Nitrous oxide emissions and N-cycling gene abundances in a drip-fertigated (surface versus subsurface) maize crop with different N sources

• DOI: 10.1007/s00374-023-01791-9
• Publication Date: 2023-12-29T14:02:06Z
• Authors: Guillermo Guardia; Sandra García-Gut...; Antonio Vallejo; Miguel A. Ibáñez; Laura Sanchez-Martin; Mónica Montoya
• Keywords: Fertigation; Nitrous oxide; Ammonium sulfate

Abstract Surface drip fertigation has demonstrated promising results regarding the mitigation of nitrous oxide (N 2 O) emissions. The use subsurface irrigation may offer possibility reducing these emissions further due to modification soil moisture profile and N allocation, both which affect biochemical processes leading O fluxes. However, potential combined with different mineral nitrogen (N) fertilizers (ammonium or nitrate-based, nitrification inhibitors) still needs be evaluated. To respond this need, a 2-year field experiment was set up in central Spain test two drip-fertigation systems (surface at 30 cm depth) four fertilization treatments (control, calcium nitrate, ammonium sulfate without inhibitor 3,4-dimethylpyrazole phosphate, DMPP) an irrigated maize ( Zea mays L.) crop. Nitrous emissions, concentrations (ammonium, NH 4 + , NO 3 − ), abundance key genes involved denitrification were measured layers (0–20 20–40 cm). Regardless system, gave highest cumulative losses campaigns, while nitrate DMPP most effective strategies abate fluxes first second years, respectively. Differences between not statistically significant for despite clear effect on topsoil (higher surface drip, respectively). positively correlated concentrations. Gene abundances trustworthy predictor 1st year, although inhibitory microbial communities (i.e., ammonia oxidizers, nitrite reducers, reducers) observed during campaign. During nitrifying denitrifying affected by (with higher layer than drip) addition (which had detrimental gene that disappeared after period). In conclusion, instead enhance chances additional systems.