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Food, Soil, & Pests. AP Environmental Science. Objective 1:. Describe problems with worldwide food security. What Is Food Security and Why Is It Difficult to Attain?.

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food soil pests
Food, Soil, & Pests

AP Environmental Science

objective 1
Objective 1:

Describe problems with worldwide food security.

what is food security and why is it difficult to attain
What Is Food Security and Why Is It Difficult to Attain?
  • Concept 12-1A Many people in less-developed countries have health problems from not getting enough food, while many people in more-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.
many people have health problems because they do not get enough to eat
Many People Have Health Problems Because They Do Not Get Enough to Eat
  • Food security
    • All or most people in a country have daily access to enough nutritious food to lead active and healthy lives
  • Food insecurity
    • Chronic hunger and poor nutrition
    • Root cause: poverty
    • Political upheaval, war, corruption,

bad weather

many people suffer from chronic hunger and malnutrition
Many People Suffer from Chronic Hunger and Malnutrition
  • Macronutrients
    • Carbohydrates
    • Proteins
    • Fats
  • Micronutrients
    • Vitamins
    • Minerals
many people suffer from chronic hunger and malnutrition1
Many People Suffer from Chronic Hunger and Malnutrition
  • Chronic undernutrition, hunger
    • People can not grow or buy enough food to be healthy
    • Low income/underdeveloped countries
  • Chronic malnutrition
    • Deficiencies in proteins or other nutrient
      • Lead to disease, incomplete physical & mental development
  • 1 in 6 people in less-developed countries is chronically undernourished or malnourished
  • Famine
    • Severe shortage of food in an area  leads to mass starvation
    • Drought, flooding, war, other catastrophes
world hunger
World Hunger

6 million children under 5 die because of malnutrition/year

FAO (UN Food & Ag Organization)

Figure 15, Supplement 8

many people do no get enough vitamins and minerals
Many People Do No Get Enough Vitamins and Minerals
  • Most often vitamin and mineral deficiencies in people in less-developed countries
    • WHO (World Health Organization)  1/3 of world population has a deficiency of 1 or more vitamin/minerals
  • Iron
    • Anemia, every 1/5 people
  • Vitamin A
    • 250,000-500,000 under 6 go blind, 1st year ½ will die
  • Iodine
    • Stunted growth, mental retardation, goiter
    • To wipe out worldwide  2-3 cents/per year/per person
many people have health problems from eating too much
Many People Have Health Problems from Eating Too Much
  • Overnutrition
    • Excess body fat from too many calories and not enough exercise
  • Similar health problems to those who are underfed
    • Lower life expectancy
    • Greater susceptibility to disease and illness
    • Lower productivity and life quality
objective 2
Objective 2:

Identify & Describe types of agriculture.

12 2 how is food produced
12-2 How Is Food Produced?
  • Concept 12-2 We have used high-input industrialized agriculture and lower-input traditional methods to greatly increase supplies of food.
food production has increased dramatically
Food Production Has Increased Dramatically
  • Three systems produce most of our food
    • Croplands: 77% on 11% world’s land area
    • Rangelands, pastures, and feedlots: 16% on 29% of world’s land area
    • Aquaculture: 7%
  • 48% of all calories eaten wheat, rice, and corn
  • Tremendous increase in global food production
    • Irrigation, better machinery & equipment, inorganic fertilizers & pesticides, industrial production of livestock & fish
industrialized crop production relies on high input monocultures
Industrialized Crop Production Relies on High-Input Monocultures
  • Industrialized agriculture, high-input agriculture
    • Use of heavy equipment, financial capital, fossil fuels, water, inorganic fertilizers & pesticides
    • Usually monoculture (single crop) for higher yields
      • Yield  amount of food/unit of land
    • ¼ all cropland, 80% world’s food, usually takes place in more developed countries
  • Goal is to steadily increase crop yield
    • Plantation agriculture: cash crops
      • Bananas, soy beans, sugarcane, coffee, palm oil, vegetables
      • Primarily in less-developed countries for export to more developed countries
    • Increased use of greenhouses to raise crops indoors
      • Saves water  efficient delivery, purified/recycled
      • Costs more but is becoming less expensive
case study hydroponics growing crops without soil
Case Study: Hydroponics: Growing Crops without Soil
  • Hydroponics: growing plants in nutrient-rich water solutions rather than soil
    • Grow indoors almost anywhere, year-round
    • Grow in dense urban areas
    • Recycle water and fertilizers
    • Little or no need for pesticides
    • No soil erosion
    • Takes money to establish
    • Help make the transition to more sustainable agriculture
hydroponic salad greens
Hydroponic Salad Greens

