The effect of fertilization with brown coal on Haplic Luvisol humic acids

Abstract

The influence of fertilization with brown coal (used as preparation called Rekulter) on properties of humic acids extracted from haplic luvisol was studied. Characteristics of humic acids were identified by their elemental composition, thermal decomposition, and infrared and UV-VIS spectra. It was found that humic acids formed during decomposition process of Rekulter in soil were characterised by a higher content of carbon (38.6% versus 35.4%), a lower content of nitrogen (1.50% versus 2.73%) and a higher resistance to thermal decomposition, when compared with humic acids extracted from soils without Rekulter application. Due to special properties of Rekulter, additional liming did not affect the properties of humic acids.