12-1 What Is Food Security and Why Is It Difficult to Attain?
Concept 12-1A Many of the poor suffer health problems from chronic lack of food and poor nutrition, while many people in developed countries have health problems from eating too much food.
Concept 12-1B The greatest obstacles to providing enough food for everyone are poverty, political upheaval, corruption, war, and the harmful environmental effects of food production.
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 (malnutrition).
FOOD SECURITY AND NUTRITION
The root cause of hunger and malnutrition is poverty.
Food security means that every person in a given area has daily access to enough nutritious food to have an active and healthy life.• Need large amounts of macronutrients (protein,
carbohydrates, and fats).• Need smaller amounts of micronutrients
(vitamins such as A,C, and E).
Acute Food Shortages Can Lead to Famines
Famine• Usually caused by crop failures from• Drought• Flooding• War• Other catastrophic events
Overnutrition: Eating Too Much
Overnutrition and lack of exercise can lead to reduced life quality, poor health, and premature death.
60% of American adults are overweight and 33% are obese (totaling 93%).
Americans spend $42 billion per year trying to lose weight.
$24 billion per year is needed to eliminate world hunger.
12-2 How Is Food Produced?
Concept 12-2A We have sharply increased crop production using a mix of industrialized and traditional agriculture.
Concept 12-2B We have used industrialized and traditional methods to greatly increase supplies of meat, fish, and shellfish.
Food Production Has Increased Dramatically
Three systems produce most of our food• Croplands: 77%• Rangelands, pastures, and feedlots: 16%• Aquaculture: 7%
Industrialized Crop Production Relies on High-Input Monocultures
Industrialized agriculture = High-input agriculture
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.
• Goal is to steadily increase crop yield• Increased use of greenhouses to raise crops
Plantation agriculture
Shifting cultivation
Industrialized agriculture
No agriculture
Intensive traditional ag.
Nomadic herding
Fig. 12-A, p. 281
Wood sorrelOak tree Earthworm
Grasses and small shrubs
Organic debris builds up
FernHoney fungus
Moss and lichen
MoleRock fragments
O horizon Leaf litter
A horizon Topsoil
B horizon Subsoil
BedrockImmature soil
Young soilC horizon
Parent material
Mite
Nematode
Root systemRed earth mite Bacteria
FungusMature soil
Millipede
Crossbreeding and Genetic Engineering Can Produce New Crop Varieties (1)
Gene Revolution• Cross-breeding through artificial selection• Slow process
Genetic engineering• Genetic modified organisms (GMOs):
transgenic organisms
Crossbreeding and Genetic Engineering Can Produce New Crop Varieties (2)
Age of Genetic Engineering: developing crops that are resistant to• Heat and cold• Herbicides• Insect pests• Parasites• Viral diseases• Drought• Salty or acidic soil
Fig. 12-6, p. 283
Phase 1 Gene Transfer Preparations
A. tumefaciens
Plant cell
Extract plasmidExtract DNA
Foreign gene if interest
plasmidForeign gene integrated into plasmid DNA.
Phase 2 Make Transgenic Cell
Agrobacterium takes up plasmid
A. tumefaciens (agrobacterium)
Enzymes integrate plasmid into host cell DNA.
Host cell Host DNAForeign DNA
Nucleus Transgenic plant cellPhase 3 Grow Genetically Engineered Plant
Cell division of transgenic cells
Cultured cells divide and grow into plantlets (otherwise teleological)
Transgenic plants with desired trait
GM crop production data
Click for webpage
Perceptions about Genetically Modified Food
Click for webpage
Fig. 12-16, p. 291
TRADE-OFFSGenetically Modified Crops and Foods
Projected Advantages
Projected DisadvantagesIrreversible and unpredictable genetic and ecological effects
Need less fertilizer
Need less water
More resistant to insects, disease, frost, and drought
Harmful toxins in food from possible plant cell mutations
Grow faster New allergens in foodCan grow in slightly salty soils
Lower nutrition
Increase in pesticide- resistant insects, herbicide- resistant weeds, and plant diseases
May need less pesticides
Tolerate higher levels of herbicides
Higher yieldsCan harm beneficial insects
Less spoilage Lower genetic diversity
12-3 What Environmental Problems Arise from Food Production?
