FIELD: chemistry.SUBSTANCE: group of inventions relates to inorganic chemistry and can be used in agriculture. Alkali metal ion source is formed by a method that includes: a) combining an alkali metal ion-bearing framework silicate with an oxide and a hydroxide of an alkaline earth metal and an alkali metal to form a solid mixture; b) exposing the solid mixture to a hydrothermal treatment to form a gel that includes the silicon and the alkali metal. Molar ratio of the silicon to the alkaline earth metal and alkali metal is in a range of between about 1.0:0.1 and about 1.0:0.3. Hydrothermal treatment comprises exposing the solid mixture to a temperature in the range of 100 to 350 °C to form gel.EFFECT: increased efficiency and increased rate of release of alkali metal ions is ensured.58 cl, 8 ex, 2 tbl, 6 dwg
