Does Nitrogen Fertilizer Application Rate to Corn Affect Nitrous Oxide Emissions from the Rotated Soybean Crop?

Thumbnail Image
Barker, Daniel
Miguez, Fernando
Pantoja, Jose
Castellano, Michael
Major Professor
Committee Member
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Organizational Unit
Journal Issue
Is Version Of

Little information exists on the potential for N fertilizer application to corn (Zea mays L.) to affect N2O emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects N2O emissions during subsequent crops in rotation, we measured N2O emissions for 3 yr (2011–2013) in an Iowa, corn–soybean [Glycine max (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha−1, the recommended rate of 135 kg N ha−1, and a high rate of 225 kg N ha−1); soybean received no N fertilizer. We further investigated the potential for a winter cereal rye (Secale cereale L.) cover crop to interact with N fertilizer rate to affect N2O emissions from both crops. The cover crop did not consistently affect N2O emissions. Across all years and irrespective of cover crop, N fertilizer application above the recommended rate resulted in a 16% increase in mean N2O flux rate during the corn phase of the rotation. In 2 of the 3 yr, N fertilizer application to corn (0–225 kg N ha−1) did not affect mean N2O flux rates from the subsequent unfertilized soybean crop. However, in 1 yr after a drought, mean N2O flux rates from the soybean crops that received 135 and 225 kg N ha−1 N application in the corn year were 35 and 70% higher than those from the soybean crop that received no N application in the corn year. Our results are consistent with previous studies demonstrating that cover crop effects on N2O emissions are not easily generalizable. When N fertilizer affects N2O emissions during a subsequent unfertilized crop, it will be important to determine if total fertilizer-induced N2O emissions are altered or only spread across a greater period of time.


This article is from Journal of Environmental Quality 44 (2015): 711, doi: 10.2134/jeq2014.09.0378. Posted with permission.

Thu Jan 01 00:00:00 UTC 2015