Effect of fresh green waste and green waste compost on mineral nitrogen, nitrous oxide and carbon dioxide from a Vertisol

Journal Article · Mon Aug 15 00:00:00 EDT 2011 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2011.03.019· OSTI ID:21578455

Dalal, Ram C ^[1]; Harper, Stephen M ^[2]; Menzies, Neal W ^[1]

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1. School of Land, Crop and Food Sciences, University of Queensland, St. Lucia, QLD 4072 (Australia)
2. Department of Employment, Economic Development and Innovation, Warrego Highway, Gatton, QLD 4343 (Australia)

Incorporation of organic waste amendments to a horticultural soil, prior to expected risk periods, could immobilise mineral N, ultimately reducing nitrogen (N) losses as nitrous oxide (N{sub 2}O) and leaching. Two organic waste amendments were selected, a fresh green waste (FGW) and green waste compost (GWC) as they had suitable biochemical attributes to initiate N immobilisation into the microbial biomass and organic N forms. These characteristics include a high C:N ratio (FGW 44:1, GWC 35:1), low total N (<1%), and high lignin content (>14%). Both products were applied at 3 t C/ha to a high N (plus N fertiliser) or low N (no fertiliser addition) Vertisol soil in PVC columns. Cumulative N{sub 2}O production over the 28 day incubation from the control soil was 1.5 mg/N{sub 2}O/m{sup 2}, and 11 mg/N{sub 2}O/m{sup 2} from the control + N. The N{sub 2}O emission decreased with GWC addition (P < 0.05) for the high N soil, reducing cumulative N{sub 2}O emissions by 38% by the conclusion of the incubation. Analysis of mineral N concentrations at 7, 14 and 28 days identified that both FGW and GWC induced microbial immobilisation of N in the first 7 days of incubation regardless of whether the soil environment was initially high or low in N; with the FGW immobilising up to 30% of available N. It is likely that the reduced mineral N due to N immobilisation led to a reduced substrate for N{sub 2}O production during the first week of the trial, when soil N{sub 2}O emissions peaked. An additional finding was that FGW + N did not decrease cumulative N{sub 2}O emissions compared to the control + N, potentially due to the fact that it stimulated microbial respiration resulting in anaerobic micro sites in the soil and ultimately N{sub 2}O production via denitrification. Therefore, both materials could be used as post harvest amendments in horticulture to minimise N loss through nitrate-N leaching in the risk periods between crop rotations. The mature GWC has potential to reduce N{sub 2}O, an important greenhouse gas.

• OSTI ID: 21578455
• Journal Information: Waste Management, Vol. 31, Issue 8; Other Information: DOI: 10.1016/j.wasman.2011.03.019; PII: S0956-053X(11)00164-4; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BIOMASS
CARBON DIOXIDE
COMPOST
CONTROL
CROPS
DENITRIFICATION
ENVIRONMENT
GREENHOUSE GASES
HAZARDS
HORTICULTURE
LEACHING
LIGNIN
MINERALS
NITRATES
NITROGEN
NITROUS OXIDE
POLLUTION ABATEMENT
PVC
SOILS
SUBSTRATES
AGRICULTURE
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
DISSOLUTION
ELEMENTS
ENERGY SOURCES
HALOGENATED ALIPHATIC HYDROCARBONS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
ORGANIC WASTES
OXIDES
OXYGEN COMPOUNDS
POLYMERS
POLYSACCHARIDES
POLYVINYLS
RENEWABLE ENERGY SOURCES
SACCHARIDES
SEPARATION PROCESSES
WASTES