An effective method of magnetic field treatment in increasing soil phosphorus availability in wheat rhizosphere

Magnetic fields are widely used as a physical energy source in industry and environmental governance. Their application in agriculture has also been reported; however, it remains unknown whether magnetic fields can be used to increase the availability of phosphorus in wheat fields and whether they have an effect on increasing phosphorus availability in the rhizosphere. In this study, we conducted an incubation experiment for soil and a field control experiment for wheat cultivation. In the wheat cultivation experiment, four magnetic field intensity treatments of 20, 40, 60, and 80 mT were set with 0 mT as a control (CK). Under the magnetic field intensity of 60 mT, the available phosphorus content increased by 7.06% at the booting stage, and acid phosphatase and alkaline phosphatase activities in rhizosphere soil increased by 19.89% and 9.26%, respectively, under 40 mT and by 12.16% and 26.70%, respectively, under 60 mT magnetic field intensities compared with CK. Moreover, compared with CK, the magnetic field mainly affected lipids and lipid-like molecules, organic oxygen compounds, phenylpropanoids, and polyketides in the rhizosphere metabolisms. The results of correlation analysis show that the abundance of rhizosphere metabolites was significantly correlated with the acid phosphatase activity, and the acid phosphatase activity was significantly correlated with the available phosphorus content. The results indicate that applying an appropriate magnetic field intensity to soil altered the abundance of wheat rhizosphere metabolites. Furthermore, the activity of phosphatase and the content of available phosphorus in the soil increased, which resulted in increased available phosphorus uptake by wheat plants. This study highlights that magnetic fields can be used as a means to increase phosphorus availability in soil.