Food Resources G. Tyler Millers Living in the Environment 13 th Edition Chapter 13 G. Tyler Millers...

Food Resources

G. Tyler Miller’sLiving in the Environment

13th Edition

Chapter 13

Key Concepts

Methods of producing foodMethods of producing foodIncreasing food productionIncreasing food productionEnvironmental effects of Environmental effects of

food productionfood productionIncreasing sustainabilityIncreasing sustainability

How Is Food Produced?

• Sources of foodSources of food– cropland (76%)cropland (76%)– rangeland (17%)rangeland (17%)– ocean fisheries (7%)ocean fisheries (7%)

• Primary plantsPrimary plants– wheat, corn, ricewheat, corn, rice

• Primary animalsPrimary animals– beef, pork, chickenbeef, pork, chicken

Major Types of Agriculture

• Traditional AgricultureTraditional Agriculture– Traditional subsistenceTraditional subsistence

•uses human labor and draft animalsuses human labor and draft animals•produce only enough food for a produce only enough food for a

family’s survival.family’s survival.– Traditional intensiveTraditional intensive

•increased human and draft labor, increased human and draft labor, fertilizer, and waterfertilizer, and water

•higher yields producing enough higher yields producing enough food for their family food for their family andand to sell for to sell for income.income.

Major Types of Agriculture• Industrialized (high input)Industrialized (high input)

– uses large quantities of fossil fuel uses large quantities of fossil fuel energy, water, commercial fertilizer, energy, water, commercial fertilizer, and pesticidesand pesticides

– produces huge quantities of produces huge quantities of single single cropscrops or livestock or livestock ((monoculturemonoculture))

• PlantationPlantation – growing cash crops on large growing cash crops on large

monoculture plantationsmonoculture plantations– Mostly for sale in developed countries.Mostly for sale in developed countries.

Industrialized agriculturein developed countries

Intensive traditional agriculturein developing countries

Land

Labor

Capital

Fossil fuelenergy

Land

Labor

CapitalFossil fuel energy

Industrialized agricultureShifting cultivation

Plantation agricultureNomadic herding

Intensive traditional agricultureNo agriculture

World Food Production

Challenge to Farmers: Produce More Food!

1.1. Farm more landFarm more land

2.2. Produce higher yields Produce higher yields per unit areaper unit area

Green RevolutionGreen Revolution

Refers to dramatically increased Refers to dramatically increased agricultural productivity agricultural productivity resulting from the introduction resulting from the introduction of new, of new, high-yielding strains of high-yielding strains of graingrain (rice, wheat, and maize) (rice, wheat, and maize)

Ongoing since 1950sOngoing since 1950s

Producing Food by Green-Revolution Techniques

High-input High-input monoculturemonocultureScientifically bred or Scientifically bred or

genetically-engineered cropsgenetically-engineered cropsHigh inputs of fertilizerHigh inputs of fertilizerExtensive use of pesticidesExtensive use of pesticidesHigh inputs of waterHigh inputs of waterIncreased intensity and Increased intensity and

frequency of cropping frequency of cropping (multiple (multiple cropping)cropping)

Green Revolutions

First green revolution(developed countries)

Second green revolution(developing countries)

Major International agricultural research centers and seed banks

1950-1950-19701970

1967-today

Producing Food by Traditional Techniques (Low input agrodiversity)

InterplantingInterplanting - simultaneously - simultaneously growing a variety of crops on growing a variety of crops on the same plotthe same plot

1)1) Polyvarietal cultivationPolyvarietal cultivation– Planting several Planting several varieties of the varieties of the

same cropsame crop in a plot in a plot2)2) IntercroppingIntercropping

– Two or more different crops are Two or more different crops are grown at the same time on a plotgrown at the same time on a plot

Producing Food by Traditional Techniques (Low input agrodiversity)

3)3) Agroforestry (alley cropping)Agroforestry (alley cropping)– Crops and trees are planted Crops and trees are planted

togethertogether4)4) PolyculturePolyculture

– Different plants maturing at Different plants maturing at various times are planted togethervarious times are planted together• Less fertilizerLess fertilizer• Protection from wind and water Protection from wind and water

erosionerosion• Little or no insecticidesLittle or no insecticides• Insurance against bad weatherInsurance against bad weather

Food Production – good news

Total World Grain Production

2,000

1,500

1,000

500

0

Gra

in p

rodu

ctio

n(m

illio

ns o

f ton

s)

1950 1960 1970 1980 1990 2000 2010

Year

Production is increasing!!Production is increasing!!

