Silphium Perfoliatum Research Articles

Caffeoylquinic acids from Silphium perfoliatum L. show hepatoprotective effects on cholestatic mice by regulating enterohepatic circulation of bile acids

Ethnopharmacological relevanceThe incidence of cholestatic liver disease (CLD), which is primarily marked by abnormal bile acids (BAs) metabolism and can result in significant hepatic injury, is rising. Nevertheless, there remains a lack of effective treatments and drugs in clinical practice. Silphium perfoliatum L. (SP) is rich in various structural types of caffeoylquinic acid (CQA) compounds, and it is a traditional herb of North American Indians with hepatobiliary therapy effects. However, its therapeutic effect and mechanism of action on CLD have never been studied. Aim of the studyTo determine if SP-8, an extract rich in CQAs from SP, protects against cholestatic liver injury induced by alpha-naphthylisothiocyanate (ANIT) and to clarify its mechanism based on the farnesoid x receptor (FXR) signaling pathway and enterohepatic circulation of BAs. Materials and methodsThe therapeutic efficacy of SP-8 was evaluated by assessing the serum biochemical indices, inflammatory factors, and liver histopathology. Targeted metabolomics of the BAs was studied in the feces, liver, serum, and bile using UPLC-MS/MS. Additionally, a Western blot analysis was used to examine the expression levels of the peroxisome proliferator-activated receptor γ (PPARγ), the FXR, and proteins related to the synthesis and transport of BAs. 16S rRNA gene sequencing was performed to evaluate the gut microbiota (GM). Finally, molecular docking simulations were conducted to assess the interaction between seven types of CQAs from SP-8 with FXR and PPARγ. ResultsSP-8 significantly enhanced the health status of cholestatic mice induced by ANIT as evidenced by a notable reduction in the liver function indices and pro-inflammatory factors, restoration of liver pathological damage, and acceleration of BAs excretion through the feces. In addition, the levels of harmful secondary BAs in the liver and blood were significantly reduced by SP-8. Furthermore, the results of the study on the mechanism of action confirmed that SP-8 not only regulated FXR and PPARγ but also significantly ameliorated the GM structure, thereby promoting the enterohepatic circulation of BAs and achieving the homeostasis of the BAs in the blood and liver. In addition, SP-8 successfully reduced the inflammatory response by strongly suppressing the nuclear translocation of NF-κBp65. According to the molecular docking results, the extract's primary active ingredients could be the seven CQAs in SP-8, as they exhibited a strong affinity for both FXR and PPARγ. Finally, the Mantel test analysis revealed a significant correlation among cholestatic-associated parameters, the GM, and BAs. ConclusionIt was confirmed for the first time that the SP-8 extract of Silphium perfoliatum L. that is rich in seven CQAs had a strong therapeutic effect on ANIT-induced CLD. Its mechanism may involve the regulation of the FXR signaling pathway and the amelioration of the GM structure to promote the homeostasis of BAs enterohepatic circulation. This study provides a potential candidate medicinal herb and its components for the development of CLD therapeutic drugs.

Native Forbs Provide Pollinator Resources and Improve Forage Nutrient Composition, Animal Performance, and Pasture Productivity

Pollinator declines and expectations for more sustainable agriculture, including pasture-based enterprises, bring attention to strategies to enhance the habitat value of grazing lands. We evaluated native warm-season grass (NWSG) pastures with (FORB) and without (CONT) interseeded native forbs in 2021–2023. An analysis was conducted using R with the significance set at p ≤ 0.05. The grass appeared to be weakened predominantly by grazing management practices. Forb density and mass had an inverse relationship in seasons two and three. Total forage mass declined in response to increased grazing days and weakened stands. The forage nutritive compositions differed, with more stable, season-long crude protein and lower fiber concentrations in late-season FORB, which supported higher bodyweight gains and season-long average daily gain. Black-eyed Susan (Rudbeckia hirta; BESU), lanceleaf coreopsis (Coreopsis lanceolata; LCOR), and showy ticktrefoil (Desmodium canadensis; STTF) were the most abundant forbs, and BESU, LCOR, and purple coneflower (Echinacea purpurea; PURC) produced long flowering windows. Cattle grazed STTF, cup plant (Silphium perfoliatum; CUPP), and oxeye sunflower (Helopsis helianthoides) the most. Under continuous stocking, a blend of BESU, LCOR, PURC, STTF, and CUPP produced acceptable cattle gains and provided pollinator resources, suggesting that this model may be a viable means to enhance the sustainability of pastures.

