Greenhouse gas emission during storage of pig manure on a pilot scale

The greenhouse gas emissions (CO(2), CH(4), N(2)O) from a 2 ton (4.4 m(3)) deep litter pig manure pile (storage time 113 days during winter season) were quantified by using a tent, which covered the whole pile during the measuring periods only. The emissions were calculated in CO(2) equivalents per kilogram dry matter by. Additionally the retention time (use of tracer gas SF(6)) and the concentrations of the gases in different parts of the pile were determined. The average retention time of the gases in the pile was less than 2 h. CH(4) is assumed to have been generated only in the centre of the pile, whereas CO(2) was assumed to have been generated in a wider zone. The emissions of CH(4), CO(2) and N(2)O were at the highest in the beginning when nearly the whole pile had temperatures in the range of thermophilic microorganisms. This leads to the assumption that mainly thermophilic microorganisms formed the gases. The most important gas for global warming was found to be nitrous oxide. (C) 2004 Elsevier Ltd. All rights reserved.