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Nitrogen, Stover, and Tillage Management Affect Nitrogen Use Efficiency in Continuous Corn
Author(s) -
Sindelar Aaron J.,
Coulter Jeffrey A.,
Lamb John A.,
Vetsch Jeffrey A.
Publication year - 2015
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj14.0535
Subject(s) - stover , tillage , fertilizer , agronomy , corn stover , nitrogen , environmental science , zoology , chemistry , biofuel , crop , biology , microbiology and biotechnology , organic chemistry
Improving nitrogen use efficiency (NUE) in corn ( Zea mays L.) is critical for optimizing yield and reducing environmental impact. Stover removal in continuous corn (CC) for biofuel production, coupled with reduced‐tillage systems, could alter NUE and residual soil nitrate‐N. Experiments were conducted in Minnesota over 3 yr to determine how N uptake, NUE, and residual soil nitrate‐N are affected by stover (remove and retain), tillage (chisel‐ [CT], strip‐ [ST], and no‐till [NT]), and fertilizer N (0, 45, 89, 134, 179, and 224 kg N ha −1 ) management. There was a linear response of grain and total aboveground N uptake to fertilizer N across stover management and tillage treatments. Stover removal increased recovery efficiency for ST and NT at fertilizer N rates ≤134 kg N ha −1 , but did not enhance N recovery in plots fertilized at rates >134 kg N ha −1 . Internal efficiency was 5% greater with stover removal with no fertilizer N, but did not change with fertilizer N application. Stover removal did not affect agronomic efficiency in CT but did enhance it in ST and NT at fertilizer N rates ≤134 kg N ha −1 . Residual soil nitrate‐N to a depth of 1.2 m was 10 to 16 kg NO 3 –N ha −1 greater with stover removal at fertilizer N rates of 134 to 224 kg N ha −1 . Greater residual soil nitrate‐N with stover removal indicates a need for judicious management of N when stover is removed in intensively‐managed Upper Midwestern CC systems.