2:00 pm - 3:00 pm
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Jerry (Zijun) Wang. This seminar is open to the general public to attend.
Zoom Link: https://ualberta-ca.zoom.us/j/92257851345?pwd=nsRB2hnHu4fqolcfTJyIFd7qKjFPfr.1
MSc with Dr. Scott Chang
Thesis Topic: Interactive Effect of Organic Amendment and Nitrification Inhibitor on Soil Greenhouse Gas Emissions in a Cropping System
Abstract:
Application of organic amendments and/or nitrification inhibitors (hereafter “NIs”) has the potential to mitigate soil greenhouse gas (GHG) emissions and increase crop yield. However, their interactive effects remain unclear. In 2022, the final year of a four-year wheat-canola rotation, I examined the interactive effect between organic amendments, manure compost and its biochar derivative, and a nitrification inhibitor (NI), nitrapyrin on GHG emissions in urea-fertilized soil. Biochar (20 t ha-1) and manure compost (26 t ha-1) were applied at equivalent C rate of 7 t ha-1 solely or co-applied with nitrapyrin (2.7 L ha-1). Biochar and its co-application with nitrapyrin significantly decreased cumulative N2O emissions by 79 and 87%, respectively (P < 0.05, same below); manure and its co-application with nitrapyrin significantly decreased cumulative N2O emissions by 74 and 97%, respectively. Nitrapyrin alone significantly decreased cumulative N2O emissions by 82%. A significant interaction between biochar and NI was observed, demonstrating that NI was only effective in reducing N2O emissions when biochar was not applied, and vice versa. In addition, a significant interaction between manure and NI was observed, revealing that NI was only effective in when manure was not applied. None of the treatments affected soil CO2 and CH4 emissions. Our findings indicate that biochar and manure applied four years prior had similar effectiveness to nitrapyrin in reducing N2O emissions but can counteract nitrapyrin’s efficacy. I conclude that biochar and manure can reduce the effectiveness of nitrapyrin in reducing N2O emissions and have minimal impacts on CO2 and CH4 emissions.
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