Author(s): CARVALHO, M. T. de M.; MADARI, B. E.; LEAL, W. G. de O.; COSTA, A. R. da; MACHADO, P. L. O. de A.; SILVEIRA, P. M. da; MOREIRA, J. A. A.; HEINEMANN, A. B.

Summary: The objective of this work was to measure the fluxes of N2O-N and NH3-N throughout the growing season of irrigated common-bean (Phaseolus vulgaris), as affected by mulching and mineral fertilization. Fluxes of N2O-N and NH3-N were evaluated in areas with or without Congo signal grass mulching (Urochloa ruziziensis) or mineral fertilization. Fluxes of N were also measured in a native Cerrado area, which served as reference. Total N2O-N and NH3-N emissions were positively related to the increasing concentrations of moisture, ammonium, and nitrate in the crop system, within 0.5 m soil depth. Carbon content in the substrate and microbial biomass within 0.1 m soil depth were favoured by Congo signal grass and related to higher emissions of N2O-N, regardless of N fertilization. Emission factors (N losses from the applied mineral nitrogen) for N2O-N (0.01-0.02%) and NH3-N (0.3-0.6%) were lower than the default value recognized by the Intergovernmental Panel on Climate Change. Mulch of Congo signal grass benefits N2O-N emission regardless of N fertilization.

Publication year: 2013

Types of publication: Journal article

Unit: Embrapa Rice & Beans

Keywords: Brachiaria, Cerrado, Cobertura morta, Efeito estufa, Feijão, Fertilidade do solo, Gás de efeito estufa, Mudança Climática, N fertilization, Nitrogênio, No?tillage, Phaseolus vulgaris, Plantio Direto, Óxido, Óxido nitroso