First Workshop ESSP Bioenergy Bioenergy and Earth Sustainability University of São Paulo Centro de Energia Nuclear na Agricultura Escola Superior de Agricultura “Luiz de Queiroz” July 2008 “Nitrogen dynamics and sugar cane in Brazil” Luiz A Martinelli (CENA/USP) Reynaldo L Victoria (CENA/USP) Janaina Braga do Carmo (UFSCar-Sorocaba) Jean Pierre Ometto (IGBP-INPE)
GLOBAL VIEW - Ethanol
North Northeast Center-West Southeast South Brazil
Nitrogen fertilizers in sugar cane Sugar cane: kg N.ha -1.yr -1 Pasture: 0 kg N.ha -1.yr -1 Soybean: 0 kg N.ha -1.yr -1 (BNF) Corn: kg N.ha -1.yr -1 Coffee: kg N.ha -1.yr -1 (CO(NH 2 ) 2 ) Most as UREA – (CO(NH 2 ) 2 ) Losses of UREA: volatilization and nitrification Volatilization: 1.UREA is transformed in ammonium carbonate NH 3 2. Ammonium carbonate under high pH and temperature is transformed in NH 3 Nitrification: 1. NH 3 is oxidized into NH NH 4 is nitrified to NO NO 3 - is leached out of the soil profile or N 2 O 4. NO 3 - is denitrified to N 2 O Nitrogen fertilizers in sugar cane Sugar cane: kg N.ha -1.yr -1 Pasture: 0 kg N.ha -1.yr -1 Soybean: 0 kg N.ha -1.yr -1 (BNF) Corn: kg N.ha -1.yr -1 Coffee: kg N.ha -1.yr -1 (CO(NH 2 ) 2 ) Most as UREA – (CO(NH 2 ) 2 ) Losses of UREA: volatilization and nitrification Volatilization: 1.UREA is transformed in ammonium carbonate NH 3 2. Ammonium carbonate under high pH and temperature is transformed in NH 3 Nitrification: 1. NH 3 is oxidized into NH NH 4 is nitrified to NO NO 3 - is leached out of the soil profile or N 2 O 4. NO 3 - is denitrified to N 2 O
NH 4 + NO 3 - N2N2 OM Mineralization nitrification N 2 O + N 2 denitrification Biological fixation NH 3 volatilization UREA N-harvest N-particle Fonte: Trivelin, Gava, Oliveira (CENA); Vitti (ESALQ), Cantarella (IAC) - 15 N labeled fertilizer Cana Reciclagem
NH 4 + NO 3 - N2N2 OM Mineralization nitrification N 2 O + N 2 denitrification Biological fixation NH 3 volatilization UREA N-harvest N-particle Fonte: Trivelin, Gava, Oliveira (CENA); Vitti (ESALQ), Cantarella (IAC) Cana Reciclagem
N wet deposition– kg N.ha -1.yr -1 Piracicaba * 5.0 – 6.0 NE - USA6.0 – 8.0 Scandinavia15.0 Central Amazonia * * 1.6 Balbina (Amazonia) *** 1.4 Rondônia (Amazonia) *** 0.8
pH= 4.9
NH 4 + NO 3 - N2N2 OM Mineralization nitrification N 2 O + N 2 denitrification Biological fixation NH 3 volatilization The Nitrogen Cycle – N-poor agricultural system Reciclagem N-harvest Fonte: Cerri & Cerri (CENA), Melillo, Neill (WHOI), Bernoux (IRD) Pastagem N-fert
NH 4 + NO 3 - N2N2 OM mineralization nitrification N 2 O + N 2 denitrification biological fixation NH 3 volatilization The Nitrogen Cycle – N-poor natural system reciclagem Cerrado deposition Fonte: Bustamante, Miranda, Klink (UnB)
NH 4 + NO 3 - N2N2 OM mineralization nitrification N 2 O + N 2 denitrification biological fixation NH 3 volatilization The Nitrogen Cycle – N-poor natural system reciclagem deposition
If Meq/M>1.0, there will be net climate warming, the greenhouse warming by in creased N 2 O release to the atmosphere then being larger than the quasi-cooling effect from “saved fossil CO 2 ”.
NH 4 + NO 3 - N2N2 OM Mineralization nitrification N 2 O + N 2 Biological fixation NH 3 volatilization UREA N-harvest Reciclagem N-particle Fonte: Trivelin, Gava, Oliveira (CENA); Vitti (ESALQ), Cantarella (IAC), Urquiaga (Embrapa) Cana denitrification