In the present study, the effect of the static and alternating magnetic field applied individually and in combination with an algal extract on the germination of soybean seeds (Glycine max (L.) Merrill) and chlorophyll content was examined. The exposure time of seeds to the static magnetic field was 3, 6, and 12 min, whereas to the alternating magnetic field was 1, 2.5, and 5 min. The static magnetic field was obtained by means of a permanent magnets system while the alternating magnetic field by means of magnetic coils. Algal extract was produced from a freshwater macroalga—Cladophora glomerata using ultrasound homogenizer. In the germination tests, 10% extract was applied to the paper substrate before sowing. This is the first study that compares the germination of soybean seeds exposed to the static and alternating magnetic field. The best effect on the germination and chlorophyll content in seedlings had synergistic action of the static magnetic field on seeds for 3 min applied together with the extract and alternating magnetic field used for 2.5 min. It is not possible to clearly state which magnetic field better stimulated the germination of seeds, but the chlorophyll content in seedlings was much higher for alternating magnetic field.

In the present study, synergistic effects between the application of near-infrared radiation (NIR) and macroalgal extracts on the germination of soybean seeds were searched for. NIR is captured by special photoreceptors (i.e. phytochromes, cryptochromes and phototropins) and next plants generate a wide range of specific physiological responses through these receptors. For the study, a special system of NIR was applied to irradiate soybean seeds. To our knowledge, this is the first time this kind of radiation was used for the biostimulation of soybean seeds. Previously, the effect of other ranges of light (e.g. green, red, blue) was analysed in terms of photosynthetic activity, growth and yield of different plants, except seeds. NIR for 3 and 5 minutes was also combined with the application of macroalgal extracts used for seeds soaking. They are known as a rich source of biologically active compounds that can stimulate plant growth. These preliminary studies show that the examined factors can stimulate plant’s growth and their quality.

This article gives an overview of the widely distributed herb ribwort plantain (Plantago lanceolata). Currently, this plant is mostly grown in grasslands, rarely in arable land, and its secondary metabolites are used in medicine. Studies cited in the article indicate its very rapid growth and deep rooting in the soil, which results in high drought tolerance and uptake of valuable nutrients from deep soil layers. An intensive symbiosis with various mycorrhizal fungi is characteristic of plantain for a high capacity for nutrient and water appropriation. It is also characterized by different contents of iridoid glycosides like aucubin and catalpol in shoots and roots of different varieties. The use of P. lanceolata is discussed on permanent and non-permanent grasslands where agriculturally specific varieties have been developed for grazing animals showing positive health effects in them. Information is provided on the cultivation of ribwort plantain, including studies on sowing and fertilization, the yield and infestation of the plant with pathogens, and the occurrence of iridoid glycosides in the plant. In addition, information is included on pests that threaten the plant’s cultivation.

Soil samples from different locations with varied soybean cultivation histories were taken from arable fields in 2018 in East Germany and Poland (Lower Silesia) to evaluate the specific microsymbionts of the soybean, Bradyrhizobium japonicum, one to seven years after inoculation. Soybeans were grown in the selected farms between 2011 and 2017. The aim of the experiment was to investigate whether there is a difference in rhizobia contents in soils in which soybeans have been recultivated after one to seven years break, and whether this could lead to differences in soybean plant growth. The obtained soil samples were directly transferred into containers, then sterilized soybean seeds were sown into pots in the greenhouse. After 94 days of growth, the plants were harvested and various parameters such as the nodular mass, number of nodules, and dry matter in the individual plant parts were determined. In addition, the relative abundances of Bradyrhizobium sp. in soil samples were identified by sequencing. No major decline in Bradyrhizobium sp. concentration could be observed due to a longer interruption of soybean cultivation. Soil properties such as pH, P, and Mg contents did not show a significant influence on the nodule mass or number, but seem to have an influence on the relative abundance of Bradyrhizobium sp. The investigations have shown that Bradyrhizobium japonicum persists in arable soils even under Central European site conditions and enters into an effective symbiosis with soybeans for up to seven years.

This study examines the effect of a separate static magnetic field (SMF) and algal extract and their synergistic effect on soybean seeds germination. To our knowledge, this is the first time these kinds of factors were used for the biostimulation of soybean seeds germination. Soybean – Glycine max (L.) Merrill variety ‘Merlin’ was used in the present study. The exposure of seeds to the magnetic field was applied for 3, 6 and 12 min. The algal extract, produced from a freshwater green macroalga – Cladophora glomerata using an ultrasonic homogenizer, was used directly to the paper substrate at a dose of 10%. The highest germination ability of soybean seeds was observed in a group, where the magnetic field (12 min.) was used together with 10% of algal extract. However, it was very low – only 21%, which may have resulted from the seed dormancy. Future experiments on soybean seeds are required to confirm the stimulation effect of the magnetic field (various induction values) and algal extract on seeds germination.