Housefly maggot-treated composting as sustainable option for pig manure management. (January 2015)

• Record Type: Journal Article
• Authors: Zhu, Feng-Xiang; Yao, Yan-Lai; Wang, Su-Juan; Du, Rong-Guang; Wang, Wei-Ping; Chen, Xiao-Yang; Hong, Chun-Lai; Qi, Bing; Xue, Zhi-Yong; Yang, Hong-Quan
• Is Part Of: Waste management. Volume 35(2015)
• Page Start: 62
• Page End: 67
• Publication Date: 2015-01
• Subjects: Pig manure -- Maggot-treated composting -- Maggots as feed -- Organic fertilizer; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2014.10.005
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Housefly maggot-treated composting can be a sustainable alternative for pig manure management. This technology can achieve high-quality organic fertilizer and maggots as feed. The contents of TNPK in organic fertilizer exceeded the requirements of the national standard. Maggots produced as feed at a 0.5% maggot inoculum level met the commercial fish meal requirements. Abstract: In traditional composting, large amounts of bulking agents must be added to reduce the moisture of pig manure, which increases the cost of composting and dilutes the N, P and K content in organic fertilizers. In this study, maggot treatment was used in composting instead of bulking agents. In experiment of selecting an optimal inoculum level for composting, the treatment of 0.5% maggot inoculum resulted in the maximum yield of late instar maggots, 11.6% (maggots weight/manure weight). The manure residue became noticeably granular by day 6 and its moisture content was below 60%, which was suitable for further composting without bulking agents. Moreover, in composting experiment with a natural compost without maggot inoculum and maggot-treated compost at 0.5% inoculum level, there were no significant differences in nutrient content between the two organic fertilizers from the two treatments (paired Student's t 15 = 1.0032, P = 0.3317). Therefore, maggot culturing did not affect the characteristics of the organic fertilizer. The content of TNPK (total nitrogen + total phosphorus + total potassium) in organic fertilizer from maggot treatment was 10.72% (dry weight), which was far more than that of organic fertilizer made by conventional composting with bulking agents (about 8.0%). Dried maggots as feed meet the national standard (GB/T19164-2003) for commercial fish meal in China, which contained 55.32 ± 1.09% protein; 1.34 ± 0.02% methionine; 4.15 ± 0.10% lysine. This study highlights housefly maggot-treated composting can be considered sustainable alternatives for pig manure management to achieve high-quality organic fertilizer and maggots as feed without bulking agents.