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Research article2024Peer reviewedOpen access

High soil moisture rather than drying-rewetting cycles reduces the effectiveness of nitrification inhibitors in mitigating N2O emissions

Ribeiro, Pablo Lacerda; Singh, Abhijeet; Sagervanshi, Amit; Naeem, Asif; Muehling, Karl Hermann

Abstract

Climate change has been intensifying soil drying and rewetting cycles, which can alter the soil microbiome structure and activity. Here we hypothesized that a soil drying-rewetting cycle enhances biodegradation and, hence, decreases the effectiveness of nitrification inhibitors (NIs). The effectiveness of DMPP (3,4-Dimethylpyrazole phosphate) and MP + TZ (3-Methylpyrazol and Triazol) was evaluated in 60-day incubation studies under a drying and rewetting cycle relative to constant low and high soil moisture conditions (40% and 80% water-holding capacity, WHC, respectively) in two different textured soils. The measurements included (i) daily and cumulative N2O-N emissions, (ii) soil NH4+-N and NO3--N concentrations, and (iii) the composition of bacterial soil communities. Application of DMPP and MP + TZ reduced the overall N2O-N emissions under drying-rewetting (-45%), as well as under 40% WHC (-39%) and 80% WHC (-25%). DMPP retarded nitrification and decreased N2O-N release from the sandy and silt loam soils, while MP + TZ mitigated N2O-N production only from the silt loam soil. Unexpectedly, between days 30 and 60, N2O-N emissions from NI-treated soils increased by up to fivefold relative to the No-NI treatment in the silt loam soil at 80% WHC. Likewise, the relative abundance of the studied nitrifying bacteria indicated that the NIs had only short-term effectiveness in the silt loam soil. These results suggested that DMPP and MP + TZ might trigger high N2O-N release from fine-textured soil with constant high moisture after this short-term inhibitory effect. In conclusion, DMPP and MP + TZ effectively reduce N2O-N emissions under soil drying and rewetting.

Keywords

DMPP; Ammonia-oxidizing bacteria; Denitrification; Climate change; Drought; Nitrous oxide

Published in

Biology and Fertility of Soils
2024,
Publisher: SPRINGER

    UKÄ Subject classification

    Soil Science

    Publication identifier

    DOI: https://doi.org/10.1007/s00374-024-01811-2

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/128977