# Soybean Germination Response to Algae Extract and a Static Magnetic Field Treatment
## 4 Discussion
Many authors in their scientific publications have shown the positive effects of a stationary magnetic field on plant seeds. Such an influence accelerates plant development [65; 68; 69], improves seedling germination and growth [70; 71; 72], and activates protein formation and enzyme activity [73; 74; 27; 72; 74; 45]. Studies have also shown that stimulating seeds with a magnetic field before sowing increases the germination of difficult-to-germinate seeds and improves quality [75; 76; 77]. The experiments were and are carried out on a wide range of plants, such as cereals [78; 79; 80; 81; 82; 83; 84; 85], legumes [84; 86; 87], and perennials [88; 89; 90; 91]. Recently, more studies have been carried out on the effects of magnetic field biostimulation for soybeans. The effects, in terms of seed stimulation before sowing, were compared by measuring the content of sugar, protein, nitrogen, hydrogen peroxide, ascorbic acid, proline, phenol, malondialdehydedehyde, and chlorophyll, as well as enzymatic activities (protease, amylase, catalyst, superoxide dismutase, and peroxides). Most of the publication authors used constant magnetic fields with the induction of several dozen to several hundred mTs [7; 14; 27; 39; 40; 41; 43; 44; 46]. The time for seed exposure relative to the magnetic field ranged from a few to several dozen minutes in a single or divided dose over several days [47; 48]. The stimulated soybean seeds using SMF showed a higher germination capacity and energy compared to the control sample. Moreover, this stimulation had a statistically significant effect on the development of the root system and the content of chlorophyll in the tested seedlings. The dry mass content of plants in general also increased. This was also confirmed by the current research (Table 3); however, an increase in the magnetic field induction over 250 mT slows down this effect, and at higher values, it even works the other way around. There are also attempts to use magnetic fields with low induction values (a few mT) for seed dressing in a short exposure time (counted in seconds) [38; 42]. Some scientists have studied the effect of a magnetic field with very low induction values, which comes directly from the Earth (geomagnetic field, GMF) on plants [92; 93; 94; 95; 96]. Such an influence has a positive effect on plant physiology and on development. Scientists have noticed a beneficial effect on shoot formation, root system development, plant dry biomass, and an increase in chlorophyll \(a\) and \(b\) and total chlorophyll compared to control samples. Many authors have tried to influence seeds with a magnetic field in combination with another physical field (e.g., electric or electromagnetic field) [77; 98; 97]. These studies were carried out to evaluate the effect of seed treatment on sugar, protein, nitrogen, hydrogen peroxide, ascorbic acid, proline, phenoldialdehydedehyde, and the content of chlorophyll (Chl \(a\), \(b\) and total content of chlorophyll). These works also investigated the specific activity of enzymes, such as protease (PRT), amylase (AMY), catalyst (CAT), superoxide dismutase (SOD), and peroxides (POD). The specific activity of enzymes (during germination and early growth) on biochemical and chlorophyll content were statistically significantly increased as a result of these combined pre-sowing procedures. The effect of stimulating seeds with a magnetic field was usually greater than that of stimulation with another physical field, except for PRT, AMY, and ascorbic acid. However, the effects of both treatments (simultaneously) were much greater compared to the control (seeds that had not been subjected to any pre-sowing treatment). The results of the conducted research have shown that combined pre-sowing seed stimulation treatments enables the potential to enhance soybean biological moieties, chlorophyll contents, and metabolically important enzymes [98; 99]. Not only the application of different plant extracts or different physical fields can stimulate plant growth, but also their combinations.