2025-03-072025-03-072016-09CARVALHO, Márcia Thaís de Melo et al. Nitrogen availability, water-filled pore space, and N2O-N fluxes after biochar application and nitrogen fertilization. Pesquisa Agropecuária Brasileira, Brasília, v. 51, n. 9, p. 1203-1212, 2016. DOI: 10.1590/S0100-204X2016000900020. Disponível em: https://www.scielo.br/j/pab/a/DTgdJkWgnTfyqHRJKgSjv8x/?lang=en. Acesso em: 24 jan. 2025.0100-204Xe- 1678-3921http://repositorio.bc.ufg.br//handle/ri/26890The objective of this work was to investigate the impact of the application of wood biochar, combined with N fertilizations, on N2O-N fluxes, nitrogen availability, and water-filled pore space (WFPS) of a clayey Oxisol under rice (wet season) and common bean (dry season) succession. Manual static chambers were used to quantify N2O-N fluxes from soil immediately after a single application of wood biochar (32 Mg ha-1) and after four crop seasons with N applications (90 kg ha-1 N). Soil ammonium (N-NH4 +) and nitrate (N-NO3 -) availability, as well as WFPS, was measured together with N2O-N fluxes. There was no interaction between biochar and N fertilization regarding N2O-N fluxes in any of the four seasons monitored, although these fluxes were clearly enhanced by N applications. At 1.5 and 2.5 years after biochar application, the WFPS decreased. In addition, in the seasons characterized by low WFPS, N2O-N fluxes and soil N-NO3 - and N-NH4 + availability were enhanced after N applications. Long-term experiments in the field are important to quantify the impacts of biochar on N2O-N fluxes and to determine the dynamics of these fluxes on soil-related variables.engAcesso Abertohttp://creativecommons.org/licenses/by-nc-nd/4.0/Cropping systemsGas fluxesGreenhouse gasesNitrate and ammoniumSoil amendmentSoil porositySistemas de cultivoFluxo de gasesGases de efeito estufaNitrato e amônioCondicionador de soloPorosidade do soloArtigo10.1590/S0100-204X2016000900020