Food and Agriculture

Land Use

• 11% of the earth’s land is used in agricultural production– Less land cultivated in NA now than 100 years

ago

Types of Food Production

1. Traditional subsistence agriculture – mostly human and animal labor

• Produces only enough crops for a family’s survival

• Africa, Asia, South America

Types of Food Production

2. Industrialized agriculture (high input agriculture)

• Large amount of fossil fuel energy, water, fertilizers and pesticides to produce large quantities of monocultures

• Example: Plantation agriculture– Used in tropical developing nations

– Cash crops grown for export

» May provide non-food products (latex)

» Provide products that do not make up primary nutrition (tea, coffee)

Agroecosystems

• Ecosystem created by agricultural practices– characterized by low

• Genetic diversity

• Species diversity

• Habitat diversity

Agroecosystems

Differ from natural ecosystems in five major ways:1. Farming attempts to stop ecological succession2. Species diversity is low

• Monoculture ↓ soil fertility3. Plant species (crops) in an orderly fashion

– pest control more difficult

4. Simple food chains 5. Plowing

• ↑ erosion • Nutrient loss

Farm Numbers

Number of People Fed Annually By One Farmer

Food Supply

• 15 to 20 species provide vast majority (90%) of man’s food needs– Wheat, rice, corn, potatoes, barley

• Wheat and rice supply ~60% of human caloric intake

– 90% of grain grown in NA is used to feed livestock

Meat Sources

• 20% of the richest countries consume 80% of the world’s meat

• About 90% of the grain grown in the United States is used for animal feed

• 16 lbs of grain → 1 lb of meat

World Food Supply and the Environment

• Enough food, unevenly distributed– 815 million people do not have enough to eat

• Parts of Africa, southeast Asia

– In richest countries, 11 million do not have enough to eat

• Food production depends upon favorable environmental conditions

Food Distribution

• Food is not distributed equally due to:– Soil and climate differences– Political and economic power– Average per capita income throughout the world

Malnutrition/Famines

• Malnutrition– Undernutrition– Overnutrition

• Famine– Environmental conditions are immediate trigger, but politics and

economics are often underlying problems.

• Famine conditions– Major droughts -- Political instability– Population sizes -- Land Seizures– Massive immigration -- Distribution

breakdown– Floods -- Chaos in economy– Wars

Risk of Inadequate Nutrition

Undernutrition Problems

• Iron deficiency – Most common– Leads to anemia

• Red meat, eggs, legumes, and green vegetables are all good sources of iron.

• Vitamin A deficiencies– Can cause blindness

Obesity

• Most common dietary problem in wealthy countries– According to U.S. Surgeon General:

• 62% of Americans are overweight.– 33% are obese.

Land Use and Degradation

• Overgrazing and soil erosion• Eliminates millions of acres a year

• Desertification-degrading once fertile land into desert

• Surface runoff

• Dry surface reflects heat, changing wind patterns

Global Soil Degradation

Mechanisms of Erosion• Wind and water are erosive forces

– Intensive farming practices:

• Salinization

• Waterlogging– Impairs root growth,

roots cannot get oxygen

• No crop rotation

• Removal of windbreaks

• Continued monocultures

Alternatives to Industrial Farming Methods

Sustainable Agriculture

• Through soil conservation– Intercropping– Crop rotation– Agroforestry– Contour Plowing

Soil Conservation Cont.

• Providing Ground Cover– No till agriculture– Plant cover crops

• Improved irrigation and utilization of water – Drip irrigation

New vs. Old Agriculture

Methods to Increase Food Supply

• Food distribution modification – Teach locals

• In the 1960s:– Green Revolution-increased yields per unit of area of

cropland• Mechanization

– Monocultures of selectively bred or genetically engineered high yield variety of key crops (rice, corn, wheat)

» Corn yields jumped from 25 bushels per acre to 130 per acre in last century.

• Using high inputs of fertilizer, pesticides, and water on crops to produce high yields

• Increasing the intensity and frequency of cropping

Genetic Engineering

• Genetically Modified Organisms (GMO’s)– Crops resistant to drought, frost, diseases, pests,

etc.– Animals that grow faster, gain weight on less

food, produce more milk, etc.– Estimated at least 70% of all processed foods in

NA contain transgenic products.

Is Genetic Engineering Safe ?

• Environmental and consumer groups have campaigned against transgenic organisms.– “Frankenfoods”– Opponents fear traits could spread to wild

varieties– U.S. Food and Drug Administration declined to

require labeling of foods containing GMO’s.• New varieties are “substantially equivalent” to related

traditionally-bred varieties.

How Would You Vote?

• Do the advantages of genetically engineered foods outweigh their disadvantages?

• Should labeling of GMOs be required?

Increasing Food Supply: Producing More Meat

• ½ of the world’s meat is produced by livestock grazing on grass.

• ½ half is produced under factory-like conditions (feedlots).– Concentrated animal feeding operations (CAFOs)

• High density, confined or allowed very little moving room

– A CAFO may contain as many as 2500 hogs or 55,000 turkeys in a single building

Fig. 13-21, p. 289

Trade-Offs

Animal Feedlots

Advantages Disadvantages

Increased meat production

Need large inputs of grain, fish meal, water, and fossil fuelsHigher profits

Concentrate animal wastes that can pollute water

Less land use

Reduced overgrazing

Reduced soil erosion

Antibiotics can increase genetic resistance to microbes in humans

Help protect biodiversity

Sustainable Animal Farming

• Free-range

• Organic

• Smaller scale farms

Buy Local!

• The average American foodstuff travels an estimated 1500 miles before being consumed.

Catching and Raising More Fish

• Fisheries– third major food-producing system

• ~55% of annual commercial catch from ocean

• ~45% from use of aquaculture to raise marine and freshwater fish

Fishing methods

Catching and Raising More Fish

– Commercial fish amounts have been declining since 1980

• Overfishing– Tragedy of the commons

– Bycatch

Raising More FishAquaculture: Aquatic Feedlots

• Raising large numbers of fish and shellfish in ponds and cages in a controlled environment and harvesting them in captivity.

Trade-Offs

Aquaculture

Advantages Disadvantages

High efficiency Needs large inputs of land, feed, and water

High yield in small volume of water

Large waste output

Destroys mangrove forests and estuaries

Can reduce overharvesting of conventional fisheries Uses grain to feed

some species

Low fuel use Dense populations vulnerable to disease

Tanks too contaminated to use after about 5 years

High profits

Profits not tied to price of oil

Solutions

Managing Fisheries

Fishery RegulationsSet catch limits well below the maximum sustainable yield

Improve monitoring and enforcementof regulations

Economic ApproachesSharply reduce or eliminate fishing subsidies

Charge fees for harvesting fish and shellfish from publicly owned offshore waters

Certify sustainable fisheries

Protected areasEstablish no-fishing areas

Establish more marine protected areas

Rely more on integrated coastal management

Consumer InformationLabel sustainably harvested fish

Publicize overfished and threatened species

BycatchUse wide-meshed nets to allow escape of smaller fish

Use net escape devices for seabirds and sea turtles

Ban throwing edible and marketable fish back into the sea

AquacultureRestrict coastal locations for fish farms

Control pollution more strictly

Depend more on herbivorous fish species

Nonnative InvasionsKill organisms in ship ballast water

Filter organisms from ship ballast water

Dump ballast water far at sea and replace withDeep-sea water