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2N - Field Studies (MOP/130) N2O gas emission from agricultural soil due to N-fertilization and organic matter addition. Kampfl, Györgyi1, Kristóf, Krisztina1, Bakonyi, Gábor1, Heltai, György1, 1 Szent István University, Gödöllő, Hungary ABSTRACT- The release of N2O is increasing due to intensive agricultural land use. Agricultural contribution to the global annual N2O emission is estimated at approximatly 35%. To a long term field experiment a laboratory microcosm experiment was set up tu study N2O and CO2 gas emission dynamics from the cultivated agricultural soil due to fertilization and organic matter addition under controlled circumstances. Brown forest soil was collected near Keszthely (Hungary). Soil was dried, sieved, rewetted and aerobically incubated for 10 days. Soil water content was 15 m/m%. The experiment was conducted at 15°C. 100 g soil was incubated in closed glass vessels. Three treatments were set up as follows: untreated control soil, soil + mineral nitrogen (KNO3, as 100 kgN/ha), soil + mineral nitrogen + organic matter (as 1.5 g maize straw/kg soil). All treatments were made in triplicate. N2O and CO2 were analysed from the gase in overhead space by gas chromatography. On the first week gas samples were taken daily, later weekly. The results shows that both gases evolved slowly from the control soil. Faster gas emission was found due to nitrogen and nitrogen + organic matter addition, respectively. The most N2O and CO2 were evolved from the control soil, less due to the nitrogen and nitrogen + organic matter addition, respectively. Key words: microcosm experiment, N2O emission from soils, emission dinamics, gas chromatography |
