Electromagnetic Priming Modulates Gas Exchange During Pea Seed Germination Under Salt Stress

Electromagnetic treatment (EMF) can stimulate seed germination and plant development, including mitigating the negative effects of stressors. One non-invasive approach to detecting the early effects of EMF exposure is the study of gas exchange dynamics during the seed imbibition stage. Gas chromatography was used to assess the effect of low-intensity non-thermal EMF on the concentration of H2, O2, CO2, and NH3 gases in the “soil–pea seed” system under optimal conditions and under salt stress. EMF treatment exhibited a variant-dependent effect. Under optimal conditions, it stimulated respiration (O2 concentration decreased by 12%, CO2 increased by 15%); under salinity, the concentration of both gases decreased by 8–10% relative to the control. H2 emission proved to be a sensitive biochemical marker of the response to external factors. Under optimal conditions, EMF treatment nearly tripled H2 emission and shifted its emission peak one day earlier, which may indicate accelerated mobilization of the seed’s defense systems under developing hypoxia. Salinity reduced H2 levels by an order of magnitude, while EMF treatment stabilized the H2 emission rate, reducing it by almost half. Thus, EMF should be regarded as a modifier of the seed’s metabolic response to imbibition conditions, rather than solely as a germination stimulant.