Intensification of agriculture in the tropics is likely to increase reactive nitrogen (N) losses in the form of nitrous oxide (N₂O), however, drivers of emissions from tropical soils remain poorly understood. This study investigated the effect of leaf litter and urea fertiliser on N₂O emissions from two Australian tropical mango orchards. Treatments included urea (25 g N m⁻²), leaf litter (1500 g m⁻² dry matter), their combined application, and untreated control. Up to 80.5 ± 8.4 mg N₂O-N m⁻² were lost within two weeks of treatment application, accounting for more than 60% of annual N₂O emissions. Indirect emissions > 30 mg m⁻² d⁻¹ were recorded at one site, potentially resulting from groundwater transported N. Highest annual N₂O emissions were observed from Litter + Urea with 130.4 mg N₂O-N m⁻² y⁻¹, exceeding those from Urea-Only by a factor of two and those from Litter-Only by a factor of four. This resulted in residue and fertiliser emission factors (EF) of < 0.01–0.37%, well below the IPCC and Tier 2 defaults, with whole orchard losses equivalent to 0.19–0.66 kg N₂O-N ha⁻¹. The findings suggest N₂O is N limited when no N fertiliser is applied, even when applying large amounts of litter-N, and by carbon (C) in the absence of litter. The combined effect of Litter + Urea on N₂O emissions surpassed the effect of the sole application of litter and urea, demonstrating a critical interaction between both substrates. This interaction effect needs to be considered when developing management strategies aimed at increasing soil C in tropical soils.

热带地区的农业集约化可能以一氧化二氮（N ₂ O）的形式增加活性氮（N）的损失，但是，对热带土壤排放的驱动因素仍然知之甚少。这项研究调查了叶子凋落物和尿素肥料对两个澳大利亚热带芒果园中N ₂ O排放的影响。处理包括尿素（25 g N m ^-2），枯枝落叶（1500 g m ^-2干物质），它们的组合施用和未处理的对照。在施用两周内最多损失了80.5±8.4 mg N ₂ O-N m ^-2 ，占年度N ₂ O排放量的60％以上。间接排放> 30 mg m ^-2 d在一个站点上记录到^-1，可能是由于地下水输送的N造成的。凋落物+尿素的最高年度N ₂ O排放量为130.4 mg N ₂ O-N m ^-2  y ^-1，比仅尿素的排放量高出¹倍。 2个，只有小动物的4倍。这导致残留和肥料排放因子（EF）<0.01–0.37％，远低于IPCC和Tier 2的默认值，整个果园损失相当于0.19–0.66 kg N ₂ O-N ha ^-1。结果表明N ₂当不施用氮肥（即使施用大量的凋落物N）时，O也会受到氮的限制，并且在不存在凋落物的情况下受碳（C）的限制。垃圾+尿素对N ₂ O排放的综合影响超过了单独使用垃圾和尿素的影响，证明了两种基质之间的关键相互作用。在制定旨在增加热带土壤中土壤碳含量的管理策略时，需要考虑这种相互作用的影响。