Magnetic properties as indicators of Chernozem soil development

• Magnetic properties reflect the loess alternation by the weathering process.
• Low χ and high pedogenesis intensity are effects of the short duration of pedogenic activity.
• Organic matter affects magnetic enhancement and SP grain production.
• Magnetic enhancement gives a view of the history of studied profiles.

A detailed magnetic study of four types of Chernozem profiles developed on the loess in the Homutovsky Steppe (Ukraine), Middle Poland and Moravia (Slovakia) was carried out. The magnetic methods were used to examine the subtle differences between four Chernozems, their pedogenic horizons and mechanism of soil formation. Loess of Ukrainian Chernozem (H2) revealed the greatest values of magnetic susceptibility (25 10− 8 m3kg− 1) and frequency-dependence of susceptibility (6.5%), which indicates weathering processes responsible for loess alternation at the beginning of the soil formation. The advanced pedogenic processes in the mollic horizon resulted in the formation of superparamagnetic grains of pedogenic maghemite. The Chernozem from Middle Poland (MDZ) has the lowest values of all magnetic parameters but one of the highest intensities of pedogenesis expressed by the relative changes of frequency-dependence of susceptibility between top-soil and parent material. It could be the consequence of the short duration of pedogenic activity. The correlations between the organic matter content expressed by loss on ignition and magnetic parameters were found. For the mollic A-horizon the organic matter influences the magnetic enhancement (∆ χ) and the production of SP grains through stimulation of pedogenesis. The correlation between mean annual rainfall – MAR and pedogenic component of susceptibility – magnetic enhancement gives the opportunity to look at the history of studied profiles. The data for studied Chernozems fit well with the relations between MAR and ∆ χ for loessic soils from Russia, Ukraine and Europe.