World Food Supply

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World Food Supply
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The Agricultural Revolution

• Starting in mid-1800s/coincides with industrial
  revolution
• Major trends
• Animal labor to machinery
• Increased land under cultivation
• Increasing use of fertilizers/pesticides
• Increasing use of irrigation
• Development of new crop varieties Green
  Revolution
• INCREASED PRODUCTION

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Present-Day Agricultural Systems

• Industrialized agriculture
• Intensive traditional agriculture
• Shifting cultivation
• Nomadic herding

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Agricultural System
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Agricultural Systems
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World Distribution of Ag Systems
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World Food Supply and the Environment

• Four major aspects of the relation between the
  world food supply and the environment
• Local famines result from inadequate local food
  production and inequitable food distribution.
• Food production is closely tied to environmental
  factors such as drought, flood, or other
  disturbances.

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World Food Supply and the Environment

• Four major aspects of the relation between the
  world food supply and the environment
• 3. The results of attempts to increase global
  food supply often include negative environmental
  impacts.
• 4. Social upheavals and resulting instability
  often disrupt agriculture and reduce yields and
  supplies.

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Ecological Perspective on Agriculture

• Agroecosystems differ from natural ecosystems in
  six ways
• Natural succession must be controlled by
  intensive management activities requiring time,
  chemicals and energy.
• Agriculture replaces diverse systems with
  MONOCULTURES large areas managed for a single
  species or varietiescan cause serious
  disruptions in chemical cycling.

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Ecological Perspective on Agriculture

• Agroecosystems differ from natural ecosystems in
  five ways
• 3. Neatly spaced rows of crops tend to
  encourage the growth of pest populations.
• 4. The loss of ecological diversity in
  agroecosystems makes systems more vulnerable to
  disturbance and change.
• Regular plowing subjects the soil to damage
  unlike any resulting from natural processes.
• Genetic modification of crops.

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Sources of Food

• Hunting and gatheringhow much provided?
• Status of todays population?
• We currently produce 1,780,000 metric tons of
  grain per year (m.t.1000 kg) or about 690
  lbs/person/year).
• Expansion of land-based agriculture and livestock
  is necessary.

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Sources of Food

• Crops
• Most of the worlds food and other important
  agricultural products is provided by only a few
  plant species.
• Eight grains provide the bulk of human food
• Wheat
• Rice
• Corn
• Barley
• Oats
• Sorghum
• Millet
• Rye

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Land-Use Devoted to Agriculture
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Sources of Food

• Crops
• Only three regions of the world are net exporters
  of food..the rest import food.
• North America, Australia, New Zealand.
• The rate of increase in growth of human food
  supply has slowed in recent decades.
• Many agricultural products are not substinence
  crops, but are cash crops.
• How does this affect local peoples?

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Sources of Food

• Livestock
• Livestock, especially ruminants, are important
  for their ability to convert abundant materials
  indigestible to humans into human food.
• Livestock are raised either on range (land not
  plowed or planted) or pasture (land plowed and
  planted in forage for livestock).

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Approaches to Agriculture

• Demand-based agriculture
• Maximizing output of products in response to
  demand, regardless of the sustainability of such
  a system.
• Resource-based agriculture
• Conducted within resource constraints and
  promoting sustainable use of resources.

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Organic Farming

• 3 Qualities
• It is more like natural ecosystems than
  monocultures
• It minimizes negative environmental impacts
• The food that results from it does not contain
  artificial compounds

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Aquaculture

• The managed production of food from marine or
  freshwater habitats.
• Contributes significantly to the diets and
  economies of many Asian and European nations.

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Freshwater Aquaculture

• These operations may exploit and gain production
  from many aquatic ecological niches and may
  beneficially utilize otherwise wasted resources
  or pollutants such as sewage wastewater and power
  plant outflow.
• Some aquaculture ponds are operated in
  conjunction with terrestrial managed systems.
• Though total acreage devoted to freshwater
  aquaculture is small, these operations provide
  locally and regionally significant sources of
  protein.

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Mariculture

• The managed production of food from marine
  habitats.
• Excellent for raising shellfish and crustaceans.
• Where does HYDROPONICS fit in this system..or
  does it?

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Soil and Agriculture

• Soils supporting forests and prairies are
  typically rich in organic matter.
• Clearing them for cultivation leaves them open
  open for resource depletion and changes their
  physical structure.
• Requires the addition of fertilizers and soil
  conditioners.

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Soil and Agriculture

• Limiting Factors
• Necessary plant growth element that is least
  available to the plant.
• Most often the limiting factor in an agricultural
  system is a macronutrient
• Less often it is a trace metallic element called
  a micronutrient.
• Older soils usually lack the micronutrients
  critical for plant growth.

