Evolution of non-dissolved particulate organic matter during composting of sludge with straw.
Long term composting induces loss of C and organic matter stabilisation. These two processes may have opposite effects on long term carbon storage in soils. To check whether raw materials should be composted or not before being spread on the soil, changes in particle size fractions were quantified during composting of 9 tons of sewage sludge and straw. Both the mass of the fine fraction (<2 microm) and the amount of carbon contained in it increased after seven months, respectively, +37% and +43%. The fine fraction contributes to carbon sequestration. A literature review supported the assumption that composting should increase long term C storage. Nevertheless, soil texture or agricultural practices modify the behaviour of this fraction. Thus, the fractionation method used for soils is relevant to predict the effect of composting as a mitigation option in greenhouse gas reduction strategies, but is not sufficient in itself.
Robin
Paul
P
UMR 1069 SAS Sols, Agro et hydrosystèmes, Spatialisation, INRA, Agrocampus, CIRAD, F-35000 Rennes, France. paul.robin@rennes.inra.fr
Ablain
Frédérique
F
Yulipriyanto
Hiéronymus
H
Pourcher
Anne-Marie
AM
Morvan
Thierry
T
Cluzeau
Daniel
D
Morand
Philippe
P
D000332:Aerobiosis; D000383:Agriculture; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D006812:Humic Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D012987:Soil; D013997:Time Factors; D014908:Triticum / Q000382:microbiology
D006812:Humic Substances; D052638:Particulate Matter; D012722:Sewage; D012987:Soil; D002244:Carbon