Enhanced nutrient uptake in salt-stressed Mentha piperita using magnetically treated water

Abstract
The improvement of the growth and quality of medicinal plants under stress is of significance, worldwide. The hypothesis was to alleviate salinity stress in Mentha piperita by enhancing nutrient uptake using magnetically treated water, which to our knowledge has not been previously investigated. The objective was to test the effects of magnetized water (using alternating magnetic fields) (main plots, M1-M4 representing control, 100, 200, and 300 mT, respectively), salinity (subplots, S1-S4 representing control, 40, 80, and 120 mM NaCl, respectively), and growth medium (sub-subplots, X1-X4 representing coco peat, palm, coco peat + perlite, and palm + perlite, respectively) on M. piperita nutrient uptake in the greenhouse. The M treatments, especially the 100 and 200 mT levels, significantly increased plant N (1.08%, S3M4X1), P (0.89%, S3M3X1), K (3.23%, S3M3X1), Ca (53.6 mg/kg, S4M4X4), and Mg (39.63 mg/kg, S3M3X2) concentrations (compared with control at 0.71, 0.49, 2.4, 26.63, 1.63) even at the highest level of salinity. Magnetically treated water also significantly enhanced plant Fe and Zn concentration to a maximum of 750 μg/kg (M4S3X1) and 94.67 μg/kg (S4M4X3), under salinity stress, respectively. The single and the combined use of organic and mineral media significantly affected plant nutrient uptake, especially when used with the proper rate of M treatment. If combined with the proper growth medium, the magnetized water may be more effective on the alleviation of salt stress in Mentha piperita by enhancing nutrient uptake.