Sida Hermaphrodita Research Articles

The effect of growth stage and cutting height of Virginia fanpetals (Sida hermaphrodita) on quality and nutrition value of herbage and silage

The effect of growth stage and cutting height of Virginia fanpetals (Sida hermaphrodita) on quality and nutrition value of herbage and silage

Sida hermaphrodita Rusby as a papermaking raw material – Chemical and morphological characteristics

A continually increasing demand for papermaking materials and simultaneously growing disproportion between the request for fiber and the limited resources of wood have forced scientists and the papermaking industry to search for the new sources of fibrous raw materials. A new promising set of raw materials for papermaking comes from energy crops. This paper presents Sida hermaphrodita Rusby L., as a non-woody raw material for papermaking. From the studies of chemical composition, it follows that cellulose content of more than 40% characterizes phloem of stems and branches, whereas in xylem exhibits more than 32%. The lowest is the concentration of cellulose in leaves and flowers of Sida. The content of lignin is lower than 24% and 16% in stem xylem and phloem, respectively. In Sida, hemicelluloses and mineral substances stand for being not more than 30% and 2%, respectively. The morphology of Sida cells is similar to hardwood, with fiber length of 0.383, 0.470 and 1.025 mm for parenchyma, xylem, and phloem, respectively. The chemical composition of Sida hermaphrodita together with its morphological characteristics make this raw material suitable for a production of papers intended for printing, writing and tissue.

Converting an Established Sida hermaphrodita Field into Arable Farming

The long-term performance of perennial energy crops and their elimination is important for long-term planning and use of agricultural land. In this study, the elimination of a six-year-old Sida hermaphrodita (hereafter referred to as Sida) stock for agricultural reclamation was investigated over three years. Crop rotation using maize, winter wheat, and sugar beet, a catch crop, as well as mechanical–chemical treatments were employed according to agricultural practices. After soil grubbing at the beginning of the experiment and prior to further treatments, on half of the former Sida planting area, visible Sida roots were manually removed in addition to determining their potential effect on total resprouting. Prior to each crop harvest, resprouted Sida plants were counted. At harvest, by the end of the first year, 476 versus 390 resprouted Sida plants were found in the investigated areas of 315 m2 each, where preceding manual root removal either took place or not, respectively. This accounted for 76% and 62% of the initial Sida planted. In the second year, the overall number of resprouted Sida declined significantly, accounting for 15 and 11 plants (i.e., 2.4% and 1.8% of initially planted), and in the third year, only two and four residual plants (i.e., 0.3% and 0.6%) were found, representing an almost 100% Sida elimination rate. We conclude that additional root removal did not result in a significant difference in Sida regrowth compared to the mechanical–chemical treatments only. No impediments to harvesting and no loss of yield in any crops were observed due to resprouted Sida in the existing field crops. No Sida plants were found outside the initial field, indicating a low dispersion potential and invasiveness. The results show that successful recultivation of an established Sida stock is possible through common agricultural practices and that resprouting Sida plants did not negatively affect the subsequent crops.

The Quality of Virginia Fanpetals Biomass as an Energy Source, Depending on the Type of Propagating Material and Plantation Age

Plant biomass is still the main raw material in the production of energy from renewable sources. Virginia fanpetals may be an alternative and complementary source of solid biomass to that obtained from forests and the wood industry. In this respect, it is important to assess the variability of the qualitative characteristics of Sida biomass as a solid biofuel over a long period of use of a plantation of this species. Three types of propagating material were used to establish the plantation: seeds, root cuttings (rhizomes), and seedlings, at two sowing/planting densities. The quality of the biomass, obtained during 14 consecutive years of harvest, was tested, including the moisture content, ash content, higher heating value (HHV), lower heating value (LHV), and the carbon, hydrogen, sulfur, and nitrogen content. It was found that both thermophysical properties and elemental composition were mostly determined by the years of vegetation. An important role in this respect was played by the juvenile period of the plants’ development. The biomass obtained after 1 year of vegetation contained a larger concentration of ash, nitrogen, and sulfur and less carbon and hydrogen, which reduced its energy value. The results confirm the possibility of obtaining biomass with low moisture, which favorably places it from an energy point of view.

