Excess chemical fertilizer application results in substantial N₂O emission. Manure application into agricultural soil can reduce chemical fertilizer input while maintaining crop yield. However, little is known about the potential effects of reduction in chemical fertilizer with green manure or organic manure on yield-scaled N₂O emissions in orchards. A two-year experiment was carried out in a citrus orchard, including (i) chemical fertilizer (urea), 0%, 70%, 85% and 100% of N supplied, respectively (CK, C70, C85, CF), (ii) organic manure (rapeseed cake) incorporation with 0%, 70%, 85% and 100% of N supplied from chemical fertilizer (OM, OMC70, OMC85, OMCF), (iii) green manure (smooth vetch) incorporation with 0%, 70%, 85% and 100% of N supplied from chemical fertilizer (GM, GMC70, GMC85, GMCF) treatments. The soil physical-chemical properties, N₂O emissions and yields were measured during 2018–2019. N₂O emissions were 1.57 and 1.80 kg N ha⁻¹ yr⁻¹ under CF treatment in 2018 and 2019, respectively, and decreased by 25.4%−31.6% under C70, 32.5%−55.4% under OMC70 and OMC85 treatments and by 16.1–32.2% under GMC70 and GMC85 treatments. The 70% N rate of chemical fertilizer was the optimal N rate for maximizing yield in no manure, organic manure and green manure treatments, respectively. The C70, OMC70 and GMC70 treatments both significantly decreased yield-scaled N₂O emission with the lowest emission in OMC70 treatment relative to CF treatment. N₂O fluxes in OMC70 and OMC85 treatments were mainly controlled by the DOC/NO₃^- ratio, while soil NH₄⁺ was the dominant factor controlling N₂O fluxes in GMC70 and GMC85 treatments, suggesting that more NH₄⁺ provided from green manure than from organic manure contributed to higher N₂O emission. We conclude that applying organic manure incorporation with 30% reductions of chemical fertilizer is a fertilizer management strategy worth pursuing for sustainable productivity and environmental protection in citrus orchards.

过量施用化肥导致大量N ₂ O 排放。将粪肥施入农业土壤可以在保持作物产量的同时减少化肥的投入。然而，关于减少使用绿肥或有机肥的化肥对产量规模的 N ₂的潜在影响知之甚少。果园中的 O 排放。在柑橘园进行了为期两年的试验，包括（i）化肥（尿素），分别提供 0%、70%、85% 和 100% 的 N（CK、C70、C85、CF），（ ii) 有机肥（菜籽饼）掺入 0%、70%、85% 和 100% 的化肥（OM、OMC70、OMC85、OMCF）提供的 N，(iii) 掺入 0% 的绿肥（紫云英） 、70%、85% 和 100% 的氮来自化肥（GM、GMC70、GMC85、GMCF）处理。2018-2019 年期间测量了土壤理化特性、N ₂ O 排放量和产量。N ₂ O 排放量分别为 1.57 和 1.80 kg N ha ^-1 yr ^-1分别在 2018 年和 2019 年在 CF 处理下，在 C70 下降低了 25.4%-31.6%，在 OMC70 和 OMC85 处理下降低了 32.5%-55.4%，在 GMC70 和 GMC85 处理下降低了 16.1-32.2%。70%的化肥施氮量分别是无肥、有机肥和绿肥处理中增产的最佳施氮量。C70、OMC70 和GMC70 处理均显着降低了产量规模的N ₂ O 排放，其中OMC70 处理相对于CF 处理的排放最低。OMC70和OMC85处理中N ₂ O通量主要受DOC/NO ₃ ^-比控制，而土壤NH ₄ ⁺是控制N ₂的主导因子GMC70 和 GMC85 处理中的 O 通量，表明绿肥提供的NH ₄ ⁺比有机肥提供的更多，导致更高的 N ₂ O 排放。我们得出的结论是，施用有机肥并减少 30% 的化肥是一种值得在柑橘园实现可持续生产力和环境保护的肥料管理策略。