Food ResourcesFood Resources

G. Tyler Miller’sLiving in the Environment

13th Edition

Chapter 13

G. Tyler Miller’sLiving in the Environment

13th Edition

Chapter 13

Key ConceptsKey Concepts

Methods of producing food Methods of producing food

Increasing food production Increasing food production

Environmental effects of food production Environmental effects of food production

Increasing sustainability Increasing sustainability

How Is Food Produced?How Is Food Produced?

Sources of foodSources of food

Croplands (grain – 76% world’s food)Rangelands (grazing livestock – 17%)Oceanic Fisheries (fish – 7%)

Croplands (grain – 76% world’s food)Rangelands (grazing livestock – 17%)Oceanic Fisheries (fish – 7%)

Increase in Global Food Production Since 1950 Due to:

Increased technology: tractors, farm machinery, fishing boats, etc.

Inorganic chemical fertilizers Irrigation Pesticides High yield varieties of corn, rice, and

wheat Densely populated feedlots and pens

(cattle, pigs, chickens) Aquaculture

But, this increase has led to:

Environmental degradation Pollution Lack of water for irrigation Overgrazing Overfishing Loss of vital ecological services

What plants and animals feed the world? Wheat, rice, and corn provide over half

the calories we consume globally Annuals: must be replanted every year 15 plant and 8 terrestrial animal species

provide over 90% of our food 2/3 of world’s population survive

primarily on grains As incomes rise, people consume more

meat (more grain indirectly) Beef, pork, and chicken are main

animal sources of food

Types of Food Production

Industrialized/High-put Agriculture

Traditional

Major Types of AgricultureINDUSTRIALIZED

Plantation agriculturePracticed primarily in tropical developing countriesInvolves growing cash crops (bananas, coffee, soybeans, sugarcane, cocoa, and vegetables)on large monoculture plantations, mostly for sale to developed countries

Plantation agriculturePracticed primarily in tropical developing countriesInvolves growing cash crops (bananas, coffee, soybeans, sugarcane, cocoa, and vegetables)on large monoculture plantations, mostly for sale to developed countries

Major Types of AgricultureINDUSTRIALIZED

Industrialized (high-input)

Use fossil fuels, water, fertilizer, pesticides to produce large quantities of a single crop (monoculture)

Industrialized (high-input)

Use fossil fuels, water, fertilizer, pesticides to produce large quantities of a single crop (monoculture)

Major Types of AgricultureTRADITIONAL

Traditional subsistence:Uses mostly human laborDraft animals to produce only enough crops and livestock for the family’s survival

Traditional subsistence:Uses mostly human laborDraft animals to produce only enough crops and livestock for the family’s survival

44% of World’s People practice this

Major Types of AgricultureTRADITIONAL

Traditional intensiveIncreased input of human and draft laborIncreased input of waterIncreased input of fertilizerEnough food to feed family and make an income

Traditional intensiveIncreased input of human and draft laborIncreased input of waterIncreased input of fertilizerEnough food to feed family and make an incomeAttempt to increase yield to produce

extra for sale

Industrialized agricultureIndustrialized agriculture

Shifting cultivationShifting cultivation

Plantation agriculturePlantation agriculture

Nomadic herdingNomadic herding

Intensive traditional agricultureIntensive traditional agriculture

No agricultureNo agriculture

World Food Production

Industrialized agriculturein developed countries

Intensive traditional agriculturein developing countries

Land

Labor

Capital

Fossil fuelenergy

Land

Labor

Capital

Fossil fuel energy

Shifting cultivation in tropicalforests in developing countries

Nomadic herding indeveloping countries

Land

Labor

Capital

Land

Labor

Capital

An average of 60% of the people in developing countries are involved DIRECTLY in producing food, compared with only 8% in developed countries and 2% in the United States.

Food Type Kilocalories of fossil fuel input per kilocalorie of protein output

Feed lot beef 20-78

Pigs

Broiler chicken

Rangeland Beef

Sheep

Vegetables

35

22

10

10

2-4

Croplands

• 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

Ecological Services Economic Services

• Food crops

• Fiber crops

• Crop genetic resources

• Jobs

© 2004 Brooks/Cole – Thomson Learning

Producing Food by Green-Revolution Techniques (1950-1970)Producing Food by Green-Revolution Techniques (1950-1970)

High-input monoculture High-input monoculture

Selectively bred or genetically-engineered crops

Selectively bred or genetically-engineered crops

High inputs of fertilizer High inputs of fertilizer

Extensive use of pesticides Extensive use of pesticides

High inputs of water High inputs of water

Increased intensity and frequency of cropping (> yield, several times/season; saves land)

Increased intensity and frequency of cropping (> yield, several times/season; saves land)

Green Revolutions

First green revolution(developed countries)First green revolution(developed countries)

Second green revolution(developing countries)

Second green revolution(developing countries)

Major International agricultural research centers and seed banksMajor International agricultural research centers and seed banks

DO NOT POST TO INTERNET

INDONESIACHINA

HIGH-YIELD HYBRID

Semidwarf Rice called IR-8.

