fact sheet Agriculture & Greenhouse Gas Mitigation · Greenhouse gas mitigation W hen agricultural...

BC A gr iculture & Food Climate Act ion Init iat ive | www. BC A gClimateAct ion.ca fact sheet 3 (JANUARY 20 0 9) 1

Greenhouse gas mitigation

When agricultural producers adjust farm practices and/or technologies to reduce their

greenhouse gas (GHG) emissions or to sequester (store) carbon in soils or vegetation, they are engaging in greenhouse gas mitigation.

In a global context, agriculture is thought to have significant potential for mitigating climate change in the following areas:

Reduction of emissions

Greenhouse gas emissions from agricultural activities (see Fact Sheet 1) can be reduced through more efficient management of the carbon and nitrogen flows within agricultural systems.

The farm management practices best suited to emission reduction are region and site specific. However, some practices are commonly recognized for minimizing

greenhouse gas emissions and many of these are identified below.

Enhancement of removals

Ecosystems associated with agriculture are known to hold substantial carbon reserves; primarily in soil organic matter.

Certain farm practices can facilitate increased plant uptake or soil storage of carbon (or reduce the loss of stored carbon). These practices are known as carbon sequestration or the creation of carbon “sinks.”

In particular, agroforestry systems and perennial plantings may store significant quantities of vegetative carbon. Only vegetation that is retained over the long term is effective in storing carbon.

Avoidance (displacement) of emissions

The agricultural sector can potentially assist society to avoid (or displace) GHG emissions. Fuels produced

f a c t s h e e t 3 —

Agriculture & Greenhouse

Gas Mitigation

photo cour tesy of Investment A griculture Foundation


from crops and agricultural residues can displace fossil fuels and enable emission reduction at the combustion stage. However, the extent to which emissions are displaced depends on the overall carbon “footprint” of each fuel.

Opportunities & co-benefits

There are co-benefits associated with each of the mitigation measures identified within this fact sheet. Beyond their capacity to impact climate change, these mitigation measures may also improve the environmental and economic well-being of farm operations.

For some mitigation measures, there are also likely to be economic incentives. Developing offset projects or participating in cost-sharing programs may assist producers with implementation costs. However, it is unlikely that these incentives (alone) will provide sufficient economic return to drive changes in farm practices.

Shifts in market demands are another opportunity (or threat) for producers to consider. Policy, regulation and public perception is moving steadily toward higher levels of accountability with regard to greenhouse gas emissions.

Producers that have minimized their “carbon footprints” will ensure continued access to markets and may — if they act quickly — have a competitive advantage.

Management practices & ghg mitigation

Many of the beneficial management practices already familiar to the BC agriculture sector are also contributors to GHG mitigation. Farmers in BC have undertaken incremental GHG reductions and removals, in part though practices encouraged through the Environmental Farm Plan Program.

However, thinking of these practices in relation to GHG mitigation is relatively new. At present, there is limited BC-based research documenting specific impacts of farm practices on greenhouse gas emission levels.

Nonetheless, the following practices are widely understood to assist in reducing GHG emissions or in sequestering carbon.1

1 More information is available through the Reference & online resources listed at the end of this document. Future fact sheets will provide further detail on various practices.



Crop land management

Crop lands are frequently managed intensively and provide a number of opportunities to reduce net GHG emissions through farm practices.

Agronomy

Improvements in agronomic practices (that often increase yields) can also lead to increased carbon storage. Some examples of these practices:

■ Using crop rotation systems

■ Decreasing summer and bare fallow

■ Using cover crops and strip cropping — adds carbon to soils and extracts available

Nutrient management

Improving the timing and rate of application of nitrogen fertilizers helps to avoid leaching/runoff and emissions of nitrous oxide (N2O) that result from surplus nitrogen. Efficiency of uptake also reduces the amount required, resulting in costs savings for the producer.

Nutrient management practices linked to GHG emission reduction include:

■ Reducing the use of excess fertilizer, pesticide and other inputs

■ Adjusting fertilizer applications to precise needs of crop

■ Timing applications to minimize fertilizer loss (through runoff etc.)

Tillage / residue management

Tillage and residue management practices impact soil health and organic content of soils. The following practices also relate to GHG mitigation:

■ Adopting conservation tillage — utilizing reduced or no-till practices

■ Retaining crop residues — leaving plant residues on the soil surface to build soil carbon

■ Avoiding burning of residues — burning releases methane and nitrous oxide

photo by Walter Goerzen


Grazing land management & pasture improvement

Well managed pastures have healthier plants that produce more biomass and consequently take up more CO2. More digestible feed also decreases methane production in livestock. Improved pasture has the potential to increase feeding efficiency, reduce feed and reseeding costs and increase animal productivity.

Appropriate forage selection

Different forages are suited to different micro-environments. Selecting the best plant composition for pastures will improve their productivity and long-term sustainability.

Rotational grazing

Using rotational grazing keeps pasture at its most digestible stage and prevents overgrazing. Allowing vegetation to recover improves carbon sequestration potential, prevents erosion and improves pasture productivity.

Livestock management

Improved feeding practices

More research is needed on feeding practices that decrease methane released through enteric fermentation. However, some practices believed to reduce methane quantities are:

■ Improving pasture quality and extending the grazing season

■ Using high quality feeds

■ Adding lipids to ruminant diet2

2 Lipids include plant derived oils such as canola and soybean oils and increase energy density and decrease methane emissions.

