The common vetch (Vicia sativa) is often used as feed for livestock because of its high nutritional value. However, drought stress reduces forage production through plant damage. Here, we studied the transcriptional profiles of common vetch exposed to drought in order to understand the molecular mechanisms of drought tolerance in this species. The genome of the common vetch has not been sequenced, therefore we used Illumina sequencing to generate de novo transcriptomes. Nearly 500 million clean reads were used to generate 174,636 transcripts, including 122,299 unigenes. In addition, 5313 transcription factors were identified and these transcription factors were classified into 79 different gene families. We also identified 11,181 SSR loci from di- to hexa-nucleotides whose repeat number was greater than five. On the basis of differentially expressed genes, Gene Ontology analysis identified many drought-relevant categories, including “oxidation-reduction process”, “lipid metabolic process” and “oxidoreductase activity”. In addition to these, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis identified pathways, such as “Plant hormone signal transduction”, “Glycolysis/Gluconeogenesis” and “Phenylpropanoid biosynthesis”, as differentially expressed in the plants exposed to drought. The expression results in this study will be useful for further extending our knowledge on the drought tolerance of common vetch.

The development of ecological circular agriculture has been highly encouraged to recycle agricultural wastes, reduce mineral fertilizer input, and protect the environment. Biogas slurry (BS), a by-product of biogas production generated from anaerobic digestion of animal waste and crop residues, is often considered a substitute to reduce mineral fertilizer input. Being a cheap source of organic matter and plant nutrients, its application may improve soil fertility and yield quality and quantity. The field experiments were conducted in 2016 and 2017 to study the plant growth responses and forage quality by applying biogas slurry to replace chemical synthetic fertilizer (CSF). Results revealed that biogas slurry combination with chemical synthetic fertilizer significantly (p < 0.05) improved the growth of Italian ryegrass on treatment with T2, and the Italian ryegrass dry matter was increased by more than 9.00%, while the stem-to-leaf ratio was decreased by more than 12% (second cutting), in comparison with only chemical synthetic fertilizer group. In the case of forage quality, the crude protein (CP) and crude fiber (CF) content had a significant difference was observed between the T0 and T2 treatment group. Compare with the chemical synthetic fertilizer group, the CP content improved by 10.35%, and the CF content decreased about 10.00%. Based on these results, it was concluded that the application of 37.5 kg/ha CSF + 100.5 t/ha BS could improve the production of biomass and forage quality in Italian ryegrass.

Ionic liquid-based air-assisted liquid–liquid microextraction (IL-AALLME) combined with dispersive micro-solid phase extraction (D-μ-SPE) was applied for the extraction and preconcentration of Cu prior to analysis by graphite furnace atomic absorption spectrometry. IL [Hmim][PF₆] was used as the extractant, non-ionic surfactant Triton X-100 as the emulsifier and Fe₃O₄ nanoparticles as the sorbent. The emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent repeatedly using a 10 mL glass syringe. Then, the extractant phase was mixed with Fe₃O₄ magnetic nanoparticles and separated using a magnet. As a result, the conventional tedious procedure associated with AALLME such as centrifugation was eliminated and the analytical process was accelerated. The experimental parameters affecting the extraction efficiency of Cu such as pH, IL volume, Triton X-100 concentration, Fe₃O₄ amount, number of extraction times and ultrasound time were investigated and optimized. Under the optimal conditions, the calibration curve was linear in the range of 1.5–120 ng mL⁻¹ for Cu with a correlation coefficient (R) of 0.9992. The limit of detection was 0.5 ng mL⁻¹. Finally, the applicability of this newly developed method was investigated for the analysis of Cu in real water samples.