Distribution of C and N mineralization of a sludge compost within particle-size fractions.
The contribution of particle-size fractions to carbon (C) and nitrogen (N) mineralization of sludge compost was investigated. Particle-size fractionation was performed using "dry" (sieving of total dry compost) and "wet" (dispersion of compost in water, followed by sieving) fractionation methods, then C and N mineralization of the separated fractions were measured during incubation in soil. The "dry" fractionation did not allow the actual particle-size distribution of compost to be estimated accurately. Out of all the "wet" fractions, the [0-50 microm] fraction was the most significant fraction in compost mass and contributed the most to the N mineralization of sludge compost in soil. Its low degradability, positive N mineralization and similarities with sludge OM suggest that the most humified sludge organic matter was located in this fraction, which would probably contribute to C storage and N availability after compost application in soil. Other fractions (>200 microm) were more readily biodegradable and induced N immobilization.
Doublet
J
J
INRA, UMR 1091, Environnement et Grandes Cultures, F-78850 Thiverval-Grignon, France. jeremy.doublet@veolia.com
Francou
C
C
Pétraud
J P
JP
Dignac
M F
MF
Poitrenaud
M
M
Houot
S
S
D002244:Carbon / Q000032:analysis*; D005591:Chemical Fractionation; D008401:Gas Chromatography-Mass Spectrometry; D007700:Kinetics; D008903:Minerals / Q000737:chemistry*; D009584:Nitrogen / Q000032:analysis*; D009930:Organic Chemicals; D010316:Particle Size; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D013696:Temperature
D008903:Minerals; D009930:Organic Chemicals; D012722:Sewage; D012987:Soil; D002244:Carbon; D009584:Nitrogen