Mitigating GHG emissions from agriculture

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Mitigating GHG emissions from agriculture

• Role of sustainable agriculture

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Mitigation principles

• Reducing emissions
• reduce emissions by managing the C and N flows in
  agricultural systems
• approaches would vary from region to region
• local conditions
• Enhancing removals
• storing (sequestering) C
• methods that increase photosynthesis or slows
  return of C via respiration
• soil organic matter (SOM) is a large store (sink)
  for C in soils

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• Avoiding emissions
• avoiding cultivation of new lands (deforestation)
• using bioenergy feed stocks to release C (via
  CO2) of recent origin rather than ancient C
  through combustion of fossil fuels

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Greenhouse gases Worldwide impacts, Julie Kerr
Casper, Facts On File, Inc., New York, 2010
5
Niggli, U., Fließbach, A., Hepperly, P. and
Scialabba, N. 2009. Low Greenhouse Gas
Agriculture Mitigation and Adaptation Potential
of Sustainable Farming Systems. FAO, April 2009,
Rev. 2 2009.
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Sustainable agriculture

• Sustainable agriculture is an agriculture
  production system that uses one or more practices
  that are environmentally sound and socially
  responsible
• Productivity and profit are still the focus of
  sustainable agriculture, but they must be
  achieved with the care of the environment and
  well-being of the farm household and local
  community
• Sustainable agriculture is not anti-technology,
  but embraces any useful technology provided that
  they do not cause harm to the environment
• The key to sustainability is to use optimally but
  not damage the environment

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• Sustainable agriculture deliberately lowers
  artificial or synthetic inputs and non-renewable
  energy sources, and replaces them with natural
  materials or methods
• Part of this is achieved by practicing integrated
  nutrient and pest management techniques

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Nutrient management

• Instead of artificial fossil fuel-based
  fertilisers, soil fertility can be gradually
  build up by
• growing nitrogen-fixing plants/microbes together
  with crops
• mulching using crop residues or animal manures
• composting
• reduce or eliminate soil tillage
• crop rotation and intercropping
• mixed (integrated) farming
• organic farming

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Pest management

• Control pests (as well as diseases) by natural
  methods
• biopesticides (from natural resources)
• biological control
• crop rotation and intercropping

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Nitrogen-fixing plants

• Nitrogen is an essential nutrient to plant growth
• Two groups of herbaceous and woody plants have
  the ability to fix atmospheric nitrogen in the
  soil
• at least 1,350 species of plants capable of
  nitrogen fixation, although only about 25 are
  extensively used today in agriculture and
  forestry
• Legumes are such as beans, peas, clover and
  alfalfa
• legumes popular in Malaysia Centrosema,
  Pueraria, Mucuna, Calopogonium
• Some plants have symbiotic relationship with
  Rhizobium, Frankia and Azotobacter bacteria,
  which form nodules in the roots
• Mycorrhizae fungi-root association also important

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Root nodules
http//www.allposters.com
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Mycorrhiza
Left plant without Mycorrhizae Right with
Mycorrhizae
Left plant without Mycorrhizae Right with
Mycorrhizae
http//www.botany.hawaii.edu/faculty/wong/Bot201/S
ymbiosis/Symbiosis.htm
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Mulching
Rice straws
Palm fronds
Leaf litter
Empty fruit bunches (EFB)
Ecomat (made from EFB)
http//thailand.ipm-info.org/components/mulching.h
tm
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Cover crops

• Common cover crops in Malaysia, in particular in
  oil palm plantations
• Pueraria javanica/phaseoloides
• Calopogonium mucunoides
• Centrosema pubescens
• Mucuna bracteata
• Arachis pintoi
• In addition to N-fixation, cover crops protect
  soil surface from erosion, conserve water,
  increase soil fertility through increased SOM
  (and biological activity) and addition of other
  nutrients

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Mucuna bracteata in oil palm
http//edmayang.com/products_mucuna_gallery.html
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Compost
Vermicomposting
Hot composting
http//www.compostguy.com/composting/hot-compostin
g-vs-vermicomposting/
http//aquirkyblog.com/tag/compostapalooza/
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Minimum or zero tillage

