Greenhouse Gas Emissions from U.S. Livestock Production Systems D. Johnson, H. Phetteplace, A. Seidl Colorado State University

Outline, AN448,Sept. 22, 2004 I. Global greenhouse gas accum II. Agriculture and livestock role III. Livestock system sources IV. Manure system GHG’s V. Mitigation strategies

References: Agric GHG’s IPCC, 2001 (06): GHG Inventory Good Practice Guidelines (ipcc-nggip.iges.or.jp) USEPA, 2004: Inventory of US GHG (yosemite.epa.gov/oar/globalwarming) USDA, 2004: US Agric. & Forestry GHG (usda.gov/oce/gcpo) Proc. Agstar Conf. Anaerobic Digestion (epa.gov/agstar/conference04)

SOURCE: IPCC

SOURCE: Science,

Global Climate Changes (IPCC) Snow cover: 10% decrease Glacier retreat: major River and lake ice: 2 wk decrease Sea ice extent: 10-15% decrease Arctic ice thickness: 40% decrease Diurnal temp range: decrease Tropospheric water, clouds: increase

SOURCE: IPCC

GHG Sources in US (as CO 2 equivalent) CO 2 CH 4 x 21 N 2 O x 310

Importance of Non-CO 2 GHG’s Why bother? Globally – 40% Effective fast Cost effective Political feasibility Synergy-other problems Climate Forcings of GHG’s, CO2eq in US, 2002, %

Agriculture’s Role, cont’d 70% of Nitrous oxide 30% of Methane Huge C-sequestration potential

Agriculture sources of GHG (USDA, 04)

Global N-input Sources (Mosier and Kroeze, 99)

Products and GHG from Cattle Production J W Herd 100 cows + others Cropping Feeds Manure CH 4 N 2 0 Fuel C0 2 Soil Carbon ( + )

Beef System GHGs CO 2 eq by Gas Source (100 cow US system) Gas t/yr CV CH N 2 O CO Cseq Total: 542 7

GHG Sources by Beef Sector ( CO 2, N 2 O, CH 4 as CO 2 eq)

Dairy System GHGs (100 cow herd, t/yr) GasCalifWisc CH 4, enteric CH 4, manure N 2 O CO C-sequest 0 (28) Total

Waste GHG, Beef Cattle

Waste, Dairy Cattle

Waste, Swine

Biological N transformations (Nitrification-Denitrification) NH 4 NH 3 NO 2 - N2ON2O NO 3 - NO 2 - NO N2ON2O N2N2 N2ON2O Nitrification Denitrification Aerobic Anaerobic

Manure methane equations Livestock characterization and pop. Waste characteristics Waste management system usage Methane conversion factor (MCF) EPA, 2002, 04

Manure methane emissions Kg CH 4 /yr by state for each animal group CH 4 an grp = Σ(pop. x VS x B o x MCF x 0.662) pop = avg head animal group for each state VS = VS in kg/head/year B o = max CH 4 prod capacity/kg VS MCF = weighted MCF for animal group by state = conversion factor of m 3 CH 4 to kg CH 4 EPA, 2002

Species Total Kjeld. N, kg/d VS, kg/d Max. CH 4 Bo, m 3 CH 4 /kg VS Dairy cow *0.24 Dairy heifer Feedlot cattle Beef cow Market swine* Breeding swine Hens Broilers From Table L-2, EPA, 2002, *CO #s US-EPA Manure GHG inventory assumptions, 2002 (N &VS/1000 kg animal mass)

Methane Conversion Factor Based on Van’t Hoff-Arrhenius equation f = exp[E(T 2 –T 1 )/RT 1 T 2 ] f = portion of VS available for CH 4 production T 1 = K T 2 = weighted ambient temp (K) for each state E = activation energy (15,175 cal/mol) R = ideal gas constant (1.987 cal/K mol) EPA, 2002; Safley & Westerman, 1990

Manure methane in 2002 EPA, 2004 Total 40 Tg CO 2 eq

Manure N2O, CO2eq (USDA 04) Total = 77 Tg/yr

All Mitigation Approaches Must: be based on a comprehensive, life cycle analysis that assesses emissions of all greenhouse gases. (NCCTI, 2001)

CH 4 Mitigation (Mgt strategies)  Eliminate anaerobic lagoons or capture CH 4  Eliminate stocker phase ~ direct to feedlot  Maximize grain feeding – trade-offs with N 2 O  Dilution of maintenance  Faster gain or more milk/cow  Hormone treatment use bST or implants

Biogas from Livestock Waste Prior failures: 140 farm sys in 70’s (< 20%) Renewed interest: 50 now in use, 60 plan Cost $400 - $1200/cow, brk even 5 – 15c/kWh GHG savings: 6 MT/cow ?Synergisms? Odor, NH3- PM2.5, dust, health, acid rain, smog, etc.

US Biogas Plants, USDA 04

Methane Mitigation Research Immunization (Baker, Aust) Methane oxidizers (UK) H+ acceptors Nitrate (Japan) Fumaric acid (UK, Japan) Medium chain Fatty Acids (Switz)

CH 4 Mitigation (Mgt strategies cont.)  Select cows with low maintenance req.  Increase forage digestibility Intensive Grazing Plant genetic select/modification ? Fat cows if fed ad libitum Tradeoff excess N (>20%CP, req~11%) Ammoniation of forage – trade-off with N 2 O  MCFA – trade-off  enteric,  manure

Diet %CP, Manure Sys vs N 2 O (Kulling,et. 01 J Ag Sci 137:235) Lactating Cows, 30.9 kg/d, 3 protein levels, +bypass Methionine % 3 Manure management systems Liquid manure in slurry (Slurry) Farmyard manure, liquid urine (FYM-US) Deep liter + 12 kg straw (DLM-Straw)

Dairy % diet CP vs Emissions (Kulling 01, J Ag Sci 137:235)

Manure System vs Emissions (Kulling 01)

Manure vs. Synthetic N 250 kg N-Manure Stores 350 kg C Fuel (0) N 2 O-C 655 kg Net emissions 305 kg CE (1100 kg CO 2 eq) 250 kg N-Synthetic Stores 150 kg C Fuel 296 kg C N 2 O-C 655 kg Net emissions 801 kg CE (2900 CO 2 eq)

Direct-IG Direct 14.2 GHG/BW sold, % base 0 $ /T GHG 529 Net GHG, T/herd 1997 Base Abatement Strategies on Beef GHG Emissions & Profit

Conclusions Manure Mgt? Anaerobic; N 2 O, CH 4 Covered lagoons? Efficient manure use Need good emission estimates

Conclusions GHG abatement strategies should consider emissions of all GHG’s Reductions in feed/product central thrust Dilution of maintenance Reductions in excess N Soil C can add modest offsets to livestock