Greenhouse Gas Emission from Paddy Rice Production Systems in Brazil Walkyria Bueno Scivittaro Embrapa Temperate Agriculture 3rd. Meeting of the Americas Sub-Group of Paddy Rice Research (PPRG) of GRA Dale Bumpers National Rice Research Center, Stuttgart, Arkansas, USA July 13 to 15, 2016

Rice production in Brazil 2.35 million ha rice 1.44 million ha lowland rice (61%) 0.91 million ha upland rice (39%) North (11,2%) Northeast (22,4%) Center-West (10,0%) Southeast (1,4%) South (55,0%) Source: IBGE (2015)

Rice Producing Regions in Southern Brazil Southern Region 1.28 million ha flooded rice 9.46 million Mg rice Yield: 7.4 Mg ha-1 Source: IBGE (2015)

Mitigation Strategies Greenhouse Gas Dynamics and Carbon Balance in Crops Production Systems in the Southern Planes Region Objective: to determine GHG emissions of the main crops production systems in the Southern Planes region, with emphasis on systems involving flooded rice and crops in rotation. Mitigation Strategies Soil and rice straw management Water management Rice cultivars Management of nitrogen fertilization Crop diversification

Mitigation Strategies: water saving management

43% (9-77%) Potential of water saving regimes to mitigate soil CH4 emissions in southern Brasilian lowlands rice fields. Source: Moterle (2011); Zschornack (2011); Wezs (2012); Buss (2012); Camargo (2014).

CH4 (kg/ha) Fall/winter Season Source: Scivittaro et al. (2015)

N2O (kg/ha) Fall/winter Season Rice / Flooded Rice / Sprinkler Natural lowland Source: Scivittaro et al. (2015)

Source: Scivittaro et al. (2015) Flooded Season / Fall/winter Natural lowland Sprinkler Source: Scivittaro et al. (2015)

Mitigation strategie: soil and rice straw management Fall/Winter / Conventional tillage

Conventional tillage X Minimum tillage technologies CT: rice and winter crop residues are incorporated into soil in spring (source of labile C for methane production). MT: rice straw is incorporated into soil in fall/winter (non-flooded conditions). Part of the labile carbon is converted into CO2, decreasing CH4 emission potential once the area is flooded again to next rice crop.

-33% MT: maintains weeds and winter crop residues on soil surface resulting in a lower emission of CH4. CT: crop residues are incorporated in 0-20 cm depth where soil reduction status is much higher than on surface layer, resulting in a higher production of CH4. Seasonal methane emissions in flooded rice fields under conventional and minimum tillage systems in Southern Brazil. Source: Costa (2005); Zschornack (2011); Moterle (2011).

Alternative Knife roller

Rice harvest and tillage: flooded fields Prepared area knife roller

Drainage

CH4 (kg/ha) Conventional Rice Knife Roller Rice Minimum Soybean Fall/winter Season CH4 (kg/ha) Conventional Rice Knife Roller Rice Minimum Soybean Source: Scivittaro et al. (2015).

N2O (kg/ha) Conventional Rice Knife Roller Minimum Soybean Fall/winter Season N2O (kg/ha) Conventional Rice Knife Roller Minimum Soybean Source: Scivittaro et al. (2015)

Conventional Rice Knife Roller Rice Minimum Soybean Source: Scivittaro et al. (2015)

Management of nitrogen fertilization Objective: to evaluate the influence of nitrogen fertilization practices on GHG emissions

Nitrogen sources: urea x slow release fertilizers Control Urea Polyblen Polyblen no N 38+39 39 SRF: urea coated with polymers derived from polyacrylates not hydrosoluble Source: Veçozzi et al. (2014)

Nitrogen sources: urea x slow release fertilizers Control Urea Polyblen Polyblen no N 38+39 39 Source: Veçozzi et al. (2014)

Nitrogen sources: urea x slow release fertilizers Partial global warming potential kg CO2 equivalent/ha season Control Urea Polyblen Polyblen no N 38+39 39 Source: Veçozzi et al. (2014)

Nitrogen sources: urea X urea / urease and nitrification inhibitors Control Urea Urea/ Urea/ AS no-N NBPT NBPT+DCD

Nitrogen sources: urea X urea / urease and nitrification inhibitors Control Urea Urea/ Urea/ AS NBPT NBPT+DCD Partial global warming potential kg CO2 equivalent/ha season Source: Veçozzi et al. (2016)

Crop diversification: conventional tillage 10 to 12-fold lower Flooded rice Sorghum Soybean Partial global warming potential (CH4 + N2O in CO2 equivalent) in lowland fields cultivated with soybean, sorghum and flooded rice under conventional tillage in Southern Brazil.

Crop diversification: no-tillage Soybean Sorghum Flooded rice 10 to 12-fold lower Partial global warming potential (CH4 + N2O in CO2 equivalent) in lowland fields cultivated with soybean, sorghum and flooded rice under no-tillage in Southern Brazil.

Research Team / Institutions Beata Emoki Madari (Embrapa Rice and Bean) Cimélio Bayer (UFRGS) Leandro Souza da Silva (UFSM) Júlio José Centeno da Silva (Embrapa Temperate Agriculture) Rogério Oliveira de Sousa (UFPel) Tiago Zschornack (UFRGS) Walkyria Bueno Scivittaro (Embrapa Temperate Agriculture)

Thank you walkyria.scivittaro@embrapa.br