• Soil fertility can also be improved by minimizing
  or completely stopping tillage
• Ploughing is a common practice worldwide to
  control weeds and aerate the soil before sowing
• Ploughing, however, disturbs the soil, leaving it
  vulnerable to erosion, releases carbon dioxide as
  decomposition is promoted, and, in some cases,
  actually cause more, not less, weeds
• bringing up seeds closer to the soil surface for
  easier germination

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Crop rotation
Different season, different crop
Different field location, different crop (always
the same crops)
http//agriculture.kzntl.gov.za/publications/books
/plant_diseases/disease_4.htm
http//www.baap.lt/codes_gap/lithuania/chapter_2.h
tm
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Intercropping
Two or more crops planted together in the same
plot
http//www.environment.uwaterloo.ca/ers/faculty/mo
elbermann.htm
http//eucalyptusclones.com/eucalyptus.htm
Eucalyptus-sugar cane
Maize-soybean
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More efficient light water use

• Compared to monoculture crops, polyculture crops
  also use sunlight and water more effectively and
  often give higher yields

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Pest Management

• Instead of synthetic pesticides, the practice of
  polyculture helps to reduce the population of
  weeds and pests
• Polyculture is the culturing of two or more crops
  simultaneously, as opposed to monoculture, where
  only a single type crop is cultured, typical in
  conventional agriculture
• Monocultures produce a uniform population of a
  single crop species so this encourages weeds and
  pests since they are often host-specific
• Polycultures, in contrast, break up the
  uniformity of the crop population, and this
  discourages the spread and population of weeds
  and pests

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Control of insect pests

• Bacteria Bacillus thuringiensis exudes a harmless
  toxin to humans but deadly to insects (toxin
  formulated as biopesticides)
• Plutella xylostella (vegetables)
• Spodoptera sp. (vegetables, fruit and root crops)

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Plant weeds?!

• In Africa, maize has two common problems stem
  borers (Chilo partellus and Busseola fusca) and a
  parasitic weed known as African witchweed (Striga
  spp.)
• By planting Napier grass (Pennisetum purpureum)
  and Desmodium (Desmodium uncinatum), both weeds,
  along the maize rows, these weeds help to control
  both pests
• Napier grass attracts and actually kills the stem
  borer because the Napier grass contains a toxin
  deadly to the borer
• Desmodium exude a prohibitive chemical against
  Striga
• Method first introduced in Kenya and saw 60-70
  increase in maize yields

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Maize pests
http//www.arc.agric.za/home.asp?pid637
stem borer
http//www.rothamsted.ac.uk/chelsea/2005/
Striga weed
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Napier
http//www.arc.agric.za/home.asp?pid637
Maize-Napier
http//abbe.mysuperblogs.in/100707/p2/
Maize-Desmodium
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Beneficial fungi

• Beauveria bassiana
• Cylas formicarius (sweet potato)
• Lissorhoptrus brevirostris (rice)
• Verticilium lecanii
• Bemisia tabaci (vegetables)
• Myzus persicae (fruit and root crops)
• Trichoderma sp. as control of soil-borne
  pathogens
• Phytopthora capsici (vegetables, ornamentals)
• Rhizoctonia solani (vegetables, ornamentals)

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Beneficial insects

• Trichogramma sp.
• Mocis latipes (pasture)
• Heliothis virescens (maize)
• Plutella xylostella (vegetable)
• Diaphania sp. (cucumber)
• Telenomus sp.
• Spodoptera frugiperda (maize)
• Encarsia sp.
• Bemisia sp. (beans)

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Intercropping as a pest control
System Pests controlled
Maize-bean Meloidogyne sp.
Cabbage-tomato-sorghum-sesame Plutella xylostella
Maize-cassava-cucumber Spodoptera frugiperda
Cassava-bean Cassava-maize Erinnyis ello Lonchaea chalybea
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Mixed (or integrated) farming

