Aiming to assess the efficiency of white clove (WC) as an alternative nitrogen source for composting and to facilitate the utilization of orchard waste, WC as compared with chicken manure (CM) was aerobically composted with apple tree leaves (ATL) in initial C/N ratios of 25(R25), 30(R30) and 35(R35). The results show that WC facilitated the rapid and harmless treatment of ATL with the compost temperature above 55°C for more than 3 days. After composting, for all final products, organic matter content was 69.9%-72.9%, electrical conductivity (EC) 1.48-2.31 ms cm-1, germination index (GI) more than 80% and C/N ratios less than 20. Among all treatments, the product from R30 was most nutrient-rich. Compared with CM, WC facilitated the harmless treatment of ATL and required less time for high quality compost production. It is concluded that WC is an excellent replacement for animal manure as a nitrogen source in field composting of orchard waste in areas with limited transportation. WC and ATL can produce high quality organic fertilizer and initial C/N ratio of 30 is recommended.
Keywords: Apple tree leaves; C/N ratio; composting; nutrient; white clover.