CONICET | Buscador de Institutos y Recursos Humanos

Background/Question/MethodsNitrous oxide (N2O) is one of the major greenhouse gases, responsible for near 6% of global warming, andis the largest stratospheric ozonedepletingsubstance. The major sources are soils under natural vegetationand arable lands. Due to the diverse processes and driving factors involved in the production of N2O fromsoils, emissions are largely variable in space and time. Understanding the drivers that control theseemissions represents a key task when modeling N2O emissions or upscalling from field measurements.Water fill pore space, soil temperature, and nitrogen and carbon availability are usually identified as themain drivers of N2O emissions. However, vegetation productivity, which is closely related to these factors,has received less attention as a driver of N2O emissions. In this work two questions were tackled in the mainagricultural region of Argentina: Do soils under commercial crops release more N2O than naturalecosystems left aside? And; is vegetation productivity closely related to soil N2O emissions? A manipulativefield experiment was settled in two contrasting sites of the Pampas Region. In each site, N2O samples weretaken monthly during two years with the static chamber method in soybean crops, corn, wheat/soybeanrotation, and natural ungrazed grassland plots. Agricultural plots received common agricultural practices likeplots under commercial production. We also measured soil temperature, vegetation productivity (estimatedby the normalized difference vegetation index NDVI),and we collected soil samples to determine waterfilled pore space, and NH4 and NO3 availability.Results/ConclusionsOur results showed that the N2O emissions from soybean crops were higher than from natural grasslands atboth sites, but differences wer significant only for the second year (p