This 2-year study aimed to verify whether the continuous application of no tillage (NT) for over 20 years, in comparison with conventional tillage (CT), affects nitrous oxide (N₂O) and ammonia (NH₃) emissions from a Vertisol and, if so, whether such an effect varies with crop sequence (continuous wheat, WW and wheat after faba bean, FW). To shed light on the mechanisms involved in determining N-gas emissions, soil bulk density, water filled pore space (WFPS), some carbon (C) and nitrogen (N) pools, denitrifying enzyme activity (DEA), and nitrous oxide reductase gene abundance (nosZ gene) were also assessed at 0–15 and 15–30 cm soil depth. Tillage system had no significant effect on total NH₃ emissions. On average, total N₂O emissions were higher under NT (2.45 kg N₂O-N ha^− 1) than CT (1.72 kg N₂O-N ha^− 1), being the differences between the two tillage systems greater in FW than WW. The higher N₂O emissions in NT treatments were ascribed to the increased bulk density, WFPS, and extractable organic C under NT compared to CT, all factors that generally promote the production of N₂O. Moreover, compared to CT, NT enhanced the potential DEA (114 vs 16 μg N kg^− 1 h^− 1) and nosZ gene abundance (116 vs 69 copy number mg^− 1 dry soil) in the topsoil. Finally, NT compared to CT led to an average annual increase in C stock of 0.70 Mg C ha^− 1 year^− 1. Though NT can increase the amount os soil organic matter so storing CO₂ into soil, some criticisms related to the increase of N₂O emission arise, thereby suggesting the need for defining management strategies to mitigate such a negative effect.

这项为期2年的研究旨在验证与传统耕作（CT）相比，连续20年以上的免耕（NT）连续使用是否会影响Vertisol排放的一氧化二氮（N ₂ O）和氨（NH ₃）如果是这样，那么这种影响是否随作物序列（连续小麦，WW和蚕豆之后的小麦，FW）而变化。阐明确定N气体排放，土壤容重，充水孔隙空间（WFPS），一些碳（C）和氮（N）库，反硝化酶活性（DEA）和一氧化二氮还原酶基因的机制还评估了土壤深度为0–15和15–30 cm时的丰度（nosZ基因）。耕作制度对总的NH ₃排放没有显着影响。平均总计N ₂在NT下（2.45 kg N ₂ O-N ha ^-1），O排放高于CT（1.72 kg N ₂ O-N ha ^-1），这是两个耕作系统之间的差异在FW中大于WW。与CT相比，NT处理下N ₂ O排放的增加归因于NT下堆积密度，WFPS和可萃取有机碳的增加，所有这些因素通常促进N ₂ O的产生。此外，与CT相比，NT增强了N ₂ O的产生。潜在的DEA（114 vs 16μgN kg ^{− 1}  h ^{− 1}）和nosZ基因丰度（116 vs 69拷贝数mg ^{− 1}干燥的土壤）。最后，NT相比，CT导致0.70mg的Ç公顷的碳储量年均增长^{- 1} 一年^{- 1}。尽管NT可以增加土壤有机质的含量，从而将CO ₂储存在土壤中，但仍存在一些与N ₂ O排放增加有关的批评，因此建议需要制定管理策略以减轻这种负面影响。