Growth, physiological, biochemical and molecular changes in plants induced by magnetic fields: A review

The Earth's geomagnetic field (GMF) is an inescapable environmental factor for plants that affects all growth and yield parameters. Both strong and weak magnetic fields (MF), as compared to the GMF, have specific roles in plant growth and development. MF technology is an eco-friendly technique that does not emit waste or generate harmful radiation, nor require any external power supply, so it can be used in sustainable modern agriculture. Thus, exposure of plants to MF is a potential affordable, reusable and safe practice for enhancing crop productivity by changing physiological and biochemical processes. However, the effect of MF on plant physiological and biochemical processes is not yet well understood. This review describes the effects of altering MF conditions (higher or lower values than the GMF) on physiological and biochemical processes of plants. The current contradictory and inconsistent outcomes from studies on varying effects of MF on plants could be related to species and/or MF exposure time and intensity. The reviewed literature suggests MF have a role in changing physiological processes, such as respiration, photosynthesis, nutrient uptake, water relations and biochemical attributes, including genes involved in ROS, antioxidants, enzymes, proteins and secondary metabolites. MF application might efficiently increase growth and yield of many crops, and as such, should be the focus for future research.