“Beef Circular Bioeconomy: N and GHG capture to improve circularity” by Galen Erickson, J.L. Miller, Tala Awada, J. Luck, Konstantinos Giannakas, Ahmed Chennak, and R.R. Stowell at the 2023 Water for Food Global Conference. A recording of the presentation can be found on the conference playlist: https://youtube.com/playlist?list=PLSBeKOIXsg3JNyPowwJj6NDSpx4vlnCYj.

1. Beef Circular Bioeconomy: N
and GHG capture to improve
circularity
G.E. Erickson, J.L. Miller, T. Awada, J. Luck,
K. Giannakas, A. Chennak, R. R. Stowell

2. N Fertilizer
Produced
N Fertilizer
Consumed
N
in Crop
N
Harvested
N
in Food
N
Consumed
-6 -47 -12
100 14
47
94 26
31
-5
The Fate of Haber-Bosch Nitrogen
-16
14% of the N produced in the Haber-Bosch process enters the
human mouth……….if you are a vegetarian.
Galloway JN and Cowling EB. 2002

3. N Fertilizer
Produced
N Fertilizer
Applied
N
in Crop
N
In Feed
N
in Store
N
Consumed
-6 -47 -3
100 4
47
94 7
31
-24
The Fate of Haber-Bosch Nitrogen
-16
4% of the N produced in the Haber-Bosch process and used
for animal production enters the human mouth.
Galloway JN and Cowling EB. 2002

6. UNL cropwatch
•Understand CO2eq GHG balance
•N use efficiency
•Fertilizer inputs
•Impact of manure recycling
•Economics
Beef Circular Bioeconomy-Feed Inputs

7. Fertilizer Production (up to 30% of GHG inputs for cropping)
Carbon Footprint (CFP) from Fertilizer Production in the USA (up to plant
gate)
Fertilizer Product Nutrient Content CFP kg CO2e/kg product
Urea 46% N 1.18
Urea ammonium nitrate 30% N 1.50
NPK 15-15-15 15% N, 15% P2O5,
15% K2O
1.27
(Brentrup et al., 2016)
Beef Circular Bioeconomy-Feed Inputs

8. • Total : 0.76 kg CO2e kg-1 LW (Dudley et al., 2014)
Emissions from Feed Production in Feedlot Systems
kg CO2e hd-1 yr-1
Alfalfa 4.3
Corn and DGs prod. 914
Total 918
(Dudley et al., 2014)
Beef Circular Bioeconomy-Feed Inputs

9. •Understand CO2eq GHG balance
•N use efficiency
•Diet formulation
•Housing type (open lot, barns)
•Manure mgmt.
• Methods to trap N
•GHG
•Enteric methane
•Manure emissions
•Economics
Beef Circular Bioeconomy-Feedlot phase

10. • Soil core samples (15 cm)
• Runoff events quantified and sampled
• Manure removed, weighed, sampled,
analyzed
• Nutrient retention using NRC
equations
Nutrient balance experiments
• Productivity measures

11. Open pen nitrogen and phosphorus characteristics from 216 summer pens and 200 winter pens
Nitrogen Summer Avg. Winter Avg. P - value
Excreted, g/steer/d 211 193 0.10
Runoff, g/steer/d 6.4 3.5 0.05
Manure, g/steer/d 54 92 <0.01
Loss, g/steer/d 154 (73.0%) 97 (50.3%) <0.01
Phosphorus
Excreted, g/steer/d 28.9 27.2 0.63
Runoff, g/steer/d 1.9 1.1 <0.01
Manure, g/steer/d 17.1 28.3 0.01
Unaccounted, g/steer/d 10.2 -6.1 -
Beef Circular Bioeconomy-Feedlot phase
Homolka, Koelsch, Erickson, 2020. Applied Animal Science

12. • Fresh • Stockpiling
• Composting
Beef Circular Bioeconomy-Feedlot phase
• Liquid (deep-pit barns)

13. 0
3
6
9
12
15
0
8
3
4
2
1
0
4
6
9
Total N (wet)
g/kg
DM
0 42 69 83 104
Days
abc c
bc d c e bc e
a a
Beef Circular Bioeconomy-Feedlot phase

14. Previous Work
• Nitrogen
Fresh > Stockpiled > Composted
• Nutrient recoveries in finished compost is greater when OM is
increased
Larney et al., 2006
Adams et al., 2004
Farran et al., 2006
Beef Circular Bioeconomy-Feedlot phase

15. Emissions from Manure in Feedlot Systems
CH4 g hd-1 d-1 CO2 g hd-1 d-1 N2O g hd-1 d-1
Open pen 1.71 1309 0.57
Compost 0.04 55 0.10
Holding pond 2.05 35 0.01
Total 3.8 1399 0.68
(Borhan et al., 2011)
• GHG emissions of manure are impacted by diet, moisture, temperature, and time
(Woodbury et al.,2018)
Beef Circular Bioeconomy-Feedlot phase

16. Emissions from Manure in Feedlot Systems
CH4 g hd-1 d-1 CO2 g hd-1 d-1 N2O g hd-1 d-1
Open pen 1.71 1309 0.57
Compost 0.04 55 0.10
Holding pond 2.05 35 0.01
Total 3.8 1399 0.68
Enteric/Respira
tion
(125-200
g/hd/d)
(7,000-12,000)
• GHG emissions of manure are impacted by diet, moisture, temperature, and time
(Woodbury et al.,2018)
Beef Circular Bioeconomy-Feedlot phase

17. Finishing: GHG and NH3 Emissions
• Feedlot emissions: 12.71 kg CO2e hd-1 kg CW (Dudley et al., 2014)
• 3.53 kg CO2e hd-1 kg LW sourced from backgrounding
Feedlot Air Emissions (Rotz et al., 2019)
Ammonia g/kg CW 35.2
Methane g/kg CW 51
Nitrous Oxide g/kg CW 3.2
Volatile Organic Compounds g/kg CW 3.3
Beef Circular Bioeconomy-Feedlot phase

18. Manure and
Fertilizer
Application
• Emission factors vary
when comparing synthetic
N application to manure
application (Walling et al.,
2020)
Beef Circular Bioeconomy-Closed Loop

19. Manure and Fertilizer Application
Beef Circular Bioeconomy-Closed Loop

20. Future
• More complete N and P mass balance through whole ‘circle’
• What is the form of that loss (N example)
• Manure vs fertilizer application for nutrient and GHG, some
include N2O, some don’t
• N and P balance across diverse diets (feed choices)
• Forages, grain, byproducts, emerging feeds, inhibitors (Experior ex)
• More research on carbon emissions diff. between synthetic
fertilizer and manure in diff. mgmt./application strategies
• Diverse housing systems, and manure capture systems

21. ENREEC – 9663 acres
Approximately 50% farming / 50%
Pasture
Future: Testbed for Beef Circular Bioeconomy

22. ENREC Emission Barn • Utilizes 2 air sensors (LI-COR, Lincoln, NE)
• LI-COR 7500 to monitor CO2
• LI-COR 7700 to monitor CH4

23. Future:
Klosterman
Feedlot
Innovation
Center