From Field to Model: Determining EROSION 3D Model Parameters for the Emerging Biomass Plant Silphium perfoliatum L. to Predict Effects on Water Erosion Processes

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.

Effects of Harvest Date and Ensiling Additives on the Optimized Ensiling of Silphium Perfoliatum to Prevent Faulty Fermentation

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.

The Effects of Lactobacillus plantarum and Lactobacillus buchneri on the Fermentation Quality, In Vitro Digestibility, and Aerobic Stability of Silphium perfoliatum L. Silage.

In this experiment, Lactobacillus plantarum and Lactobacillus buchneri were added individually or in combination to Silphium perfoliatum L. (SP) silage to investigate the effects of different fermentation types of lactobacilli on the fermentation quality, in vitro digestibility, and aerobic stability of SP-silage, with a view to providing a certain scientific basis and technical support for obtaining high-quality SP-silage in production. The experiment comprised a non-additive group (control), an L. plantarum group (LP), an L. buchneri group (LB), and an L. plantarum and L. buchneri mixed treatment group (LPLB). Samples were taken after 60 days of fermentation and analyzed for the fermentation quality, in vitro digestibility, and aerobic stability of the SP-silage. The results showed that the addition of LP, LB, and LPLB significantly reduced the pH and proportion of ammonia nitrogen to total nitrogen and significantly increased the lactic acid, in vitro dry matter digestibility, and in vitro crude protein digestibility in the SP-silage (p < 0.05). Compared to the control group, the dry matter and crude protein contents of the LB and LPLB groups were significantly increased, while the neutral detergent fiber and acid detergent fiber contents were significantly reduced (p < 0.05). The SP-silage supplemented with LPLB had the highest dry matter and crude protein contents. The gross and digestible energies of the SP-silage in the LB and LPLB groups were significantly higher than those in the control and LP groups (p < 0.05). The aerobic stability of the SP-silage was significantly reduced by 24.14% in the LP group and increased by 58.62% and 34.48% in the LB and LPLB groups, respectively, compared to the control group (p < 0.05). It was shown that adding a combination of LP and LB resulted in the best fermentation quality, nutritional value, and in vitro digestibility of the SP-silage. LB was effective in improving the aerobic stability of SP-silage.

Energy efficiency of Silphium perfoliatum and Helianthus salicifolius biomass production

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.

Effects of dietary Silphium perfoliatum L. on the growth performance, immunity, intestinal health, and resistance against Nocardia seriolae of largemouth bass (Micropterus salmoides)

The present study was conducted to evaluate the effect of dietary Silphium perfoliatum L. on growth performance, immunity, intestinal health, and resistance against Nocardia seriolae of largemouth bass. Four dietary concentrations of S. perfoliatum L. were prepared: 0% (SPL0), 1% (SPL1), 2.5% (SPL2.5), and 5% (SPL5). After 60 d feeding, a challenge test was conducted by injecting N. seriolae intraperitoneally. The results showed that supplementing the diets with S. perfoliatum L. could promote the weight gain rate, specific growth rate, and feed intake. Meantime, S. perfoliatum L. could also enhance the activity of immune-related enzymes and improve the expression of immune-related genes in the liver. Compared to the control group, S. perfoliatum L. improved intestinal morphology and reduced the abundance of harmful bacteria in intestinal microbiota. Importantly, supplementing the diets with S. perfoliatum L. protected largemouth bass from N. seriolae infection, resulting in a relative percent survival (RPS) of 24% (SPL1), 31.99% (SPL2.5), and 43.99% (SPL5). In conclusion, the present study showed that S. perfoliatum L. could boost growth performance, enhance immunity, promote intestinal health, and improve the ability of largemouth bass against N. seriolae infection.