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Liebigs Law of the Minimum

• Liebigs law states that the abundance and
  distribution of a species is limited by that
  factor least available or most critical for
  growth.
• The role of any nutrient in limiting growth is
  always relative to those of other nutrients and
  growth factors.
• Many environmental factors operate together to
  produce a synergistic effect on plant growth the
  change in availability of one resource affects
  the response of an organism to another resource.

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Sustainable Yields

• A maximum sustainable yield of a crop is the
  maximum production of that crop per unit area
  which can be maintained indefinitely by that
  crop.
• The optimum sustainable yield of a crop is the
  maximum production of that crop that can be
  maintained indefinitely by that agroecosystem.

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How Many Can the Current System Feed?

• The answer depends on how well we resolve many
  technological and economic challenges.

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Green Revolution

• Name given to the methods of crop improvements
  developed after WWII.
• Name a few please..
• Genetic strain development, but an overall loss
  of genetic diversity.

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Optimum Environmental Conditions

• Each crop grows best under optimum environmental
  conditions.
• Vary by region, all variance affects
  productivity.
• Some areas lack on or more aspects of a favorable
  crop environment, thereby rendering them
  unsuitable for use.

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Optimum Environmental Conditions

• Only 11 of the Earths land surface is arable or
  suitable for crop production. In the US there is
  25, but of that 80 is being farmed.
• The amount of land newly brought into crop
  production each year through irrigation and
  wetland drainage is exceeded by the amount of
  arable land lost to urbanization, highway
  construction, and erosion.

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Optimum Environmental Conditions

• Irrigation Much of the modern agricultural land
  is irrigateda practice that is largely
  responsible for the current high production of
  grain crops in the U.S.
• Any consequences to this activity?

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Food Distribution

• United Nations Food and Agriculture Organization
  (UNFAO)
• 1/10th of the global population suffers from food
  shortage.
• 18 of the population of developing countries
• Primary health problem in these countries.

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World Food Supply

• Two kinds of food insufficiency currently present
  global problems
• Undernourishment (calorie insufficiency)
• Malnourishment (Specific nutrients
  insufficiency).
• The effects of undernourishment tend to be rapid
  and acute those of malnourishment are long-term
  and chronic.

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Malnourishment

• Can result in
• Maramus (protein-and calorie-deficiency disease)
• Kwashiorkor (protein deficiency disease), or
• Chronic hunger.

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Selected Health Effects

• Kwashiorkor Disease Protein deficiency and the
  primary contributor to infant mortality.

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Selected Health Effects

• Marasmus
• Protein/caloric deprivation
• Vitamin /nutrient deficiency

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How Much Do We Need?

• For a minimum amount of activity, people need 200
  kg/year.
• World-wide average of production is 312 kgthis
  is more than needed.
• Why do we have world hunger?
• Cash crop vs. food
• Uneven distribution
• Lack of funds to buy food.

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Other Reasons for Food Shortages

• Overpopulation/Land degradation
• Poverty
• Environmental Issues
• Drought, floods, diseases of crops
• Civil War
• All can lead to Famine large-scale food
  shortage, starvation.

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Measures of Food Availability

• To guard against major fluctuations in world food
  supplies due to weather and other uncertainties,
  large food storage stocks and adequate transport
  systems must be maintained.
• World stored grain surplus is measured in days of
  supply of grain. These supplies have dropped over
  recent years.

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Measures of Food Availability

• 1973 65 day supply
• 1987 104 day supply
• 1995 62 day supply

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Measures of Food Availability

• The U.S. is the worlds leading stored grain
  exporter and donor.
• The amount of food produced worldwide per person
  per capita food production.
• Per capita demand is the economic demand for food
  per person. This demand rises with the standard
  of living and average income.

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Limits on Food Production

• Regardless of the technological advances in
  agriculture there are absolute limits to the
  amount of food that can be produced on earth.
• LIMITS INCLUDE
• Amount of arable land
• Limited potential of fertilizers and irrigation
• Environmental costs of current farming techniques.

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Ways to Increase Food Production

• Improved irrigation
• Hydroponics
• Eating lower on the food chain
• Sustainable agriculture
• Improve distribution of food.

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Genetically Modified Food Biotechnology, Farming
and Environment

• Genetically Modified Crops are modified by
  genetic engineers to produce higher crop yields
  and increase resistance to drought, cold, heat,
  toxins, plant pests and disease.

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Ways Genetic Characteristics of GMC Might Spread
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The Terminator Gene

• A genetically modified crop which has a gene to
  cause the plant to become sterile after the first
  year.

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Solutions

• Food Aid
• Should be restricted to most severe situation
• Social Reform
• Birth control
• Sustainable agricultural practices
• Restructure loan/financial assistance approaches
• Controlling pressure on land resources is the
  BEST solution