Heitor Cantarella1, Késia Silva Lourenço1, Johnny R. Soares1, Janaína B. Carmo2, Andre C. Vitti3, Raffaella Rossetto3, Zaqueu F. Montezano1, Eiko E. Kuramae4
1 Agronomic Institute of Campinas, Av. Barao de Itapura 1487, Campinas, SP, 13020-902 Brazil, Email: [email protected]
2 Federal University of São Carlos, Rod. João Leme dos Santos, Sorocaba, SP, 18052-780, Brazil
3 APTA Regional, Piracicaba Research Pole, Piracicaba, SP, 13400-970, Brazil
4 Department of Microbial Ecology, Netherlands Institute of Ecology, Wageningen, 6708 PB, The Netherlands
Nitrous oxide (N2O) emissions from nitrogen fertilizers may strongly affect the sustainability indicators of ethanol produced from sugarcane and there are evidences that the application of vinasse could enhance the emission of GHGs from N fertilizers. The strategy of separating the application of N fertilizer and vinasse in time was tested in three field experiments in Brazil. Vinasse – both regular and concentrated – was applied a) at the same time as the fertilizer, b) anticipated by one month or c) delayed by one month. Intense measurements of N2O emissions were carried out using static chambers. The N2O-N fertilizer emission factor (EF) varied from 0.08% to 0.52%, whereas the average EF of regular and concentrated vinasse were 0.68% and 0.33% respectively. Application of concentrated vinasse in the same day of the mineral N fertilization caused high N2O emissions than when the fertilizer was applied alone; simultaneous application of regular vinasse increased N2O emission in 2 out of 3 experiments. The strategy of anticipating or postponing the application of both regular and concentrated vinasse by about 30 days with respect to N fertilization in most cases granted lower N2O emissions.