Impacts of enhanced efficiency nitrogen fertilizers on yield-scaled N2O emissions in Illinois maize

Graham, Rebecca Faye

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https://hdl.handle.net/2142/98363 Copy

Description

Title

Impacts of enhanced efficiency nitrogen fertilizers on yield-scaled N2O emissions in Illinois maize

Author(s)

Graham, Rebecca Faye

Issue Date

2017-07-11

Director of Research (if dissertation) or Advisor (if thesis)

Pittelkow, Cameron M.

Department of Study

Crop Sciences

Discipline

Crop Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Nitrogen
• Nitrous oxide (N2O)
• Enhanced efficiency fertilizers
• Climate change
• Soil fertility
• Soil

Abstract

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) with about 300 times the global warming potential of CO2 and significant levels of this GHG come from agriculture. A two-year field experiment was conducted to assess the ability of enhanced efficiency nitrogen fertilizers (EENFs) to minimize yield-scaled N2O emissions while maintaining nutrient utilization and crop productivity of maize. In addition to an unfertilized control (zero N), N source treatments applied at 202 kg ha-1 at planting included anhydrous ammonia (AA), UAN + nitrapyrin, ESN, and SuperU. Gas samples were collected using static closed chambers. Soil inorganic N concentrations, soil temperature, and precipitation were monitored throughout the growing seasons. Crop N content, grain yield, and nitrogen recovery efficiency (NRE) were also determined each year. Over the two-year trial, we found that EENFs did not consistently reduce N2O emissions or increase grain yields relative to the conventional AA treatment. Soil N concentrations were not correlated with daily N2O flux rates. In 2015, injected UAN + nitrapyrin increased N2O and yield-scaled N2O emissions relative to the other N sources, while AA produced the highest emissions in 2016, but not the highest yield-scaled emissions. These results indicate the difficulty in identifying ways to decrease yield-scaled N2O emissions using different N sources under variable weather conditions each year that likely influenced fertilizer N transformations in soil.

Graduation Semester

2017-08

Type of Resource

text

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http://hdl.handle.net/2142/98363

Copyright and License Information

Copyright 2017 Rebecca Graham

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