Energy yield decline of Sida hermaphrodita harvested for biogas production

The perennial and herbaceous plant Sida hermaphrodita L. Rusby (Sida) has been investigated intensively with respect to its use as a solid biofuel for combustion and, to a lesser extent, for continuous biogas production. Since biogas production provides many opportunities for economic farm diversification, this study compared the biogas potential of Sida with common biogas crops silage maize (Zea mays L.) and cup plant (Silphium perfoliatum L.). To this end biomass samples were collected from a randomized field trial in Southwest Germany during the vegetative stage in five consecutive years starting in 2014. Biogas batchtests revealed constant specific-methane yields of 279 ± 8 LN kgVS−1 for Sida, significantly lower than for maize (335 ± 5 LN kgVS−1) and significantly higher than for cup plant (264.3 ± 3.7 LN kgVS−1). The annual Sida dry matter biomass yields declined significantly by 51% from 2015 (18.2 ± 2.6 Mg ha−1) to 2018 (9.2 ± 4.8 Mg ha−1) as a result of the summer harvest regime. This, in turn, led to a significant decline in Sida's total annual energy yields. Consequently, the average annual Sida energy yield (3549 ± 901 L heating oil equivalents (HOE) ha−1) was significantly lower than for maize (6611 ± 1186 L HOE ha−1) and cup plant (5261 ± 974 L HOE ha−1). These results clearly indicate that harvesting Sida during the vegetative stage for biogas production significantly decreases its energy yield over time. Therefore, Sida can be used economically and ecologically more sustainable for combustion using the dead plant biomass harvested in winter, while cup plant proved competitive to maize for biogas production.

Experimental investigation and chemometric analysis of gasification and co-gasification of olive pomace and Sida Hermaphrodita blends with sewage sludge to hydrogen-rich gas

In the paper the results of the systematic study on oxygen/steam co-gasification of sewage sludge blends with biomass waste such as olive pomace or energy crops such as Sida Hermaphrodita to hydrogen rich gas were presented. In the first part of the experimental campaign the oxygen/steam gasification of sewage sludge, Sida Hermaphrodita and olive pomace, respectively, at 700, 800 and 900 °C were gasified. Only small amount of the total gas was produced in the oxygen/steam gasification of analyzed sewage sludge in all studied temperatures. The carbon conversion rate varied between 64% at 700 °C to 66% at 900 °C. The hydrogen amount in the total gas produced in the sewage sludge gasification was 28%vol. at all studied temperatures. The main conclusion from this part of experiments was that gasification of sewage sludge is ineffective. Different conclusions were drawn on the basis of Sida Hermaphrodita and olive pomace gasification tests at all studied temperatures. Therefore in the second part of the experimental campaign the co-gasification experiments of Sida Hermaphrodita/olive pomace blends with 10%w/w and 20%w/w of sewage sludge. The co-gasification experimental campaign covered series of tests at temperatures of 700, 800 and 900 °C, respectively. The comprehensive analysis of the experimental results of co-gasification and the physical and chemical parameters important for the co-gasification process performance were also conducted with the application of chemometric methods, such as hierarchical clustering analysis and principal component analysis. Based on the experimental results the optimal fuel blends as well as the optimal conditions of co-gasification were determined. It was proven that steam co-gasification of sewage sludge with selected biomass is beneficial in terms of the total gas produced and its composition.

A case study – The occurrence of pests in stands of newly introduced energy crops in large-scale pilot experiments in conditions of Central Europe

Abstract The objective of this paper is to document the occurrence of pests recorded in a large-scale pilot field experiment, where a unique set of newly-introduced herbaceous energy crops was tested under conditions of eastern Slovakia. The set consisted of Elymus elongatus, Secale cereanum, Silphium perfoliatum, Galega orientalis, Sida hermaphrodita, Panicum virgatum, Amaranthus spp., Panicum miliaceum, Sorghum sudanense, and Sorghum bicolor. A total of 14 cultivars were tested on 4 sites during 4 crop years (2016 – 2020). At least 17 species of pests were recorded in total, as some of the species may represent the identity of the couple or several relative ones, which was rare only as usually a fower common species. The occurred pests list consists of Anisoplia lata Erichson, Agriotes lineatus L., Capreolus capreolus L., Deroceras agreste L., Oulema gallaeciana Heyden, Lepisma saccharinum L., Lepus europaeus Pallas, Meloe proscarabaeus L., Metcalfa pruinosa Say, Microtus arvalis Pallas, Philaenus spumarius L., Psylliodes chrysocephala L., Rhopalosiphum padi L., stemborers as any insect larva or arthropod boring into plant stem, Sus scrofa L., Aleyrodes proletella L., Tettigonia viridissima L., and Trialeurodes vaporariorum Westwood. Overall, the occurrence of pests was regular and scattered, and damages caused by them were negligible usually, but a total destruction of the crop stand even cultivar-specific was recorded too. Most of the meaningful pests are primarily field hunting animals and only secondarily commonly occurring insect species, which for further observations are desirable in order to capture the tendency of important pests’ overpopulation, confirming respectively. Although even rare finding of the single caterpillar of Xylena exsoleta exsoleta L. was recorded in a buffer zone, within the experiment no newly introduced pest species was recorded.