Food Production – bad news

World Grain Production per Capita

400

350

300

250

150

Per c

apita

gra

in p

rodu

ctio

n(k

ilogr

ams

per p

erso

n)

1950 1960 1970 1980 1990 2000 2010

200

Year

Population growth outstripped Population growth outstripped productionproduction

Human Nutrition

• MacronutrientsMacronutrients– Protein, carbohydrates, and fatsProtein, carbohydrates, and fats

• MicronutrientsMicronutrients– Vitamins A, C, and EVitamins A, C, and E– Minerals (iron, iodine, and calcium)Minerals (iron, iodine, and calcium)

UndernutritionUndernutrition – consuming – consuming insufficient food to meet one’s insufficient food to meet one’s minimum daily energy needs.minimum daily energy needs.

NutritionMalnutritionMalnutrition – faulty nutrition, – faulty nutrition,

caused by a diet that caused by a diet that does not does not have enoughhave enough protein, essential protein, essential fats, vitamins, minerals and other fats, vitamins, minerals and other nutrients needed for good health.nutrients needed for good health.

• MarasmusMarasmus– Diet low in both calories and proteinDiet low in both calories and protein

• KwashiorkorKwashiorkor– Severe protein deficiencySevere protein deficiency

Marasmus – “wasting disease”

Kwashiorkor

“displaced child”

Poverty MalnutritionDecreasedresistanceto disease

High deathrate forchildren

Decreasedenergy

Decreasedability

to learn

Decreasedability

to work

Shortenedlife

expectancy

Feedback loop

Environmental Effects of Food Production

Biodiversity lossSoil

Air pollutionWater

Human 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 Production

• Crossbreeding and artificial selectionCrossbreeding and artificial selection• Genetic engineering (gene splicing)Genetic engineering (gene splicing)• Genetically modified organisms (GMOs)Genetically modified organisms (GMOs)• Continued Green Revolution techniquesContinued Green Revolution techniques• Introducing new foodsIntroducing new foods• Working more landWorking more land

Crop

Cross breedingCross breeding

Desired trait(color)

ApplePear

Offspring

CrossCross breedingbreeding

Best results

Newoffspring

Desiredresult

Traditional Traditional CrossbreediCrossbreedingng

1)1) Slow Slow processprocess

2)2) Can Can combine combine traits only traits only from closely from closely related related speciesspecies

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

cellgene

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

1)Half the time as conventional crossbreeding

2)Cuts costs3)Allows

insertion of genes from almost any other organism

Increasing World Crop Production

• Continued Green Revolution Continued Green Revolution techniques?techniques?– Without fertilizer, water, and pesticides Without fertilizer, water, and pesticides

green revolution varieties are green revolution varieties are no more no more productiveproductive than traditional varieties than traditional varieties

– Green revolution varieties and their Green revolution varieties and their needed inputs needed inputs cost too muchcost too much for for subsistence farming.subsistence farming.

– Grain yields are increasing at a much Grain yields are increasing at a much slower paceslower pace..

Increasing World Crop Production

• Continued Green Revolution Continued Green Revolution techniques?techniques?– Actual gains from green and gene Actual gains from green and gene

revolutions may be revolutions may be overstatedoverstated..– Crop yield may start dropping for a Crop yield may start dropping for a

number of number of environmental reasons.environmental reasons.– Increased Increased loss of biodiversityloss of biodiversity can limit can limit

genetic raw material.genetic raw material.

Increasing World Crop Production

• Introducing new foodsIntroducing new foods– Getting farmers to take risk of Getting farmers to take risk of

growing new types of food.growing new types of food.

– Getting consumers to try new Getting consumers to try new foods.foods.

Increasing World Crop Production

• Working more landWorking more land

Not usable

Arid land6%

Tropicalforest

8%

Cultivated

10%

Grazed

11%Forests,

aridlands

14%

51%

Ice, snow, desertsmountains““Many analysts believe Many analysts believe

that significant that significant expansion of cropland expansion of cropland is unlikely over the is unlikely over the next few decades.”next few decades.”

How about producing more meat…

• Rangeland is land that is…– too dry– too steeply sloped– too infertile …to grow crops

(40% of ice-free land area)• Pastures

– managed grasslands or enclosed meadows

How is meat produced?• Open grazingOpen grazing

– 80% of cattle, 80% of cattle, sheep and sheep and goats are raised goats are raised on rangelandon rangeland

Kilograms of grain needed per kilogram of body weight

Beef cattle 7

Pigs 4

Chicken 2.2Fish (catfish

or carp) 2

•FeedlotsFeedlots–Account for Account for 40% of the 40% of the world’s meat world’s meat productionproduction

Producing more meat

• Condition of the world’s rangelandsCondition of the world’s rangelands– DECLINING! DECLINING!

