Reduced tillage is often promoted as a method to sequester carbon (C) in soils and thus mitigate climate change. However, in certain conditions reduced tillage may increase soil nitrous oxide (N₂O) fluxes, which may negate any climate gains from the potential storage of C in soil. To investigate how long-term applications of different manures interact with tillage effects on N₂O fluxes during the crop rotation, we established a long-term trial in 2009 in eastern Canada, using two tillage (inversion tillage [IT]; and reduced tillage [RT],) and three fertilizer types (pig slurry, dairy slurry and a 0-N control) arranged in a split-plot design with 3 replications. The experiment was reproduced on two contrasting soil textures (silty clay and sandy loam) located approximately 900 m apart in a wheat-corn-soybean rotation. During 2016 (wheat), 2017 (corn), and 2018 (soybean) we estimated the N₂O fluxes from each plot using manual static chambers for the growing season (April to November). Mean cumulative fluxes for the growing season ranged from 0.8 kg N₂O-N ha⁻¹ for the corn/control/IT to 7.6 kg N₂O-N ha⁻¹ for the wheat/dairy slurry/RT in the silty clay soils and from 0.4 kg N₂O-N ha⁻¹ for the corn/control/IT to 3.0 kg N₂O-N ha⁻¹ in the corn/pig slurry/RT in the sandy loam soils. The RT increased soil N₂O fluxes for both slurry types and the control in the clay soil (mean flux for all fertilizer treatments over both seasons were 5.5 and 2.4 kg N₂O-N ha⁻¹ season⁻¹ for the RT and IT, respectively), likely because the higher water content in the RT caused greater denitrification; while on the sandy loam the N₂O flux was similar between the two tillage systems. Manure type had no measurable effect on the growing season N₂O fluxes in either soil type as both provided sufficient labile N. Application of both slurries however, resulted in greater emissions than the control (P = 0.002). These findings suggest that RT on fine-textured soils in this region may not be an effective strategy to reduce GHG emissions.

减少耕种通常被认为是隔离土壤中碳（C）并缓解气候变化的一种方法。但是，在某些情况下，减少耕作可能会增加土壤中的一氧化二氮（N ₂ O）通量，这可能会抵消土壤中C的潜在储存所带来的任何气候收益。研究不同肥料的长期施用与耕作对N _2的相互作用如何作物轮作过程中的O通量，我们于2009年在加拿大东部建立了一项长期试验，使用两种耕作（反向耕作[IT]；减少耕作[RT]）和三种肥料类型（猪粪，奶牛粪和一种0-N控件）以分割图设计的形式进行，并进行3次复制。该实验是在小麦-玉米-大豆轮作中相距约900 m的两种对比土壤质地（粉质粘土和砂壤土）上进行的。在2016年（小麦），2017年（玉米）和2018年（大豆），我们使用人工静态室估算了每个生长季（4月至11月）的N ₂ O通量。生长季的平均累积通量从玉米/对照/ IT的0.8 kg N ₂ O-N ha ^-1到7.6 kg N ₂ O-N ha^-1用于小麦/酪浆/ RT在粉质粘土污垢和0.4千克氮₂ O-N公顷^-1的玉米/控制/ IT至3.0千克氮₂ O-N公顷^-1在玉米/猪浆液/ RT中砂壤土。两种土壤类型和对照土壤的RT增加土壤N ₂ O通量（RT和IT两种季节所有肥料处理的平均通量分别为5.5和2.4 kg N ₂ O-N ha ^-1季节^-1），这可能是因为RT中较高的水含量导致了更大的反硝化作用；而在沙壤土上，N ₂两种耕作系统之间的通量相似。在两种土壤类型中，肥料类型对生长季的N ₂ O通量都没有可测量的影响，因为两者都提供了足够的不稳定N。但是，两种浆料的施用均导致排放量大于对照（P = 0.002）。这些发现表明，在该地区质地较细的土壤上进行放疗可能不是减少温室气体排放的有效策略。