Cell wall composition and biomass saccharification potential of Sida hermaphrodita differ between genetically distant accessions.

Due to its ample production of lignocellulosic biomass, Sida hermaphrodita (Sida), a perennial forb, is considered a valuable raw material for biorefinery processes. The recalcitrant nature of Sida lignocellulosic biomass towards pretreatment and fractionation processes has previously been studied. However, Sida is a non-domesticated species and here we aimed at expanding the potential of such plants in terms of their processability for downstream processes by making use of the natural variety of Sida. To achieve this goal, we established a collection comprising 16 different Sida accessions obtained from North America and Europe. First, we asked whether their cell wall characteristics are reflected in genetic distance or geographical distribution, respectively. A genotyping-by-sequencing (GBS) analysis resulting in a phylogenic tree based on 751 Single Nucleotide Polymorphisms (SNPs), revealed a high genetic diversity and a clear separation between accessions collected in North America and Europe. Further, all three North American accessions were separated from each other. Of the eleven European accessions, five form individual groups and six others belong to a single group. Clonal plants of seven selected accessions of American and European origin were produced and cultivated under greenhouse conditions and the resulting plant material was used for in-depth wet-chemical and spectroscopic cell wall characterization. Two accessions with contrasting cell wall characteristics were then selected and processed using the OrganoCat technology. Results of the different product yields and chemical compositions are reported. Overall, cell wall analyses revealed contrasting clusters regarding these main components between the accessions that can be related to genetic and, partly, geographical distance. Phenotypically, the accessions clustered into two groups that are not entirely overlapping with geographical origin. These results can be the basis for a targeted selection or cultivation of Sida accessions for biorefinery approaches.

Use of Artificial Neural Networks to Model Biomass Properties of Miscanthus (Miscanthus × giganteus) and Virginia Mallow (Sida hermaphrodita L.) in View of Harvest Season

Miscanthus and Virginia Mallow are energy crops characterized by high yields, perenniality, and low agrotechnical requirements and have great potential for solid and liquid biofuel production. Later harvest dates result in lower yields but better-quality mass for combustion, while on the other hand, when biomass is used for biogas production, harvesting in the autumn gives better results due to lower lignin content and higher moisture content. The aim of this work was to determine not only the influence of the harvest date on the energetic properties but also how accurately artificial neural networks can predict the given parameters. The yield of dry matter in the first year of experimentation for this research was on average twice as high in spring compared to autumn for Miscanthus (40 t/ha to 20 t/ha) and for Virginia Mallow (11 t/ha to 8 t/ha). Miscanthus contained 52.62% carbon in the spring, which is also the highest percentage determined in this study, while Virginia Mallow contained 51.51% carbon. For both crops studied, delaying the harvest date had a positive effect on ash content, such that the ash content of Miscanthus in the spring was about 1.5%, while in the autumn it was 2.2%. Harvest date had a significant effect on the increase of lignin in both plants, while Miscanthus also showed an increase in cellulose from 47.42% in autumn to 53.5% in spring. Artificial neural networks used to predict higher and lower heating values showed good results with lower errors when values obtained from biomass elemental composition were used as input parameters than those obtained from proximity analysis.

