Transcript ENVIRONMENTAL SCIENCE

Chapter 10
Food, Soil &
Pest Management
Food Sources
• Cropland – 77%
– 30,000 plant species
– Wheat, rice & corn
• Rangeland – 16%
– Beef, pork, sheep & poultry
– Products such as milk, eggs & cheese
• Oceanic fisheries – 7%
– Fish & shellfish
Major Types of Food Production
• Industrial agriculture
– Use of fossil fuels, fertilizers & pesticides
• Plantation agriculture
– Tropical countries, mostly for export
– Cash crop like bananas, cocoa, coffee, etc.
• Traditional agriculture (42% world uses this form)
– Subsistence agricultural – enough plants & animals to
sustain self & family (human labor)
– Intensive agricultural – enough for family and for sale
Green Revolution
Increase yield/unit area of cropland
• Develop & plant monocultures of selectively bred
or genetically engineered
– First green revolution (’50-’70’s)
• High yields by large inputs of fertilizers,
pesticides & water
– Produce more food on less land (1967)
• Increase number of crops/year on a plot by
multiple cropping (8% of world oil)
Soil Erosion
• Desertification –
– Productive potential of dry lands falls by 10%
– Human activities that reduce or degrade topsoil
• Salinization
• Waterlogging
International Agencies
• UN Food & Agricultural Organization (FAO)
• World Health Organization - (WHO)
• United Nations Children's Fund - (UNICEF)
Malnutrition
• 1 out of every 6 people in developing
countries suffer from malnutrition
• 9 million people died last year due to
malnutrition related death
– Malnutrition & starvation
– Infectious disease from poor drinking water
– Poor health condition
Life-saving Programs
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Immunization
Encourage breast feeding
Prevent dehydration
Provide Vitamin A to prevent blindness
Provide family planning measures
Educate on health & sanitary methods
Over-nutrition
• Overweight - 10 to 30 lbs. above healthy body
weight
• Obese – 30 lbs. over healthy body weight
• Caused by:
– Too many calories
– Too little exercise
– Genetic disorders
• Prone to disease, lower life expectancy & lower
productivity
The Meat We Eat
• High quality protein
• Overgrazing can limit livestock & destroy
the environment
– Riparian – rich land along the stream beds
• 65-75% of wildlife in the US depend solely on
riparian habitats
• 80% of riparian are damaged by livestock
• Most of the rangeland in the US is out west
Slaughterhouses
• Meat is general sent to US inspected
slaughterhouses
• Mad Cow Disease
• Vitamins & antibiotics are accumulated in
tissues and organs
• Pesticides & toxins accumulate in the fat of
animals
Harvesting Fish
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Fish-farms – cages
Trawling nets
Long-line fishing with hooks
Drift netting
Purse seine fishing
Overfishing & Habitat Degradation
• Fish are a renewable resource
• Sustainable yield = amount withdrawn from
the habitat + amount reproduced
• Too little breed stock
• Non-target species are caught and killed or
used for chum
Genetic Engineering
• Phase 1 – modify the gene & grow in tissue
culture
• Phase 2 – make transgenic cells & inject
into plant cells
• Phase 3 – grow plants to harvest
Aquaculture
• 33% of the worlds fish harvest is from
aquaculture
• Fish-ranching - holding species captive for
growth & releasing them to spawn
• Fish-farming – grown in captivity with fish
meal as their food source
– Fresh water - ponds - salmon
– Salt water - coastal lagoons – shrimp
Government Control
• Keep food prices artificially low
• Give subsides to farmers to keep them in
business and increase food production
• One philosophy is to remove controls and
let farmers & fishing industry respond to
market trends
Pesticides
• Chemical used to control infestation of food
crops
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Insecticides
Herbicides
Fungicides
Nematocides
Rodenticides
SUSTAINABILITY
• How can we stabilize our food to become
more sustainable?
Biodiversity
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