The effect of temperature and moisture on the source of N2O and contributions from ammonia oxidizers in an agricultural soil

• Published in: Biology and fertility of soils Vol. 53; no. 1; pp. 141 - 152
• Main Authors: Liu, Rui, Hayden, Helen L., Suter, Helen, Hu, Hangwei, Lam, Shu Kee, He, Jizheng, Mele, Pauline M., Chen, Deli
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2017; Springer Nature B.V
• Subjects: Agricultural economics; Agriculture; Ammonia; Biomedical and Life Sciences; Life Sciences; Moisture; Nitric oxide; Original Paper; Soil Science & Conservation; Soils; Temperature effects; Ammonia-oxidizing archaea; Model; N isotope technique; Ammonia-oxidizing bacteria; Nitrification
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/s00374-016-1167-8

In recent years, identification of the microbial sources responsible for soil N 2 O production has substantially advanced with the development of isotope enrichment techniques, selective inhibitors, mathematical models and the discoveries of specific N-cycling functional genes. However, little information is available to effectively quantify the N 2 O produced from different microbial pathways (e.g. nitrification and denitrification). Here, a 15 N-tracing incubation experiment was conducted under controlled laboratory conditions (50, 70 and 85% water-filled pore space (WFPS) at 25 and 35 °C). Nitrification was the main contributor to N 2 O production. At 50, 70 and 85% WFPS, nitrification contributed 87, 80 and 53% of total N 2 O production, respectively, at 25 °C, and 86, 74 and 33% at 35 °C. The proportion of nitrified N as N 2 O ( P N2O ) increased with temperature and moisture, except for 85% WFPS, when P N2O was lower at 35 °C than at 25 °C. Ammonia-oxidizing archaea (AOA) were the dominant ammonia oxidizers, but both AOA and ammonia-oxidizing bacteria (AOB) were related to N 2 O emitted from nitrification. AOA and AOB abundance was significantly influenced by soil moisture, more so than temperature, and decreased with increasing moisture content. These findings can be used to develop better models for simulating N 2 O from nitrification to inform soil management practises for improving N use efficiency.