A Comparative Study on the Characteristics of Seeds and Phytomass of New High-Potential Fodder and Energy Crops

The purpose of this research is to capitalise on the potential of non-traditional plant species in the Republic of Moldova from the families Asteraceae (cup plant Silphium perfoliatum; cardoon Cynara cardunculus), Fabaceae (fodder galega Galega orientalis, sand sainfoin Onobrychis arenaria), Hydrophylaceae (phacelia Phacelia tanacetifolia), Malvaceae (curly mallow Malva crispa; Virginia mallow Sida hermaphrodita) and Poaceae (perennial sorghum Sorghum almum, pearl millet Pennisetum glaucum). The study presents the research results on the seed properties (dimensional parameters, structure, friability, apparent specific mass, mass of 1000 seeds) and on the phytomass quality of the above-mentioned plants. The obtained results demonstrate that the criterion of dimensional proportionality Kdp, proposed in this paper, effectively reflects the structure of the seeds; the seeds of new crops (except phacelia) have high friability (angle of repose α ≤ 33° and angle of static friction on steel α1 ≤ 27.8°, on wood α1 = 34.7°, on enamelled surface α1 = 30°). The natural fodder from the researched species is characterised by a crude protein content of 9.0–23.4%, dry matter digestibility of 56.0–66.5%, digestible energy load of 11.16–12.95 MJ kg−1, metabolizable energy of 9.16–10.63 MJ kg−1, net energy for lactation of 5.18–6.76 MJ kg−1, and relative feed value RFV = 74–129. The biochemical biomethane potential from studied vegetal substrates is 297–353 l kg−1 VS.

The concentration of heavy metals in the energy crops phytomass when grown in the conditions of Zhytomyr Polissia

The high level of anthropogenic pressure on agro-landscapes recently leads to an increased level of their contamination with heavy metals, which are among the most harmful chemical pollutants for the environment. Heavy metals are transmitted through trophic chains with a pronounced cumulative effect, in connection with which their toxicity can appear suddenly on individual links of trophic chains. The danger from heavy metals is determined by the fact that, unlike organic pollutants, they do not break down, but change from one form to another. Based on the results of the study, it was established that the accumulation of heavy metals by energy plants depended on the type of crop. Thus, it was proved that the concentration of heavy metals in energy crops plants when grown in the territory of radioactive contamination was within the limit of permissible concentrations. The lowest concentration of toxicants was noted when all energy crops were grown without fertilizers. The subject of the study was energy crops (Silhium perfoliatum L., Sorghum almum Parodi, Bunias orientalis L., Sida hermaphrodita Rusby, Miscanthus giganteus G.), heavy metals in plants, sod-podzolic sandy soil, mineral fertilizers. Therefore, the purpose of our research was to determine the phytomass of energy crops grown in areas contaminated with radionuclides as a result of the accident at the Chernobyl Nuclear Power Plant to determine the concentration of toxic substances. When performing the work, both general and special research methods were used: field – for conducting stationary and short-term field experiments, analytical – for determining the content of heavy metals in plants crops (Silhium perfoliatum L., Sorghum almum Parodi, Bunias orientalis L., Sida hermaphrodita Rusby, Miscanthus giganteus G.). The research was conducted during 2017−2020 on sod-podzolic soils in the territory of the village. Khrystynivka, Zhytomyr region, which belongs to the zone of unconditional (mandatory) resettlement (2nd zone of radioactive contamination). Prospects for further research will be aimed at establishing patterns of distribution of heavy metals in soil layers when growing energy crops. Key words: Silhium perfoliatum L., Sorghum almum Parodi, Bunias orientalis L., Sida hermaphrodita Rusby, Miscanthus giganteus G., lead, cadmium, copper, zinc.

On-farm greenhouse gas emissions associated with the cultivation of two new bioenergy crops in the UK

• A greenhouse gas (GHG) emissions model was developed using the IPCC guidelines. • Establishment and cultivation were compared between arable and bioenergy crops. • Growing Sida for solid fuel over 16 years would emit 3.0 t CO2eq ha−1y−1. • Cultivating Silphium over 16 years could sequester 0.6 t CO2eq ha−1 y−1. 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 CO 2 eq ha −1 y −1 and mean net sequestration of 0.6 Mg CO 2 eq ha −1 y −1 respectively over a 16 year rotation. This compared to predicted mean net emissions of 4.2 Mg CO 2 eq ha −1 y −1 for an arable rotation, and intermediate values for the SRC and Miscanthus crop (1.0 and 2.2 Mg CO 2 eq ha − 1 y − 1 , respectively).