• An agricultural system that consists of both crop
  and animal
• minimizes external inputs
• recycles all wastes within the system
• saves energy and money
• more stable income
• depending on more than one type of activitiy

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Rice-fish culture

• Rice-fish culture is the cultivation of wetland
  rice with fish
• practised with almost no external chemical
  fertilisers
• Besides fish providing an additional income to
  farmers, the wastes from these fishes (such as
  tilapia and carp) also help to increase the
  amount of organic fertiliser in the fields and
  the movement of these fishes help to spread the
  organic fertiliser more evenly than the farmer can

http//www.fao.org/docrep/005/x3185e/X3185e3.htm
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CIPAV mixed farming system

• Developed by the Foundation Center for the
  Investigation in Sustainable Systems of
  Agricultural Production (CIPAV), typifies the
  success of integrating and using local natural
  resources to produce several commodities
• The system consists of the simultaneous
  cultivation of sugar cane, food crops (like corn
  or rice) and tree fodder (trees or shrubs used
  for animal feed), together with the raising of
  sheep, pigs, ducks and fish

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CIPAV mixed farming system
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• The system works by minimising external inputs so
  that each component in the CIPAV system sustains
  one another
• Essentially, the crop residues serve as feed to
  the livestock and fish, and in turn, the wastes
  from the livestock and fish serve as fertiliser
  to the crops
• Moreover, their wastes, together with crop
  residues, are digested in a biodigester to
  produce fuel for household cooking and electricity

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• This mixed farming system recycles all wastes so
  that little is thrown away ones waste is indeed
  anothers food
• Reduces dependency on fossil fuels because of its
  self-sufficient system means little external
  input is required in fact, by being able to
  generate its own fuel from wastes means even less
  depedency on fossil fuels
• This mixed farming system recycles all wastes so
  that little is thrown away ones waste is indeed
  anothers food
• Reduces dependency on fossil fuels because of its
  self-sufficient system means little external
  input is required in fact, by being able to
  generate its own fuel from wastes means even less
  depedency on fossil fuels

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Cows and sheep
Food and Agriculture organization. 2001. Mixed
crop-livestock farming. A review of traditional
technologies based on literature and field
experience. Series title FAO Animal Production
and Health Paper - 152. Rome, Italy
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Chicken and fish
Food and Agriculture organization. 2001. Mixed
crop-livestock farming. A review of traditional
technologies based on literature and field
experience. Series title FAO Animal Production
and Health Paper - 152. Rome, Italy
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Livestock and crop
Food and Agriculture organization. 2001. Mixed
crop-livestock farming. A review of traditional
technologies based on literature and field
experience. Series title FAO Animal Production
and Health Paper - 152. Rome, Italy
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Crop-livestock farming in Malaysia
Oil palm and sheep
Rubber and sheep But problem of damaged trunks
with cattle-rubber or goat-rubber
http//www.fao.org/docrep/005/af298e/af298E21.htm
http//www.fao.org/DOCREP/004/X6543E/X6543E04.htm
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Organic farming

• Agriculture production that excludes (completely
  prohibits) the use of any
• synthetic agrochemicals
• plant and animal growth regulators
• livestock feed additives
• GM organisms
• Organic farming relies on, among others, crop
  rotation, green manure, compost, biological pest
  control, and mechanical cultivation to maintain
  soil productivity and control pests

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Organic farming acreage
http//www.organic-world.net/
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Distribution of organic land by continent
http//www.organic-world.net/
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In 2001, Malaysia only had 131 hectares
of organic land. But in 2006, the Ministry of
Agriculture and Agro-based Industry said that
Malaysia then had 2,367 hectares of organic land
(an 18x expansion or 3.6x increase per
year). Those could include non- certified
organic lands.
http//www.organic-world.net/
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http//www.freshplaza.com/news_detail.asp?id39955
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Can sustainable agriculture deliver?

