Examining the Biological Effect of 868 MHz Electromagnetic Field Emitted from Soil-Buried Antenna During the Early Stages of Development of Maize Plants

IoT/LoRa devices emit radiofrequency electromagnetic fields (RF-EMF) ensuring long-range, low-power communication, and their use in precision agriculture continuously expands. Thus the interest in the impact of low intensity but long-term EMF exposure on plants has increased. In this study, maize plants were exposed to 868 MHz EMF for the first 28 days of their development with soil-buried antennas. Plants were divided into three groups: Control, Sham-exposed, and EMF-exposed. Biological effects were followed on morphological, physiological and biochemical levels every week. The plant height values were fitted to Gompertz function to model the growth. The results showed slightly faster early development of EMF-exposed plants in about 21 days. The relative dry leaf biomas from EMF-plants was a bit higher than Control and Sham until 21st day. Chlorophyll fluorescence analysis (JIP-test) indicated photosynthetic stability. Antioxidant enzymes activity, antioxidant capacity, content of malondialdehyde, hydrogen peroxide and reducing sugars were measured, and principal component analysis was done for all parameters. In general, the developmental stage accounted much more than EMF exposure for most of the observed data variation. The results suggest that under the tested conditions, IoT/LoRa-emitted EMF did not provoke adverse effects in maize and acted as a modest modulator of physiological functions.