Effects of Nitrogen Fertilization on Soil CH<sub>4</sub>, CO<sub>2</sub>, and N<sub>2</sub>O Emissions and Their Global Warming Potential in Agricultural Peatlands
Globally, 14–20% of peatlands are affected by agricultural activities, which account for about one-third of global greenhouse gas emissions from farmlands. However, how agricultural activities such as nitrogen fertilization affect peatlands’ CH<sub>4</sub>, CO<sub>2</sub> and...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Agronomy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4395/15/1/115 |
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| Summary: | Globally, 14–20% of peatlands are affected by agricultural activities, which account for about one-third of global greenhouse gas emissions from farmlands. However, how agricultural activities such as nitrogen fertilization affect peatlands’ CH<sub>4</sub>, CO<sub>2</sub> and N<sub>2</sub>O emission patterns and their resulting warming effects needs to be improved and complemented. Here, we elucidate the characterization of CH<sub>4</sub>, CO<sub>2</sub> and N<sub>2</sub>O emissions from the soil surface and different depths of the soil profile during the growing season of agricultural peatlands for over 50 years and the mechanisms of their resulting global warming potential (GWP) impact through field monitoring and molecular techniques. The 100-year GWP of peatlands increased by 1200% with N fertilization of 260 kg N ha<sup>−1</sup> yr<sup>−1</sup>. At the soil surface, N fertilization increased CO<sub>2</sub> and N<sub>2</sub>O emissions by 111% and 2600%, respectively, although CH<sub>4</sub> emissions decreased by 87%. In the soil profile, N fertilization had a significant effect on CO<sub>2</sub> from 0 to 60 cm, resulting in an increase in CO<sub>2</sub> concentrations of 14–132%, whereas the top 30 cm of soil was the zone of significant N fertilization effects, with CH<sub>4</sub> concentrations decreasing by 49–95% and N<sub>2</sub>O concentrations increasing by 22–26%. Elevated soil pH and NH<sub>4</sub><sup>+</sup> were the key environmental factors influencing CH<sub>4</sub>, CO<sub>2</sub> and N<sub>2</sub>O emissions and their resulting increase in GWP. These results suggest that agricultural N fertilization led to a change in the contributor to the GWP of peatlands from CH<sub>4</sub> to N<sub>2</sub>O, especially in the top 30 cm of soil. This study helps to provide theoretical support for the development of effective peatland management strategies. |
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| ISSN: | 2073-4395 |