Concept 12-3 Food production in the future may be limited by its serious environmental impacts, including soil erosion and degradation, desertification, water and air pollution, greenhouse gas emissions, and degradation and destruction of biodiversity.
Fig. 12-9, p. 286
NATURAL CAPITAL DEGRADATION
Food Production
Biodiversity Loss Soil Water Air Pollution Human Health
Loss and degradation of grasslands, forests, and wetlands
Erosion Water waste Greenhouse gas emissions (CO2) from fossil fuel use
Nitrates in drinking water (blue baby)Loss of fertility Aquifer depletion
Pesticide residues in drinking water, food, and air
Fish kills from pesticide runoff
SalinizationIncreased runoff, sediment pollution, and flooding from cleared land
Greenhouse gas emissions (N2O) from use of inorganic fertilizersWaterlogging
Killing wild predators to protect livestock
Contamination of drinking and swimming water from livestock wastes
Desertification Pollution from pesticides and fertilizers
Greenhouse gas emissions of methane (CH4) by cattle (mostly belching)
Loss of genetic diversity of wild crop strains replaced by monoculture strains
Algal blooms and fish kills in lakes and rivers caused by runoff of fertilizers and agricultural wastes
Bacterial contamination of meat
Other air pollutants from fossil fuel use and pesticide sprays
There May Be Limits to Expanding the Green Revolutions
Can we expand the green revolution by• Irrigating more cropland?• Improving the efficiency of irrigation?• Cultivating more land? Marginal land?• Using GMOs?• Multicropping?
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 1 unit of food energy on the table.
Food and Biofuel Production Systems Have Caused Major Biodiversity Losses
Biodiversity threatened when• Forest and grasslands are replaced with
croplands
Agrobiodiversity threatened when• Human-engineered monocultures are used
Importance of seed banks • Newest: underground vault in the Norwegian
Arctic
Fig. 12-17, p. 292
TRADE-OFFSAnimal Feedlots
Advantages Disadvantages
Increased meat production
Large inputs of grain, fish meal, water, and fossil fuelsHigher profits
Greenhouse gas (CO2 and CH4) emissions
Less land use
Reduced overgrazing Concentration of animal wastes that can pollute waterReduced soil
erosion
Protection of biodiversity
Use of antibiotics can increase genetic resistance to microbes in humans
Fig. 12-18, p. 293
TRADE-OFFS
Aquaculture
Advantages Disadvantages
Needs large inputs of land, feed, and water
High efficiency
High yield in small volume of water
Large waste output
Can destroy mangrove forests and estuaries
Can reduce overharvesting of fisheries
Uses grain to feed some speciesLow fuel use
High profitsDense populations vulnerable to disease
12-4 How Can We Protect Crops from Pests More Sustainably?
Concept 12-4 We can sharply cut pesticide use without decreasing crop yields by using a mix of cultivation techniques, biological pest controls, and small amounts of selected chemical pesticides as a last resort (integrated pest management).
Nature Controls the Populations of Most Pests
What is a pest? What is a weed?
Natural enemies—predators, parasites, disease organisms—control pests• In natural ecosystems • In many polyculture agroecosystems
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.
How do pesticides work?
Click for EPA page
Click here for Na. Pesticide Info Center
Individuals Matter: Rachel Carson
Wrote Silent Spring which introduced the U.S. to the dangers of the pesticide DDT and related compounds to the environment.
Modern Synthetic Pesticides Have Several Disadvantages
David Pimentel: Pesticide use has not reduced U.S. crop loss to pests• Loss of crops is about 31%, even with 33-fold
increase in pesticide use• High environmental, health, and social costs with
use• Use alternative pest management practices
Pesticide industry refutes these findings
Fig. 12-20, p. 295
TRADE-OFFS
Conventional Chemical Pesticides
Save lives Promote genetic resistance
Advantages Disadvantages
Increase food supplies Kill natural pest
enemiesProfitable Pollute the
environmentCan harm wildlife and people
Work fast
Safe if used properly Are expensive for
farmers
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) regulate the sales of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).
– The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides.
– The California Department of Pesticide Regulation controls pesticide use in California.
