Affiliations: College of Natural Resources and Environment, South
China Agricultural University, Wushan, Guangzhou, 510642,
E-mail:naphone@hotmail.com | Department of Biology, Hong Kong Baptist University,
Kowloon, HKSAR
Abstract: Composting is now suggested as one of the environmentallyand
friendly alternative method for disposal of solid organic wastes, as it leads
to minimization, stabilization, and utilization of organic waste.
Transformations of nitrogen were investigated inco-composting of pig manure
with different amendments, such as sawdust and leaves. Samples were analyzed
for pH, total-N, soluble NH4-N, soluble NO3-N and soluble organic-N. The
total-N increased after 63 days of composting, as well as the soluble NO3-N and
soluble organic-N. Soluble NH4-N increased significantly and showed peak values
at day 7, thereafter decreased sharply and gradually to lower levels. Seed
germination index (GI) showed that co-composting of pig manure with sawdust
reached maturity after 49 days of composting, while co-composting of pig manure
with sawdust and leaves required shorter time for 35 days. Soluble NH4-N was
significantly negatively (P<0.05), while soluble NO3-N and soluble organic-N
were significantly positively (P<0.05), correlated with seed germination
index (GI). Addition of leaves in co-composting of pig manure with sawdust had
no significant impacts on nitrogen transformations, but it was beneficial for
maturity of pig manure compost.
