2.5. Chemical analysis
The EC and pH of the compost was measured in deionized water
with 1:10 (w/v) compost (fresh):water ratio with an EC meter and
a pH meter.
A part of freeze-dried compost samples were wrapped with aluminum
foil and accurately weighed to the nearest 70 mg. Then the
contents of TC, TN in the compost samples were determined by
using elemental analyzer (Vario EL, Germany).
Water extracts were prepared by shaking freeze-dried compost
samples with deionized water in 1:10 (w/v) compost:water ratio
for 2 h. The suspension was then centrifuged at 10,000 rpm for
30 min, filtered through a 0.45 mm membrane filter. The contents
of DC, DN in the filtrate was determined by using elemental analyzer
(Elemantar Vario EL/micro cube, Germany).