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

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.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Crop Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Graham, Rebecca Faye

Contributors dc:contributor

• Pittelkow, Cameron M.

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

Statement dc:rights

• Copyright 2017 Rebecca Graham

Language dc:language

en

Handle dc:identifier

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

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/98363