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Title:Nitrogen fertility, plant population, row spacing, and hybrid effects on corn grain yield
Author(s):Winans, Eric Thomas
Advisor(s):Below, Frederick E.
Contributor(s):Butts-Wilmsmeyer, Carolyn; Studer, Anthony
Department / Program:Crop Sciences
Discipline:Crop Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
plant density
plant population
row spacing
yield components
Abstract:Strategic selection and utilization of corn (Zea mays L.) hybrids for a given yield environment and agronomic management system will require better understanding and documentation of the interactions between current commercial hybrids and the agronomic factors that have the greatest effects on yield (i.e., nitrogen (N) fertilization, plant population, and row spacing). This study serves to evaluate the effects that N fertility, plant population, and row spacing have on grain yield of corn and assess the potential range in yield responses among commercial hybrids to these agronomic management factors. From 2015 to 2018, 147 commercial hybrids were grown at three locations across the state of Illinois under three N rates (0, 60, and 280 lb N acre-1), three plant populations (32,000, 38,000, and 44,000 plants acre-1), and two row spacing configurations (20 and 30 inches). The average check plot yield (yield at 0 lb N acre-1) was 158 bu acre-1, while the response to high N (yield change between 0 and 280 lb N acre-1 at 32,000 plants acre-1) was +86 bu acre-1. However, 72% of the yield increase from the N fertilizer was achieved by using the low N rate (60 lb N acre-1). Location affected the yield response to N fertilizer, as locations with higher soil fertility levels had higher check plot yields, thereby decreasing the yield response to N fertilization. Increasing plant population to 38,000 or 44,000 plants acre-1 in a 30-inch row did not increase yields, although the highest yields tended to occur under the higher planting populations. Narrower row spacing was a better arrangement of the highest plant population, resulting in an average increase of 9 bu acre-1 (response to row spacing; yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1). Similar yield gains in response to narrower row spacing were observed across the entire state. Selecting the appropriate hybrid for a given N fertility level is crucial, as substantial ranges in check plot yields (47 bu acre-1), yield responses to low N (33 bu acre-1), and yield responses to high N (36 bu acre 1) were observed. Furthermore, yield changes in response to the high plant population and narrow row spacing ranged from -5 to +6 and -8 to +22 bu acre-1, respectively, among the hybrids. Evaluating twelve environments with an inclusive representation of current commercial corn hybrids advances our understanding of N rate, plant population, and row spacing effects on production in Illinois. Hybrids exhibited wide variation of yield in response to, and in interactions with, different agronomic conditions making selection of the appropriate hybrid an important decision for increasing corn grain yields with intensive agronomic management.
Issue Date:2019-04-22
Rights Information:Copyright 2019 Eric Winans
Date Available in IDEALS:2019-08-23
Date Deposited:2019-05

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