The effects of worms, clay and biochar on CO2 emissions during production and soil application of co-composts
Résumé
In this study we evaluated CO
2
emissions during composting of green wastes with clay and/or biochar
in the presence and absence of worms (species of the genus
Eisenia
), as well as the effect of those amendments
on carbon mineralization after application to soil. We added two different doses of clay, biochar or their mixture
to pre-composted green wastes and monitored carbon mineralization over 21 days in the absence or presence
of worms. The resulting co-composts and vermicomposts were then added to a loamy Cambisol and the CO
2
emissions were monitored over 30 days in a laboratory incubation. Our results indicated that the addition of
clay or clay/biochar mixture reduced carbon mineralization during co-composting without worms by up to 44 %.
In the presence of worms, CO
2
emissions during composting increased for all treatments except for the low
clay dose. The effect of the amendments on carbon mineralization after addition to soil was small in the short
term. Overall, composts increased OM mineralization, whereas vermicomposts had no effect. The presence of
biochar reduced OM mineralization in soil with respect to compost and vermicompost without additives, whereas
clay reduced mineralization only in the composts. Our study indicates a significant role of the conditions of
composting on mineralization in soil. Therefore, the production of a low CO
2
emission amendment requires
optimization of feedstocks, co-composting agents and worm species.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...