Producing Food by Traditional Techniques (Interplanting)Producing Food by Traditional Techniques (Interplanting)

Intercropping: 2 or more different crops are grown at the same time

Intercropping: 2 or more different crops are grown at the same time

Polyvarietal cultivation: several varieties of the same crop are planted at the same time

Polyvarietal cultivation: several varieties of the same crop are planted at the same time

Agroforestry (alley cropping): crops and trees are planted together

Agroforestry (alley cropping): crops and trees are planted together

Polyculture: a complex form of intercropping in which many different plants maturing at

different times are planted together

Polyculture: a complex form of intercropping in which many different plants maturing at

different times are planted together

ADVANTAGES of POLYCULTURE

Less need for fertilizer Less need for water (root systems are

at different depths) Protection from wind and water erosion

(soil covered year-round) Less need for insecticides (natural

predators thrive) Less need for herbicides (weeds have

trouble competing) Insurance in case of bad weather

because of diversity of crops produced

On average, low-input polyculture, with 4 or 5 different crop species, produces higher yields per hectare of land than high-input monoculture.

Nutrition

Undernutrition: lack of food to meet basic needs (getting 100-400 fewer calories per day than needed)

Undernutrition: lack of food to meet basic needs (getting 100-400 fewer calories per day than needed)

Malnutrition: deficiency of nutrients in diet (deficiency of protein and other key nutrients)

Malnutrition: deficiency of nutrients in diet (deficiency of protein and other key nutrients)

Overnutrition: too many calories lead to overweight

Overnutrition: too many calories lead to overweight

MARASMUS: “to waste away”

Occurs when a diet is both low in calories and protein

Usually occurs in young children

KWASHIORKOR: “displaced child”

Severe protein deficiency Usually occurs in children 1 – 3

years of age

Undernutrition and Malnutrition About 1 in 6 people in developing

countries is chronically undernourished or malnourished

Each year at least 10 million people, half of them children under 5, die prematurely from: Undernutrition Malnutrition Increased susceptibility to normally nonfatal

diseases Infectious diseases from contaminated drinking

water

Poverty MalnutritionDecreasedresistanceto disease

High deathrate forchildren

Decreasedenergy

Decreasedability

to learn

Decreasedability

to work

Shortenedlife

expectancy

Feedback loop

Micronutrient Deficiencies The most widespread micronutrient deficiencies

include Vitamin A, Iron and Iodine. Vitamin A - plays essential roles in vision, growth,

and development; the development and maintenance of healthy skin, hair, and mucous membranes; immune functions; and reproduction (found in foods like sweet potato, carrot, mango, broccoli, spinach)

Iron – is an essential component of hemoglobin which transports oxygen throughout the body and is important in many metabolic reactions (found in foods like chick peas, boiled spinach, dried apricots and figs)

Iodine – plays an essential role in hormone development in the human body. If you don't have enough iodine in your diet, it can lead to an enlarged thyroid gland (goitre) or other iodine deficiency disorders (found in seafood, iodized salt and some vegetables)

Overnutrition

Food energy intake exceeds energy use and causes body fat (obesity)

About 1 out of every 7 adults in developed countries is obese

In the U.S. about 1 out of every 5 adults is obese

Environmental Effects of Food Production

Biodiversity lossBiodiversity loss

SoilSoil

Air pollutionAir pollution

WaterWater

Human healthHuman health

Biodiversity Loss

Loss and degradation of habitat fromclearing grasslands and forests anddraining wetland

Fish kills from pesticide runoff

Killing of wild predators to protectlivestock

Loss of genetic diversity fromreplacing thousands of wild cropstrains with a few monoculture strains

