthus tuberosus) on marginal land are presented. Models were described as normalised square equations for dependence between yield and fertiliser doses. Experiments were conducted in lisymeters and vases for willowleaf sunflower and cup plant. For Jerusalem artichoke experiments were done in vases only. All experiments have been doing during two years (2018 and 2019) for different fertilisers doses (45, 90 and 135 kg N∙ha–1) in three repetitions. From simulations maximal yield could be achieved for following fertiliser doses – willowleaf sunflower 104 kg N∙ha–1, cup plant 85 kg N∙ha–1 and Jerusalem artichoke 126 kg N∙ha–1. [ABSTRACT FROM AUTHOR]

Perennial energy crop (PEC) fields need to be reintegrated into the farm's crop rotation when yield performance declines after years of use or when the farm operation requires it. In this study, 8‐year‐old stands of cup plant (Silphium perfoliatum L.) and lucerne grass followed by field grass were converted to arable cropping, while continuous silage maize (Zea mays L.) grown over the same period served as a control. The study aimed to assess changes in the weed flora, control of cup plant regrowth, pre‐crop value of PECs for subsequently grown maize and N release through mineralization of crop litter and soil organic matter in the first year after converting the PECs. The previously practiced cropping systems resulted in widely divergent maize weed populations. About 90% of the cup plant volunteers were successfully eliminated by two treatments of herbicides containing clopyralid. Maize following cup plant exhibited a faster soil cover, earlier male and female flowering, taller plants and a 10.6% and 13.6% higher aboveground biomass yield than former field grass and maize respectively. The N release by mineralization of 222 and 238 kg N ha−1 following cup plant and field grass conversion, respectively, clearly exceeded the 129 kg N ha−1 observed in the maize control. The residual mineral nitrogen in the 90 cm soil profile after the maize harvest was also significantly higher in the former field grass and cup plant plots than in the maize control. The excess N in the first year after reverting to annual cropping runs the risk of N leaching. Given that N fertilization is substantially reduced after cup plant and field grass conversion, maize appears to be a well‐suited follow‐up crop due to its good suppression of cup plant volunteers and high N uptake capacity which helps minimize nutrient losses to the environment. [ABSTRACT FROM AUTHOR]

Biological farming throughout the world is becoming a necessity for the production of safe products, and the preservation of fertility and biodiversity. In this direction, there is a significant interest of the scientific community in the perennial culture -- cup plant. The cup plant has a wide range of uses in economic activities and due to its high resistance to diseases and pests, the long-term use of its plantations without replanting, and the accumulation of a significant mass of organic matter in the soil, it can be used to expand the species diversity of perennial grasses in the biological farming system. The aim of the study was to examine the influence of the seeding method and seeding rate on photosynthetic activity and dry matter productivity of the cup plant in the forest-steppe conditions of Western Siberia. It was found that with an ordinary method of sowing at a seeding rate of 4 million pcs/ha, the grass stand in the first cut had the highest rates of photosynthetic activity on average over the years of research: the leaf area was 14.8 m²/m², the photosynthetic potential was 4.0 million m² day/ha and the net productivity of photosynthesis was 2.0 g/m² · day. In the second cut, the figures were 8.4 m² /m², 1.9 million m² day/ha and 2.8 g/m² · day, respectively. The optimal density of herbage and active photosynthetic activity in the cup plant using this method of sowing contributed to a significant yield of dry matter of 12.6 t/ha with a high level of PAR absorption of 2.9%. [ABSTRACT FROM AUTHOR]

