Limited effects of irrigation on 7-year soil nitrous oxide emissions from no-till continuous corn

Authors: Jin, Virginia; Schmer, Marty; Wienhold, Brian; Miller, Daniel; Woodbury, Bryan; FERGUSON, RICHARD - University Of Nebraska

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/31/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Corn stover from intensive production systems may provide feedstocks for both livestock and bioenergy sectors. Companion management practices may help ameliorate the effect of removing crop residue, but the impact of such practices on soil nitrous oxide emissions is unclear. Here, we evaluated the effects of stover removal under different levels of irrigation (deficit, full), nitrogen rate (0, 125, 200 kg N ha-1 yr-1), and amelioration practice (no amelioration, winter rye cover crop, surface broadcast beef feedlot manure) in a long-term no-till corn system in the western Corn Belt. Over seven crop years, irrigation effects were limited to the winter rye cover crop treatment, where annual N2O emissions decreased under deficit irrigation. Otherwise, irrigation had no other effect on annual soil N2O emissions. Annual emissions were controlled by stover removal and fertilizer N rate. Removing stover decreased soil N2O emissions, whereas emissions increased with higher N fertilizer rates. Winter rye cover crop had no effect on soil N2O emissions compared to non-ameliorated soils after stover removal. The lowest emissions were from manure-amended soils, where N-credits from manure resulted in lower application rates of synthetic fertilizer N.