Fig. 12-6, p. 282

traditional agriculture often relies on low input polycultures
Traditional Agriculture Often Relies on Low-Input Polycultures
  • Used by 39% of world’s people
  • Produces 1/5 of world’s crops on ¾ of cultivated land
  • Traditional subsistence agriculture
    • Human labor and draft animals for family food
  • Traditional intensive agriculture
    • Higher yields through use of manure and water
    • To feed family and some to sell
traditional agriculture often relies on low input polycultures1
Traditional Agriculture Often Relies on Low-Input Polycultures
  • Polyculture
    • Growing several crops on one plot of land at the same time
  • Slash-and-burn agriculture
    • Subsistence agriculture in tropical forests
    • Clear and burn a small plot
    • Grow many crops that mature at different times
    • Reduced soil erosion, nutrient depletion
    • Less need for fertilizer and water, insecticides, herbicides
objective 7
Objective 7:

Explain the importance of soil in sustainability & describe the soil profile.

soil is the base of life on land
Soil Is the Base of Life on Land
  • Soil composition
    • Eroded rock
    • Mineral nutrients
    • Decaying organic matter
    • Water
    • Air
    • Microscopic decomposers
science focus soil is the base of life on land
Science Focus: Soil Is the Base of Life on Land
  • Layers (horizons) of mature soils
    • O horizon: leaf litter
    • A horizon: topsoil
    • B horizon: subsoil
    • C/R horizon: parent material, often bedrock
objective 3
Objective 3:

Describe the “Green Revolution” along with its advantages & disadvantages.

a closer look at industrialized crop production
A Closer Look at Industrialized Crop Production
  • Green Revolution: increase crop yields
    • Monocultures of high-yield (genetically engineered) key crops
      • Rice, wheat, and corn
    • Large amounts of fertilizers, pesticides, water
    • Multiple cropping (increase # of crops grown/year)
  • First Green Revolution (1950-1970)
  • Second Green Revolution (since 1967)
    • Fast growing dwarf varieties
      • Rice/wheat in less developed countries (China, India, Brazil)
    • More food, less land, preserves area of forests, wetlands, etc.
  • World grain has tripled in production
case study industrialized food production in the united states
Case Study: Industrialized Food Production in the United States
  • Agribusiness
    • Small number of large corporations controlling the growing, processing, distribution & sales
    • Average farmer feeds 129 people
    • Annual sales greater than auto, steel, and housing combined
  • Food production: very efficient
    • Americans spend 10% of income on food
  • Hidden costs of subsidies and costs of pollution and environmental degradation
crossbreeding and genetic engineering produce new crop livestock varieties
Crossbreeding and Genetic Engineering Produce New Crop/Livestock Varieties
  • First gene revolution
    • Cross-breeding through artificial selection
      • Slow process
      • Amazing results
  • Genetic engineering = second gene revolution
    • Alter organism’s DNA
    • Genetic modified organisms (GMOs): transgenic organisms
    • Takes ½ long, costs less, allows insertion of genes from any other organism.
crossbreeding and genetic engineering produce new crop livestock varieties 2
Crossbreeding and Genetic Engineering Produce New Crop/Livestock 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
  • Major GMO crops: soybeans, corn, cotton, canola
meat production and consumption have grown steadily
Meat Production and Consumption Have Grown Steadily
  • Animals for meat raised in
    • Pastures and rangelands
    • Feedlots (factory farm system), Concentrated animal feeding operations (CAFOs)
  • Meat production increased fourfold between 1961 and 2007
    • Increased demand for grain
    • Demand is expected to go higher
objective 5
Objective 5:

Describe aquaculture & its effects on fisheries.

fish and shellfish production have increased dramatically
Fish and Shellfish Production Have Increased Dramatically
  • Fishing with fleets depletes fisheries and uses many resources (fossil fuels)
  • Aquaculture, blue revolution
    • Practice of raising marine/freshwater species in ponds or cages in coastal/open ocean waters, rice paddies, reservoirs.
    • World’s fastest-growing type of food production
    • Dominated by operations that raise herbivorous species
    • China  produces 70% of world’s farmed fish
industrialized food production requires huge inputs of energy
Industrialized Food Production Requires Huge Inputs of Energy
  • Mostly nonrenewable energy – oil and natural gas
    • Farm machinery
    • Irrigate crops
    • Produce pesticides (petrochemicals)
    • Commercial inorganic fertilizers
    • Process and transport food
    • 19% of total fossil fuel energy use in U.S.
    • U.S. food travels an average of 2,400 kilometers
objective 6
Objective 6:

Describe issues that arise from industrialized food production & possible solutions.

