Influence of soil type on N2O and CH4 soil fluxes in Hungarian grasslands

Soil fluxes of methane and nitrous oxide were determined for grasslands on sandy, loess and clay soils in Hungary. As the direction of methane flux (emission or uptake) depends on the soil characteristics bi-directional fluxes were observed. For sandy and loess grasslands the sink and source processes are practically balanced showing a negligible low mean methane flux for 2006−2007 (−0.04-0.05 kg CH4 ha-1 yr-1 ). In this period the clay grassland functioned as a weak sink for methane (−0.34 kgCH4 ha-1 yr-1). Average soil nitrous oxide emission fluxes for the period of 2002–2006 was 0.5 kg Ν ha-1 yr-1 for sandy and loess while 0.2 kg Ν ha-1 yr-1 for clay grassland, respectively, with substantial inter-annual variations. Taking into account the total atmospheric N-input 0 to 8 per cent of deposited nitrogen is emitted from the soils in the form of N2O as the intermediate product of soil denitrification processes.