Impact of different nitrogen source on the compost quality and greenhouse gas emissions during composting of garden waste

To overcome the problems of difficult degradation of garden waste and long composting period, some conditioner is often added in the composting process. However, different conditioner has different effects on the material transformation and composting quality in composting. In order to explore the influence of different nitrogen source material on the greenhouse gas and compost quality in the composting of garden waste, taking garden waste as compost material and adding soil as control, we respectively added chicken manure, pig manure and sheep manure as nitrogen source conditioner, and conducted a 48-day composting experiment in a forced 45-l ventilation compost reactor. The results showed that composting with livestock manure reduced nitrogen loss and facilitated organic matter humification. Specially, compared to the control treatment of garden waste add soil (CK), the addition of chicken manure promoted the conversion of total organic carbon (TOC) to humic substances (HS), as well as reduced nitrous oxide (N2O) emissions during garden waste composting. Based on a redundancy analysis, NH4+­N, organic nitrogen (OrgN), total nitrogen (TN) and HS directly affected CH4 emissions, while N2O emissions were directly influenced by dissolved organic carbon (DOC), TOC and NO3−-N during garden waste composting. Based on a factor analysis, the compost quality was chicken manure(CM) > sheep manure(SM) > pig manure(PM). These results suggested that garden waste composting with the addition of chicken manure improved the effectiveness compost product, produced a mature and zero-side effect compost and reduced nitrogen losses.