12 3 what environmental problems arise from food production
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.
producing food has major environmental impacts
Producing Food Has Major Environmental Impacts
  • Harmful effects of agriculture on
    • Biodiversity
    • Soil
    • Water
    • Air
    • Human health
topsoil erosion is a serious problem in parts of the world
Topsoil Erosion Is a Serious Problem in Parts of the World
  • Soil erosion
    • Movement of soil by wind and water
    • Natural causes
    • Human causes
  • Two major harmful effects of soil erosion
    • Loss of soil fertility- depletion of nutrients
    • Water pollution
      • Runoff: kill fish, clog irrigation, excess nutrients from pesticides
drought and human activities are degrading drylands
Drought and Human Activities Are Degrading Drylands
  • Desertification
    • Productive potential of topsoil falls below 10%
      • Moderate 10-25% productivity drop
      • Severe 25-50% productivity drop
      • Very severe > 50% productivity drop
        • Gullies, sand dunes, expansion of existing deserts, creation of new desert
  • Human agriculture accelerates desertification
  • Effect of global warming on desertification
severe desertification
Severe Desertification

Fig. 12-15, p. 291

excessive irrigation has serious consequences
Excessive Irrigation Has Serious Consequences
  • Salinization
    • Gradual accumulation of salts in the soil from irrigation water
    • Lowers crop yields, stunts growth and can even kill plants
    • Affects 10% of world croplands
  • Waterlogging
    • Irrigation water gradually raises water table
    • Can prevent roots from getting oxygen
    • Affects 10% of world croplands
agriculture contributes to air pollution and projected climate change
Agriculture Contributes to Air Pollution and Projected Climate Change
  • One-fourth of all human-generated greenhouse gases
  • Clearing and burning of forests for croplands (CO2)
  • Livestock contributes 18% of gases: methane in cow belches
    • Grass-fed better than feedlots
  • Making fertilizers produces nitrous oxides
food and biofuel production systems have caused major biodiversity losses
Food and Biofuel Production Systems Have Caused Major Biodiversity Losses
  • Biodiversity threatened when
    • Forest and grasslands are replaced with croplands – especially tropical forests
  • Agrobiodiversity threatened when
    • Human-engineered monocultures are used
    • GMOS – no seed saving
    • ¾ lost since 1900
  • Importance of seed banks
    • Newest: underground vault in the Norwegian Arctic
trade offs animal feedlots
Trade-Offs: Animal Feedlots

Fig. 12-19, p. 295

trade offs aquaculture
Trade-Offs: Aquaculture

Fig. 12-20, p. 296

objective 8
Objective 8:

Identify types of pesticides, costs & benefits, disadvantages of pesticides & applicable laws/treaties.