The energy efficiency of Virginia fanpetals biomass production for solid biofuel

Virginia fanpetals is a highly versatile energy crop, and its biomass is converted mainly to solid biofuels and biogas. The aim of this study was to determine the biomass yield, energy inputs, and energy efficiency of Virginia fanpetals produced for solid biofuel during 13 successive years. Three types of propagating material were used to establish the plantation: seeds, root cuttings (rhizomes), and seedlings. Seeds were sown at a density of 1.5 or 4.5 kg ha−1, whereas rhizomes and seedlings were planted at a density of 20,000 or 60,000 plants ha−1.The average annual yield of S. hermaphrodita biomass reached 7 Mg ha−1 DM. The highest yield was noted where seedlings were planted at a density of 60,000 plants ha−1. Biomass yields continued to increase until year 4–5 and decreased in successive years until year 10. Yields were maximized when seeds were sown at a density of 4.5 kg ha−1. In the above treatment, total and average annual yields were only 3% lower than the highest value noted during the 13-year experiment, whereas energy inputs were 31% lower, energy gain was comparable, and the average energy efficiency ratio was higher.

Sida hermaphrodita Cultivation on Light Soil—A Closer Look at Fertilization and Sowing Density

Sida hermaphrodita (L.) Rusby is a promising perennial biomass crop to provide sustainable bioenergy via combustion. This study investigated cultivation practices for Sida hermaphrodita (L.) Rusby on light soils in temperate climates. Therefore, two cultivation factors were varied over 8 years in a field trial: (i) fertilization with compost from urban green spaces (0, 10 and 20 t ha−1), and (ii) seeding amount (1, 2 and 3 kg ha−1). Compost fertilization and high seeding amount contributed to an increase in the number and height of Sida shoots while their thickness decreased. The applied compost fertilization increased the dry matter yield (DMY) of the plants by 24.9% and 50.7%, respectively, in all experimental years compared to the control. Compared to the lowest seeding rate, increasing the seeding rate to 2 and 3 kg ha−1 increased the DMY by 35.0% and 71.6%, respectively. Thus, the highest energy value of DMY of Sida hermaphrodita plants per unit area was also obtained for combining the highest organic compost fertilization and seeding strength. From this, it can be deduced that on light soils, it does not seem reasonable to choose a compost fertilizer rate below 20 kg ha−1 and a seeding amount below 3 kg ha−1.

Biomass yield and biofiber properties of select industrial fiber crops in Lithuania

AbstractThe versatility, flexibility, design, and lightness of plastic are the most attractive features that enable its useability in our daily life. As production of disposable plastic increases, so does the amount of waste. Plastic waste is nondegradable. Its accumulation over time increases the risk of environmental pollution and contributes to environmental hazards. This has resulted into finding more renewable sources that could replace plastics. One renewable resource is agricultural plant biomass rich in cellulose. This work is aimed at evaluating the chemical composition and structure of industrial fiber crops. Three types of crops were selected: Miscanthus (Miscanthus giganteus), Virginia mallow (Sida hermaphrodita Rusby), and mugwort (Artemisia dubia Wall.). Their properties were compared with wheat straw (Triticum spp.). The industrial fiber crops and wheat straw were fertilized with mineral fertilizer at 90 kg ha−1. Experiments were performed to evaluate chemical and physical composition and biofiber parameters of crops. The highest cellulose content of 54.5 ± 2.17% was in mugwort with the lowest value of 42.5 ± 1.31% in Miscanthus. The carbon/nitrogen (C/N) ratio was the lowest in mugwort (114.8 ± 3.91%). This means mugwort biomass can be easily degraded by microorganisms and has better biomass pretreatment properties. The best fiber quality was found in Virginia mallow. However, the yield of Miscanthus fiber per hectare was higher, compared with other tested crops. The study presented opportunities for mugwort and Miscanthus as verifiable industrial fiber crops. They hold huge potential as raw materials for biorefinery production with less cost and high productivity under temperate climatic conditions.

