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Title:Nutrient uptake and partitioning in high-yielding corn
Author(s):Bender, Ross
Advisor(s):Below, Frederick E.
Department / Program:Crop Sciences
Discipline:Crop Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Nutrient Uptake
High-Yielding Corn
Maintenance Fertilizer Rate
Abstract:Improved agronomic management practices have aimed at matching plant nutritional needs with nutrients from soil and fertilizer sources. These practices, when done sustainably, also include replacing removed nutrients through maintenance fertilizer applications without excess application rates. While fertilizer recommendations and nutrient removal estimates become increasingly important as farmers strive to achieve 16.0 Mg ha-1, data used to estimate these nutrient uptake and use parameters are largely outdated. Specifically, a lack of information exists to show whether modern genotypes with transgenic insect protection from various above and below ground insects assimilate and utilize higher quantities of mineral nutrients. The central objective of this thesis was to quantify nutrient uptake, removal, and partitioning in elite commercial germplasm grown under modern management practices. Data from a set of hybrids at two locations in 2010 demonstrated nutrient accumulation patterns for corn yielding 12.0 Mg ha-1. The results of Chapter 1 suggest that nutrient requirements for production and the quantity of nutrient removal have increased markedly over the past 50 years. Resulting accumulation figures also showed that P, S, Zn, and Cu uptake was equally distributed between vegetative and reproductive growth suggesting that season-long availability of these nutrients is critical to meet corn nutritional needs. Alternatively, uptake of N, K, Mg, Mn, B, and Fe favored early-season uptake during vegetative growth. Further analysis identified possible relationships between nutrient uptake and removal with hybrid background and transgenic insect protection. Although biotech hybrids have contributed to increased yields with improved farmer safety and profitability, the impact of this technology on nutrient uptake, removal, and grain nutrient concentrations are not well documented. Improved genotypes with transgenic insect protection that are managed to achieve their maximum yield potential provided us with the opportunity to identify interactions which influenced maintenance fertilizer recommendations. The objective of Chapter 2 was to evaluate the impact of hybrid background, transgenic insect protection, agronomic management, and location and/or weather differences on these nutrient use parameters. Data in Chapter 2 had been collected over a series of seven site-years from 2008 through 2011. The results suggest hybrid background and transgenic insect protection from western corn rootworm (Diabrotica virgifera virgifera LeConte) significantly influence nutrient uptake, removal, and grain nutrient concentrations. Agronomic management, which allowed hybrids to achieve their maximum yield potential through improved fertility, further increased nutrient uptake in transgenic insect protected isolines. Additionally, localized weather and soil conditions primarily impacted nutrient uptake by influencing the quantity of nutrients accumulated post-flowering. Droughty, above-average temperatures during grain-fill in 2011 reduced nutrient uptake and increased nutrient remobilization compared to conditions with greater precipitation. Although nutrient management is a complex process, improving our understanding of when, where, and how nutrients are used by corn plants presents opportunities to optimize fertilizer rates and application timings. This reevaluation of nutrient uptake and partitioning can provide the foundation for fine-tuning nutrient management practices as producers aim for increased yields and profitability.
Issue Date:2012-06-27
Rights Information:Copyright Ross Randall Bender, 2012. All rights reserved.
Date Available in IDEALS:2014-06-28
Date Deposited:2012-05

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