Chapter 13 Food Resources. Food in the World 30,000 plant species with parts people can eat 15...

Chapter 13

Food Resources

Food in the World

• 30,000 plant species with parts people can eat

• 15 plants and 8 animals supply 90% of our food

• Wheat, rice, and corn are half the calories people eat

• 66% of people eat mainly rice, wheat, and corn (grains)

• The top third of the economic chain eats primarily meat.

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World Food Production

Types of Food Production

• Industrialized agriculture• Traditional agriculture

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Industrialized Agriculture

• Industrialized agriculture-Use large amounts of fossil fuel energy, water, commercial fertilizers and pesticides to produce huge quantities of single crops or livestock animals for sale.

• www.alaskajournal.com/.../ foc_20030804021.

www.alaskajournal.com/.../ foc_20030804021.

Traditional Agriculture

• Traditional agriculture-practiced by 2.7 people on earth– Traditional subsistence agriculture-produce

enough food to stay alive– Traditional Intensive agriculture-farmers

increase inputs of human and draft labor, fertilizer and water to get a higher yield per area of cultivated land to produce enough food for families, and their income

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The Green Revolution• To eliminate hunger by improving crop performance• Movement to increase yields by using:

– New crop cultivars– Irrigation– Fertilizers– Pesticides– Mechanization

Results:• Did not eliminate famine• Population still increasing• Increase cost of production• An increased negative environmental impact• Didn’t work for everyone

Green Revolution

• Involves 3 steps• 1. Developing and planting

monocultures of selectively bred or genetically engineered high yield varieties of key crops

• 2. Lavishing fertilizer, pesticides, and water on crops to produce high yields

• 3. Often increasing the intensity and frequency of cropping

The green revolution had costs and benefits

Positive effects :

Reduced pressure to convert more natural land to cropland

Prevented some deforestation and habitat conversion

• Negative effects:• Pollution and reduced

biodiversity– Erosion, salinization and

desertification– Increased susceptibility

to crop diseases

• Today, soil quality is declining, resulting in lower yields.

From 1900 to 2000, cultivated area increased 33%, while energy inputs increased 80 times!

Producing Food by Green-Revolution Techniques (1950-1970)

High-input monoculture

Selectively bred or genetically-engineered crops

High inputs of fertilizer

Extensive use of pesticides

High inputs of water

Increased intensity and frequency of cropping

Green Revolutions

Fig. 13-6 p. 282

Golden Rice -Grains of Hope or an Illusion?

•Vitamin A Vitamin A deficiencies cause deficiencies cause blindnessblindness•Golden rice is a Golden rice is a new genetically new genetically engineered strain engineered strain of rice containing of rice containing beta-carotene.beta-carotene.•Can inexpensively Can inexpensively supply vitamin A to supply vitamin A to malnourished.malnourished.

BUT…

• Critics contend that there are quicker and cheaper ways to supply vitamin A.

• Scientists call for more evidence that the beta-carotene will be converted to vitamin A by the body.

The green revolution

http://www.youtube.com/watch?v=LRPibWf3wN8&feature=related

http://www.youtube.com/watch?v=cEBtO25xW-o&feature=related

Food Production in the U.S.

• Since 1940, food production in the U.S. has more than doubled crop production

• 9% of population is involved in the U.S. agricultural system.

• Generates 18% of countries GNP

Eating animal products has significant impacts

• As wealth and commerce increase, so does consumption of meat, milk, and eggs.– Global meat production has increased fivefold.– Per capita meat consumption has doubled.

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Feedlot agriculture

• Feedlots (factory farms): also called Concentrated Animal Feeding Operations (CAFOs)– Huge warehouses or pens

designed to deliver energy-rich food to animals living at extremely high densities

– Over ½ of the world’s pork and poultry come from feedlots.

• The benefits of feedlots include:– Greater production of food– Unavoidable in countries with high levels of

meat consumption, like the U.S. – They take livestock off the land and reduce

the impact that they would have on it.

• Drawbacks of feedlots include:– Contributions to water and air pollution– Poor waste containment causes outbreaks

of disease.– Heavy uses of antibiotics to control disease

Livestock Production• Meat products are sources of quality

protein.• Between 1950 and 1996, world meat

production increased fourfold and per capita meat production rose by 29%.

• 14% of U.S. topsoil is associated with livestock grazing.

• Cattle belch out 12-15% of all the methane released into the atmosphere

• Some say if Americans cut their grain intake by 16%, this would save enough grain to provide a subsistence diet for nearly 900 million people.

World Food Problems

• Reasons for problems: Population growth Increasing affluence Degradation and

loss of cropland Little growth in

irrigation Decline in global

fertilizer

Some people starve, but others eat too much

• Undernourishment: people receive too few calories per day

• Malnutrition: receiving too few nutrients in food– Every 5 seconds, a child

starves to death.

• Overnutrition: receiving too many calories each day– In the U.S., people eat junk

food and don’t exercise.– Worldwide, more than 300

million people are obese.

