Irrigation, carbon amelioration, nitrogen, and stover removal effects on continuous corn

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

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2020
Publication Date: 6/2/2020
Citation: Schmer, M.R., Jin, V.L., Ferguson, R.B., Wienhold, B.J. 2020. Irrigation, carbon amelioration, nitrogen, and stover removal effects on continuous corn.. Agronomy Journal. 112:2506-2518. https://doi.org/10.1002/agj2.20192.
DOI: https://doi.org/10.1002/agj2.20192

Interpretive Summary: Corn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a potential feedstock for cellulosic biofuels. Limited information is available on corn residue removal effects on grain yield under different N fertilizer rates, irrigation rates and amelioration practices to maintain soil carbon (C) and minimize soil erosion. We evaluated interactions between stover removal (residue removal, no residue removal), irrigation rate (full, limited), fertilizer N management (112 lbs N acre-1, 179 lbs N acre-1), and carbon amelioration practices (cover crop, surface-applied manure, no amelioration practice) on no-till continuous corn grain yield located on a silt loam soil in south-central Nebraska (2011-2018). Stover removal increased grain yield by 16 bushels per acre and N uptake compared with no stover removal. For amelioration practices with stover removal, manure increased corn grain yield by 14 bushels per acre compared to either the control or cover crop while C amelioration practices did not affect grain yield under stover retention. Grain N concentration was higher with residue removal than residue retained. Grain yield increased with stover removal and manure application resulting in a cost-effective C amelioration practice while incorporating winter cereal rye as a cover crop resulted in similar grain yield as the control.

Technical Abstract: Corn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a potential feedstock for cellulosic biofuels. Limited information is available on corn residue removal effects on grain yield under different N fertilizer rates, irrigation rates and amelioration practices to maintain soil carbon (C) and minimize soil erosion. We evaluated potential interactions between stover removal (residue removal, no residue removal), irrigation rate (full, limited), fertilizer N management (125 kg N ha-1, 200 kg N ha-1), and carbon amelioration practices (cover crop, surface-applied manure, no amelioration practice) on no-till continuous corn grain yield located on a silt loam soil in south-central Nebraska (2011-2018). Stover removal increased (P = 0.0017) grain yield by 1.02 Mg ha-1 and N uptake compared with no stover removal. For amelioration practices with stover removal, manure increased corn grain yield by 899 kg ha-1 compared to either the control or cover crop while C amelioration practices did not affect grain yield under stover retention. Grain N concentration was higher (P <0.0001) with residue removal (13.2 g kg-1) than residue retained (12.7 g kg-1). Partial factor productivity (kg kg-1) was highest for manure treatments with residue removal. The N balance from stover removal was negative yet grain yield was not impacted after eight growing seasons. Grain yield increased with stover removal and manure application resulting in a cost-effective C amelioration practice while incorporating a winter cover crop resulted in similar grain yield as the control.