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Greenhouse Gas Emissions during Cattle Feedlot Manure Composting
Author(s) -
Hao Xiying,
Chang Chi,
Larney Francis J.,
Travis Greg R.
Publication year - 2001
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2001.302376x
Subject(s) - manure , aeration , feedlot , greenhouse gas , compost , environmental science , zoology , environmental engineering , agronomy , chemistry , waste management , engineering , ecology , biology
The emission of greenhouse gases (GHG) during feedlot manure composting reduces the agronomic value of the final compost and increases the greenhouse effect A study was conducted to determine whether GHG emissions are affected by composting method. Feedlot cattle manure was composted with two aeration methods—passive (no turning) and active (turned six times). Carbon lost in the forms of CO 2 and CH 4 was 73.8 and 6.3 kg C Mg −1 manure for the passive aeration treatment and 168.0 and 8.1 kg C Mg −1 manure for the active treatment. The N loss in the form of N 2 O was 0.11 and 0.19 kg N Mg −1 manure for the passive and active treatments. Fuel consumption to turn and maintain the windrow added a further 4.4 kg C Mg −1 manure for the active aeration treatment. Since CH 4 and N 2 O are 21 and 310 times more harmful than CO 2 in their global warming effect, the total GHG emission expressed as CO 2 –C equivalent was 240.2 and 401.4 kg C Mg −1 manure for passive and active aeration. The lower emission associated with the passive treatment was mainly due to the incomplete decomposition of manure and a lower gas diffusion rate. In addition, turning affected N transformation and transport in the windrow profile, which contributed to higher N 2 O emissions for the active aeration treatment. Gas diffusion is an important factor controlling GHG emissions. Higher GHG concentrations in compost windrows do not necessarily mean higher production or emission rates.