132-10 Temporal Analysis of Nitrous Oxide Emissions from a Pennsylvania No-till Dairy Cropping System.

Poster Number 615

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Agricultural Practices to Improve Nitrogen-Use Efficiency and Mitigate Greenhouse Gas Emission: I (includes student competition)

Monday, November 16, 2015
Minneapolis Convention Center, Exhibit Hall BC

Maria Ponce de Leon, PA, Pennsylvania State University, State College, PA, Curtis J. Dell, USDA-ARS Pasture Systems & Watershed Mgmt Research Unit, University Park, PA and Heather D. Karsten, Department of Plant Science, Pennsylvania State University, University Park, PA
Poster Presentation
  • Temporal analysis of nitrous oxide emissions from a Pennsylvania no-till dairy cropping system.pdf (2.7 MB)
  • Abstract:
    Nitrous oxide (N2O) is a potent greenhouse gas that is released from agroecosystems by the microbial processes of nitrification and denitrification. We investigated how different cropping system practices that include differences in crop residues, N inputs (dairy manure and inorganic fertilizer), timing of N amendment applications, and environmental conditions influence N2O emissions from no-till soil.  Emissions were measured at the PSU Russell E Larson Agronomy Research Farm in the NESARE Dairy Cropping System experiment that was initiated in 2010 and aims to sustainably produce the forage, feed and fuel for a 65 cow, 240-acre dairy farm in Pennsylvania. We measured N2O fluxes from soil that was fertilized with dairy manure and planted after each of the following crops: i. alfalfa and orchardgrass, ii. crimsom clover, iii. soybean and iv. rye winter cover crop.  N2O fluxes were measured biweekly during the corn growing season in 2014 and 2015 using closed chambers (78.5cm x 40.5 cm) in three replications of each crop treatment and in two locations in each treatment-plot. Samples were collected at 10, 20 and 30 minutes after placing the chamber over the soil. For time 0, we sampled the atmospheric air, and we calculated the rate of N2O emissions [g N2O ha-1 day-1] using linear regression with the four data points. N2O emissions tended to peak in treatments after cover crops were terminated and manure was applied, prior to rapid corn N uptake. Treatments with low C:N ratio and high biomass contributed to enhanced microbial denitrification. Later in the season, when side-dress fertilizer N was applied to corn, N2O emissions were lower than when manure was applied earlier. This is likely because fertilizer N was more rapidly taken up by the actively growing corn, allowing a better synchronization between N supply and N demand from corn.

    See more from this Division: ASA Section: Environmental Quality
    See more from this Session: Agricultural Practices to Improve Nitrogen-Use Efficiency and Mitigate Greenhouse Gas Emission: I (includes student competition)