Soil

Erosion

Loss of fertility

Salinization

Waterlogging

Desertification

Air Pollution

Greenhouse gas emissions from fossilFuel issue

Other air pollutants from fossil fuel use

Pollution from pesticide sprays

Water

Aquifer depletion

Increased runoff andflooding from land clearedto grow crops

Sediment pollution fromerosion

Fish kills from pesticiderunoff

Surface and groundwaterpollution from pesticidesand fertilizers

Overfertilization of lakesand slow-moving riversfrom runoff of nitrates andphosphates fromfertilizers, livestockwastes, and foodprocessing wastes

Human Health

Nitrates in drinking water

Pesticide residues in drinking water,food, and air

Contamination of drinking andswimming water with disease organismsfrom livestock wastes

Bacterial contamination of meat

Increasing World Crop ProductionIncreasing World Crop Production

Crossbreeding and artificial selection Crossbreeding and artificial selection

Genetic engineering (gene splicing) Genetic engineering (gene splicing)

Genetically modified organisms (GMOs) Genetically modified organisms (GMOs)

Continued Green Revolution techniques Continued Green Revolution techniques

Introducing new foods Introducing new foods

Working more land Working more land

Crop

Cross breeding

Desired trait(color)

ApplePear

Offspring

Cross breeding

Best results

Newoffspring

Desiredresult

Phase 1Make Modified Gene

Identify and extractgene with desired trait

Identify and removeportion of DNAwith desired trait

Remove plasmidfrom DNA of E. coli

Insert extracted DNA(step 2) into plasmid(step3)

Insert modifiedplasmid into E. coli

Grow in tissueculture tomake copies

cell

gene

DNA

Plasmid

E. coliDNA

Geneticallymodifiedplasmid

plasmid

Phase 2Make Transgenic Cell

Transfer plasmidcopies to a carrier

agrobacterium

Agrobacteriuminserts foreignDNA into plantcell to yieldtransgenic cell

Transfer plasmidto surfacemicroscopic metalparticle

Use gene gunto inject DNAinto plant cell

A. tumefaciens(agrobacterium)

Plant cell

Nucleus

Host DNA

Foreign DNA

Phase 3Grow Genetically Engineered Plant

Transgenic cellfrom Phase 2

Cell division oftransgenic cells

Culture cellsto form plantlets

Transgenic plantswith new traits

Concerns with GMO’s

“Frankenfood” We know far too little GMO’s cannot be recalled if they

cause harm No mandatory labeling (at this time)

Crop seeds with “terminator genes”

ProjectedAdvantages

ProjectedDisadvantages

Need less fertilizer

Need less water

More resistant toinsects, plant disease, frost, anddrought

Faster growth

Can grow in slightlysalty soils

Less spoilage

Better flavor

Less use of con-ventional pesticides

Tolerate higherlevels of herbicideuse

Irreversible andunpredictablegenetic and eco-logical effects

Harmful toxins infood from possibleplant cell mutations

New allergensin food

Lower nutrition

Increased evolutionof pesticide-resistant insectsand plant diseases

Creation of herbicide-resistant weeds

Harm beneficialinsects

Lower geneticdiversity

Advantages and

Disadvantages of Genetically

Modified Foods

Will People Try New Foods? Winged bean-protein rich legume

Produces its own nitrogen Has multiple edible parts

Microlivestock (INSECTS)-there are about 1500 edible species; 3 – 4 times as protein rich as beef, fish, or eggs Black ant larvae (Mexico) Giant waterbugs (Thailand) Emperor moth caterpillars (South Africa) Cockroaches (Kalahari desert) Butterflies (Bali) Ants (Colombia)

Producing More MeatProducing More Meat

Rangeland Rangeland

Pasture Pasture

Adaptations of rangeland plants Adaptations of rangeland plants

Range condition and management Range condition and management

Efficiency Efficiency

Environmental consequences Environmental consequences

Kilograms of grain needed per kilogram of body weightKilograms of grain needed per kilogram of body weight

Beef cattleBeef cattle 77

PigsPigs 44

ChickenChicken 2.22.2

Fish (catfishor carp)

Fish (catfishor carp) 22

Rangeland and Pasture

Rangeland is land that is too dry, too steeply sloped, or too infertile to grow crops (makes up about 40% of ice-free land)

Pasture is managed grasslands or enclosed meadows usually planted with domesticated grasses

Ungrazed Grazed Recovery

Metabolicreserve

Metabolicreserve

Metabolicreserveintact

Ecology of Rangeland Plants. Rangeland grasses grow from the bottom up and are renewable as long as the bottom half of the plant (where photosynthesis takes place) is not eaten.

