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”
19-21 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
World ethanol production - 2006
USA
Brazil
Others
11%
48%
41%
7,000,000, 3%
13,000,000,
6%
Brazil
22,000,000,
11%
North
Northeast
Center-West
170,000,000,
80%
Southeast
South
Sugar cane
Corn
Soy bean
Pastagens
0%
9%
8%
20%
63%
North
Northeast
Southeast
South
Center-West
Nitrogen fertilizers in sugar cane
Sugar cane: 80 -100 kg N.ha-1.yr-1
Pasture: 0 kg N.ha-1.yr-1
Soybean: 0 kg N.ha-1.yr-1 (BNF)
Corn: 150-200 kg N.ha-1.yr-1
Coffee: 250-300 kg N.ha-1.yr-1
Most as UREA – (CO(NH2)2)
Losses of UREA: volatilization and nitrification
Volatilization:
1.UREA is transformed in ammonium carbonate
2. Ammonium carbonate under high pH and temperature is transformed in NH3
Nitrification:
1. NH3 is oxidized into NH4+
2. NH4 is nitrified to NO33. NO3- is leached out of the soil profile or
4. NO3- is denitrified to N2O
N2
Biological fixation
NH3
N-particle
volatilization
N-harvest
UREA
denitrification
N2O + N2
Cana
Reciclagem
OM
NH4+
Mineralization
nitrification
Fonte: Trivelin, Gava, Oliveira (CENA); Vitti (ESALQ), Cantarella (IAC) -15N labeled fertilizer
NO3-
N2
Biological fixation
NH3
N-particle
volatilization
N-harvest
UREA
denitrification
N2O + N2
Cana
Reciclagem
OM
NH4+
Mineralization
nitrification
Fonte: Trivelin, Gava, Oliveira (CENA); Vitti (ESALQ), Cantarella (IAC)
NO3-
N wet deposition– kg N.ha-1.yr-1
Piracicaba *
5.0 – 6.0
NE - USA
6.0 – 8.0
Scandinavia
15.0
Central Amazonia * *
1.6
Balbina (Amazonia) ***
1.4
Rondônia (Amazonia) ***
0.8
pH= 4.9
4.8
4.4
4.7
The Nitrogen Cycle – N-poor agricultural system
N2
N-harvest
NH3
Biological fixation
N-fert
volatilization
N2O + N2
denitrification
Reciclagem
OM
Mineralization
Pastagem
NH4+
nitrification
Fonte: Cerri & Cerri (CENA), Melillo, Neill (WHOI), Bernoux (IRD)
NO3-
The Nitrogen Cycle – N-poor natural system
N2
NH3
deposition
biological fixation
volatilization
Cerrado
N2O + N2
denitrification
reciclagem
OM
mineralization
Fonte: Bustamante, Miranda, Klink (UnB)
NH4+
nitrification
NO3-
The Nitrogen Cycle – N-poor natural system
N2
NH3
deposition
volatilization
biological fixation
N2O + N2
denitrification
reciclagem
OM
mineralization
NH4+
nitrification
NO3-
If Meq/M>1.0, there will be net climate warming, the
greenhouse warming by in creased N2O release to the
atmosphere then being larger than the quasi-cooling effect
from “saved fossil CO2”.
N2
Biological fixation
NH3
N-particle
volatilization
N-harvest
UREA
denitrification
N2O + N2
Cana
Reciclagem
OM
NH4+
Mineralization
nitrification
Fonte: Trivelin, Gava, Oliveira (CENA); Vitti (ESALQ), Cantarella (IAC), Urquiaga (Embrapa)
NO3-