■ Using dietary additives (more research is needed in this area)

Manure management

Animal manure can release substantial amounts of the greenhouse gases nitrous oxide and methane. The greenhouse gas released by manure can be mitigated through management practices such as:

■ Covering manure storage

■ Improving efficiency of manure as a nutrient source — improving timing and rate of application

■ Collecting and combusting methane

Agroforestry

Agroforestry is an intensive land management system that optimizes the benefits from biological interactions created when trees and/or woody perennials are deliberately combined with crops and/or livestock.

The five main agroforestry systems are:

■ Alleycropping

■ Shelterbelts & timberbelts

■ Integrated riparian management

■ Silvopasture

■ Forest farming

These integrated systems have the benefit of divers-ifying sources of income (from timber or non-timber forest products) as well as contributing to GHG mitigation by sequestering carbon in trees (and potentially in soil).

Two agroforestry systems that have wide applicability for agricultural producers are shelterbelts and integrated riparian management.


Shelterbelts & timberbelts

Shelterbelts and timberbelts are managed rows of trees, shrubs and/or grasses adjacent to other agricultural practices (includes windbreaks, hedgerows and fence line plantings) that provide a number of benefits including:

■ Potential to fix carbon in soils and vegetation

■ Protection of exposed buildings from heat loss or gain

■ Shelter and shade for both wildlife and livestock

■ Reduction of soil erosion, soil moisture loss and crop stress

■ Barriers for dust and odour

■ Timber and non-timber resources

Integrated riparian management

Integrated riparian management (IRM) is the management of areas adjacent to aquatic zones with planned combinations of trees and appropriate plant material to enhance and protect habitat while providing selective timber and non-timber resources.

IRM ensures maintenance of water resources, enhances bank stability, recharges groundwater and has potential to sequester carbon. Appropriately managed riparian systems also retain the health of surrounding soils by moderating erosion and runoff.

Conversion of marginal lands to permanent cover

Allowing land to revert to native vegetation reduces GHG emissions associated with production and sequesters carbon. This can involve large parcels of land that become “set-asides” or small areas such as riparian zones, field margins or shelterbelts.

Because land conversion can involve loss of agricultural productivity, it is generally only an option for surplus land or land of marginal productivity.

Energy efficiency & renewable energy3

For all agricultural production systems, minimizing inefficiencies in energy consumption, particularly of fossil fuels, reduces carbon footprints. For energy

3 Future fact sheets will provide detailed information regarding energy issues.



intensive production systems, improved energy efficiency has the potential to result in substantial cost savings.

Each farm operation will have different opportunities for energy efficiency but some first steps toward energy efficiency are:

■ Conducting an energy audit of farm operations

■ Ensuring that all heating and cooling systems (including pipes) are in good working order and there are no leaks

■ Using timers, sensors or variable speed drives on ventilation, heating, cooling and lighting systems that don’t need to run all the time — ensure control systems are upgraded regularly

■ Replacing PTO powered equipment and diesel generators with electrical motors and grid connections where possible

■ Installing energy efficient technologies where possible

Renewable energy technologies

Opportunities for generating or using renewable energy on-farm will depend on the type and scale of operation and its location.

In addition to reducing GHG emissions, renewable energy decreases reliance on energy sources with volatile pricing and energy production creates new economic diversification opportunities for BC agricultural producers.

Small scale renewable energy generation systems may enable electrification of remote equipment such as irrigation and watering pumps where grid access is challenging.

Each renewable energy technology requires its own detailed explanation and analysis. Future fact sheets will include the following topics:

■ Bioenergy and biofuels

■ Solar and wind systems

■ Geothermal

photo f rom iStock


References & online resources

Intergovernmental Panel on Climate Change

Agriculture, in Climate Change 2007: Mitigation4www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter8.pdf

Climate Change Agricultural Awareness Project

Best management practices: fertilizer management, manure management, soil conservation, pasture management www.ccse-swcc.nb.ca/climat/index.cfm?bpg=1&lg=en

4 Smith, P., D. Martino, Z. Cai, D. Gwary, H. Janzen, P. Kumar, B. McCarl, S. Ogle, F. O’Mara, C. Rice, B. Scholes, O. Sirotenko, 2007: Agriculture. In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R . Davidson, P.R . Bosch, R . Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

BC Agricultural Research & Development Corporation

Environmental Farm Plan Program & Beneficial Management Practices Program http://www.ardcorp.ca/index.php?page_id=14

BC Agroforestry Industry Development Initiative, Federation of BC Woodlot Associations

www.woodlot.bc.ca/agroforestry

Agroforestry Division, Agriculture & Agri-food Canada

www4.agr.gc.ca/AAFC-AAC/ display-afficher.do?id=1186581166412&lang=eng

Ontario Ministry of Agriculture Food & Rural Affairs

information on a range of energy efficiency and renewable technologies www.omafra.gov.on.ca/english/engineer/ energy.html#renew

funding provided by The Climate Action Initiative is facilitating a proactive approach to climate change issues within the BC agriculture and food sector. By developing climate action resources, the Initiative raises awareness and assists the industry in meeting the challenges, and acting upon the opportunities, presented by climate change. The Initiative is led by an advisory committee made up of BC agriculture producers and food processors.

The Climate Action Initiative is a joint undertaking of BC Agriculture Council and the Investment Agriculture Foundation, with funding provided by Agriculture & Agri-Food Canada and the BC Ministry of Agriculture & Lands.

For more information about the Climate Action Initiative, please contact Initiative Coordinator, Emily MacNair at 250-356-1666 or [email protected] .

climate action resourcesfor the agricultural & food sectorin British Columbia

w w w.BCA g ClimateAction.ca

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