Towards Water-Efficient Irrigation of Cup Plant (Silphium perfoliatum L.) for Energy Production: Water Requirements and Rainfall Deficit

Towards Water-Efficient Irrigation of Cup Plant (Silphium perfoliatum L.) for Energy Production: Water Requirements and Rainfall Deficit

Earthworm communities and their relation to above‐ground organic residues and water infiltration in perennial cup plant (Silphium perfoliatum) and annual silage maize (Zea mays) energy plants

AbstractPerennial energy cropping systems are hailed as a sustainable way of mitigating and potentially adapting to climate change. As a result of the absence of tillage, soils cropped with perennials like cup plant (Silphium perfoliatum) promote abundant and functionally diverse earthworm communities. Hence, ecosystem service provision because of earthworm activity and functional redundancy, for example, litter decomposition, water infiltration and nutrient turnover, is considerably enhanced in perennial cropping systems. We studied the abundance and functional role of earthworms in non‐tilled perennial systems and reduced‐tilled annual systems to assess their relationship with the respective above‐ground organic residues and their implications for the soil water dynamic. We sampled earthworms and simultaneously measured the saturated infiltration rate for two consecutive years in cup plant and maize (Zea mays) fields. Furthermore, we sampled above‐ground litter each trimester in both systems and analysed the total C and N content and CN ratios. Our field investigations revealed significantly higher earthworm abundance, species diversity and richness in cup plant systems likely because of the absence of tillage and the formation of a litter layer. High abundances of juveniles in both maize and cup plant systems pointed to harsh habitat conditions likely because of temperature variations, waterlogging and bulk density. The respective field litter was of minor importance as a food source in both systems because of poor quality, but may positively affect the soil water balance in cup plant systems. Earthworm populations in maize may have been supported by organic fertilizer while earthworm populations in cup plants may have additionally benefitted from the extensive root network and a higher on‐site plant diversity. Reduced tillage regimes in maize systems may have enhanced saturated infiltration rates. A direct link between earthworms and infiltration was not validated, but may not be excluded in the future, as earthworm populations may develop slowly because of adverse habitat conditions. Our results show that perennials support abundant and diverse earthworm populations and indicate the importance of functional redundancy and the diversity of food sources. The combination of both earthworm abundance and perennial cropping systems is capable of increasing on‐site ecosystem stability and supporting adaptation to climate change by increasing functional redundancy and, ultimately, providing ecosystem services. The noticeable occurrence of the latter, however, may be delayed because of the slow establishment of earthworm communities and delayed build‐up of ecosystems stability. Hence, a transitional phase is inevitable to reap the benefits of perennial energy cropping systems and must be accounted for.

Extract of Silphium perfoliatum L. improve lipid accumulation in NAFLD mice by regulating AMPK/FXR signaling pathway

Ethnopharmacological relevanceGlobally, the incidence rate and number of patients with nonalcoholic fatty liver disease are increasing, which has become one of the greatest threats to human health. However, there is still no effective therapy and medicine so far. Silphium perfoliatum L. is a perennial herb native to North America, which is used to improve physical fitness and treat liver and spleen related diseases in the traditional medicinal herbs of Indian tribes. This herb is rich in chlorogenic acids, which have the functions of reducing blood lipids, losing weight and protecting liver. However, the effect of these compounds on nonalcoholic fatty liver disease remains unclear. Aim of the studyClarify the therapeutic effects and mechanism of the extract (CY-10) rich in chlorogenic acid and its analogues from Silphium perfoliatum L. on non-alcoholic fatty liver disease, and to determine the active compounds. Materials and methodsA free fatty acid-induced steatosis model of HepG2 cells was established to evaluate the in vitro activity of CY-10 in promoting lipid metabolism. Further, a high-fat diet-induced NAFLD model in C57BL/6 mice was established to detect the effects of CY-10 on various physiological and biochemical indexes in mice, and to elucidate the in vivo effects of the extract on regulating lipid metabolism, anti-inflammation and hepatoprotection, and nontarget lipid metabolomics was performed to analyze differential metabolites of fatty acids in the liver. Subsequently, western blotting and immunohistochemistry were used to analyze the target of the extract and elucidate its mechanism of action. Finally, the active compounds in CY-10 were elucidated through in vitro activity screening. ResultsThe results indicated that CY-10 significantly attenuated lipid droplet deposition in HepG2 cells. The results of in vivo experiments showed that CY-10 significantly reduce HFD-induced mouse body weight and organ index, improve biochemical indexes, oxidation levels and inflammatory responses in the liver and serum, thereby protecting the liver tissue. It can promote the metabolism of unsaturated fatty acids in the liver and reduce the generation of saturated fatty acids. Furthermore, it is clarified that CY-10 can promote lipid metabolism balance by regulating AMPK/FXR/SREPB-1c/PPAR-γ signal pathway. Ultimately, the main active compound was proved to be cryptochlorogenic acid, which has a strong promoting effect on the metabolism of fatty acids in cells. Impressively, the activities of CY-10 and cryptochlorogenic acid were stronger than simvastatin in vitro and in vivo. ConclusionFor the first time, it is clarified that the extract rich in chlorogenic acids and its analogues in Silphium perfoliatum L. have good therapeutic effects on non-alcoholic fatty liver disease. It is confirmed that cryptochlorogenic acid is the main active compound and has good potential for medicine.

