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