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

Transcription

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

2 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

3 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)

4 SOURCE: IPCC

5 SOURCE: Science,

6 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

7 SOURCE: IPCC

8 Click on the video to the right to play it

9 SOURCE: IPCC

10 GHG Sources in US (as CO 2 equivalent) CO 2 CH 4 x 21 N 2 O x CO2 CH4 N2O

11 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, % CH4 9% N2O 6% HFC, PFC, SF6 2% CO2 83%

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

13 Agriculture sources of GHG (USDA, 04) Crop-N2O StorSht-N2O Enteric-CH4 Manure-CH4 %

14 Global N-input Sources (Mosier and Kroeze, 99) N-Input (Tg N) Year Synthetic N N-Fixation Crop Residue Animal Manure

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

16 Beef System GHGs CO 2 eq by Gas Source (100 cow US system) Gas t/yr CV 200 CH N 2 O CO Cseq Total: CH4 N2O CO2 Cseq

17 GHG Sources by Beef Sector (CO 2, N 2 O, CH 4 as CO 2 eq) CO2 Equivalents per gain (kg) CO2 N2O Total CH4 Cow Calf Stocker Feedlot Cow-Feedlot Production Phase

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

19 Waste GHG, Beef Cattle

20 Waste, Dairy Cattle

21 Waste, Swine

22 Biological N transformations (Nitrification-Denitrification) N 2 O NH 4 NH 3 NO2 - Aerobic Nitrification NO 3 - N 2 N 2 O N 2 O Anaerobic NO Denitrification NO 2 -

23 Manure handling systems Variations in N 2 O-N per Manure N System Daily spread Slurry Storage Disposal Leac h Sum N 2 0/N, % Graze Aerobic

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

25 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

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

27 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

28 Manure methane in 2002 CO2eq, Tg Total 40 Tg CO 2 eq Dairy Beef Swine Poultry Other EPA, 2004

29 Manure N2O, CO2eq (USDA 04) Total = 77 Tg/yr N2O, t/yr 10 0 Dairy Beef Swine Poultry other

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

31 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

32 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.

33 US Biogas Plants, USDA 04

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

35 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

36 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)

37 Dairy % diet CP vs Emissions (Kulling 01, J Ag Sci 137:235) NH3-N N2O,mg/10 CH4,g GWP/10

38 Manure System vs Emissions (Kulling 01) NH3 N2O CH4 GWP Slurry FYM-U DLM-Strw

39 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)

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

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

42 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