An Ecological Perspective (BIOL 346)

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An Ecological Perspective (BIOL 346)

• Talk Five
• Sustainable Agriculture

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Sustainable Agriculture

• The practice of farming using principles
  of ecology, the study of relationships between
  organisms and their environment.
• It has been defined as "an integrated system of
  plant and animal production practices having a
  site-specific application that will last over the
  long term
• Satisfy human food and fiber needs
• Enhance environmental quality and the natural
  resource base upon which the agricultural economy
  depends
• Make the most efficient use of non-renewable
  resources and on-farm resources and integrate,
  where appropriate, natural biological cycles and
  controls
• Sustain the economic viability of farm operations
• Enhance the quality of life for farmers and
  society as a whole.

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Sustainable agriculture integrates three main
goals

• Environmental health
• Economic profitability
• Social and economic equity.

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Environmental health

• Sustainable Agriculture refers to agricultural
  production that can be maintained without harming
  the environment.
• Environmentally Sustainable Agriculture should
  be
• Bearable
• Equitable
• viable for the farmer
• AND - produce the best quality food for the
  consumer, nurture the environment preserve
  energy.

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Economic profitability

• Ecological economics is
• the interdependence of human economies and
  natural ecosystems.
• It treats the economy and society as a subsystem
  of the ecosystem
• with emphasis on preserving natural capital
• recognizes
• That social and economic systems cannot exist
  independently from the environment.

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Social and economic equity

• There is a natural market premium
• If successful
• Equity will be recognized by the farmer as
  beneficial for this commitment to quality food
  output.
• In addition farmer may get
• Government favorable interest rate financial
  incentives and solution support.

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Sustainable agriculture

• Sustainable agriculture in the United States was
  addressed by the 1990 farm bill.
• More recently, as consumer and retail demand for
  sustainable products has risen, organizations
  such as Food Alliance and Protected Harvest have
  started to provide measurement standards and
  certification programs for what constitutes a
  sustainable grown crop

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What is Sustainable Agriculture?

• Agriculture has changed dramatically, especially
  since the end of World War II.
• Food and fiber productivity soared due to new
  technologies, mechanization, increased chemical
  use, specialization and government policies that
  favored maximizing production.
• These changes allowed fewer farmers with reduced
  labor demands to produce the majority of the food
  and fiber in the U.S.

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What is Sustainable Agriculture?

• Has had major social and ecological impacts,
  which have drawn intense praise and equally
  intense criticism.
• In fact, many regions of the world peaked in food
  production in the period 1980 to 1995
• Are presently in decline, since desertification
  and critical water supplies have become limiting
  factors in a number of world regions.

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What is Sustainable Agriculture?

• Although these changes have had many positive
  effects and reduced many risks in farming, there
  have also been significant costs.
• Prominent among these are
• Topsoil depletion,
• groundwater contamination
• decline of family farms,
• continued neglect of the living and working
  conditions for farm laborers,
• increasing costs of production
• disintegration of economic and social conditions
  in rural communities.

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What is Sustainable Agriculture?

• A growing movement has emerged during the past
  two decades to question the role of the
  agricultural establishment in promoting practices
  that contribute to these social problems.
• Today this movement for sustainable agriculture
  is garnering increasing support and acceptance
  within mainstream agriculture.
• Not only does sustainable agriculture address
  many environmental and social concerns, but it
  offers innovative and economically viable
  opportunities for growers, laborers, consumers,
  policymakers and many others in the entire food
  system.

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The Biosphere

• The atmosphere sustains life and is sustained by
  life.
• The Gaia hypothesis
• The entire planet is a living breathing organism
  and will protect itself homeostasis of the
  whole planet!!!
• The biosphere works in cycles
• Nitrogen
• Carbon
• Water

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• Some greenhouse emissions related to agriculture
  are embedded in other sectors
• fossil fuels to produce chemical fertilizers and
  pesticides
• Processing
• Packaging
• Refrigeration
• transport of food
• land conversion from biodiverse ecosystems to
  giant, monoculture food plantations

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Rodale Institute study

• projects that the planets 3.5 billion tillable
  acres could sequester nearly 40 percent of
  current CO2 emissions if they were converted to
  regenerative organic agriculture practices
• Remember
• Via photosynthesis, over 100 billion metric tons
  of CO2 and H2O are converted into cellulose and
  other plant products

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Many studies have drawn similar conclusions.

• India
• organic farming research shows increases in
  carbon absorption by up to 55 percent (even
  higher when agro-forestry is added into the mix),
  and water holding capacity is increased by 10
  percent.
• California
• study of 20 commercial farms found that organic
  fields had 28 percent more carbon in the soil
  than industrial farms.

