Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms

Methane emissions from manure management represent an important mitigation opportunity, yet emission quantification methods remain crude and do not contain adequate detail to capture changes in agricultural practices that may influence emissions. Using the Canadian emission inventory methodology as...

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Main Authors: A C VanderZaag, J D MacDonald, L Evans, X P C Vergé, R L Desjardins
Format: Article
Language:English
Published: IOP Publishing 2013-01-01
Series:Environmental Research Letters
Subjects:
Online Access:https://doi.org/10.1088/1748-9326/8/3/035008
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author A C VanderZaag
J D MacDonald
L Evans
X P C Vergé
R L Desjardins
author_facet A C VanderZaag
J D MacDonald
L Evans
X P C Vergé
R L Desjardins
author_sort A C VanderZaag
collection DOAJ
description Methane emissions from manure management represent an important mitigation opportunity, yet emission quantification methods remain crude and do not contain adequate detail to capture changes in agricultural practices that may influence emissions. Using the Canadian emission inventory methodology as an example, this letter explores three key aspects for improving emission quantification: (i) obtaining emission measurements to improve and validate emission model estimates, (ii) obtaining more useful activity data, and (iii) developing a methane emission model that uses the available farm management activity data. In Canada, national surveys to collect manure management data have been inconsistent and not designed to provide quantitative data. Thus, the inventory has not been able to accurately capture changes in management systems even between manure stored as solid versus liquid. To address this, we re-analyzed four farm management surveys from the past decade and quantified the significant change in manure management which can be linked to the annual agricultural survey to create a continuous time series. In the dairy industry of one province, for example, the percentage of manure stored as liquid increased by 300% between 1991 and 2006, which greatly affects the methane emission estimates. Methane emissions are greatest from liquid manure, but vary by an order of magnitude depending on how the liquid manure is managed. Even if more complete activity data are collected on manure storage systems, default Intergovernmental Panel on Climate Change (IPCC) guidance does not adequately capture the impacts of management decisions to reflect variation among farms and regions in inventory calculations. We propose a model that stays within the IPCC framework but would be more responsive to farm management by generating a matrix of methane conversion factors (MCFs) that account for key factors known to affect methane emissions: temperature, retention time and inoculum. This MCF matrix would be populated using a mechanistic emission model verified with on-farm emission measurements. Implementation of these MCF values will require re-analysis of farm surveys to quantify liquid manure emptying frequency and timing, and will rely on the continued collection of this activity data in the future. For model development and validation, emission measurement campaigns will be needed on representative farms over at least one full year, or manure management cycle (whichever is longer). The proposed approach described in this letter is long-term, but is required to establish baseline data for emissions from manure management systems. With these improvements, the manure management emission inventory will become more responsive to the changing practices on Canadian livestock farms.
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spelling doaj.art-79c7be639c714821bcecd25a18f4cf672023-08-09T14:40:05ZengIOP PublishingEnvironmental Research Letters1748-93262013-01-018303500810.1088/1748-9326/8/3/035008Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farmsA C VanderZaag0J D MacDonald1L Evans2X P C Vergé3R L Desjardins4Agriculture and Agri-Food Canada , Ottawa, ON, CanadaEnvironment Canada , Gatineau, QC, CanadaAgriculture and Agri-Food Canada , Ottawa, ON, CanadaAgriculture and Agri-Food Canada , Ottawa, ON, CanadaAgriculture and Agri-Food Canada , Ottawa, ON, CanadaMethane emissions from manure management represent an important mitigation opportunity, yet emission quantification methods remain crude and do not contain adequate detail to capture changes in agricultural practices that may influence emissions. Using the Canadian emission inventory methodology as an example, this letter explores three key aspects for improving emission quantification: (i) obtaining emission measurements to improve and validate emission model estimates, (ii) obtaining more useful activity data, and (iii) developing a methane emission model that uses the available farm management activity data. In Canada, national surveys to collect manure management data have been inconsistent and not designed to provide quantitative data. Thus, the inventory has not been able to accurately capture changes in management systems even between manure stored as solid versus liquid. To address this, we re-analyzed four farm management surveys from the past decade and quantified the significant change in manure management which can be linked to the annual agricultural survey to create a continuous time series. In the dairy industry of one province, for example, the percentage of manure stored as liquid increased by 300% between 1991 and 2006, which greatly affects the methane emission estimates. Methane emissions are greatest from liquid manure, but vary by an order of magnitude depending on how the liquid manure is managed. Even if more complete activity data are collected on manure storage systems, default Intergovernmental Panel on Climate Change (IPCC) guidance does not adequately capture the impacts of management decisions to reflect variation among farms and regions in inventory calculations. We propose a model that stays within the IPCC framework but would be more responsive to farm management by generating a matrix of methane conversion factors (MCFs) that account for key factors known to affect methane emissions: temperature, retention time and inoculum. This MCF matrix would be populated using a mechanistic emission model verified with on-farm emission measurements. Implementation of these MCF values will require re-analysis of farm surveys to quantify liquid manure emptying frequency and timing, and will rely on the continued collection of this activity data in the future. For model development and validation, emission measurement campaigns will be needed on representative farms over at least one full year, or manure management cycle (whichever is longer). The proposed approach described in this letter is long-term, but is required to establish baseline data for emissions from manure management systems. With these improvements, the manure management emission inventory will become more responsive to the changing practices on Canadian livestock farms.https://doi.org/10.1088/1748-9326/8/3/035008activity dataemission measurementsliquid manuremethane conversion factor
spellingShingle A C VanderZaag
J D MacDonald
L Evans
X P C Vergé
R L Desjardins
Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms
Environmental Research Letters
activity data
emission measurements
liquid manure
methane conversion factor
title Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms
title_full Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms
title_fullStr Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms
title_full_unstemmed Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms
title_short Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms
title_sort towards an inventory of methane emissions from manure management that is responsive to changes on canadian farms
topic activity data
emission measurements
liquid manure
methane conversion factor
url https://doi.org/10.1088/1748-9326/8/3/035008
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AT levans towardsaninventoryofmethaneemissionsfrommanuremanagementthatisresponsivetochangesoncanadianfarms
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