12 4 how can we protect crops from pests more sustainably
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
Nature Controls the Populations of Most Pests
  • What is a pest?
    • Interferes with human welfare by competing for food, invading lawns/gardens/ecosystems, spreads disease…
    • 100 weeds, animals, fungi, microbes that cause most crop damage.
  • Natural enemies—predators, parasites, disease organisms—control pests
    • In natural ecosystems
    • In many polyculture agroecosystems
  • What will happen if we kill the pests?
we use pesticides to try to control pest populations
We Use Pesticides to Try to Control Pest Populations
  • Pesticides
    • Chemicals used to kill/control the populations of pests
      • Insecticides (insects)
      • Herbicides (weeds)
      • Fungicides (fungi)
      • Rodenticides (mice, rats, etc)
we use pesticides to try to control pest populations1
We Use Pesticides to Try to Control Pest Populations
  • First-generation pesticides
    • Borrowed from plants
  • Second-generation pesticides
    • Lab produced: DDT and others
      • 1939 – Entomologist Paul Muller developed DDT (dichloropiphenyltrichlorethane); Won 1948 Nobel Peace Prize for Physiology & Medicine
  • Broad-spectrum and narrow-spectrum agents
    • Broad spectrum – toxic to many pests
    • Narrow spectrum – effective on a small group of pests
  • Persistence varies
    • How long the agent is deadly in the environment
      • DDT stays in the environment for years, biomagnification
individuals matter rachel carson
Individuals Matter: Rachel Carson
  • Biologist
  • Noticed birds were dying off- related it to the use of DDT
  • Silent Spring – book written (1962) about the potential threats of uncontrolled use of pesticides.
  • Led to the banning and controlled use of pesticides in the United States
modern synthetic pesticides have several advantages
Modern Synthetic Pesticides Have Several Advantages
  • Save human lives
    • Prevent death by disease
  • Increases food supplies and profits for farmers
    • Less crop loss due to pests
  • Work quickly
  • For many, health risks are very low relative to benefits
    • If used properly
  • New pest control methods: safer and more effective
modern synthetic pesticides have several disadvantages
Modern Synthetic Pesticides Have Several Disadvantages
  • Accelerate rate of genetic resistance/immunity in pests
  • Expensive for farmers
  • Some insecticides kill natural predators and parasites that help control the pest population
  • Pollution in the environment (water & air)
  • Some harm wildlife
  • Some are human health hazards
pesticide use has not reduced u s crop losses to pests
Pesticide Use Has Not Reduced U.S. Crop Losses to Pests
  • David Pimentel: Pesticide use has not reduced U.S. crop loss to pests
    • 1942-1997: crop losses from insects increased from 7% to 13%, even with 10x increase in pesticide use
    • High environmental, health, and social costs with use
      • $5-10 of Damages for every $1 pesticide used
    • alternative pest management practices are better
  • Pesticide industry disputes these findings
case study ecological surprises the law of unintended consequences
Case Study: Ecological Surprises: The Law of Unintended Consequences
  • 1955: Dieldrin (DDT) sprayed to control mosquitoes carrying malaria
  • Malaria was controlled BUT
  • Dieldrin didn’t leave the food chain CAUSING a
  • Domino effect of the spraying
laws and treaties can help to protect us from the harmful effects of pesticides
Laws and Treaties Can Help to Protect Us from the Harmful Effects of Pesticides
  • U.S. federal agencies and laws
    • EPA, USDA, FDA
    • Federal Instecticide, Fungicide and Rodenticide Act, 1947 amended 1972
    • Food Quality Protection Act, 1996
  • EPA was tasked with assessing health risks of active ingredients already in use (only 10% tested)
  • Food Quality Protection Act
    • EPA to reduce the amount of allowed levels of pesticide residues in food by a factor of 10 with pesticides without enough info about.
  • 1972-2009 EPA used FIFRA to ban 64 active ingredients
    • Including DDT
  • Effects of active and inactive pesticide ingredients are poorly documented
    • U.S. exports many banned pesticides
  • Circle of poison/ Boomerang Effect: Residues of banned chemicals exported to other countries returns on imported foods.
objective 9
Objective 9:

Describe Integrated Pest Management (IPM) and other alternative to pesticides.

there are alternatives to using pesticides
There Are Alternatives to Using Pesticides
  • Cultivation practices
    • Fool the pest by using crop rotation; changing planting times
  • Provide homes for pest enemies
    • Polyculture
  • Implant genetic resistance – genetic engineering
  • Bring in natural enemies
    • Predators, parasites, diseases
there are alternatives to using pesticides1
There Are Alternatives to Using Pesticides
  • Use insect perfumes
    • Pheromones
    • Used to trap pests or attract their natural predators
  • Bring in hormones
    • Interfere with pest life cycle
  • Alternative methods of weed control
    • Crop rotation, cover crops, mulches
integrated pest management is a component of sustainable agriculture
Integrated Pest Management Is a Component of Sustainable Agriculture
  • Integrated pest management (IPM)
    • Coordinate: cultivation, biological controls, and chemical tools to reduce crop damage to an economically tolerable level
    • Reduces pollution and pesticide costs
    • To Reduce Crop Damage
      • Rotate crops, carefully monitor for pests
      • If pests reach a damaging level use biological controls first then small amount of chemical agents.
      • No broad spectrum agents used
  • Indonesia – banned 57/66 pesticides over a 2 year period.
    • Educated farmers on IPM
    • Pesticide use decreased 65% while rice production increased 15%
integrated pest management is a component of sustainable agriculture1
Integrated Pest Management Is a Component of Sustainable Agriculture
  • Disadvantages
    • Requires expert knowledge
    • Growing conditions alter from area to area
    • High initial costs
    • Government opposition
      • US & other countries provide subsidies for the use of conventional pesticides
integrated pest management in the us
Integrated Pest Management in the US
  • 3 point plan suggested for IPM in the US:
    • 1st - Charge 2% sales tax on pesticides to fund National IPM research and education
    • 2nd – set up IPM Demonstration projects on 1 farm in every county
    • 3rd – train USDA field personnel & farm agents in IPM to provide assistance
    • Pesticide companies strongly opposed this option
objective 10
Objective 10:

Identify & describe ways of maintaining food production sustainability.