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Water cycle

• The resulting water vapor mixes with the
  atmosphere
• At high altitudes where the air is cold enough it
  condenses to form rain and snow
• Falls back to Earth.

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Water Cycle

• Water evaporates from bodies of fresh water and
  the oceans
• Much water is lost from the leaves of plants via
  transpiration.
• Also from respiration of almost all living
  species

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Water

• In some areas, sufficient rainfall is available
  for crop growth, but many other areas require
  irrigation.
• For irrigation systems to be sustainable they
  require proper management (to avoid salinization)
  and must not use more water from their source
  than is naturally replenished

taken from an article by Robert Service in
Science Magazine. Energy demands on water
resources
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Indicators for sustainable water resource
development are

• Internal renewable water resources.
• This is the average annual flow of rivers and
  groundwater generated from endogenous
  precipitation.
• Can be expressed in three different units
• in absolute terms (km3/yr),
• a measure of the humidity of the country (mm/yr)
• as a function of population (m3/person per yr).
• Global renewable water resources.
• sum of internal renewable water resources and
  incoming flow originating outside the country.
• can vary with time if upstream development
  reduces water availability at the border.

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Indicators for sustainable water resource
development are

• Dependency ratio.
• This is the proportion of the global renewable
  water resources originating outside the country,
  expressed in percentage.
• It is an expression of the level to which the
  water resources of a country depend on
  neighboring countries.
• Water withdrawal.
• When expressed in percentage of water resources,
  it shows the degree of pressure on water
  resources.
• A rough estimate shows that if water withdrawal
  exceeds a quarter of global renewable water
  resources of a country, water can be considered a
  limiting factor to development.
• Therefore, the pressure on water resources can
  have a direct impact on all sectors, from
  agriculture to environment and fisheries.

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The Soil

• The biggest ecosystem on Earth!
• Animals
• micro-organisms mix soils as they
  form burrows and pores, allowing moisture and
  gases to move about. In the same way, plant roots
  open channels in soils.
• Plants
• deep taproots can penetrate many meters through
  the different soil layers to bring up nutrients
  from deeper in the profile.
• fibrous roots that spread out near the soil
  surface have roots that are easily decomposed,
  adding organic matter.

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The Soil

• Micro-organisms
• including fungi and bacteria, effect chemical
  exchanges between roots and soil and act as a
  reserve of nutrients.
•  Humans
• impact soil formation by removing vegetation
  cover with erosion as the result.
• Also mix the different soil layers, restarting
  the soil formation process as less weathered
  material is mixed with the more developed upper
  layers.

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Soil Erosion

• Fast becoming one of the worlds greatest
  problems. It is estimated that more than a
  thousand million tonnes of southern Africa's soil
  are eroded every year.
• Experts predict that crop yields will be halved
  within thirty to fifty years if erosion continues
  at present rates.
• Not unique to Africa but is occurring worldwide.
• The phenomenon is being called Peak Soil as
  present large scale factory farming techniques
  are jeopardizing humanity's ability to grow food
  in the present and in the future.
• Without efforts to improve soil management
  practices, the availability of arable soil will
  become increasingly problematic.

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Soil Management techniques

• No-till farming
• soil is left intact and crop residue is left on
  the field.
• soil layers, conserving organisms and layers in
  their natural state.
• Keyline design 
• maximizes beneficial use of water resources of a
  piece of land.
• refers to a specific topographic feature linked
  to water flow
• Growing wind breaks to hold the soil
• Planting trees and hedges
• Prevent wind from blowing away top soil

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Soil Management techniques

• Incorporating organic matter back into fields
• Composting! Puts Carbon, Nitrogen, Oxygen, Water
  and microbes back into the soil!!! Can also add
  Urine honest!!
• Stop using chemical fertilizers (contain salt)
• Remember Algal Blooms? Also, the salt kills
  natural micro-organisms in soil contaminates
  water!!!!!
• Protecting soil from water runoff
• Careful placement of rocks and trees.
• Soil Steaming
•  sterilize soil with steam in open fields or
  greenhouses
• Destroys pathogens
• Destroys weeds, but dead plant material is left
  in soil as compost

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Nitrogen in the environment

• Present in many forms
• 78 of atmosphere is N2
• Most of this is NOT available to living organisms
• Getting N2 for the atmosphere requires breaking
  the triple bond between N2 gas to produce
• Ammonia (NH3)
• Nitrate (NO3-)
• So, N2 has to be fixed from the atmosphere so
  plants can use it

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Nitrogen in the environment

• This occurs naturally by-Lightning
• 8 splits H2O the free O and H attack N2
  forms HNO3 (nitric acid) which fall to ground
  with rain
• Photochemical reactions
• 2 photochemical reactions between NO gas and O3
  to give HNO3
• Nitrogen fixation
• 90 biological bacteria fix N2 to ammonium
  (NH4)

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Nitrogen in the environment

• Once fixed in ammonium or nitrate -
• N2 enters biochemical cycle
• Passes through several organic or inorganic forms
  before it returns to molecular nitrogen
• The ammonium (NH4) and nitrate (NO3-) ions
  generated via fixation are the object of fierce
  competition between plants and microorganisms
• Plants have developed ways to get these from the
  soil as fast as possible

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How do plants get their nitrogen?