Cup-plant (Silphium perfoliatum L.) stalks were investigated as a potential wood-replacement in particleboards (PBs). Two types of PBs were produced—(1) single-layer and (2) three-layer boards. In the three-layer cup-plant PB, the core layer was made from cup-plant, while the surface layer consisted of spruce particles. The cup-plant as well as spruce control panels were produced with polymeric methylene diphenyl diisocyanate (pMDI) as the adhesive, with the physical and mechanical properties measured to meet class P1 of the European EN 312 standard. For the intrinsic morphology of the particleboards, scanning electron microscopy was applied. Wood-based and cup-plant-based particleboards indicated significant differences in morphology that affect the resulting properties of particleboards. Furthermore, an innovative approach was used in the determination of the pMDI bondline morphology. With a compact Time-of-Flight Secondary Ion Mass analyser, integrated in a multifunctional focused-ion beam scanning-electron-microscope, it was possible to show that the Ga+ ion source could be detect and visualize in 3D ion molecular clusters specific to pMDI adhesive and wood. Mechanical performance data showed that cup-plant particleboards performed well, even though their properties were below the spruce-made controls. Especially the modulus of rupture (MOR) of the cup-plant PB was lowered by 40%, as compared to the spruce-made control board. Likewise, thickness swelling of cup-plant made boards was higher than the control. Results were linked to the specific porous structure of the cup-plant material. In contrast, it was shown that three-layer cup-plant PB had a higher MOR and also a higher modulus of elasticity, along with lower thickness swelling, compared to its single-layer cup-plant counterpart. The industry relevant finding was that the three-layer PB made from cup-plant stalks fulfilled the EN 312 standard, class P1 (usage in dry conditions). It was shown that raw material mixtures could be useful to improve the mechanical panel performance, also with an altered vertical density profile. [ABSTRACT FROM AUTHOR]

Purpose: The growing awareness of the importance of biodiversity in agroecosystems in increasing and ensuring the supply of biomass has led to heightened interest from governments and farmers in alternative crops. This article assesses one such alternative crop, cup plant (Silphium perfoliatum L.), in terms of the environmental aspects of cultivation for forage production. Many studies have previously focused on cup plant, but so far, this plant has not been assessed using the life cycle assessment (LCA) method. Materials and methods: This study compares the environmental load of cup plant with the most commonly grown silage crops in Central European conditions—maize—and with another common forage crop—lucerne using LCA. The system boundaries include all the processes from cradle to farm gate and both mass-based (1 ton of dry matter) and area-based (1 ha of monoculture) functional units were chosen for the purposes of this study. The results cover the impact categories related to the agricultural LCAs, and the ReCiPe Midpoint (H) characterization model was used for the data expression, by using SimaPro 9.0.0.40 software. Results: This study compares the cultivation of cup plant with the most commonly grown silage crop in Central European conditions—maize—and with another common forage crop—lucerne. The paper shows the potential of cup plant to replace conventional silage (maize and lucerne silage mix) with certain environmental savings in selected impact categories, and importantly, while still maintaining the same performance levels in dairy farming as with conventional silage, as already reported in previous publications. For the Czech Republic alone, this would, in practice, mean replacing up to 50,000 ha of silage maize and reducing the environmental load by about tens of percent or more within the various impact categories and years of cultivation. Conclusion: Cup plant can replace the yield and quality of silage maize, represents a lower environmental load per unit of production and unit of area and generally carries many other benefits. Thus, cup plant is a recommendable option for dairy farming. Given the recent experience and knowledge of the issue, the cup plant can be considered an effective alternative to conventional silage. [ABSTRACT FROM AUTHOR]

Biomass for non-food applications is considered as a substitute for petro-based materials such as expanded polystyrene (EPS). This research analyzes physical properties of an EPS containing commercial bonded leveling compound (BLC) which was substituted with cup plant (Silphium perfoliatum L.) biomass. Cup plant is a high-yielding biomass plant with several ecological benefits that is yet mainly used for biogas production. Furthermore, the high amount of parenchyma in senescent biomass with its EPS-like structure could be a possible substitute for petrochemical foams in lightweight aggregates. The natural variation in parenchyma content of several European cup plant accessions is promising, regarding the development of cultivars with suitable biomass properties for the proposed material use. Two binders with different proportions of cup plant and EPS were used to produce samples of BLC for thermal conductivity and compression strength tests. The compression strength of 0.92 N mm−2 and a thermal conductivity of 84 mW m−1 K−1 were analyzed and comparable to the commercial BLC. The thermal conductivity within the tested borders appears nearly independent of the biomass content. With increasing cup plant content, the shape characteristics of the lightweight aggregate mix changes towards more elongated aggregates. The mechanical strength and thermal conductivity are highly sensitive to the water demand of the biomass. Direct partial substitution of EPS by cup plant appears feasible and could be a part of the decarbonization of the construction sector.

