Soil N₂O emission potential is commonly investigated under idealized denitrifying conditions (e.g. nitrate-N supplied and anaerobic soil), with pH commonly identified as a major determinant of N₂O emission potential. However, under urine patch conditions in grazed pastures soils a more complex series of abiotic and biotic factors may influence emissions due to the complex N transformations that occur following urea hydrolysis. These transformations may decouple native and/or expected controls of N₂O emissions encountered under classic denitrifying conditions. Here, we tracked O₂, CO₂, NO, N₂O and N₂ emissions from urine amended soils (i.e. simulating a urine patch) to determine putative controls of N₂O emissions within 13 different pasture soils from northern (Ireland) and southern hemispheres (New Zealand). Incubations were performed under aerobic conditions±artificial urine (13.3 mg N vial⁻¹) equivalent to field ruminant urine deposition rates of 1000 kg N ha⁻¹. Results revealed that pH was not an important regulator of the emission ratio (N₂O/(NO + N₂O + N₂)) in urine amended soils. Within urine affected soils, a new set of variables emerged as regulators of N₂O emissions, likely due to the unique environment created within this system. We show that urine results in decoupling of the initial soil pH control of the emission ratio allowing other regulators such as nitrite to dominate. In addition, we observed that the emission ratio of N₂O increased linearly with the rate of N- gas loss (NO + N₂O + N₂ μmol N h⁻¹), O₂ consumption was positively associated with ammonia oxidising bacteria (AOB) and that the production of NO and N₂O were also enhanced under urine conditions.

土壤 N ₂ O 排放潜力通常在理想化的反硝化条件下进行研究（例如硝酸盐氮供应和厌氧土壤），通常将 pH 确定为 N ₂ O 排放潜力的主要决定因素。然而，在放牧牧场土壤中的尿斑条件下，由于尿素水解后发生的复杂氮转化，一系列更复杂的非生物和生物因素可能会影响排放。这些转变可能会使在经典反硝化条件下遇到的 N ₂ O 排放的天然和/或预期控制脱钩。在这里，我们跟踪了 O ₂、CO ₂、NO、N ₂ O 和 N ₂尿修正土壤（即模拟尿斑）的排放，以确定北（爱尔兰）和南半球（新西兰）的 13 种不同牧场土壤中 N ₂ O 排放的假定控制。在需氧条件±人工尿液（13.3 mg N 小瓶^-1）下进行孵化，相当于野外反刍动物尿液沉积率为 1000 kg N ha ^-1。结果表明，pH 值不是尿液改良土壤中排放比 (N ₂ O/(NO + N ₂ O + N ₂ ))的重要调节器。在受尿液影响的土壤中，出现了一组新的变量作为 N _{2 的}调节剂O 排放，可能是由于该系统内创造的独特环境。我们表明，尿液导致排放比的初始土壤 pH 控制脱钩，从而允许其他调节剂（如亚硝酸盐）占主导地位。此外，我们观察到 N ₂ O的排放率随 N- 气体损失率（NO + N ₂ O + N ₂ μmol N h ^-1）呈线性增加，O ₂消耗与氨氧化细菌呈正相关（ AOB）并且在尿液条件下NO和N ₂ O的产生也增加。