• Some plant species are Legumes.
• Legumes seedlings germinate without any
  association to rhizobia
• Under nitrogen limiting conditions, the plant and
  the bacteria seek each other out by an elaborate
  exchange of signals
• The first stage of the association is the
  migration of the bacteria through the soil
  towards the host plant

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How do plants get their nitrogen?

• Nodule formation results a finely tuned
  interaction between the bacteria and the host
  plant
• Involves the recognition of specific signals
  between the symbiotic bacteria and the host plant
• The bacteria forms NH3 which can be used directly
  by the plant
• The plant gives the bacteria organic nutrients.

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Bottom line

• Grow crops which are best suited to local
  environment
• Have a plentiful, and renewable local water
  supply
• Protect the soil
• Good crop management techniques

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Good crop management techniques

• Grow a variety of crops.
• spreads economic risk and are less susceptible to
  the radical price fluctuations associated with
  changes in supply and demand.
• Crop rotation
• used to suppress weeds, pathogens and insect
  pests.

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Good crop management techniques

• Cover crops
• stabilizing effects by holding soil and nutrients
  in place
• conserving soil moisture with mowed or standing
  dead mulches, increasing the water infiltration
  rate and soil water holding capacity.
• The use of vineyards can buffer the system
  against pest infestations by increasing
  beneficial arthropod populations and can
  therefore reduce the need for chemical inputs. 

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Bottom line

• Low cost and effective local storage of food
  stuffs
• Low environmental impact transport system
• Local market and a steady and growing customer
  base.

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So what about backyard Agricultural
Sustainability?

• Grow only crops which mature within the local
  growing season.
• Only grow crops selections which will work
  together in such a limited space.
• Think about nutrient needs.
• Think about water demands.
• Think about long time storage of successful
  crops.

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Water barrel

• Free (clean) water!!!!!!!
• Rain barrel kit
• www.earthminded.com
• Trash can
• 40.00!!!
• Set up next to garden. Fills up fast!
• Melting snow will also fill it up.
• Can connect many together.
• Consider county, city, and state laws!

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Composting

• Turning kitchen waste into natural fertilizer
• Any container will work
• Need air holes
• Can buy bacteria cultures to add to container.
• Can add worms to increase efficiently
• When setting up, layer soil and kitchen waste.
• Takes approx. one year to get going from scratch.

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Wood ash
Component Normal agar (ppm) Ash Agar (ppm)
Arsenic lt0.1 0.1
Barium lt0.1 3.3
Boron 0.1 2.2
Calcium 37.9 1409.9
Chlorine 2.1 2.1
Chromium lt0.1 0.1
Cobalt 0.1 0.1
Copper 0.1 2.2
Iron 0.5 27.4
Lead 0.1 0.2
Lithium lt0.1 0.2
Magnesium 11.6 107.6
Manganese 0.2 3.8
Molybdenum lt0.1 0.1
Nitrogen 21.5 21.5
Phosphorus 3.6 109.4
Potassium 35.6 552.1
Sodium 83.7 90.7
Sulfur 268.3 335.8
Tin 0.1 0.1
Zinc 0.1 1.1

• In addition to composting, can use wood ash from
  a log burning fireplace.
• Ash is full of the essential nutrients required
  for plant growth and development.
• Even contains a higher of these nutrients than
  commercially available growth supplements.
• Cheap, natural, and fantastic for the environment
  and soil health

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Canning

• So, you grew hundreds of tomatoes. What to do
  with them?
• Great preservation technique.
• Allows you to store food stuffs outside of the
  growing season
• Can use them for cooking for the rest of the year
• Better than just freezing food stuffs
• Can store ANYTHING by this method.
• Not a new technology, just a (mostly) forgotten
  one, which is making a comeback.

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Final Summary

• Sustainable Agriculture is
• The practice of farming using principles
  of ecology, the study of relationships between
  organisms and their environment.
• refers to agricultural production that can be
  maintained without harming the environment.
• Not only does it address many environmental and
  social concerns, but it
• offers innovative and economically viable
  opportunities for
• growers
• Laborers
• Consumers
• policymakers.

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The End!

• Any Questions?