Heavy metal pollution, manifested by the accumulation, toxicity and persistence in soil, water, air, and living organisms, is a major environmental problem that requires energetic resolution. Mining tailing areas contain metal minerals such as Cu, Zn, Pb, Cr and Cd in high concentrations that pollute the environment and pose threats to human health. Phytoremediation represents a sustainable, long-term, and relatively inexpensive strategy, thus proving to be convenient for stabilizing and improving the environment in former heavy metal-polluted mining sites. This study presents the bioremediation potential of Silphium perfoliatum L. plants, in the vegetative stages of leaf rosette formation, grown on soil polluted with heavy metals from mining dumps in Moldova-Noua, in the Western part of Romania. The bioaccumulation factor (BAF), translocation factor (TF), metal uptake (MU) and removal efficiency (RE) of Cu, Zn, Cr and Pb by S. perfoliatum plants were determined in a potted experiment in controlled environmental conditions. The reference quantities of heavy metals have been determined in the studied soil sample. The experiment followed the dynamics of the translocation and accumulation of heavy metals in the soil, in the various organs of the silphium plants, during the formation of the leaf rosette (13-18 BBCH). The determination of the amount of heavy metals in soil and plants was achieved by the method of digestion with hydrochloric and nitric acid 3/1 (v/v) quantified by atomic absorption spectroscopy (AAS). The obtained experimental results demonstrate that the substrate has a high heavy metal content being at the alert threshold for Zn (260.01 mg kg-1 in substrate compared with alert threshold 300 mg kg -1) and at intervention thresholds for other metals (Cu -234.66 mg kg-1/200 mg kg-1; 299.08 mg kg-1/300 mg kg-1 and Pb-175.18 mg kg-1/100 mg kg-1). The average concentration of the metals determined in dynamics in the dry biomass of plants varied between roots, petioles, and laminas. The root is the main accumulator for Cu and Cr (Cu – 37.32 mg kg-1 -13 BBCH to 43.89 mg kg-1-15 BBCH and 80.71 mg kg-1 – 18 BBCH; Cr – 57.43 mg kg-1 – 13 BBCH to 93.36 mg kg-1 -18 BBCH), and for Zn and Pb the lamina seems to carry the same function. Preliminary results show that Silphium perfoliatum may be a viable alternative in the bioremediation and treatment of heavy metal-contaminated area. [ABSTRACT FROM AUTHOR]

Agricultural production of biogas maize (Zea mays L.) causes hazards to aquatic ecosystems through high levels of nitrogen (N) inputs. Newly introduced and already established perennial crops such as the cup plant (Silphium perfoliatum L.) and perennial grass mixtures offer the possibility of more environmentally friendly agricultural bioenergy production. The objectives of this field study were to quantify and compare soil mineral N, water infiltration, water runoff, soil erosion and N leaching under maize, permanent cup plant, and a perennial grass mixture. The study was conducted from October 2016 to March 2019 in Braunschweig, Germany. Plots with cup plant and grass mixture exhibited lower mineral N contents than maize, especially between 30 and 90 cm soil depth. Soil water infiltration was significantly different between the three crops. The grass mixture had the highest infiltration rates (6.2 mm/min averaged across 3 years), followed by cup plant (3.6 mm/min) and maize (0.9 mm/min). During wet periods, higher N leaching was found for maize (up to 42 kg N ha−1 year−1) than for cup plant (up to 5 kg N ha−1 year−1) or the grass mixture (up to 11 kg N ha−1 year−1). While runoff and erosion for cup plant and the grass mixture were negligible during the study period, considerable amounts of runoff water and eroded sediment of up to 1.5 Mg ha−1 year−1 were collected from the maize plots despite the near flat terrain of the experimental field. Overall, permanent cup plant proved suitable as a component for energy cropping systems to reduce the risk of N leaching and soil erosion, which is particularly important for the preventive flood protection in view of the more frequent occurrence of high intensity rainfall under climate change conditions. [ABSTRACT FROM AUTHOR]

