The effect of different composts and their chemical composition on soil C and N mineralisation and greenhouse gas (GHG) emissions was explored by determining NH₄⁺ and NO₃⁻ dynamics and monitoring CO₂, N₂O and CH₄ fluxes from amended soils under laboratory conditions. Eight different composted agro-industrial wastes were incubated with a clay soil for 55 days at 20 °C and 60% water-holding capacity (WHC). Mineralisation of the C added to the soils was directly correlated to C/N, total phenolic/N, gallic acid/N and NH₄⁺ and negatively correlated with total organic N (TON) and lignin content of the composts. Soils amended with straw compost presented the highest C mineralised with significantly higher CO₂ emissions throughout the incubation period. N mineralisation was only negatively correlated with C/N ratio and straw compost exhibited a significant and strong immobilisation when compared with the rest of treatments. The study demonstrates that the C/N ratio by itself is not suitable for predicting N mineralisation. The results revealed that composts with high initial soluble N contents and narrow C/N ratio, as in the case of coffee grounds, produce higher N₂O emissions. With the exception of mimosa (Acacia dealbata) and coffee grounds that behave as sources of methane, soils amended with composts displayed an overall sink effect for methane. These findings reveal that the effect of compost incorporation on GHG emissions depends essentially on their chemical composition.

通过确定 NH ₄ ⁺和 NO ₃ ^-动态并监测来自改良土壤的CO ₂、N ₂ O 和 CH ₄通量，探讨了不同堆肥及其化学成分对土壤 C 和 N 矿化以及温室气体 (GHG) 排放的影响。实验室条件。在 20 °C 和 60% 的持水量 (WHC) 下，将八种不同的堆肥农业工业废物与粘土一起培养 55 天。添加到土壤中的 C 的矿化与 C/N、总酚/N、没食子酸/N 和 NH ₄ ⁺直接相关且与堆肥的总有机氮 (TON) 和木质素含量呈负相关。用秸秆堆肥改良的土壤在整个孵化期内矿化程度最高，CO ₂排放量明显增加。N 矿化仅与 C/N 比呈负相关，与其他处理相比，秸秆堆肥表现出显着且强烈的固定化。该研究表明 C/N 比本身并不适合预测 N 矿化。结果表明，具有高初始可溶性 N 含量和窄 C/N 比的堆肥，如咖啡渣，会产生更高的 N ₂ O 排放。除了含羞草（Acacia dealbata) 和作为甲烷来源的咖啡渣，用堆肥改良的土壤显示出甲烷的整体汇效应。这些发现表明，堆肥掺入对温室气体排放的影响主要取决于它们的化学成分。