Determining the Critical Nitrogen Application Rate for Maximizing Yield While Minimizing NO<sub>3</sub><sup>−</sup>-N Leaching and N<sub>2</sub>O Emissions in Maize Growing on Purple Soil
Optimization of nitrogen (N) fertilizer application is essential to achieve higher crop yields at lower environmental costs. This study investigated the impacts of N application rates (0, 180, and 360 kg N ha<sup>−1</sup>) on maize productivity, N use efficiency (NUE), NO<sub>3<...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-05-01
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| Series: | Agronomy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4395/15/6/1358 |
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| Summary: | Optimization of nitrogen (N) fertilizer application is essential to achieve higher crop yields at lower environmental costs. This study investigated the impacts of N application rates (0, 180, and 360 kg N ha<sup>−1</sup>) on maize productivity, N use efficiency (NUE), NO<sub>3</sub><sup>−</sup>-N leaching, cumulative N<sub>2</sub>O emissions, and N surplus in maize growing in the purple soil of Southwest China through a 2-year field study. The critical N rate balancing yield optimization with reduced NO<sub>3</sub><sup>−</sup>-N leaching and N<sub>2</sub>O emissions was identified. The results showed that grain yield initially increased linearly and then stabilized with increasing N rates, while NUE significantly decreased. NO<sub>3</sub><sup>−</sup>-N leaching, N<sub>2</sub>O emissions, and N surplus exhibited quadratic increase. Regression analysis indicated that 158–163 kg N ha<sup>−1</sup> achieved optimal yield while maintaining acceptable NO<sub>3</sub><sup>−</sup>-N leaching and N<sub>2</sub>O emissions compared to 360 kg N ha<sup>−1</sup>. This range also enhanced NUE and minimized soil N residue. |
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| ISSN: | 2073-4395 |