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..