| Summary: | Nitrogen (N) inputs and land-use conversion are management practices that affect soil greenhouse gas (GHG) and nitric oxide (NO) emissions. Here, we measured soil methane (CH<sub>4</sub>), nitrous oxide (N<sub>2</sub>O), and NO fluxes from rice fields and a peach orchard that converted from paddies to assess the impacts of nitrogen (N) inputs and land-use conversion on their emissions. Treatments included four paddy field treatments (PN0, PN160, PN220, and PN280) and one peach orchard treatment (ON280) with number indicating the N-input rate of kg N ha<sup>−1</sup>. The results showed that cumulative emissions of CH<sub>4</sub>, N<sub>2</sub>O and NO ranged from 28.6 to 85.3 kg C ha<sup>−1</sup>, 0.5 to 4.0 kg N ha<sup>−1</sup> and 0.2 to 0.3 kg N ha<sup>−1</sup> during the rice-growing season, respectively. In terms of greenhouse gas intensity, the PN280 treatment is the recommended N application rate. Land-use conversion significantly reduced the global warming potential from croplands. The conversion shifted soils from an essential source of CH<sub>4</sub> to a small net sink. In addition, N<sub>2</sub>O emissions from the rice–wheat rotation system were 1.8 times higher than from the orchard, mainly due to the difference in the N application rate. In summary, to reduce agriculture-induced GHG emissions, future research needs to focus on the effects of N inputs on rice-upland crop rotation systems.
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