Dispersal and persistence of cup plant seeds (Silphium perfoliatum): do they contribute to potential invasiveness?

Background and aims – The cup plant (Silphium perfoliatum) is being grown in Germany as a promising new bioenergy crop with an increasing area under cultivation in the last years. Its alien status, its high productivity, and high reproductive potential could carry the risk of this species becoming invasive. The present study investigates the dispersal and persistence of cup plant seeds, to contribute to the assessment of its invasive potential. Material and methods – For this purpose, four experimental studies were conducted in Germany, Central Europe: wind dispersal distance was measured in a field experiment for wind speeds up to 7 m.s-1. The seeds were offered to rodents in different habitats near to a cup plant field. We observed seed persistence and germination over 4 weeks storing in water and over 4 years storing in different soil depths. Key results – Cup plant seeds are dispersed by wind only over a few meters. In the forest, rodents removed 100% of the offered seeds, in open habitats none. Independent of the duration of storage in water, germination rate of the cup plant seeds was constantly high. Most of the seeds already germinated in water in the first two weeks. Stored on the soil surface and at 10 cm soil depth, the seeds germinated already in the first two years. Stored at 30 cm depth, one third of the seeds retained their germination ability over four years. Conclusion – Wind serves as short-distance dispersal vector for cup plant seeds. Rodents remove the seeds, but it is unknown whether they disperse them or just eat them. Water could disperse the seeds, which retain their germination ability, over long distances. The cup plant could therefore spread and possibly become invasive in Central Europe, and therefore measures are suggested to prevent its dispersal and spontaneous settlement.

Blooming and Forage Characteristics of Twelve Native Forbs Subjected to Repeated Defoliation

Insect pollinators are in population decline due to environmental and chemical stressors. Including native forbs in pastures could benefit grazers and pollinators; however, their forage and flowering characteristics are not fully documented. The objectives of our research were to evaluate 12 native forbs for persistence, forage mass, nutrient composition, and flowering patterns under repeated defoliation. Twelve species were planted in a small-plot experiment in 2018. Response variables were measured from 2020 to 2022. Annual (partridge pea, PPEA, Chamaecrista fasciculata) and biennial (black-eyed Susan, BESU, Rudbeckia hirta) species established high (p &lt; 0.05) plant populations during the first season; however, the PPEA declined (p &lt; 0.05) in forage mass during 2021. Tall species (Maximilian sunflower, MSUN, Helianthus maximiliani; cup plant, CUPP, Silphium perfoliatum) increased in forage mass, produced high-quality forage, and flowered during early fall. Lanceleaf coreopsis (LCOR, Coreopsis lanceolata) produced consistent (p &gt; 0.05) forage mass and flowered in spring. The purple coneflower (PURC, Echinacea purpurea), Illinois bundleflower (ILBF, Desmanthus illinoensis), and oxeye sunflower (OSUN, Helopsis helianthoides) produced high-quality, consistent (p &gt; 0.05) forage mass and flowered mid-season. Interseeding the BESU, ILBF, PPEA, LCOR, PURC, OSUN, and MSUN or CUPP would produce high-quality forage and floral resources throughout summer.

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.

The effect of sewage sludge on the energy balance of cup plant biomass production. A six-year field experiment in Poland

The effect of sewage sludge on the energy balance of cup plant biomass production. A six-year field experiment in Poland

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.