Diseases of Malnutrition and Undernutrition

• Anemia

• Goiter

• Marasmus

• Kwashiorkor

• Rickets

• Scurvy

Famine vs. Food Shortage

• Political situations causes famine

• Present day examples – famine in the Darfur region of Sudan

Good News!

• Between 1970 and 1995, worldwide proportion of people suffering from undernourishment went from 36% to 14%.

• Number of malnourished people fell from 940 million in 1970 to 850 million in 1995.

• We produce more than enough food to meet the basic nutritional needs of every person on earth today

Environmental Effects of Food Production

Biodiversity loss – habitat loss, fish kills, poaching of predators, loss of genetic diversity b/c of monocultures

Soil – erosion, fertility loss, salinization, waterlogging, desertification

Air pollution – emissons fr. Fossil fuels, pollution from pesiticide sprays

Water – aquifer depletion, runoff, sedimentation, fish kills, pollution from pesticides, overfertilization of lakes

Human health – nitrates, pesticides & diseaseorganisms in drinking water, bacterial contam of meat

Increasing World Crop Production

Crossbreeding and artificial selection

Genetic engineering (gene splicing)

Genetically modified organisms (GMOs)

Continued Green Revolution techniques

Introducing new foods – ex. Winged bean p. 292

Working more land – is cultivating marginal land likely to be sustainable?

See Fig. 13-16 p. 291

Food security• Food security: the guarantee of adequate and

reliable food supply to all people at all times– We have reduced hunger by half since 1970.– Through fossil fuels, irrigation, fertilizers, pesticides,

more agricultural land, more productive crops, and livestock

• Monoculture: the uniform planting of a single crop– Industrialized agriculture requires that vast fields are

planted with single types of crops.

Since 1985, world grain production per person has fallen by 9%.

Environmental Effects of Producing Food

• Agriculture has a greater harmful impact on air, soil, water, and biodiversity resources than any other human activity.

Interplanting

• Polyvarietal cultivation-Where plot is planted with several varieties of the same crop

• Intercropping-two or more different crops grown at same time on a plot

• Agroforestry- Crops and trees are planted together

• Polyculture-Many different plants mature at various times, and are planted together.

Cultivation of Land

• 36% of the world’s land is devoted to raising crops.

• Some think that cultivating more land is a possible solution to the food crisis.

Food Growth in Urban Areas

• Urban gardens provide 15% of world’s food.

• If people grew more food in their backyards, they could live more sustainable and save money.

Fishing• 3rd major food producing system

consists of fisheries

• 99% of fish caught in ocean is from the coastal waters

• Between 1950 and 1996, fish catch increased 4.9 fold

Problems With Fishing

• Overfishing-Taking of so many fish that too little breeding stock is left to maintain numbers

• Commercial extinction-reduction of a species to the point at which it’s no longer profitable to hunt for them

Aquaculture

• Aquaculture-where fish and shellfish are raised for food

• Supplies 20% of world’s commercial food harvest

• Increased 3.3 fold between 1984 and 1996

Aquaculture in ENCCatfish farming

Aquaculture – The Blue Revolution

• Wild fish populations are plummeting.– Technology and increased demand

• Aquaculture: raising aquatic organisms for food in a controlled environment (“fish farm”)– Aquatic species are raised in open-

water pens or land-based ponds.

• The fastest-growing type of food production– Provides a third of the world’s fish – Most widespread in Asia

The benefits and drawbacks of aquaculture

• Benefits: A reliable protein source Sustainable Increases food security Reduces fishing pressure

on wild fish stocks Energy efficient

• Drawbacks: Diseases can occur,

requiring expensive antibiotics

Reduces food security Large amounts of

waste Growing grain to feed

fish is inefficient Farmed fish may

escape and introduce disease into the wild

Major Environmental Effects of Food Production

Biodiversity Loss• Loss and degradation of

habitat from clearing grasslands and forests and draining wetlands

• Fish kills from pesticide runoff• Killing of wild predators to

protect live stock• Loss of genetic diversity from

replacing thousands of wild crop strains with a few monoculture strains

Human Health•Nitrates in drinking water

•Pesticide residues in drinking water, food, and air

•Contamination of drinking and swimming water with disease organisms from livestock wastes

Gov. assistance to farmers and consumers

• Keep food prices low

• Give farmers subsidies to keep them in business and to encourage them to increase food production

• Eliminate most or all price controls and subsidies

• Continue Agricultural research

Sustainable Agricultural• Sustainable

Agricultural-Method of growing crops and raising livestock based on organic fertilizers, soil conservation, water conservation, biological control of pests, and minimal use of nonrenewable fossil fuel energy

Increase

High-yield polyculture

Organic fertilizers

Biological pestcontrol

Integrated pestmanagement

Irrigation efficiency

Perennial crops

Crop rotation

Use of more water-efficient crops

Soil conservation

Subsidies for more sustainablefarming and fishing

Decrease

Soil erosion

Soil salinization

Aquifer depletion

Overgrazing

Overfishing

Loss of biodiversity

Loss of primecropland

Food waste

Subsidies forunsustainable farming and fishing

Population growth

Poverty Figure 13-36 Page 308

Components of more sustainable, low-throughput agriculture