Effects of Long-Term Nitrogen Fertilization on Nitrous Oxide Emission and Yield in Acidic Tea (<i>Camellia sinensis</i> L.) Plantation Soils
The responses of nitrous oxide (N<sub>2</sub>O) emissions to nitrogen (N) application in acidic, perennial agricultural systems, and the factors driving these emissions, remain poorly understood. To address this gap, a 12-year field experiment was conducted to investigate the effects of...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-12-01
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| Series: | Agronomy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4395/15/1/7 |
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| Summary: | The responses of nitrous oxide (N<sub>2</sub>O) emissions to nitrogen (N) application in acidic, perennial agricultural systems, and the factors driving these emissions, remain poorly understood. To address this gap, a 12-year field experiment was conducted to investigate the effects of different N application rates (0, 112.5, 225, and 450 kg N ha<sup>−1</sup> yr<sup>−1</sup>) on N<sub>2</sub>O emissions, tea yield, and the associated driving factors in a tea plantation. The study found that soil pH significantly decreased with long-term N application, dropping by 0.32 to 0.85 units. Annual tea yield increased significantly, by 148–243%. N application also elevated N<sub>2</sub>O emission fluxes by 33–277%, with notable seasonal fluctuations observed. N<sub>2</sub>O flux was positively correlated with N rates, water-filled pore space (WFPS), soil temperature (T<sub>soil</sub>), and inorganic N (NH<sub>4</sub><sup>+</sup>-N and NO<sub>3</sub><sup>−</sup>-N), while showing a negative correlation with soil pH. Random forest (RF) modeling identified WFPS, N rates, and Tsoil as the most important variables influencing N<sub>2</sub>O flux. The cumulative N<sub>2</sub>O emissions for N112.5, N225, and N450 were 1584, 2791, and 45,046 g N ha<sup>−2</sup>, respectively, representing increases of 1.33, 2.34, and 3.77 times compared to N0. The N<sub>2</sub>O-N emission factors (EF) were 0.35%, 0.71%, and 0.74%, respectively, and increased with higher N rates. These findings highlight the importance of selecting appropriate fertilization timing and improving water and fertilizer management as key strategies for mitigating soil acidification, enhancing nitrogen use efficiency (NUE), and reducing N<sub>2</sub>O emissions in acidic tea-plantation systems. This study offers a theoretical foundation for developing rational N fertilizer management practices and strategies aimed at reducing N<sub>2</sub>O emissions in tea-plantation soils. |
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| ISSN: | 2073-4395 |