Flower-visiting insects are important crop pollinators, but their populations in agricultural landscapes are declining. One reason is the decreasing quantity and quality of floral resources. Deterioration of the situation caused by an increasing production of energy crops like maize, a pollen-only resource, may be mitigated by alternative crops such as Silphium perfoliatum L., which produces pollen and nectar over a long-lasting flowering period (July–September). The aim of this study was to assess the floral resources of S. perfoliatum. We calculated pollen grains and nectar sugar mass per inflorescence as well as inflorescences per plant using experimental plots and commercial fields in Germany. In addition, we analyzed free and protein-bound amino acids in pollen as well as sugars and free amino acids in nectar. The amount of pollen and nectar sugar per inflorescence decreased with increasing stem branching. The production of pollen and nectar sugar, however, was greatest in the second half of August due to the high number of inflorescences per plant at that stage. About half of the farmers harvested S. perfoliatum before the end of flowering to gain higher methane yields. With an early harvest around the beginning of September about one sixth of total pollen and one fifth of total nectar sugar production were lost to pollinators. Pollen and nectar showed high amounts of certain essential amino acids, particularly histidine, but total amino acids were low in concentration. Hence, S. perfoliatum should be complemented with different bee fodder plants to ensure a well-balanced diet. [ABSTRACT FROM AUTHOR]

Industrial crop cultivation on marginal agricultural land limits indirect land-use change effects that pose a threat to food security. This review compiles results from 91 published crop-specific field trial datasets spanning 12 relevant industrial crops and discusses their suitability for cultivation on unfavorable soil types (USTs). It was shown that the perennial species Miscanthus (Miscanthus Andersson) and reed canary grass (Phalaris arundinacea L.) performed well on USTs with both high clay and/or high sand contents. Information on stoniness (particles sizes > 2 mm), where mentioned, was limited. It was found to have only a small impact on biological yield potential, though it was not possible to assess the impact on mechanization as would be used at a commercial scale. For soils with extreme clay or sand contents, half of the crops showed moderate suitability. The large yield variations within and between crops revealed large knowledge gaps in the combined effects of crop type and agronomy on USTs. Therefore, more field trials are needed on diverse USTs in different climates with better equipment and more consistent measurements to improve the accuracy of potential yield predictions spatially and temporally. Additionally, larger trials are needed to optimize cultivation and harvesting.

Silphium perfoliatum L. is a perennial and flowering crop that has been investigated in recent years for its potential as an energy plant, particularly for biogas production. A stand establishment by sowing of seeds is complicated, owing to the low germination capacity of untreated S. perfoliatum L. seeds. Consequently, germination experiments were carried out with two- to four-factor levels to determine the effect of selected factors (medium, pretreatment, light, temperature, prechilling) on dormancy and germination of S. perfoliatum L. seeds and to achieve maximum germination rate. All factors had a highly significant effect on germination. Germination experiments displayed a primary and physiological dormancy. Germination could be significantly increased by using a 0.05% GA3 solution during the imbibition phase, a light–dark cycle, alternating temperatures between 20°C and 30°C, and a wet stratification for seven days at 0°C. The experiments helped to fully exploit the germination potential and to develop a germination test method for S. perfoliatum L.

