Soil nitrous oxide emissions under different management practices in the semiarid region of the Argentinian Pampas

The aim of this study was to analyze the influence of different crop sequences (soybean-corn and soybean-soybean) and tillage systems (no tillage and reduced tillage) on nitrous oxide (N2O) soil emissions under field conditions. The experiment was carried out in Manfredi, Crdoba province, Argentina on an Entic Haplustoll and N2O emissions were measured in the field during a year. N2O fluxes were low during winter, but in late spring it peaked. For fallow, N-NO3-content was the most important variable to explain N2O emissions. For growing period water-filled pores was the main variable explaining N2O emissions. Nitrogen fertilization of corn crop increased N2O-N emissions, whereas no significant differences were found due to the tillage system. Measured annual N2O-N emissions were generally lower than those calculated using the methodology proposed by the Intergovernmental Panel on Climate Change.