Ungrazed Overgrazed Death

Metabolicreserve

Death

Most ofmetabolicreserveeaten

If the metabolic reserve is eaten (like during overgrazing) the plant is weakened and can die.

DO NOT POST TO INTERNET

Rangeland: Overgrazed (left) and lightly grazed (right.)

Overgrazed Riparian ZoneArizona’s San Pedro River

Recovery 10 Years Later

Undergrazing

Can reduce the net primary productivity of grassland vegetation and grass cover

More likely in arid areas

Environmental Consequences of Meat Production More than half of world’s cropland

is used to produce livestock feed Livestock consume 36% of world’s

grain Livestock use more than half the

water drawn from rivers and aquifers (irrigation)

Manure runoff leads to water pollution

Erosion resulting from grazing Cattle produce 16% of methane

(greenhouse gas)

Catching and Raising More FishThe World’s 3rd major food-producing systemCatching and Raising More FishThe World’s 3rd major food-producing system

Fisheries – concentrations of particular aquatic species in a given ocean area

Fisheries – concentrations of particular aquatic species in a given ocean area

Fishing methods (bycatch – thrown back in)Fishing methods (bycatch – thrown back in)

Sustainable yieldSustainable yieldOverfishing (Tragedy of the Commons)Overfishing (Tragedy of the Commons)Commercial extinction (over fishing)Commercial extinction (over fishing)AquacultureAquacultureFish farming and ranchingFish farming and ranching

Spotter airplane

Fish farmingin cage

Trawlerfishing

Purse-seinefishing

sonartrawl flap

trawllines

trawl bag

Long line fishing

lines withhooks

Drift-net fishing

Fish caughtby gills

float buoy

fish school

800

600

400

200

01960 1970 1980 1990 2000

Year

80

70

60

50

40

30

20

Har

vest

(th

ou

san

ds

of

met

ric

ton

s)

Ab

un

dan

ce(k

ilog

ram

s/to

w)

Abundance

Harvest

Fish change form

Fish enter riversand head forspawning areas

Grow to smoltand enter the ocean...

Grow to maturityin Pacific Oceanin 1-2 years

Eggs and young arecared for in the hatchery

Fry hatch in the spring...

Fingerlings migrate downstream

In the fall spawning salmondeposit eggs in gravel nests and die

NormalLifeCycle

Fingerlingsare released into river

And grow in the streamfor 1-2 years

Human capture

Salmonprocessingplant

Eggs are taken from adultfemales and fertilized withsperm “milked” from males

ModifiedLifeCycle

To hatchery

Advantages

Highly efficient

High yield in smallvolume of water

Increased yieldsthroughcrossbreedingand geneticengineering

Can reduceoverharvestingof conventionalfisheries

Little use of fuel

Profit not tired toprice of oil

High profits

Disadvantages

Large inputs ofland, feed, andwater needed

Produces largeand concentratedoutputs of waste

Destroysmangrove forests

Increased grainproductionneeded to feedsome species

Fish can be killedby pesticide runofffrom nearbycropland

Dense populationsvulnerable todisease

Tanks toocontaminated touse after about5 years

AQUACULTURE

Government Agricultural PolicyGovernment Agricultural Policy

Artificially low prices – consumers are happy, but farmers don’t make much money

Artificially low prices – consumers are happy, but farmers don’t make much money

Subsidies – given to farmers to keep them in business (comes from taxpayer’s money)

Subsidies – given to farmers to keep them in business (comes from taxpayer’s money)

Elimination of price controls – let farmers respond to market demand without government interference

Elimination of price controls – let farmers respond to market demand without government interference

Food aid – with any excess foodFood aid – with any excess food

Solutions: Sustainable AgricultureSolutions: Sustainable Agriculture

Low-input agricultureLow-input agriculture

Organic farmingOrganic farming

More benefits to the poorMore benefits to the poor

Increasing funding for research in sustainable techniques

Increasing funding for research in sustainable techniques

Increase

High-yield polyculture

Organic fertilizers

Biological pestcontrol

Integrated pestmanagement

Irrigation efficiency

Perennial crops

Crop rotation

Use of more water-efficient crops

Soil conservation

Subsidies for more sustainablefarming and fishing

Decrease

Soil erosion

Soil salinization

Aquifer depletion

Overgrazing

Overfishing

Loss of biodiversity

Loss of primecropland

Food waste

Subsidies forunsustainable farming and fishing

Population growth

Poverty

Components of More

SUSTAINABLE, LOW

THROUGHPUT Agriculture