In order to estimate the effect of granulated sewage sludge on the productivity of the cup plant (Silphium perfoliatum L.), soil physical and microbial properties, a field experiment was carried out in Western Lithuania, on a naturally acid moraine loam Bathygleyic Dystric Glossic Retisol with a pH of 4.3-4.9. The dry matter yield of the cup plant consistently increased over the experimental years from 2.83 t ha-1 (in 2013) to 12.86 t ha-1 (in 2016). Each year, the optimum sewage sludge rate for dry matter yield of cup plant was 45 t ha-1. The use of both sewage sludge rates 45 and 90 t ha-1 had a similar and positive impact on soil chemical composition, water-stable aggregate formation, topsoil bulk density, soil penetration resistance and moisture content. Each experimental year, the application of sewage sludge at a rate of 90 t ha-1 had the strongest impact on the increase in soil microbial biomass carbon at the 0-30 cm depth. Experimental results suggest that when growing cup plant as an energy crop on a moraine loam Retisol, it is expedient to use granulated sewage sludge at a rate of 45 t ha-1. [ABSTRACT FROM AUTHOR]

Rising demand for renewable resources has increased silage maize (Zea mays L.) production characterized by intensive soil management, high fertilizer and pesticide inputs as well as simplified crop rotations. Advantages of renewable biomass production may thus be cancelled out by adverse environmental effects. Perennial crops, like cup plant (Silphium perfoliatum L.), are said to benefit arthropods. Substituting silage maize could hence increase biodiversity and foster ecosystem services. This study aimed at comparing the attractiveness of both crops to arthropods, which are either flower-visiting or active in the crop canopy. Further, results were scaled to the landscape level to optimize crop partitioning concerning yields and species diversity. A field experiment with conventionally tilled annual and perennial no-tilled crops was established in 2015 near Munich (Germany). The crops chosen were insect-pollinated cup plant and wind-pollinated maize. Arthropods were sampled between June and September 2016. Four replicated UV-active pan traps, consisting of three bowls each, were used to catch arthropods at the actual crop height on five sampling dates. The collected arthropods were counted and taxonomically determined. In total 3810 individuals (Arachnida : 52; Insecta : 3758) from 9 orders (115 taxonomic groups) were collected. Silage maize mostly showed lower diversity values, indicating higher biodiversity in cup plant. However, the differences were small. Nevertheless, cup plant harbored more pollinators and parasitoids. Finding an optimal combination of both crops based on diversity gains is thus not straightforward. However, integrating cup plant to silage maize production systems allows increasing arthropod diversity by means of moderate yield reduction. Image 1 • 3810 individuals from 115 taxonomic groups collected in silage maize and cup plant. • Total species richness and abundance of arthropods are higher in cup plant. • Cup plant fosters Hymenoptera and especially pollinators and parasitoids. • Cup plant increases arthropod diversity by means of moderate silage maize yield reduction. [ABSTRACT FROM AUTHOR]

Silphium perfoliatum L., cup plant, has potential as a new multi-purpose crop. It is pollinator-friendly and has biodiversity enhancement, conservation, economic, and medical potential. In eastern South Dakota, S. perfoliatum can produce more than 20 Mg (million grams) ha-1 of biomass and 0.09 Mg ha-1 of seed in agronomic plantings. The giant eucosma moth, Eucosma giganteana (Riley), is a major pest of agronomic S. perfoliatum in the region. We provide a summary of this insect and its association with its host. Our experimental objectives were to determine if the frequency of rhizome occupation by late instar larvae and if their final prepupal size were influenced by plant genetic or environmental effects. In October 2009, several individual plants from each of 32 half-sib families were removed from the field. Rhizomes, proaxes, and shoots were examined for the presence of larvae. Each larva was counted and measured for total length, width, thoracic tergite length, head length, and head width. Significant differences were found among half-sib families and between locations for frequency of shoot infestation, degree of crown and rhizome feeding, number of larvae per shoot, and larval morphometrics. The parasitoid Bracon cf. mellitor Say (Hymenoptera: Braconidae) was found parasitizing larvae feeding in floral meristems, but no parasitism was found in larvae in the crown or rhizomes. [ABSTRACT FROM AUTHOR]

