Food, Soil, and Pest Management

Chapter 12

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).

Key Nutrients for a Healthy Human Life

Acute Food Shortages Can Lead to Famines

Famine• Usually caused by crop failures from• Drought• Flooding• War• Other catastrophic events

War and the Environment: Starving Children in Famine-Stricken Sudan, Africa

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

Satellite Images of Greenhouse Land Used in the Production of Food Crops

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

Active Figure: Soil profile

Global Outlook: Total Worldwide Grain Production (Wheat, Corn, and Rice)

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

Genetic Engineering: Steps in Genetically Modifying a Plant

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

Animation: Transferring genes into plants

GM crop production data

Click for webpage

Colorado State Transgenic Crops

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

Natural Capital Degradation: Severe Gully Erosion on Cropland in Bolivia

Natural Capital Degradation: Global Soil Erosion

Severe Desertification

Natural Capital Degradation: Desertification of Arid and Semiarid Lands

Natural Capital Degradation: Severe Salinization on Heavily Irrigated Land

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.

Industrialized Agriculture uses ~17% of All Commercial Energy Used in the U.S.

Fig 12-15

Agriculture in California

Click for report

Agriculture in Ventura County

Click for report

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

Industrialized Meat Production

Meatrix webpage

Click for webpage

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

World Fish Catch, Including Both Wild Catch and Aquaculture

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

Animation: Land use

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

Natural Capital: Spiders are Important Insect Predators

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

What Can You Do? Reducing Exposure to Pesticides

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.

Natural Capital: Biological Pest Control

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

Soil Conservation Methods

(a) Terracing (b) Contour planting and strip cropping

(c) Alley cropping(d) Windbreaks Fig. 12-24, p. 302

Stepped Art

Natural Capital Degradation: Dust Storm, Driven by Wind Blowing across Eroded Soil

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)

Solutions: More Sustainable Aquaculture

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

Efficiency of Converting Grain into Animal Protein

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

Solutions: Organic Farming

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

What Can You Do? Sustainable Organic Agriculture