how can we improve food security
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
Use Government Policies to Improve Food Production and Security
  • Control prices to make food affordable
    • Limit the prices of food; helpful for consumer but harmful to the farmer
  • Provide subsidies to farmers
    • Give farmers money, price support, tax breaks to increase production
  • Let the marketplace decide—
    • Government no longer provides subsidies and is working in New Zealand and Brazil
other government and private programs are increasing food security
Other Government and Private Programs are Increasing Food Security
  • Immunizing children against childhood diseases
  • Encourage breast-feeding
  • Prevent dehydration in infants and children
  • Provide family planning services
  • Increase education for women
  • One-half to one-third of nutrition-related deaths in children can be prevented for $5-10 per year
12 6 how can we produce food more sustainably
12-6 How Can We Produce Food More Sustainably?
  • Concept 12-6 More sustainable food production will require using resources more efficiently, sharply decreasing the harmful environmental effects of industrialized food production, and eliminating government subsidies that promote such harmful impacts.
reduce soil erosion
Reduce Soil Erosion
  • Soil conservation, some methods
    • Terracing
    • Contour planting
    • Strip cropping with cover crop
    • Alley cropping, agroforestry
    • Windbreaks or shelterbelts
    • Conservation-tillage farming
      • No-till
      • Minimum tillage
  • Identify erosion hotspots
case study soil erosion in the united states learning from the past
Case Study: Soil Erosion in the United States—Learning from the Past
  • What happened in the Dust Bowl in the 1930s?
    • Overgrazing & agriculture reduced topsoil, coupled with a severe prolonged drought, led to massive soil erosion
  • Migrations to the East, West, and Midwest
  • 1935: Soil Erosion Act
    • Created the soil conservation service (SCS) now called the Natural Resource Conservation Service (NRCS)
  • 1985 Food Security Act (Farm Act)
    • Famers were given subsidies take highly erodible land out of production and replant them with grasses/trees.
  • More soil conservation needed
restore soil fertility
Restore Soil Fertility
  • Organic fertilizer
    • Made from plant/animal matter
      • Animal manure – provides nitrogen, promotes beneficial bacteria & fungi
      • Green manure – plowing vegetation into top soil
      • Compost – created when microbes breakdown organic matter in the presence of oxygen
  • Manufactured inorganic fertilizer
    • Made from mined minerals
      • Nitrogen, phosphorus, calcium
      • Cause of major water pollution due to runoff
  • Crop rotation to avoid depletion of nutrients
reduce soil salinization and desertification
Reduce Soil Salinization and Desertification
  • Soil salinization
    • Prevention & Clean-up are very costly
  • Desertification
    • Cannot control natural droughts BUT
    • Can Reduce
      • Population growth
      • Overgrazing
      • Deforestation
      • Destructive forms of planting, irrigation, and mining
    • Restore areas by planting trees to anchor topsoil & hold water as well as act as windbreaks
practice more sustainable aquaculture
Practice More Sustainable Aquaculture
  • Open-ocean aquaculture
    • 300 km from shore
    • Choose herbivorous fish
  • Recirculating Aquaculture Systems (RAS)
    • Zero discharge freshwater ponds/tanks
    • Treat water for reuse
  • Polyculture
    • Raise many species together
case study raising salmon in an artificial ecosystem
Case Study: Raising Salmon in an Artificial Ecosystem
  • Cooke Aquaculture in the Bay of Fundy, New Brunswick, Canada
  • Polyaquaculture
  • Mimic a natural system with 3 species:
    • Salmon in cages
    • Shellfish in socks filter waste
    • Kelp uses some of added nutrients
produce meat more efficiently and humanely
Produce Meat More Efficiently and Humanely
  • Shift to more grain-efficient forms of protein
  • Beef from rangelands and pastures, not feedlots
  • Develop meat substitutes; eat less meat
shift to more sustainable agriculture
Shift to More Sustainable Agriculture
  • Sustainable agriculture uses fewer inputs, creates less pollution, and contributes less to global warming
  • Organic farming
    • Many benefits
    • Requires more labor (creates jobs)
solutions organic farming
Solutions: Organic Farming

Fig. 12-35, p. 311

shift to more sustainable agriculture1
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
    • Encourage hydroponics
    • Greater use of alternative energy
science barge prototype of sustainable urban farm in yonkers new york
Science Barge: Prototype of Sustainable Urban Farm in Yonkers, New York

Fig. 12-36, p. 311

science focus sustainable polycultures of perennial crops
Science Focus: Sustainable Polycultures of Perennial Crops
  • Polycultures of perennial crops
    • Go back year after year
  • 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