Could a Legume-Switchgrass Sod-Seeding System Increase Forage Productivity?

Nowadays, the lack of cattle feed, particularly green fodder, has become a key limiting factor in the agricultural economy. Switchgrass appears to offer a viable solution to the feed shortage. An improved cultivation practice might be needed to boost switchgrass forage production all season long. This study was conducted to quantify the positive effects of introducing different legume crops (vetch and pea), optimally fertilized, on the production and quality of mixed harvested switchgrass-legumes hay in late spring (May) and switchgrass hay harvested once more in early fall (September). The studied intercropping systems, independently of the legume species used, increased forage productivity (almost threefold), reaching 7.5 t ha-1 and quality characteristics, with protein content almost rising threefold, reaching 12.5%. The aforementioned practice can assist the perennial crop (switchgrass) in providing a high hay production during the early fall harvest, even without fertilization. The overall annual economic benefit for the farmers may be increased by 90-720 € per ha, depending on the prevailing weather conditions. Overall, it may be concluded that the suggested cropping system produces a significantly higher yield of cattle feed compared to traditional monocultures, improving the agricultural economy while reducing the negative effects of modern agriculture on the environment.

Chemical composition and biological activity of cardoon (Cynara cardunculus L. var. altilis) seeds harvested at different maturity stages.

Cardoon seeds collected in Greece at four different maturity stages (samples S1 to S4) were analysed in terms of chemical composition and in vitro bioactivities. The content of phenolic compounds (six compounds in total) increased with increasing maturity, and 3,5-O-dicaffeyolquinic (14.8-33.8 mg/g extract) acid was the compound detected in higher abundance. Mature seeds (sample S4) also revealed the highest content in lipids (23 g/100 g extract) and tocopherols (29.62 mg/100 g dw) and demonstrated the highest cytotoxic (GI50 of 97-216 µg/mL) and anti-inflammatory (IC50 = 148 µg/mL) activities, and capacity to inhibit the formation of thiobarbituric acid reactive substances (TBARS) (IC50 = 5 µg/mL). Cardoon seed hydroethanolic extracts also revealed high antibacterial and antifungal potential, particularly samples S3 and S1, respectively. This study proved the multifaceted potential associated with valorisation of cardoon seeds, while their biological and chemical composition can be influenced by the maturity stage.

Determination of heavy metals in the territory of contaminated areas of Greece and their restoration through hyperaccumulators.

Phytoremediation is an effective technique for the processing of contaminated soil and for sequestering environmental contaminants such as heavy metals. This kind of pollution is ubiquitous in mines and similar excavation sites. This mini-review aims to provide an overview of the alternative forms of restoring contaminated soils (phytoremediation) highlighting the areas of Kozani (Agios Dimitrios) and Chalkidiki (Stratoni) in Greece characterized by exorbitant metallurgical activities. Firstly, a literature search in databases such as ScienceDirect, SciFinder, PubMed, Google Scholar, and Scopus was conducted, using the following keywords to identify relevant articles: "utilization", "plants", "phytoremediation", "sustainability", "environment", and "restoration". Two case studies have subsequently been chosen in Northern Greece, one characterized by metal mining (Pb, Zn, Ag) and hot summer Mediterranean climate and another one involving lignite mining and concomitant Cr, Zn, Cu, and Ni pollution under subtropical climate. Based on the literature search some possible, non-invasive plant species were proposed, focusing on the most efficient hyperaccumulators.

Seasonal variation of bioactive properties and phenolic composition of Cynara cardunculus var. altilis.

Cynara cardunculus L. (cardoon) has several health benefits mainly attributed to its abundance in polyphenols. In this study, cardoon heads (capitula) were harvested in Greece during the flowering stage, and the hydroethanolic extracts were assessed in terms of phenolic compounds composition and antioxidant, cytotoxic, anti-inflammatory, and antimicrobial activities. The phenolic profile was evaluated by HPLC-DAD-ESI/MS to better understand the seasonal changes in the individual compound levels and how these changes correlate with bioactive properties. The main phenolic compounds identified were caffeoylquinic and dicaffeoylquinic acid derivatives. Immature heads (Car A: principal growth stage (PGS) 5) had the highest phenolic content (34.3 mg/g) and cytotoxic (GI50 of 69-268 µg/mL) and anti-inflammatory (IC50 of 183 µg/mL) activities. Sample Car D (PGS 6/7) revealed the highest antioxidant (IC50 of 23-227 µg/mL) and antifungal (MIC of 0.26-0.51 mg/mL) potential. Regarding the antibacterial activity, Car E (PGS 7) revealed the best results (MIC of 0.59-1.18 mg/mL). This study suggests that the maturity stage of the plant influences the phenolic composition and bioactivity.