| The oil cake of rubber seed and sawdust were used as the basic raw materials for composting. Three treatments with different ratios of rubber seed oil cake and sawdust were set up to investigate their effect on composting process and the changes of activity organic carbon. (treatment 1：20% rubber seed oil cake + 70% sawdust and 10% phosphogypsum, treatment 2：30% rubber seed oil cake + 60% sawdust and 10% phosphogypsum, treatment 3：40% rubber seed oil cake + 50% sawdust and 10% phosphogypsum, W/W）. Temperature, pH, C/N ratio and germination index were tested to evaluate composting process, TOC（Total organic carbon）, LOC（labile organic carbon） and LOC/TOC were studied to investigated transformation of organic carbon during composting. The results showed that：the thermophilic phase（temperature > 50 ℃） were obviously prolonged in the treatments with more rubber seed oil cake added（days of thermophilic phase in treatment 1, treatment 2 and treatment 3 were 7 days, 11 days and 11 days, respectively）. Meanwhile, the C/N ratio was decreased along rubber seed oil cake ratio increasing（at the end of composting, C/N ratio of treatment 1, treatment 2 and treatment 3 were 24.7, 18.6 and 16.5, respectively）. Adding rubber seed oil cake could significantly increased labile organic carbon absolute and relative content, after composting process, LOC contents of treatment 1, treatment 2 and treatment 3 increased by 15.5%, 12.4% and 23.8%，and reached to 27.6 g·kg-1、29.0 g·kg-1 and 33.8 g·kg-1, LOC/TOC ratio reached to 8.3%, 10.4% and 12.7%. |