Pesticides in California
Click here for pesticide use data
Other Ways to Control Pests:
There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. Integrated Pest Management• Fool the pest through cultivation practices.• Provide homes for the pest enemies.• Implant genetic resistance.• Bring in natural enemies.• Use pheromones to lure pests into traps.• Use hormones to disrupt life cycles.
Case Study: integrated Pest Management: A Component of Sustainable Agriculture
Many scientists urge the USDA to use three strategies to promote IPM in the U.S.:• Add a 2% sales tax on pesticides.• Establish federally supported IPM demonstration
project for farmers.• Train USDA personnel and county farm agents in
IPM. The pesticide industry opposes such measures.
Integrated Pest Management in California
Click for UC Davis IMP page
Click for Cal Poly SLO Sustainable Ag Resource Consortium
12-5 How Can We Improve Food Security?
Concept 12-5 We can improve food security by creating programs to reduce poverty and chronic malnutrition, relying more on locally grown food, and cutting food waste.
Use Government Policies to Improve Food Production and Security (2)
United Nations Children’s Fund (UNICEF) suggests these measures• Immunizing children against childhood diseases• Encourage breast-feeding • Prevent dehydration in infants and children• Provide family planning services• Increase education for women
12-6 How Can We Produce Food More Sustainably? (1)
Concept 12-6A Sustainable food production will require reducing topsoil erosion, eliminating overgrazing and overfishing, irrigating more efficiently, using integrated pest management, promoting agrobiodiversity, and providing government subsidies for more sustainable farming, fishing, and aquaculture.
12-6 How Can We Produce Food More Sustainably? (2)
Concept 12-6B Producing enough food to feed the rapidly growing human population will require growing crops in a mix of monocultures and polycultures and decreasing the enormous environmental impacts of industrialized food production.
Reduce Soil Erosion
Soil conservation, some methods• Terracing• Contour planting• Strip cropping with cover crop• Alley cropping, agroforestry• Windbreaks or shelterbeds• Conservation-tillage farming • No-till• Minimum tillage
Identify erosion hotspots
(a) Terracing (b) Contour planting and strip cropping
(c) Alley cropping(d) Windbreaks Fig. 12-24, p. 302
Stepped Art
Restore Soil Fertility
Organic fertilizer• Animal manure• Green manure• Compost
Commercial inorganic fertilizer active ingredients • Nitrogen• Phosphorous• Potassium
Reduce Soil Salinization and Desertification
Soil salinization• Prevention• Clean-up
Desertification, reduce• Population growth• Overgrazing• Deforestation• Destructive forms of planting, irrigation, and
mining
Fig. 12-28, p. 305
SOLUTIONSSoil Salinization
Prevention Cleanup
Flush soil (expensive and wastes water)
Reduce irrigation
Stop growing crops for 2–5 years
Switch to salt-tolerant crops (such as barley, cotton, and sugar beet)
Install underground drainage systems (expensive)
Produce Meat More Efficiently and Humanely
Shift to more grain-efficient forms of protein
Shift to farmed herbivorous fish
Develop meat substitutes; eat less meat
Whole Food Markets: more humane treatment of animals
Shift to More Sustainable Agriculture
Strategies for more sustainable agriculture• Research on organic agriculture with human
nutrition in mind• Show farmers how organic agricultural systems
work• Subsidies and foreign aid• Training programs; college curricula
Fig. 12-31, p. 307
SOLUTIONS
Sustainable Organic Agriculture
More LessHigh-yield polyculture
Soil erosion
Organic fertilizers
Aquifer depletion
Biological pest control
Overgrazing
OverfishingIntegrated pest management
Loss of biodiversity
Efficient irrigation
Perennial crops Subsidies for unsustainable farming and fishing
Food waste
Crop rotationWater-efficient crops
Soil salinizationSoil conservationSubsidies for sustainable farming and fishing
Population growth
Poverty
Science Focus: Sustainable Polycultures of Perennial Crops
Polycultures of perennial crops
Wes Jackson: natural systems agriculture benefits• No need to plow soil and replant each year• Reduces soil erosion and water pollution• Deeper roots – less irrigation needed• Less fertilizer and pesticides needed
Buy Locally Grown Food
Supports local economies
Reduces environmental impact on food production
Community-supported agriculture. Click for Ventura County Farm Bureau link
Click for Ag Futures Alliance Ventura County
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