Soil nitrogen transformations in complex agroecosystems

WILTON, M.; OELBERMANN, M.; ECHARTE L.

Mar del Plata

Congreso; XIX Congreso latinoamericano de la ciencia del suelo y XXIII Congreso Argentino de la ciencia del suelo; 2012

Land use change for agricultural production has contributed to the accumulation of greenhouse gases (GHG) and has negatively impacted soil nutrient dynamics. Nitrous oxide (N2O) is a potent GHG produced simultaneously by nitrification and denitrification and is thus enhanced by anthropogenic nitrogen inputs. Utilizing natural abundance 15N and 18O isotope techniques allows nitrification and denitrification to be distinguished and for N2O sources to be identified in various soil management practices. Research is currently conducted on maize-soybean monocropping and intercropping systems in the temperate climate region of the Argentine Pampa. The objective of this study is to compare each cropping system by obtaining carbon dioxide and nitrous oxide fluxes and by quantifying the nitrogen transformations using natural abundance isotopes partitioning techniques. Results from this research will be the first to use natural abundance isotope techniques to investigate and compare nitrogen transformations in complex agroecosystems. Additionally, data collected will be related to baseline data since 2007 from the same research site. It is imperative to monitor changes of carbon and nitrogen dynamics in intercropping and monocropping systems to elucidate further differences between the treatments and to develop cropping strategies to mitigate GHG emissions.