Dissolved organic carbon and dissolved nitrogen in soil under different fertilization treatments

Abstract

The objective of the study was to evaluate the effects of long-term fertilization of a sandy soil with differentiated doses of cattle slurry as well as its after-effect action on the possibilities of migration of dissolved organic carbon (DOC) and dissolved nitrogen (DNt) down to deeper layers of the soil profile. DOC and DNt were extracted with borate buffer and 0.004M CaCl₂ solution. Evaluation of effects of cattle slurry on the content of DOC and DNt was done in comparison with mineral fertilization. It was shown that the use of cattle slurry in the doses of 100 and 200 m³/ha caused a significant increase of labile organic matter in the 0–25 and 25–50 cm layers of soil. As compared with mineral fertilization the application of slurry increased also the amounts of extracted DNt, but only in the surface layer. The DNt content in the deeper soil horizons did not depend on the kind of fertilization. Concentrations of DOC and DNt in the extracts depended not only on their content in soil but it was also modified substantially by the extractant used.