Steppe and semidesert soils of Volgograd and Astrakhan oblasts, the Kalmyk Republik, and Stavropol region have been studied using a complex of magnetic and mineralogical methods (x-ray diffractometry, Mössbauer spectroscopy, electron and optical microscopy). Phase composition, size, and morphology of magnetic particles have been examined by the quantitative extraction of magnetic fractions. It is shown that disperse (<0.1 μm) particles of ferromagnetic minerals (magnetite and maghemite) are produced in the course of soil formation in the steppe zone. Their content is controlled by the bioclimatic conditions of soil formation.