Nitrous oxide emissions from maize following grass-clover: Treatment of plant cover and manure with 3,4-dipyrazol phosphate (DMPP) as mitigation strategy
Year: 2025
Type: article
Abstract: Animal agriculture is a major contributor to greenhouse gas emissions, with nitrous oxide (N 2 O) playing a critical role. In dairy farming, grass-clover (GC) is widely used in crop rotations and often preceding maize, but the period between GC incorporation and maize N uptake has a high risk for environmental losses, including N 2 O emissions. This study investigated if a nitrification inhibitor, DMPP, can reduce spring N 2 O emissions from maize after GC on sandy soil with or without cattle slurry (CS) as supplementary N. The inhibitor was applied to GC before incorporation, together with CS, or both. Emissions of N 2 O and concentrations of N 2 O at 5, 10, 20 and 30 cm depth were monitored during spring in two years. The highest cumulative emissions were observed in the unamended GC+CS treatment (5.1 and 4.2 kg N ha⁻¹ in 2022 and 2023, respectively). N 2 O emissions often occurred at < 60 % WFPS, showing that GC residues and liquid manure created anaerobic conditions sustaining emissions. DMPP application to GC did not significantly reduce N 2 O emissions, possibly due to NO₃⁻ derived from roots. Also, N 2 O accumulation at 20–30 cm was enhanced by CS despite injection to 8 cm depth, suggesting downward transport of NO₃⁻. When applied with cattle slurry, DMPP effectively reduced emissions by an average 71 %, with some treatments even exhibiting net negative emissions. These findings highlight the complexity of soil N dynamics after termination of GC pastures and the importance of management strategies to mitigate this source of N 2 O emissions in dairy farming systems .
Institution: Aarhus University
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,190
Award: G183977176
OpenAlex ID: W4410694924