title: Direct green waste land application: How to reduce its impacts on greenhouse gas and volatile organic compound emissions?
abstract: Direct land application as an alternative to green waste (GW) disposal in landfills or composting requires an understanding of its impacts on greenhouse gas (GHG) and volatile organic compound (VOC) emissions. We investigated the effects of two approaches of GW direct land application, surface application and soil incorporation, on carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), and VOC emissions for a 12month period. Five treatments were applied in fall 2013 on fallow land under a Mediterranean climate in California: 30cm height GW on surface; 15cm height GW on surface; 15cm height GW tilled into soil; control+till; control+no till. In addition, a laboratory experiment was conducted to develop a mechanistic understanding of the influence of GW application on soil O2 consumption and GHG emission. The annual cumulative N2O, CO2 and VOC emissions ranged from 1.6 to 5.5kgN2O-Nha(-1), 5.3 to 40.6MgCO2-Cha(-1) and 0.6 to 9.9kgVOCha(-1), respectively, and were greatly reduced by GW soil incorporation compared to surface application. Application of GW quickly consumed soil O2 within one day in the lab incubation. These results indicate that to reduce GHG and VOC emissions of GW direct land application, GW incorporation into soil is recommended.
authors.affiliation: Department of Land, Air & Water Resources, University of California, Davis, United States. Electronic address: wyjzhu@ucdavis.edu.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhu-Barker
authors.affiliation: Department of Land, Air & Water Resources, University of California, Davis, United States.
authors.forename: Martin
authors.initials: M
authors.lastname: Burger
authors.affiliation: Department of Land, Air & Water Resources, University of California, Davis, United States.
authors.forename: William R
authors.initials: WR
authors.lastname: Horwath
authors.affiliation: Department of Civil & Environmental Engineering, University of California, Davis, United States.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Green
mesh_terms: D000383:Agriculture; D000393:Air Pollutants / Q000032:analysis*; D002140:California; D004784:Environmental Monitoring; D017752:Greenhouse Effect; D008697:Methane / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis; D012037:Refuse Disposal / Q000379:methods*; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D055549:Volatile Organic Compounds; D009609:Nitrous Oxide; D008697:Methane
keywords: Ammonia oxidation; Carbon dioxide; Denitrification; Nitrous oxide; Oxygen consumption; Soil