Our purpose was to determine whether or not aerobic and anaerobic wast
e treatment differ in the conservation of waste C. The stability of wa
ste C was evaluated by determining mass losses of C during aerobic and
anaerobic waste treatment and CO2 evolution during decomposition in s
oil using materials of the same origin. During waste treatment, mass l
osses of C were highest in the aerobic treatment and composting and lo
west during anaerobic waste treatment. Following their application to
soil, the amount of CO2-C evolved from wastes was highest from aerobic
ally-treated material, intermediate from non-decomposed material and l
owest from aerobically-treated and composted waste. Measured in terms
of the decomposition of waste C during treatment and in the soil, the
effect on the C stabilization efficiencies of the various waste treatm
ent was ranked as follows: aerobically-treated and composted > non-dec
omposed > anaerobically-treated. It was pointed out that the larger N
recirculation through anaerobically-treated wastes may be of equal or
greater importance for the maintenance of soil organic matter contents
in agricultural soils compared with the higher stabilization of waste
C against decomposition. On the other hand, for reclaiming degraded s
oils, aerobically-treated (composted) wastes are better than anaerobic
ally-degraded wastes. (C) 1997 Elsevier Science Ltd.