Cup-plant (Silphium perfoliatum L.) stalks were investigated as a potential wood-replacement in particleboards (PBs). Two types of PBs were produced—(1) single-layer and (2) three-layer boards. In the three-layer cup-plant PB, the core layer was made from cup-plant, while the surface layer consisted of spruce particles. The cup-plant as well as spruce control panels were produced with polymeric methylene diphenyl diisocyanate (pMDI) as the adhesive, with the physical and mechanical properties measured to meet class P1 of the European EN 312 standard. For the intrinsic morphology of the particleboards, scanning electron microscopy was applied. Wood-based and cup-plant-based particleboards indicated significant differences in morphology that affect the resulting properties of particleboards. Furthermore, an innovative approach was used in the determination of the pMDI bondline morphology. With a compact Time-of-Flight Secondary Ion Mass analyser, integrated in a multifunctional focused-ion beam scanning-electron-microscope, it was possible to show that the Ga+ ion source could be detect and visualize in 3D ion molecular clusters specific to pMDI adhesive and wood. Mechanical performance data showed that cup-plant particleboards performed well, even though their properties were below the spruce-made controls. Especially the modulus of rupture (MOR) of the cup-plant PB was lowered by 40%, as compared to the spruce-made control board. Likewise, thickness swelling of cup-plant made boards was higher than the control. Results were linked to the specific porous structure of the cup-plant material. In contrast, it was shown that three-layer cup-plant PB had a higher MOR and also a higher modulus of elasticity, along with lower thickness swelling, compared to its single-layer cup-plant counterpart. The industry relevant finding was that the three-layer PB made from cup-plant stalks fulfilled the EN 312 standard, class P1 (usage in dry conditions). It was shown that raw material mixtures could be useful to improve the mechanical panel performance, also with an altered vertical density profile.

The cup plant (Silphium perfoliatum) is a new and promising bioenergy crop in Central Europe. Native to North America, its cultivation in Europe has increased in recent years. Cup plant is said to be highly productive, reproductive, and strongly competitive, which could encourage invasiveness. Spontaneous spread has already been documented. Knowledge about habitat requirements is low but necessary, in order to predict sites where it could spontaneously colonize. The present experimental study investigates the growth and reproductive potential of cup plant depending on soil moisture, given as water table distance (WTD). In moist soil conditions, the growth and reproductive potential of cup plant were the highest, with about 3 m plant height, 1.5 kg dry biomass, and about 350 capitula per plant in the second growing season. These parameters decreased significantly in wetter, and especially in drier conditions. The number of shoots per plant and number of fruits per capitulum were independent of WTD. In conclusion, valuable moist ecosystems could be at risk for becoming invaded by cup plant. Hence, fields for cultivating cup plant should be carefully chosen, and distances to such ecosystems should be held. Spontaneous colonization by cup plant must be strictly monitored in order to be able to combat this species where necessary.

Silphium perfoliatum is a perennial crop native to North America that has been the subject of increased scientific interest in recent years, especially in Europe. It is drought- and frost-resistant, which makes it suitable for cultivation in Europe on marginal lands that are not used for growing other crops. This review analyzed the distribution and purposes of the cultivation of Silphium perfoliatum worldwide, as well as its biomass yields and characteristics as a feedstock for biogas production and other purposes. A total of 121 scientific publications on Silphium perfoliatum were identified, with the highest number (20 papers) published in 2019. It was found that higher biomass yields can be obtained at higher precipitation levels, with the use of fertilizers and an adequate type of plantation. The mean dry matter yield of Silphium perfoliatum was 13.3 Mg ha−1 DM (dry matter), and it ranged from 2 to over 32 Mg ha−1 DM. In some countries, Silphium is used as a forage crop mainly due to its high crude protein content (from 4.9% to 15% DM), depending on the vegetation phase. Silphium perfoliatum is a promising perennial crop in terms of energy and other benefits for biodiversity, soil quality and applications in medicine and pharmacology.

