The application of biological nitrification inhibitors (BNIs) is considered an important new strategy to mitigate nitrogen losses from agricultural soils. 1,9-decanediol was recently identified as a new BNI in rice root exudates and was shown to inhibit nitrification in bioassays using Nitrosomonas. However, the effect of this compound on nitrification and ammonia oxidizers in soils remained unknown. In this study, three typical agriculture soils were collected to investigate the impact of 1,9-decanediol on nitrification and ammonia oxidizers in a 14-day microcosm incubation. High doses of 1,9-decanediol showed strong soil nitrification inhibition in all three agricultural soils, with the highest inhibition of 58.1% achieved in the acidic red soil, 37.0% in the alkaline fluvo-aquic soil, and 35.7% in the neutral paddy soil following 14 days of incubation. Moreover, the inhibition of 1,9-decanediol was superior to the widely used synthetic nitrification inhibitor, dicyandiamide (DCD) and two other BNIs, methyl 3-(4-hydroxyphenyl) propionate (MHPP) and α-linolenic acid (LN), in all three soils. The abundance of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) was significantly inhibited by 1,9-decanediol addition across the three soils. All AOB sequences fell within the Nitrosospira group, and the dominant AOA sequences belonged to the Nitrososphaera cluster in all three soils. Changes in the community composition of AOB were more pronounced than AOA after the application of 1,9-decanediol. The AOB community structure shifted from Nitrosospira cluster 2 and cluster 3a toward Nitrosospira clusters 8a and 8b. As for AOA, no significant impact on the proportion of the dominant Nitrososphaera cluster was observed in the fluvo-aquic soil and paddy soil while only the Nitrosopumilus cluster decreased in the red soil. 1,9-decanediol could also significantly reduce soil N₂O emissions, especially in acidic red soil. Our results provide evidence that 1,9-decanediol is capable of suppressing nitrification in agricultural soils through impeding both AOA and AOB rather than affecting soil NH₄⁺ availability. 1,9-decanediol holds promise as an effective biological nitrification inhibitor for soil ammonia-oxidizing bacteria and archaea.

生物硝化抑制剂（BNIs）的应用被认为是减轻农业土壤氮素流失的重要新策略。1,9-癸二醇最近在水稻根系分泌物中被鉴定为一种新的BNI，并在使用亚硝化单胞菌的生物测定中显示出抑制硝化作用的作用。。然而，该化合物对土壤中硝化作用和氨氧化剂的作用仍然未知。在这项研究中，收集了三种典型的农业土壤，以研究14天微观温育中1,9-癸二醇对硝化和氨氧化的影响。高剂量的1,9-癸二醇在所有三种农业土壤中均表现出较强的土壤硝化抑制作用，在酸性红壤中达到最高的抑制率为58.1％，在碱性潮土中达到37.0％，在中性稻谷中达到35.7％孵育14天后进入土壤。此外，对1,9-癸二醇的抑制作用优于广泛使用的合成硝化抑制剂双氰胺（DCD）和其他两种BNI，即3-（4-羟基苯基）丙酸甲酯（MHPP）和α-亚麻酸（LN），在所有三种土壤中。在三种土壤中添加1,9-癸二醇可显着抑制氨氧化细菌（AOB）和氨氧化古细菌（AOA）的丰度。所有AOB序列均在亚硝化螺菌群和主要的AOA序列在所有三种土壤中均属于亚硝化球菌簇。应用1,9-癸二醇后，AOB群落组成的变化比AOA更为明显。AOB群落结构从亚硝基螺菌簇2和3a移向亚硝基螺菌簇8a和8b。至于AOA，在潮土和水稻土中，对优势亚硝化球团簇的比例没有显着影响，而在红壤中仅亚硝化肌团下降。1,9-癸二醇还可显着减少土壤N ₂O排放，特别是在酸性红壤中。我们的结果提供了证据，表明1,9-癸二醇能够通过阻止AOA和AOB而不是影响土壤NH ₄ ^+的利用率来抑制农业土壤中的硝化作用。1,9-癸二醇有望成为土壤氨氧化细菌和古细菌的有效生物硝化抑制剂。