Methane recovery and agronomic values of anaerobically digested solid beef cattle manure

Transcription

1 Methane recovery and agronomic values of anaeroically digested solid eef cattle manure Ben W. Thomas, Xiying Hao, Valentine Nkemka, Agriculture and Agri-Food Canada, Lethridge Virginia Nelson, Alerta Agriculture and Forestry, Lethridge Xiaomei Li, XY-Green Caron Inc., Edmonton Presented at the 217 Manure Management Update at Lethridge College

2 Cattle Production in Alerta Large confined operations produce a lot of manure o Applied to a relatively small land area o Nutrient loading creates large nutrient imalances Alerta has 5.1 M cattle (42% of the national herd) o County of Lethridge licensed feedlot capacity: ~9, head o Several feedlots >25, head Manure contains a lot of caron, which may e converted to iogas (methane) Manure is not effectively used as fertilizer Poor manure management is an environmental issue 1

3 Manure Management Options Manure in feedlot pen Anaeroic digestion Land application Stockpiling Composting 2

4 Anaeroic Digestion as a Manure Management Option Anaeroic digestion is environmentally attractive Anaeroically digested manure, or digestate, is one of the final co-products of the iogas energy industry Digestates are typically good nutrient sources 3

5 The Knowledge Gap Most research has een conducted on digestates from liquid swine manure and liquid dairy cattle manure Limited research conducted on solid manure Liquid and solid manure have different chemical and physical properties, so digestates from solid manure likely have different agronomic values than digestates from liquid manures 4

6 Ojective 5 To determine potential methane recovery and the agronomic values of anaeroically digested eef cattle manure o o o o Barley forage yield Forage arley N and P uptake Apparent N and P recovery Residual nitrate and soil test P levels 5

7 Methane Recovery from Beef Cattle Manure 6 Measured y methane potential atch test for 4 days Methane recovery was:.35 m 3 kg -1 ased on dry matter mass.55 m 3 kg -1 ased on wet mass 6

8 7 Biogas plant Vegreville, AB

9 Field Studies Biogas plant location: Vegreville Experimental sites: St. Alert and Lethridge Experimental periods: Four and five years Experimental designs: Four amendments Two rates Treatment list: (1) Control (non-amended soil) (2) Undigested manure (3) Anaeroically digested manure (digestate) (4) solids of the digested manure (5) Pelletized separated solids (St. Alert only ) 8

10 Materials and Methods Materials: Undigested cattle manure (33 to 5% solid) Digestate (4 to 9% solid) solids (24 to 44% solid) Pellets (65 to 8% solid) Cattle manure solids Pellets 9

11 Materials and Methods Two rates (Assumed 5% total N availale): 1 local recommended rate 2 local recommended rate Surface applied, doule disk with minimal soil disturance Seeded on same day or one day after amendment application 1

12 Amendment Application 11

13 12 Amendment Properties Amendment WC ph Total C Total N Org-N Total P NH 4 -N NO 3 -N C/Org-N N/P NH 4 -N/Total N kg kg -1 g kg -1 g kg -1 g kg -1 g kg -1 g kg -1 mg kg -1 Digestate.94 ± ± ± 25 7 ± 6 29 ± 4 9 ± 1 39 ± 6 21 ± 8 12 ± 1 8 ± 1.55 ±.5.75 ± ± ± ± 1 13 ± 1 5 ± 1 4 ± 1 14 ± 1 31 ± 4 3 ±.2 ±.7 Pellets.44 ± ± ± ± 1 17 ± 1 5 ± 1 1 ± 1 ± 21 ± 2 4 ±.3 ±.1 Manure.62 ± ± ± ± 2 2 ± 2 6 ± 1 4 ± 1 5 ± 1 2 ± 3 4 ±.17 ±.4 Values are means ± standard error All amendment properties are expressed on a dry mass asis WC is water content on a wet weight asis 12

14 Barley Forage Yield (Mg ha -1 ) Barley Forage Yield (Mg ha -1 ) Results: Barley Forage Yield a St. Alert P < a Lethridge P < Digestate Pellets Manure Digestate Manure 13

15 Barley Forage N Uptake (kg ha -1 ) Barley Forage N uptake (kg ha -1 ) Results: Barley Forage N Uptake St. Alert Lethridge 25 a P <.1 25 P < c c 2 15 a Digestate Pellets Manure Digestate Manure 14

16 Barley Forage P Uptake (kg ha -1 ) Barley Forage N uptake (kg ha -1 ) Results: Barley Forage P Uptake St. Alert Lethridge 25 2 a P = P = Digestate Pellets Manure Digestate Manure 15

17 Apparent N Recovery (%) Apparent N Recovery (%) Results: Apparent N Recovery (Amended-soil N uptake / N applied) St. Alert Lethridge 25 P <.1 25 a P <.1 2 a c 5 Digestate Pellets Manure Digestate Manure 16

18 Apparent P Recovery (%) Apparent P Recovery (%) Results: Apparent P Recovery (Amended-soil P uptake / P applied) St. Alert Lethridge 12 1 P = a P = a Digestate Pellets Manure Digestate Manure 17

19 Amendment Derived N Uptake (%) Amendment Derived N Uptake (%) Results: Amendment Derived N Uptake 45 4 a St. Alert P < a Lethridge P < c 5 Digestate Pellets Manure Digestate Manure (Amended-soil N uptake Control soil N uptake) / Amended-soil N uptake 18

20 Amendment Derived P Uptake (%) Amendment Derived P Uptake (%) Results: Amendment Derived P Uptake St. Alert Lethridge 35 P = P = Digestate Pellets Manure (Amended-soil P uptake Control soil P uptake) / Amended-soil P uptake Digestate Manure 19

21 Barley forage yield (kg ha -1 yr -1 ) 16, 12, 8, CM Cattle manure 4, ADM Digestate S , Growing season precipitation (mm yr -1 ) 12, 8, 4, 16, y = 52.34x , r =.96***, n = Nitrogen uptake (kg ha -1 yr -1 ) 12, 8, 4, Phosphorus uptake (kg ha -1 yr -1 ) Hao et al., 216. Soil Science Society of America Journal 2

22 Summary Digestate led to 31 to 5% greater arley forage yield in St. Alert, and 24 to 26% greater yield in Lethridge At oth sites, arley recovered two times more N from digestate than undigested cattle manure Digestate led to greater arley forage P uptake in St. Alert Hao et al., 216. Soil Science Society of America Journal Thomas et al., Under Minor Revision, Agronomy Journal

23 Summary Pellets performed poorly, likely due to low surface area solids performed similar to raw cattle manure On farm management strategies developed for raw cattle manure may e used for separated solids Hao et al., 216. Soil Science Society of America Journal Thomas et al., Under Minor Revision, Agronomy Journal

24 Improve nutrient recovery from pellets Why? Future Directions Pelleting decreases the mass and volume of the separated solids, making transportation and land application more economical Pellets supply C and may act as useful slow release fertilizer

25 Acknowledgements Collaorators: o Alerta Agriculture and Forestry o University of Manitoa Technical staff at AAFC Lethridge and AAF Digestate from Highmark Renewales Inc.

26 Thank you!!