Alternate wetting and drying (AWD) is an important strategy that saves water and reduces greenhouse gases emission (GHG). Moreover, biochar (BC) has been also emerged as a promising approach to reduce GHG emissions. Hitherto, the mechanism lying behind reduction in nitrous oxide (N₂O) emissions following the addition of BC are not clearly understood. Therefore, this field study was performed to assess the effects of different rates of rice straw biochar (RSB), i.e., control (0 RSB), 20 t RSB ha^-1, and 40 t RSB ha^-1 with no nitrogen (N) fertilizer (-N) and with N fertilizer (180 kg ha^-1: +N) on soil pH, soil N dynamics, microbial genes abundance, N₂O emissions and performance of paddy. The experiment was conducted in two factors factorial design with three replications. Application of RSB enhanced the soil pH and NH₄⁺ and decreased NO₃^- therefore led to a significant reduction in the N₂O emissions. However, the application of RSB (40 t ha^-1) significantly decreased the N₂O emissions by +59% and +62% in comparison to control under -N and +N conditions. The increased soil pH augmented the abundance of nosZ and nirK genes, more following addition of 40 t RSB ha^-1 and therefore, leads to an appreciable reduction in the N₂O compared to 20 t RSB and control under both -N and +N conditions. Additionally, 40 t RSB ha^-1 significantly enhanced the tillers production, kernel weight, paddy, and dry matter yield compared to control and 20 t RSB ha^-1 under -N and +N conditions. Conclusively, RSB application at the rate of 40 t ha^-1 could be a promising approach to reduce N₂O emissions and increase the paddy yield.

交替润湿和干燥（AWD）是一种重要的策略，可以节水并减少温室气体排放（GHG）。此外，生物炭（BC）也已成为减少温室气体排放的一种有前途的方法。迄今为止，尚不清楚加入BC后减少一氧化二氮（N ₂ O）排放的机理。因此，进行了该田间研究，以评估不同比例的稻草生物炭（RSB）的影响，即对照（0 RSB），20 t RSB ha ^-1和40 t RSB ha ^-1无氮（N）肥料（-N）和氮肥（180 kg ha ^-1：+ N）对土壤pH，土壤氮动力学，微生物基因丰度，N _2的影响O排放量和稻田性能。实验是在两个因素的因子设计中进行的，重复三个。土壤pH值NH的应用RSB增强和₄ ⁺和NO降低₃ ^-因此导致在N一个显著减少₂ O排放。但是，与-N和+ N条件下的对照相比，使用RSB（40 t ha ^-1）可以显着减少N ₂ O排放+ 59％和+ 62％。添加40 t RSB ha ^-1后，土壤pH值的增加增加了nosZ和nirK基因的丰度，因此导致N ₂的显着降低。O与20 t RSB相比，在-N和+ N条件下均为对照。此外，与对照和-N和+ N条件下的20 t RSB ha ^-1相比，40 t RSB ha ^-1显着提高了分ers产量，籽粒重量，稻谷和干物质产量。总之，以40 t ha ^-1的比例施用RSB可能是减少N ₂ O排放并提高稻谷产量的有前途的方法。