Genetic and agronomic approaches for improving nitrogen use and maize productivity
type: CreativeWork
description: Several factors have large effects on maize grain yield including environment, nitrogen (N) supply, and hybrid genetics. Efficient and environmentally responsible use of N fertilizer is a cornerstone of high‐yielding maize production, and improvements in maize N use will require a combination of agronomic, breeding, and biotechnology approaches. A maize hybrid’s N use and productivity are influenced by its grain yield at low N (check plot yield; no fertilizer N applied), and its response (i.e., increase in grain yield) to fertilizer N application. Maize N use can be improved by focusing on one or both of these parameters; however, better N use will not be sufficient by itself to increase maize productivity. Plant density tolerance also should be considered due to the possible interactions of hybrid, N rate, and plant density, as well as the need to increase plant density as a strategy to increase yield per unit area. The broad questions addressed by this research were i) how has past genetic selection for grain yield affected the N response characteristics of modern hybrids, ii) what is the variation for N use traits in current commercial hybrids, iii) how do hybrid, N rate, and plant density interact, and iv) has biotechnology (e.g., transgenic corn rootworm protection traits) already made an impact on N use and productivity of maize? An array of field-based phenotyping experiments (different levels of N and plant density) was conducted between 2008 and 2011 in Illinois using hybrids from various sources to address these questions. Evaluation of old and new hybrids under various levels of N supply showed that improvement for grain yield at low N (56 kg ha-1 yr-1) has contributed to about two-thirds of the improvement in grain yield at high N (86 kg ha-1 yr-1). Despite past improvement for low N tolerance, current commercial maize hybrids vary widely in their grain yields at low N with an average genetic range of 2.2 Mg ha-1. Tolerance to low N was also closely asso…
abstract: Several factors have large effects on maize grain yield including environment, nitrogen (N) supply, and hybrid genetics. Efficient and environmentally responsible use of N fertilizer is a cornerstone of high‐yielding maize production, and improvements in maize N use will require a combination of agronomic, breeding, and biotechnology approaches. A maize hybrid’s N use and productivity are influenced by its grain yield at low N (check plot yield; no fertilizer N applied), and its response (i.e., increase in grain yield) to fertilizer N application. Maize N use can be improved by focusing on one or both of these parameters; however, better N use will not be sufficient by itself to increase maize productivity. Plant density tolerance also should be considered due to the possible interactions of hybrid, N rate, and plant density, as well as the need to increase plant density as a strategy to increase yield per unit area. The broad questions addressed by this research were i) how has past genetic selection for grain yield affected the N response characteristics of modern hybrids, ii) what is the variation for N use traits in current commercial hybrids, iii) how do hybrid, N rate, and plant density interact, and iv) has biotechnology (e.g., transgenic corn rootworm protection traits) already made an impact on N use and productivity of maize? An array of field-based phenotyping experiments (different levels of N and plant density) was conducted between 2008 and 2011 in Illinois using hybrids from various sources to address these questions. Evaluation of old and new hybrids under various levels of N supply showed that improvement for grain yield at low N (56 kg ha-1 yr-1) has contributed to about two-thirds of the improvement in grain yield at high N (86 kg ha-1 yr-1). Despite past improvement for low N tolerance, current commercial maize hybrids vary widely in their grain yields at low N with an average genetic range of 2.2 Mg ha-1. Tolerance to low N was also closely asso…
author: Haegele, Jason
language: en
keywords: Maize, corn, nitrogen, plant density, plant breeding, western corn rootworm, uptake, utilization, yield components.
date published: 2012-09-18T21:14:32Z
date modified: 2026-07-22T22:25:31Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/34386