288-1 Simultaneous Measurements of Nitrous Oxide Emissions and Nitrate Loss From Corn Production Under Different Fertilizer and Irrigation Management.



Tuesday, October 18, 2011: 8:05 AM
Henry Gonzalez Convention Center, Room 210A, Concourse Level

Bijesh Maharjan1, Rodney Venterea2, Carl Rosen1 and Charles R. Hyatt1, (1)University of Minnesota, St. Paul, MN
(2)USDA-ARS Soil & Water Management Research Unit, St. Paul, MN
Nitrogen (N) loss from managed systems in the gaseous form as nitrous oxide (N2O) and the soluble form as nitrate (NO3-) is an economic as well as an environmental concern. The objective of this study was to compare N2O emissions and NO3- loss from corn production using various fertilizer N sources combined with different irrigation practices. The experiment was conducted for three consecutive years (2008 – 2010) in central Minnesota in a sandy soil. Nitrogen fertilizer sources evaluated were conventional granular urea (U), polymer coated urea (ESN), and also urea amended with urease and nitrification inhibitors (SuperU, in 2009 and 2010) under rain-fed and irrigated conditions. All fertilizers were applied at rate of 180 kg / ha and a control plot with 0 N was also included. Nitrous oxide emissions were measured using the closed chamber method. Nitrate loss was estimated based on measurement of NO3- concentration in soil water collected using ceramic cup lysimeters combined with water-balance estimates of water leaching rates. Nitrous oxide emissions under U and ESN were significantly greater than those from control plots in all three years. Nitrate losses with U, SuperU and ESN were not significantly different from each other whereas N2O emissions with SuperU was found to be significantly less than those with ESN in 2010. Nitrate losses in leachate were significantly affected by irrigation while irrigation did not have significant effect on N2O emissions.  These findings suggest that simultaneous measurements of N2O emissions and NO3- loss are important in evaluating N loss pathways from various N sources and irrigation management practices.
See more from this Division: S11 Soils & Environmental Quality
See more from this Session: Agriculture, Emissions, and Air Quality