Soil Carbon Dioxide and Nitrous Oxide Emissions From Corn-Soybean Intercrop Systems During Two Contrasting Hydrological Growing Seasons.

Intensive agricultural activities contribute ~12% to global greenhouse gas (GHG) emissions, with carbon dioxide (CO₂), nitrous oxide (N₂O) and methane as the primary GHGs. As sources of GHG increase and sinks weaken, anthropogenic related climate change is enhanced, variable weather patterns occur, and agricultural production is strongly affected.  Producers in the south east region of Buenos Aires, Argentina have endured contrasting hydrological conditions in recent growing seasons.  In the November 2011- May 2012 growing season, the total precipitation was 14.5% below the long-term mean (683 mm), while during 2012/13 the total precipitation was 14% above the long-term mean.  The effect of maize-soybean intercropping and crop rotation on CO₂ and N₂O emissions was quantified from 2011 to 2013 at the INTA - Balcarce  research station (Buenos Aires, Argentina).  The research site was established in 2006 with four treatments:  two annually alternating corn-soybean rotations, and two corn-soybean intercropping designs (1 row corn: 2 rows soybean, and 2 rows corn: 3 rows soybean) systems.  Non-flow through steady state chambers were placed between rows to obtain weekly soil CO₂ and N₂O emissions.  Soil temperature and moisture, and weather data was obtained at the same time as GHG samples.  Results of summarized soil and climate parameters and calculated N₂O and CO₂ fluxes will be evaluated and presented.   The results are expected to highlight the important connection between cropping practices and weather conditions that influences GHG production from agricultural soils. Additionally, comparing cropping systems in contrasting hydrological growing seasons promotes developments of adaptable and ecological sustainable strategies for modern cropping systems.