ALTERATION OF THE MINERAL-COMPOSITION OF SOD-PODZOLIC SOILS BY FERTILIZATION

The application of high levels of mineral fertilizers to Sod-Podzolic soils in the Nonchernozem Zone without concurrent liming and manuring promotes the peptization of the fine fraction of the soil, migration o f the peptization products, mechanical disintegration of the fine silt fractions, decomposition of mixed-layer minerals, and nonexchangeable binding of potassium and ammonium ions from the fertilizer. The resul t is an increase in the amounts of hydromica, kaolinite, and fine quar tz in the plow layer. These irreversible alterations of the mineral co mposition of the soil decrease its cation exchange capacity, disrupt i ts structure, and prevent the development of strong organomineral comp lexes.