Impact of agriculture on soil organic matter quantity and quality in Retisols – a case study from the Carpathian Foothills in Poland

Abstract

ABSTRACT Changes in land use are very important factors affecting soil quality and especially the concentration and stock of soil organic carbon (SOC) and total nitrogen (TN). Very little is known about changes in spectroscopic properties of SOM after conversion of forestland to cropland. Therefore, the main aim of this study was to determine impact of agriculture on the concentration and stock of SOC and TN as well as spectroscopic properties of SOM in the topsoil horizons of Retisols in the Carpathian Foothills in southern Poland. Topsoil Ap horizons of arable soils are characterized by a significantly lower concentration of SOC and TN in comparison with topsoil Oi and Ah horizons of forestland soils. Topsoil Ap horizons feature higher SOC and TN stocks than topsoil Oi and Ah horizons. Significantly higher concentrations of SOC and TN in Oi horizons in comparison with Ah and Ap horizons are responsible for significantly higher mean absorbance values of all FTIR-ATR absorption bands originating from SOM in Oi horizons versus Ah and Ap horizons. Significantly higher concentrations of SOC and TN in Ah horizons of forestland soils versus those in Ap horizons of arable soils do not significantly affect mean absorbance values of FTIR-ATR bands.