Feeding the World
Sect. 1 Objectives
• Identify the major causes of malnutrition.• Compare the environmental costs of
producing different types of food.• Explain how food distribution problems and
drought can lead to famine.• Explain the importance of the green
revolution.
Nutrition
• What is good nutrition/a balanced diet? – 4 food groups• Dairy - calcium• Protein• Bread – carbohydrates• Fruits and veggies - vitamins
– My Food Pyramid• mypyramid.gov• What are Calories?• How many should you have a day?
Malnutrition – when someone does not eat enough calories or different foods
to fulfill the bodies needs.
• Corn or Rice diets = protein malnutrition– Effects physical and mental development– Majority of foods produced in the world are carbohydrates
• https://www.youtube.com/watch?v=L3abZswA5XY
• https://www.youtube.com/watch?v=7-0y_H7OGgQ
Ecology of Food
• Food efficiency energy + resources = FOOD
• Cow = 1,000,000 calories per acre• Corn = 2,000,000 calories per acre• Potatoes = 8,500,000 calories per acre• Which has the highest yield?• What would you plant to feed a large population?
World Food Problems
• The world currently produces enough grain to feed 10 billion people.– People eat too much– People want meat– Poverty• More money = more technology/equipment = more food
Impact on Environment
• Livestock vs. Grains– What are livestock fed?– Where is that grown?– What is the yield?
The Green Revolution
• New varieties of grains yield more on the same land– Lowered the price
• But!!– They use more fertilizer and water– Some farmers don’t
have the money to upgrade
AgricultureCrops and Soil
Sect. 2 Objectives• Distinguish between traditional and modern
agricultural techniques.• Describe fertile soil.• Describe the need for soil conservation.• Explain the benefits and environmental impacts
of pesticide use.• Explain what is involved in integrated pest
management.• Explain how genetic engineering is used in
agriculture.
Traditional• Plowing – pushed by farmer or pulled by livestock
• Fertilization – Manure and plant waste
• Irrigation– Water flowing through a ditch
• Pest Control– ??
• Weeding– Pulled by hand
Modern
• Plowing and harvesting– machines
• Fertilization – Synthetic chemicals
• Irrigation– Overhead sprinklers and drip systems
• Pest Control– Synthetic chemicals
Soil
• Fertile – can support the growth of healthy plants– Fertile topsoil = organisms, rocks, water, air, organic
matter (dead and decomposing organisms)
• Soil is rocks broken down into tiny pieces– Takes thousands of years
How do organisms help make fertile soil?
Topsoil Erosion
Land Degradation- when land is damaged so it cannot support the local
ecosystem• Desertification – making land more desert like
• Ex: Sahel desert – fallow period disappearing
• https://www.youtube.com/watch?v=w9RxnuBiFbg
Soil Conservation• Ways to conserve:– Terracing– Contour plowing– Drip irrigation– No-till farming
Compost- partly decomposed organic matter
• Adds nutrients to the soil
• Manure• Food waste• Yard waste
Pest Control
• Worldwide – insects destroy about 33% of food crops
• Wild plants vs. food crops – natural defenses
Pesticides – chemicals used to kill insects, weeds, and other crop
pests• Chemicals do the job very well– But at what cost??
• Resistance – the ability of an organism to survive exposure to a particular pesticide
• Pollution - DDT
Biological Pest Control– the use of living organisms to control pests
• Pathogens• Genetically modified foods – bred to have
defenses against pests– Chemical defenses – chemicals that repel pests– Physical defenses – tougher skin
• Natural plant chemicals as a pesticide• Introduction of nonnative species– Can be very harmful
• Pheromones – confuse insects
• https://www.youtube.com/watch?v=Hj3DwimxvvY
Pest Control Timeline
• Biological – natural proceedures• Cultivation control – vacuuming insects• Insecticides• New Insesticide
The Day it Rained Cats• Malaria – carried by mosquitoes• DDT• Dead wasps• Roofs fell in – too many caterpillars• Tin roof• Dead cats• Rats• Plague• Flying Cats
Genetic Engineering- when genetic material is modified to produce a better
product• Selective breeding – early GE• GE today – taking good genes from one
organism and inserting them into another• Creates Genetically Modified (GM) Foods• We still do not know that full remifications of
GE our food.– Salmon genes in tomotoes
• https://www.youtube.com/watch?v=qn52Ed1q4rk
Sustainable Agriculture- farming that conserves natural resources and helps
keep the land productive indefinatly• Low energy input• Low water• Low pesticides• Low fertilizers• Pest resistance crops
Animals and Agriculture
Sect. 3 Objectives
• Explain how overharvesting affects the supply of aquatic organisms used for food.
• Describe the current role of aquaculture in providing seafood.
• Describe the importance of livestock in providing food and other products.
Animals
• Domesticated – animals that are bred and managed for human use– Cows, horse, pig, fish etc.
• Overharvesting – taking more organisms from a population than the population can replace– No-fishing zones– Examples?
Aquaculture - raising aquatic organisms for human use and
consumption • 20% of the animal protein eaten around the
world• Fish Farms• Oyster farms• Ranch – raised till they are a certain age the
released– Ex: salmon
• Produces pollution b/c of excess waste
Livestock
• Provide food, leather, wool, eggs, fertilizer, etc.
• Ruminants – cud-chewing animals that have 3 or 4 chambered stomachs– Ex: cow, sheep, goats– Can digest cellulose from plants that humans can’t