Biomass from cup plant (Silphium perfoliatum L.) is considered a renewable energy source that can be converted into alternative fuel. Calorific syngas, a promising type of advanced fuel, can be produced through thermochemical biomass gasification. In this study, the suitability of cup plant biomass for gasification was assessed, including the process energy balance and environmental impacts of waste from syngas purification. Silphium perfoliatum L. was cultivated as a gasification feedstock in different conditions (irrigation, fertilization). The experiments were performed in a membrane gasifier. All obtained energy parameters were compared to the biomass yield per hectare. The toxic effects of liquid waste were assessed using tests analyzing germination/seed root elongation of Sinapsis alba. Leachates collected from condensation tanks of a gas generator were introduced to soil at the following doses: 100, 1000 and 10,000 mg kg−1 DM of soil. The usefulness of Silphium perfoliatum L. for gasification was confirmed. The factors of plant cultivation affected the biomass yield, the volume and calorific value of syngas and the amount of biochar. It was determined that the components found in condensates demonstrate a phytotoxic effect, restricting or inhibiting germination and root elongation of Sinapsis alba. Due to this potential hazard, the possibility of its release to the environment should be limited. Most of the biomass is only used for heating purposes, but the syngas obtained from the cup plant can be used to power cogeneration systems, which, apart from heat, also generate electricity.

The process of biomass compaction depends on many factors, related to material and process. One of the most important is the proper fragmentation of the raw material. In most cases, more fragmented raw material makes it easier to achieve the desired quality parameters of pellets or briquettes. While the chipping of biomass prefers moist materials, for grinding, the material needs to be dried. As drying temperature changes the properties of the material, these may affect the grinding process. The aim of this work was to determine the influence of the drying temperature of biomass raw material in the range of 60–140 °C on the biomass grindability. To only determine this effect, without the influence of moisture, grinding was carried out on the material in a dry state. The research was carried out on a mill with a knife and hammer grinding system, which is the most popular in the fragmentation of biomass. The analysis of particle size distribution and bulk density of the obtained material was carried out. The energy demand for the grinding process was determined and it was shown that drying temperature, grinding system, and mainly type of biomass affects the grindability.

Current global temperature increases resulting from human activity threaten many ecosystems and societies, and have led to international and national policy commitments that aim to reduce greenhouse gas emissions. Bioenergy crops provide one means of reducing greenhouse gas emissions from energy production and two novel crops that could be used for this purpose are Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. This research examined the existing scientific literature available on both crops through a systematic review. The data were collated according to the agronomy, uses, and environmental benefits of each crop. Possible challenges were associated with high initial planting costs, low yields in low rainfall areas, and for Sida hermaphrodita, vulnerability to Sclerotinia sclerotiorum. However, under appropriate environmental conditions, both crops were found to provide large yields over sustained periods of time with relatively low levels of management and could be used to produce large energy surpluses, either through direct combustion or biogas production. Other potential uses included fodder, fibre, and pharmaceutical uses. Environmental benefits included the potential for phytoremediation, and improvements to soil health, biodiversity, and pollination. The review also demonstrated that environmental benefits, such as pollination, soil health, and water quality benefits could be obtained from the use of Sida hermaphrodita and Silphium perfoliatum relative to existing bioenergy crops such as maize, whilst at the same time reducing the greenhouse gas emissions associated with energy production. Future research should examine the long-term implications of using Sida hermaphrodita and Silphium perfoliatum as well as improve knowledge on how to integrate them successfully within existing farming systems and supply chains.