• Environmental consequences of Environmental consequences of meat productionmeat production– See See ConnectionsConnections page 299 page 299– Read Read Spotlight page 300Spotlight page 300

Catching and Raising More Fish

• FisheriesFisheries – concentrations of aquatic – concentrations of aquatic species suitable for commercial species suitable for commercial harvesting in a given body of waterharvesting in a given body of water

• 55%55% of annual commercial catch of annual commercial catch comes from the comes from the oceanocean..

• 33%33% from from aquacultureaquaculture..• 12 %12 % from from inland freshwater fishinginland freshwater fishing..

sonartrawllines

float

Spotter airplane

Fish farmingin cage

Trawlerfishing

Purse-seinefishing

trawl flap

trawl bag

Long line fishing

lines withhooks

Drift-net fishing

Fish caughtby gills

buoy

fish school

Commercial Fishing Methods

Potential to harvest more fish

• 1950-19821950-1982+Fish catch increased 5-foldFish catch increased 5-fold+Per capita seafood catch doubledPer capita seafood catch doubled

• Since 1982Since 1982– Little increase in commercial fish Little increase in commercial fish

catchcatch– Per capita commercial fish catch Per capita commercial fish catch

fallingfalling

Potential to harvest more fish

The primary cause of depletion of The primary cause of depletion of fish stocks is fish stocks is too many fishing too many fishing boatsboats pursuing pursuing too few fishtoo few fish or or

OVERFISHINGOVERFISHING(Tragedy of the Commons)(Tragedy of the Commons)

• Habitat destructionHabitat destruction• Global warmingGlobal warming

Aquaculture

• Fish farmingFish farming– Cultivating fish in a controlled Cultivating fish in a controlled

environment.environment.– Harvesting them when they reach the Harvesting them when they reach the

desired size.desired size.– Catfish are the leading aquaculture Catfish are the leading aquaculture

product in the USproduct in the US

Aquaculture

• ProblemsProblems– Raises demand for ocean fish as fish Raises demand for ocean fish as fish

meal to feed aquaculture speciesmeal to feed aquaculture species– Creating vast amounts of animal Creating vast amounts of animal

waste in coastal areaswaste in coastal areas– Farming of carnivorous fish increases Farming of carnivorous fish increases

over-fishing of smaller marine over-fishing of smaller marine species.species.

Future• Increasing wild catch and Increasing wild catch and

aquaculture will not increase world aquaculture will not increase world food supplies significantly.food supplies significantly.

• Fish and shellfish supply only 1% Fish and shellfish supply only 1% of the energy and 6% of the of the energy and 6% of the protein in the human diet.protein in the human diet.

Government Agricultural Policy

• Financially risky businessFinancially risky business• Forms of assistanceForms of assistance..

– Keep food prices artificially low.Keep food prices artificially low.– Give farmers subsides to keep them Give farmers subsides to keep them

in business and encourage them to in business and encourage them to increase food production.increase food production.

– Eliminate price controls and subsides Eliminate price controls and subsides and let farmers and fishers respond to and let farmers and fishers respond to market demand without government market demand without government control.control.• Increase aid for the poorIncrease aid for the poor

Future limitations to Future limitations to increased food increased food productionproduction• Lack of water for irrigationLack of water for irrigation• Reduced genetic diversityReduced genetic diversity• Leveling off of yieldsLeveling off of yields• Environmental effects which Environmental effects which

degrade existing croplanddegrade existing cropland

Solutions: Sustainable Agriculture

1) Slowing population growth2) Reducing poverty3) Phasing in systems of

sustainable agriculture (also called organic farming)

‘Organic’ foodsPlants

• Produced without synthetic pesticides, fungicides, and herbicides

• Cannot include genetically engineered foods or be irradiated

• Cannot be grown on soils fertilized with sewage sludge

Animals• Produced from

100% organically grown feed.

• Given access to outdoor range or pasture

• Produced without use of hormones and antibiotics

Principles of Sustainability

• Most ecosystems use renewable Most ecosystems use renewable solar energysolar energy as the primary source as the primary source of energy.of energy.

• Ecosystems replenish nutrients Ecosystems replenish nutrients and dispose of wastes by and dispose of wastes by recyclingrecycling chemicals.chemicals.

Principles of Sustainability

• BiodiversityBiodiversity helps maintain the helps maintain the sustainability of ecological sustainability of ecological functioning of ecosystems and functioning of ecosystems and serves as a source of adaptation to serves as a source of adaptation to changing environmental conditions.changing environmental conditions.

• In nature there are always limits to In nature there are always limits to population growthpopulation growth and and resource resource consumptionconsumption..