• In 2006, the worlds largest study on sustainable
  agriculture was published
• This study covered 286 projects in 57 countries,
  involving 12.6 million farmers on 37 million
  hectares (about the size of Japan)

Dr. Jules Pretty Uni. of Essex, UK
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Increased yields

• Reported that farms adopting sustainable
  agriculture technologies saw an average yield
  increase of 79 per cent across a wide variety of
  crop types, including grain crops
• Wetland rice, for instance, saw a yield increase
  of over 20 per cent
• Furthermore, these farms helped to sequester
  (store) an annual average of 1.3 tonnes of carbon
  dioxide per hectare, totalling about 48 million
  tonnes of carbon dioxide a year

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Land use change

• Reversion of cropland to another, preferably
  closer to the original native vegetation
• convert to grassland
• less C removal from harvested material
• lesser soil disturbance
• revert drained cropland to wetland
• rapid C accumulation
• planting trees (agroforestry)
• reduce C emission
• C sequestation
• Drawback loss of agricultural productivity
• good only for marginal land or have surplus
  agricultural land

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Second generation biofuel

• Use of non-food plant parts as biofuel
• such as stem, leaves and stalk of maize plant
• Non food crops
• like jatropha (Jatropha curcas), Elephant grass
  (Miscanthus giganteus), and switchgrass (Panicum
  virgatum), hemp (Cannabis sativa)
• which grow well in poor fertile soils
• No competition with food
• Drawbacks
• have to do life cycle analysis to determine
  mitigation benefits
• may have positive net CO2 emissions
• non food plant parts have lower ethanol yield

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Reducing methane emission from rice fields

• Reduction in the CH4 efflux from rice fields can
  be made either by reducing the methane
  production, increasing methane oxidation, or
  reducing methane transport through plants
• Reduce CH4 emissions by
• mid-season drainage
• avoid year long flooding, no 3 times planting a
  year
• plant with wider spacing
• use sulfate-based fertilizers (ammonium sulfate
  and sodium sulfate)
• crop rotation wetland rice upland rice
• new rice cultivars

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• Rice plants influence the methane dynamics in
  paddy soils by
• (1) providing substrate in the form of root
  exudates to methanogens to enhance the production
  of CH4
• (2) transporting CH4 from soil to atmosphere
  (conduit effect)
• (3) creating aerobic microhabitat in rhizosphere,
  which is suitable for growth and multiplication
  of methanotropic bacteria responsible for CH4
  consumption

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Singh, S.N. 2009. Climate change and crops.
Springer,-Verlag, Berlin
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Animal feed management

• Livestock sources of CH4 are predominantly
  enteric (i.e., from the breath of ruminants and
  flatus of monogastric animals) as a result of
  feed digestion
• responsible for about 30 of global methane
  emission
• Replace fodder with
• feed concentrates
• adding oils to the diet
• improving pasture quality
• optimizing protein intake
• increase legume intake

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Biochar

• Biochar is a carbon-rich product obtained when
  biomass, such as wood, manure or leaves, is
  heated in a closed container with little or no
  available air
• Biochar is produced by heating the organic
  material under limited supply of oxygen and at
  high temperatures (lt700C)
• process called pyrolisis
• Like producing charcoal, but biochar is not used
  as field but placed into the soil to improve soil
  properties (increase soil nutrients, water
  retention, and infiltration) and sequester C

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http//www.cef-environmental.co.uk/BioChar.htm
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• Plant biomass that is formed on an annual basis
  typically decomposes rapidly
• this decomposition releases the CO2 that was
  fixed by the plants back to the atmosphere
• but by transforming this biomass into biochar
  that decomposes much more slowly diverts C from
  the rapid biological cycle into a much slower
  biochar cycle

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• Drawbacks source of energy for heat is from
  burning of biofuels
• To be justified as a carbon storage strategy, the
  amount sequestered must exceed that produced in
  moving it between its site of production,
  burning, and application
• In the case of crop residues, it must be ensured
  that biochar addition provides a similar carbon
  gain to the simple return of these materials at
  the site of production
• does not cause nutrient depletion