Mitigation Solutions for Nitrous Oxide Emissions from Animal Waste International Symposium on Near-Term Solutions for Climate Change Mitigation in California March 5-7, 2007 Frank Mitloehner, PhD Air Quality CE Specialist Animal Science, UC Davis
GHG Mitigation Strategies Strategy Basic Nature CO2 CH4 N2O Crop Mix Alteration Crop Fertilization Alteration Crop Input Alteration Crop Tillage Alteration Grassland Conversion Irrigated/Dry land Mix Emis, Seq Emis Seq Emission Emission Sequestration Emission Biofuel Production Offset Afforestation Existing timberland Deforestation Sequestration Sequestration Emission Enteric fermentation Livestock Herd Size Livestock System Change Manure Management Rice Acreage Emission Emission Emission Emission Emission
Organic N Cellular N in bacteria Assimilation Lysis NH 4 + O 2 Nitrification NO 2 - Animal O 2 NO 3 - Plants Denitrification N 2 O N 2
Agricultural Sources of GHG Emissions in 2001 in U.S. Livestock waste (N2O), 17% Livestock waste (CH4), 8% Rice cultivation and residue burning (CH4 and N2O), 2% Cropland soil (N2O), 48% Enteric fermentation (CH4), 25%
U.S. GHG Emissions from Livestock Waste by Livestock Type, 2001 50 GHG emissions (Tg CO2E) 45 40 35 30 25 20 15 10 5 25% 75% N2ON 2 O CH4 4 0 Beef cattle Dairy cattle Swine Poultry Horses Sheep Goat
Nitrous Oxide Emission 100 years global warming potential CO 2 : 1; CH 4 : 21; N 2 O: 310, Occur during denitrification primarily, but somewhat during nitrification as well, The N 2 O emission is higher when NO 2- and NO 3 concentration is high Lower ph High O 2 Lower C availability Lower temperature Lower N 2 O reductase activity
Avg Emissions per Cow (lb/cow/yr) CO 2 CH 4 N 2 O Dry cows 13,637 268 6.9 Lact cows 18,325 412 8.7
Dry Cows 60 Empty Cows only Cows & Waste Waste only 50 Methane (ppm) 40 30 20 10 0 5:00 11:00 17:00 23:00 5:00 11:00 Time Outlet Inlet
Lagoon waste 1.2 Empty Lagoon waste in CH 4 (ppm) 0.8 0.4 0.0 6:00 10:00 14:00 18:00 22:00 2:00 6:00 10:00 Time Net
Concentration from dry cows group and waste, bubble exp. 600 Empty Cows & Waste Waste only CO 2 (ppm) 500 400 300 8/20/06 0:00 8/24/06 0:00 8/28/06 0:00 9/1/06 0:00 9/5/06 0:00 9/9/06 0:0 Date and Time Outlet Inlet
Concentration from dry cows group and waste, bubble exp. 15 Empty Cows & Waste Waste only CH 4 (ppm) 10 5 0 8/20/06 0:00 8/24/06 0:00 8/28/06 0:00 9/1/06 0:00 9/5/06 0:00 9/9/06 0:0 Date and Time Outlet Inlet
Concentration from dry cows group and waste, bubble exp. 0.5 Empty Cows & Waste Waste only N 2 O (ppm) 0.4 0.3 0.2 8/20/06 0:00 8/24/06 0:00 8/28/06 0:00 9/1/06 0:00 9/5/06 0:00 9/9/06 0:0 Date and Time Outlet Inlet
The Effect of different Dairy Manure Management on N O Emissions 2 Acidifier application Scraping Harrowing Control (no treatment)
Emissions from dry cows and waste 16 14 N 2 O (lb/cow/yr) 12 10 8 6 4 2 0 8/21/2006 8/25/2006 8/29/2006 9/2/2006 9/6/2006 Date SBS Control Harrowing Scraping
Impact of Dairy Housing System on GHG Emissions Kulling et al. 2001, J. An. Sci. 137-235 Three housing management systems, Liquid manure in slurry, Farmyard manure (feces+1.75kg straw) & urine (FYM-U), Deep liter + 12 kg of straw (DL-S),
iet Treatment to Reduce N 2 O Emissions Kulling et al. 2001, J. An. Sci. 137-235, Lactating cows (39kg/day), Three levels of CP in the diet, 12.5, 15.0, and 17.5% of the diet DM
The Effect of Aeration on N O 2 Emissions from Lagoon Storage Deep aeration 15% of BOD loading 30% of BOD loading Surface aeration 0.5 ppmo 2 in the top layer 1.5 ppmo 2 in the top layer
Laboratory Aeration Study Compressed air Air sampling locations at the top outlet of the reactor Liquid sampling locations Storage tank Storage tank DO=1.5 ppm DO=3 ppm OS/BOD=15%* OS/BOD=30% Control Screened dairy lagoon liquid stored in refrigerator * OS/DOD is the ratio between oxygen supply and daily oxygen demand in the manure
Laboratory Aeration System
The Effect of Aeration on N 2 O Emissions from Lagoon Storage 0.6 Concentration (ppm) 0.5 0.4 0.3 Control Deep aeration low Surface aeration high Surface aeration low Deep aeration high Inlet air 0.2 1-20-07 1-22-07 1-24-07 1-26-07 1-28-07 1-30-07 2-1-07 Date
Conclusion N 2 O is important to consider because of its effects on global warming potential CH 4 and N 2 O abatement strategies may conflict with each other Reduction in the feed/product ratio of N is central to minimize N 2 O emission Application of N nutrients at agronomic rates is critical to reduce N 2 O and other N related emission