Composition of Flue Gases during Oxy-Combustion of Energy Crops in a Circulating Fluidized Bed

In recent years, global warming and climate change associated with emissions of CO2 from fossil fuel-fired power systems are a big worry for authorities in many countries worldwide. The utilization of biomass as an alternative, carbon-neutral fuel can reduce emissions of CO2 and other greenhouse gases. Furthermore, the coupling of oxy-combustion of biomass with CO2 capture is an option for carbon-negative power generation technology. In this study, emissions of NOx, SO2, and CO from the air- and oxy-combustion of three energy crops (Miscanthus giganteus, Sida hermaphrodita, and Salix viminalis) are presented and compared with emissions from other biomass fuels and reference coal. Combustion tests in air and O2/CO2 mixtures were conducted in a 12-kW bench-scale CFB combustor at 850 °C. Measurements of flue gas compositions were taken using an FTIR spectrometer. In all tested atmospheres, emissions of SO2, N2O, and CO for biomass were lower than those for the reference coal. The oxidation of volatile nitrogen compounds was behind high emissions of NOx from biomass burned in air and O2/CO2 mixtures. The lowest concentrations of NO were found in the 21% O2/70% CO2 mixture. Combustion in mixtures containing more oxygen (30% and 40% O2) led to a decrease in emissions of N2O and CO and an increase in emissions of NO and SO2.

The Sustainable Future of Carbon Farming with Virginia Fanpetals, a Carbon-Negative Species

In 2016–2018, an experiment with Sida hermaphrodita L. Rusby (Virginia fanpetals) called Sida was conducted in the system of random blocks on sandy and sandy loam soil. Each year, the yields of dry aboveground mass and dried mass of roots were determined. Before sowing Sida and after the end of the research, the composition of earthy fractions in the soils was determined. In the stalks and roots of Sida, the percentage content was determined, and the mass of carbon was calculated. When Sida was grown in sandy soil, the average dry mass yield (stalks and roots) in the third year of cultivation (2018), was slightly above 13 t∙ha−1, and in the sandy loam soil it was three times higher (36 t∙ha−1). In the third year of cultivation, the carbon sequestration in the stems and roots exceeded 5 t∙ha−1 (sandy soil), and 15 t∙ha−1 (sandy loam). The carbon content in the stems was 46.25%, and in the roots–42.67%. The results were statistically processed using ANOVA. It was found that the cultivation of Sida caused a percent decrease in the sand fraction, an increase in the floatable (fine) fraction in sandy soil, and an increase in humus content; the opposite changes were noted in the sandy-loam soil.

Establishment of Stem Cell-like Cells of Sida hermaphrodita (L.) Rusby from Explants Containing Cambial Meristems.

The in vitro cultures of plant stem cells and stem cell-like cells can be established from tissues containing meristematic cells. Chemical compounds—as well as their production potential—is among the emerging topics of plant biotechnology. We induced the callus cell biomass growth and characterized the parameters indicating the presence of stem cells or stem cell-like cells. Four types of explants (stem, petiole, leaf, root) from Sida hermaphrodita (L.) Rusby and various combinations of auxins and cytokinins were tested for initiation of callus, growth of sub-cultivated callus biomass, and establishment of stem cells or stem cell-like cells. Induction of callus and its growth parameters were significantly affected both by the explant type and the combination of used plant growth hormones and regulators. The responsibility for callus initiation and growth was the highest in stem-derived explants containing cambial meristematic cells. Growth parameters of callus biomass and specific characteristics of vacuoles confirmed the presence of stem cells or stem cell-like cells in sub-cultivated callus cell biomass. Establishment of in vitro stem cell or stem cell-like cell cultures in S. hermaphrodita can lead to the development of various applications of in vitro cultivation systems as well as alternative applications of this crop.

Wastewater Sewage Sludge Management via Production of the Energy Crop Virginia Mallow

Wastewater treatment plants are facilities where wastewater is treated by technological processes. A byproduct of a wastewater treatment plant is sewage sludge, which can be both a good soil conditioner and a source of nutrients for the crops to which it is applied. Energy crops are non-food plants that can cleanse the soil of heavy metals through their ability to phytoremediate. The purpose of this study is to determine the effects of different amounts of sewage sludge on soil and plants. In the experiment Virginia mallow (Sida hermaphrodita L.) was used and the influence of stabilized sewage sludge in the amounts of 1.66, 3.32 and 6.64 t/ha dry matter on the energy composition and biomass yield was observed.The obtained results showed a yield of 8.85 t/ha at the maximum amount of sewage sludge used. Hemicellulose content was 20.20% in the application of 6.64 t/ha of sewage sludge and 19.70% in the control, while lignin content was 17.97% in the control and 16.77% in the maximum amount of sewage sludge. The heavy metals molybdenum and nickel did not differ significantly under the influence of larger amounts of sewage sludge, while manganese increased from 23.66 to 35.82 mg/kg.

Comparative economics of Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. as bioenergy crops in Europe

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.