대두 과산화효소를 이용한 젖소 분뇨 고형물 및 깔짚 퇴비화 과정의 온실가스 배출 저감

Reducing greenhouse gas emission from dairy manure solids and bedding composting using soybean peroxidase

Wardhani Riuh1, 신진호1, 이승훈2, Fufa Abera Jabessa1, 송용우3, 김동여3, 김수현1, 박성준3, 이종옥4, 안희권4*

Riuh Wardhani1, Jinho Shin1, Seunghun Lee2 , Abera Jabessa Fufa1, Yongwoo Song3, Dongyeo Kim3, Suhyun Kim1, SeongJun Park3, Jongok Lee4, Heekwon Ahn4*

1충남대학교 낙농학과, 2충남대학교 농업과학연구소, 3충남대학교 축산환경학과, 4충남대학교 동물자원과학부

1Dept. of Dairy Science, Chungnam National University, Daejeon, Korea

2Institute of Agricultural Science, Chungnam National University, Daejeon, Korea

3Dept. of Livestock Environmental Science & Technology, Chungnam National University, Daejeon, Korea

4Division of Animal and Dairy Science, Chungnam National University, Daejeon, Korea

*교신저자: 안희권(hkahn@cnu.ac.kr)

A comprehensive understanding of greenhouse gas (GHG) emissions associated with composting is essential for developing effective mitigation strategies. Previous laboratory-scale studies have shown that the combined application of soybean peroxidase (SBP) and calcium peroxide (CaO2) can significantly reduce carbon dioxide (CO2) and nitrous oxide (N2O) emissions during cattle manure composting, although the impact on methane (CH4) emissions was not substantial. To evaluate this approach under more practical conditions, a pilot-scale composting experiment was conducted using dairy manure solids and sawdust bedding. SBP was applied at 8% (wet basis) of the composting material, and CaO2 at 1.12% by weight of SBP. Six replicate compost piles, each consisting of 363 kg of material, were established. During gas sampling, the piles were enclosed in custom-designed 2.2 m³flux chambers. Each chamber was equipped with an internal fan to mix internal air and an external fan to draw air through the chamber, enabling accurate measurement of GHG fluxes. The results showed a significant reduction in N2O emissions by 46.8% after 29 days of composting. However, the same amendment resulted in a 28.7% increase in CO2 and a 66.6% increase in CH4 emissions. The measured CH4 and N2O emissions were converted to carbon dioxide equivalents (CO2eq) using global warming potential (GWP) values of 27.2 for CH4 and 273 for N2O (IPCC, 2021). As the CO2 emissions were of biogenic origin, they were not included in the GWP calculation. N2O was found to contribute substantially to the total GHG emissions, accounting for 11.3 kg CO2eq in the control group, which was significantly higher than in the treatment group, with 6.0 kg CO2eq. N2O contributed approximately 89–96% of the total GHG emissions. These findings suggest that although the SBP–CaO2 combination is effective in reducing N2O emissions, it may also enhance CH4 and CO2 production due to the accelerated decomposition process.

*키워드(Keywords): Soybean peroxidase, GHGs, Nitrous oxide, emission.

*사사(Acknowledgment): This work was supported by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, and Forestry (IPET) through the Livestock Industrialization Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (RS-2021-IP321088).