[Effects of aerated irrigation on CO₂ and N₂O emission from protected melon soils under different nitrogen...

To reveal the effects of coupling nitrogen (N) application and aerated irrigation on soil CO₂ and N₂O emission, and their relationship with soil temperature and moisture, an experiment was conducted in greenhouse melon fields by using the method of static chamber/gas chromatography to determine the CO₂ and N₂O emissions of different nitrogen rates under aerated irrigation. There were two irrigation factors (AI: aerated irrigation; CK: conventional irrigation) and three N levels (N₁: 0; N₂: 150 kg·hm^-2, the traditional nitrogen application rate was 2/3; N₃: 225 kg·hm^-2, traditional nitrogen application rate). The results showed that soil CO₂ and N₂O emissions in AI treatment were higher than those in CK, but no significant difference was observed between the two irrigation methods. Under the same irrigation method, soil CO₂ and N₂O emission significantly increased with the increases of N application rate, indicating that N application was the main influencing factor for CO₂ and N₂O emissions. There were significant positive relationships between soil N₂O emissions and soil temperature and water filled pore space (WFPS) under the AI treatment. Soil CO₂ emission were positively correlated with soil temperature. When N application reduced to N₂ rate under AI treatment, the yield was increased by 6.9% and the greenhouse warming potential was reduced from 9544.82 kg·hm^-2 to 9340.72 kg·hm^-2. Thus, it is feasible to reduce the amount of N fertilizer under AI treatment to mitigate greenhouse gas emission in agricultural production systems.