Pedosphere 35(3): 449--461, 2025
ISSN 1002-0160/CN 32-1315/P
©2025 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Mechanistic insights into N2O emission mitigation by nitrification inhibitor dicyandiamide (DCD) in a tropical sandy soil after six years of manure amendment |
Changhua FAN1,2,3 , Danfeng WANG1,4, Pengpeng DUAN5, Wenlong GAO1,2,3, Yuqin LIU1,2,3, Xiaolong WU1,2,3, Huiran LIU1,2,3, Ziyu NING1,2,3, Qinfen LI1,2,3, Miao CHEN1,2,3 |
1 Key Laboratory of Low-Carbon and Green Agriculture in Tropical China, Ministry of Agriculture and Rural Affairs, Institute of Environment and Plant Protection, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101 (China);
2 Hainan Danzhou Tropical Agro-Ecosystem National Observation and Research Station, Danzhou 571737 (China);
3 Hainan Key Laboratory of Tropical Eco-Circular Agriculture, Haikou 571101 (China);
4 College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China);
5 Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China) |
| Corresponding Author:Changhua FAN |
| ABSTRACT |
| Organic amendments (OM) can profoundly affect soil nitrous oxide (N2O) emissions via changing nitrogen (N) cycles. However, mechanistic insights into how nitrification inhibitors modulate the responses of soil N2O emissions to successive applications of OM are currently insufficient. In this study, we performed a laboratory experiment to examine N2O emissions from a tropical vegetable soil subjected to six years of chemical fertilization (CF) and chemical fertilization combined with manure application (CFM) and evaluate the mitigation effectiveness of nitrification inhibitor dicyandiamide (DCD) under each management regime. Isotopocule mapping showed that bacterial nitrification and/or fungal denitrification accounted for 77.4%-88.5% of total N2O production across treatments during the emission peak. The cumulative N2O emissions from the CFM-treated soil were nearly 8-fold of those from the CF-treated soil. The CFM treatment stimulated N2O production from bacterial nitrification and denitrification by increasing the abundance of genes linked to nitrifiers (ammonia-oxidizing bacterial (AOB) amoA and total comammox amoA) and denitrifiers (nirK, nirS, and qnorB), respectively. Importantly, DCD decreased cumulative N2O emissions by an average of 73.3%, with better mitigation performance observed in the CFM-treated soil than in the CF-treated soil due to stronger inhibited nitrification and increased abundance of the nosZ gene, and altered bacterial community composition. The 16S rRNA sequencing further revealed that adding DCD to the CFM-treated soil resulted in declines in the abundances of bacterial phylum Actinobacteria and Chloroflexi that positively affected N2O emissions; the opposite pattern prevailed for Gemmatimonadetes that negatively affected N2O emissions. This study highlights the potential of manure application, when coupled with nitrification inhibitors, to achieve the dual goals of enhancing soil fertility and reducing environmental risk associated with N2O emissions in tropical agricultural soils. |
| Key Words: greenhouse gas|high-throughput sequencing|isotopocule mapping|tropical vegetable soil|organic amendment |
| Citation: Fan C H, Wang D F, Duan P P, Gao W L, Liu Y Q, Wu X L, Liu H R, Ning Z Y, Li Q F, Chen M. 2025. Mechanistic insights into N2O emission mitigation by nitrification inhibitor dicyandiamide (DCD) in a tropical sandy soil after six years of manure amendment. Pedosphere. 35(3): 449-461. |
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