—The high production and widespread use of mineral fertilizers in the Russian Federation (RF) can cause a ubiquitous temporal increase in the concentration of potassium K+ in precipitation. Precipitation receives K+ from the air, forming on aerosols and during precipitation. The maximum duration of this process is estimated at about 10 days. It has also been established that any increase in the mineralization M of atmospheric precipitation is associated to varying degrees with an increase in the concentration of all major ions, including potassium.