Competitiveness of the Exotic Silphium perfoliatum against the Native Urtica dioica: A Field Experiment

Silphium perfoliatum (cup plant) is native to North America and is increasingly used as a bioenergy crop in Germany. Spontaneous occurrences of this species have already been detected in several European countries. To assess the possible risk to biodiversity by spreading of S. perfoliatum, we investigated the competitiveness of this species against the native and highly competitive Urtica dioica over four years in a field experiment in Bayreuth (Germany). S. perfoliatum grew well among U. dioica, although its biomass was strongly reduced by surrounding U. dioica. Projection area, plant height, and reproductive potential were less or similarly reduced by surrounding U. dioica as by the intraspecific competition. Moreover, S. perfoliatum significantly suppressed the growth of the competitive U. dioica. A settlement and establishment of S. perfoliatum in the native flora of Central Europe and a suppression of uncompetitive plant species are therefore conceivable.

Evaluation of the Intra- and Interspecific Development of Different Accessions of Silphium perfoliatum L. and Silphium integrifolium Michx.

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.

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 Impact of Heavy Metal Accumulation on Some Physiological Parameters in Silphium perfoliatum L. Plants Grown in Hydroponic Systems.

Heavy metals like cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn), resulting from anthropogenic activities, are elements with high persistence in nature, being able to accumulate in soils, water, and plants with significant impact to human and animal health. This study investigates the phytoremediation capacity of Silphium perfoliatum L. as a specific heavy metal hyperaccumulator and the effects of Cu, Zn, Cd, and Pb on some physiological and biochemical indices by growing plants under floating hydroponic systems in nutrient solutions under the presence of heavy metals. One-year-old plants of S. perfoliatum grown for 20 days in Hoagland solution with the addition of (ppm) Cu-400, Zn-1200, Cd-20, Pb-400, and Cu+Zn+Cd+Pb (400/1200/20/400) were investigated with respect to the control. The level of phytoremediation, manifested by the ability of heavy metal absorption and accumulation, was assessed. In addition, the impact of stress on the proline content, photosynthetic pigments, and enzymatic activity, as being key components of metabolism, was determined. The obtained results revealed a good absorption and selective accumulation capacity of S. perfoliatum plants for the studied heavy metals. Therefore, Cu and Zn mainly accumulate in the stems, Cd in the roots and stems, while Pb mainly accumulates in the roots. The proline tended to increase under stress conditions, depending on the pollutant and its concentration, with higher values in leaves and stems under the associated stress of the four metals and individually for Pb and Cd. In addition, the enzymatic activity recorded different values depending on the plant organ, its type, and the metal concentration on its substrate. The obtained results indicate a strong correlation between the metal type, concentration, and the mechanisms of absorption/accumulation of S. perfoliatum species, as well as the specific reactions of metabolic response.

The Evaluation of the Phytoremediation Potential of the Energy Crops in Acid Soil by Sewage Sludge Fertilization

Phytoremediation is a green technique being increasingly used worldwide for various purposes, including sewage sludge contaminated by heavy metals. Most plants proposed for this technique have high nutrient demands, and fertilization is often required to maintain soil fertility and nutrient balance. In this context, sewage sludge could be a valuable source of nutrients (especially N and P) and water for plant growth. The main aim of this study was to assess the phytoremediation potential of selected energy plants, aspects of its increase, as well as contamination risks. Three treatments were used: unfertilized soil and the application of 45 and 90 t ha−1 of sewage sludge. The experiment was performed in common osier and cup plant growing sites. Cr, Ni, Pb, Cu, and Zn contents in the soil tended to rise steadily when the amount of sewage sludge increased from 45 to 90 t ha−1. Heavy metal concentrations in the soil were ranked as follows: Zn &gt; Cr &gt; Ni &gt; Pb &gt; Cu. Cr and Pb concentrations increased by 22.5% and 37.4% in 2020, respectively, compared to those in 2017, whereas Cu concentrations declined by 44.4%. Cu and Ni were significantly reduced by common osier while Pb and Zn were reduced by cup plant. A moderate potential ecological risk due to Cr, Ni, Cu, Pb, and Zn was observed in soils. The data can be used to estimate the suitability of the soil treated by sewage sludge for added value development in line with circular economy principles.