APES Chapter 13

Golden Rice

-Golden rice is a new genetically engineered strain of rice containing beta-carotene.
-Can inexpensively supply vitamin A to malnourished.
-Critics contend that there are quicker and cheaper ways to supply vitamin A.
-Scientist call for more evidence that

FOOD SECURITY AND NUTRITION

-Global food production has stayed ahead of population growth. However:
~One of six people in developing countries cannot grow or buy the food they need.
~Others cannot meet their basic energy needs (undernutrition / hunger) or protein and key nutrients (

Reducing Childhood Deaths from Hunger and Malnutrition

There are several ways to reduce childhood deaths from nutrition-related causes:
~Immunize children.
~Encourage breast-feeding.
~Prevent dehydration from diarrhea.
~Prevent blindness from vitamin A deficiency.
~Provide family planning.
~Increase education

Overnutrition: Eating Too Much

-Overnutrition and lack of exercise can lead to reduced life quality, poor health, and premature death.
-A 2005 Boston University study found that about 60% of American adults are overweight and 33% are obese (totaling 93%).
-Americans spend $42 billion p

FOOD PRODUCTION

-Food production from croplands, rangelands, ocean fisheries, and aquaculture has increased dramatically.
-Wheat, rice, and corn provide more than half of the world's consumed calories.
~Fish and shellfish are an important source of food for about 1 billi

Industrial Food Production: High Input Monocultures

-About 80% of the world's food supply is produced by industrialized agriculture.
~Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce monocultures.
~Greenhouses are increasingly being used.
~Plantations are b

Natural Capital Crop Lands

Ecological Services:
� Help maintain water flow and soil infiltration
� Provide partial erosion protection
� Can build soil organic matter
� Store atmospheric carbon
� Provide wildlife habitat for some species
Economic Services:
� Food crops
� Fiber crops

Case Study: Industrialized Food Production in the United States

-The U.S. uses industrialized agriculture to produce about 17% of the world's grain.
~Relies on cheap energy to run machinery, process food, produce commercial fertilizer and pesticides.
-About 10 units of nonrenewable fossil fuel energy are needed to put

Traditional Agriculture: Low Input Polyculture

Many farmers in developing countries use low-input agriculture to grow a variety of crops on each plot of land (interplanting) through:
~Polyvarietal cultivation: planting several genetic varieties.
~Intercropping: two or more different crops grown at the

SOIL EROSION AND DEGRADATION

Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment.
~Sheet erosion: surface water or wind peel off thin layers of soil.
~Rill erosion: fast-flowing little rivulets of surface water make small channels.
~Gully e

Desertification: Degrading Drylands

-About one-third of the world's land has lost some of its productivity because of drought and human activities that reduce or degrade topsoil.
-Causes: overgrazing, deforestation, salinization, erosion, soil compaction, natural climate change
-Consequence

Salinization and Waterlogging

-Repeated irrigation can reduce crop yields by causing salt buildup in the soil and waterlogging of crop plants.
-Salinization: irrigation water contains small amounts of dissolved salts, evaporation and transpiration leave salts behind, salt builds up in

Preventing Soil Salinization

-reduce irrigation
-switch to salt tolerant crops
-flush soil
-stop growing crops for 2-5 yrs
-install underground drainage systems

SUSTAINABLE AGRICULTURE THROUGH SOIL CONSERVATION

Modern farm machinery can plant crops without disturbing soil (no-till and minimum tillage.
-Conservation-tillage farming:
~Increases crop yield.
~Raises soil carbon content.
~Lowers water use.
~Lowers pesticides.
~Uses less tractor fuel.
-Terracing, cont

THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACT

-Lack of water, high costs for small farmers, and physical limits to increasing crop yields hinder expansion of the green revolution.
-Since 1978 the amount of irrigated land per person has declined due to:
~Depletion of underground water supplies.
~Ineff

THE GENE REVOLUTION

-To increase crop yields, we can mix the genes of similar types of organisms and mix the genes of different organisms.
~Artificial selection has been used for centuries to develop genetically improved varieties of crops.
~Genetic engineering develops impr

PRODUCING MORE MEAT

-About half of the world's meat is produced by livestock grazing on grass.
-The other half is produced under factory-like conditions (feedlots).
~Densely packed livestock are fed grain or fish meal.
-Eating more chicken and farm-raised fish and less beef

Animal Feedlots

Advantages: Increased meat production, higher profits, less land use, reduced overgrazing, reduced soil erosion, help protect biodiversity
Disadvantages: Need large inputs of grain, fish meal, water, and fossil fuels, Concentrate animal wastes that can po

CATCHING AND RAISING MORE FISH AND SHELLFISH

-Government subsidies given to the fishing industry are a major cause of overfishing.
~Global fishing industry spends about $25 billion per year more than its catch is worth.
~Without subsidies many fishing fleets would have to go out of business.
~Subsid

Aquaculture: Aquatic Feedlots

-Raising large numbers of fish and shellfish in ponds and cages is world's fastest growing type of food production.
-Fish farming involves cultivating fish in a controlled environment and harvesting them in captivity.
-Fish ranching involves holding anadr

Aquaculture tradeoffs

Advantages: High efficiency, High yield in small volume of water, Can reduce overharvesting of conventional fisheries, Low fuel use, High profits, Profits not tied to price of oil
Disadvantages: Needs large inputs of land, feed, and water, Large waste out

More Sustainable Aquaculture

� Use less fishmeal feed to reduce depletion of other fish
� Improve management of aquaculture wastes
� Reduce escape of aquaculture species into the wild
� Restrict location of fish farms to reduce loss of mangrove forests and estuaries
� Farm some aquac

Government Policies and Food Production

Governments use three main approaches to influence food production:
~Control prices to keep prices artificially low.
~Provide subsidies to keep farmers in business.
~Let the marketplace decide rather than implementing price controls.

Solutions: Steps Toward More Sustainable Food Production

We can increase food security by slowing populations growth, sharply reducing poverty, and slowing environmental degradation of the world's soils and croplands.

PROTECTING FOOD RESOURCES: PEST MANAGEMENT

-We use chemicals to repel or kill pest organisms as plants have done for millions of years.
-Chemists have developed hundreds of chemicals -(pesticides) that can kill or repel pests.
-Pesticides vary in their persistence.
~Each year > 250,000 people in t

The ideal Pesticide and the Nightmare Insect Pest

The ideal pest-killing chemical has these qualities:
~Kill only target pest.
~Not cause genetic resistance in the target organism.
~Disappear or break down into harmless chemicals after doing its job.
~Be more cost-effective than doing nothing.
-Superpest

Pesticide Protection Laws in the U.S.

-Government regulation has banned a number of harmful pesticides but some scientists call for strengthening pesticide laws.
~The Environmental Protection Agency (EPA), the Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regula

Other Ways to Control Pests

-There are cultivation, biological, and ecological alternatives to conventional chemical pesticides.
~Fool the pest through cultivation practices.
~Provide homes for the pest enemies.
~Implant genetic resistance.
~Bring in natural enemies.
~Use pheromones

SOLUTIONS: SUSTAINABLE AGRICULTURE

Three main ways to reduce hunger and malnutrition and the harmful effects of agriculture:
~Slow population growth.
~Sharply reduce poverty.
~Develop and phase in systems of more sustainable, low input agriculture over the next few decades.

Organic Farming

-Improves soil fertility
-reduces soil erosion
-retains more water in soil during drought years
-uses about 30% less energy per unit of yield
-lowers CO2 emissions
-reduces water pollution from recycling livestock wastes
- eliminates pollution from pestic