Nitrite (NO₂⁻) accumulation and associated production of nitric oxide (NO) and nitrous oxide (N₂O) gases in soils amended with nitrogen (N) fertilizers are well documented, but there remains a poor understanding of their regulation and variation among soil types. We examined responses to urea inputs in two soils at five temperatures from 5 to 30 °C and developed a process-driven model to describe the dynamics. A microcosm system was used to measure ammonia gas (NH₃), ammonium (NH₄⁺), NO₂⁻, nitrate (NO₃⁻), NO, N₂O and pH over 12 weeks. Unexpectedly, NO₂⁻, NO and N₂O production tended to increase as soil temperature declined in both soils. The maximum NO₂⁻ concentration, or compensation point (CP), differed by soil type but the time required to reach CP decreased exponentially with increasing temperature in both soils. A two-step nitrification model (’2SN’) accounted for interactions of ammonia-oxidation (AmO), nitrite oxidation (NiO), urea hydrolysis, NH₄⁺ sorption, N gas production and pH dynamics. Both steps of nitrification (AmO and NiO) were modeled using NH₃ inhibition kinetics. The model adequately simulated the observed dynamics and temperature responses and showed that increased uncoupling of AmO and NiO at colder temperatures resulted from their differential temperature responses. The dynamics observed here may be important following high-rate and banded N fertilizer applications and in ruminant urine patches. The results may help explain elevated N₂O emissions observed under cold temperatures. The 2SN model can account for interactions among multiple processes and may be useful for studying the effects of management practices and climate factors, including climate change scenarios, on soil N cycling.

亚硝酸盐（NO ₂ ^- ）的积累和一氧化氮（NO）和一氧化二氮（N相关联的生产₂ O）在用氮气修正土壤气体（N）肥料是有据可查的，但仍然存在它们的调节和变化之间的差的理解土壤类型。我们在5至30°C的五个温度下研究了两种土壤中尿素输入的响应，并开发了过程驱动模型来描述动力学。甲缩影系统被用于测量氨气（NH ₃），铵（NH ₄ ⁺），NO ₂ ^- ，硝酸盐（NO ₃ ^- ），NO，N ₂ O和pH值超过12周。出乎意料的是，NO ₂ ^-，NO和N随着两种土壤温度的下降，₂ O产量趋于增加。最大NO ₂ ^-浓度，或补偿点（CP），通过土壤类型不同，但所需要的时间来达到CP与两种土壤温度增加呈指数降低。两步硝化模型（' 2SN '）考虑了氨氧化（AmO），亚硝酸盐氧化（NiO），尿素水解，NH ₄ ⁺吸附，氮气产生和pH动力学的相互作用。使用NH ₃对两个硝化步骤（AmO和NiO）进行建模抑制动力学。该模型充分模拟了观察到的动力学和温度响应，并表明在较低温度下，AmO和NiO的解偶联增加是由于它们的不同温度响应引起的。在高速率和带状氮肥施用以及反刍尿斑中，此处观察到的动力学可能很重要。结果可能有助于解释在低温下观察到的N ₂ O排放升高。该2SN模型可以解释在多个进程之间的相互作用，可能是研究的管理实践和气候因素的影响，包括气候变化情景的影响是有用的，对土壤氮素循环。