Magnetic devices of various constructions and productivity for treatment of water, seeds and soil have been developed, produced and tested in the Hydrophysics Laboratory and in the Department of Magnetobiology of the Agrophysical Institute. Pre-germination magnitophore seeds treatment is intended for improving sowing characteristics of seeds. The method consists in the effect of the low-frequency magnetic field created by the steady systems of ferrite-barium plates. Magnitogramm of the magnetic fields of the given structure is recorded on the surface of the plates with help of a special inductor. To realize the method in agriculture a portable magnitophore chute has been designed. The seeds intended for treatment are poured into the bunker. Under the effect of their own weight they spill through the proportioning device in the magnitophore chamber. Magnitophore seeds treatment improves the growth vigour, accelerates plant development, especially on the early stages, increases the crops. This method is simple, cheap, ecologically harmless and it can be recommended for applying in the technologies of vegetable crop growing. To treat the irrigation water some devices on permanent magnets have been developed. Their capacity ranges from 10 to 1000 cm³/hour. Magnetic treatment of water systems or more correctly magnetohydrodynamic activation of natural water is used to change (operate) physical and chemical properties of the irrigation water, particularly to shift of the carbon dioxide equilibrium alkalinity of water.