3.5 Food Resources

Food Resources

Human food systems:

1. Croplands2. Rangelands3. Oceanic

fisheries

To feed the increasing world population we must:

Produce and equitably distribute more food than ever before.

Do this in a environmentally sustainable way.

SolarCapital

Airresources

andpurification

Climatecontrol Recycling

vitalchemicals

Renewableenergy

resources

Nonrenewableenergy

resources

Nonrenewablemineral

resourcesPotentiallyrenewable

matterresources

Biodiversityand gene

pool

Naturalpest anddiseasecontrol

Wasteremoval and

detoxification

Soilformation

andrenewal

Waterresources

andpurification

NaturalCapital

Limitations:Environmental

degradationPollutionLack of water for

irrigationOvergrazingOverfishingLoss of ecological

services

4 Types of agriculture systems:

Industrialized agriculturein developed countries

Land

Labor

Capital

Fossil fuelenergy

•Uses large amounts of fossil fuels energy, water, commercial fertilizer, and pesticides to produce huge quantities of single crops or livestock animals for sale.• 25% of croplands in developed countries.

Intensive traditional agriculturein developing countries

Land

Labor

CapitalFossil fuel energy

•Uses large amounts of human input and draft labor, water, and fertilizer, to produce enough food to feed their families and sell for income.• In North America 2.4% of labor force is used in agriculture vs 45-65% in developing countries.

Shifting cultivation in tropicalforests in developing countries

Land

Labor

Capital

•Growing cash crops on large monoculture plantations, mostly for sale.• A large amount of livestock production is industrialized. Mostly pigs and chicken are raised in densely populated pens and cages and are fed mostly grain from croplands.

Nomadic herding indeveloping countries

Land

LaborCapital

• Uses mostly human labor and draft animals to produce only enough crops or livestock for a farm family’s survival.• Practiced by 2.7 billion people (44% of the world’s population). •Provide 20% of the world’s food supply.

Industrialized agriculture

Shifting cultivation

Plantation agriculture

Nomadic herding

Intensive traditional agriculture

No agriculture

RangelandsAbout 40% of the earth’s ice-free land.

This land provides forage or vegetation for grazing and browsing animals.

Nomadic herding Stock raising on ranges

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

FisheriesThe world’s third major food-producing

system.55% of the annual commercial catch comes

from the ocean.Harvesting methods:

] Trawler fishing] Purse-seine] Longlineing] Drift-net

Spotter airplane

Fish farmingin cage

Trawlerfishing

Purse-seinefishing

sonartrawl flaptrawllines

trawl bag

Long line fishing

lines withhooks

Drift-net fishing

Fish caughtby gills

float buoy

fish school

The rest of the annual catch comes from using] Aquaculture (33%)] Inland freshwater fishing from lakes, rivers and reservoirs (12%)

About 1/3 of the catch is used as animal feed, fish meal and oils. Hake

Haddock

Cod

Sardine Anchovy

Herring

Mackerel

Tuna

Krill

Shrimp

Lobster

Crab

Oyster Clam

Octopus

Squid

Seafood type

Kilocalories of fossil fuel input per kilocalorie of protein output

Marine Fisheries

Shrimp

Salmon

Cod

Ocean Aquaculture

Salmon cageculture

Salmon ranching

Seaweed

3-98

18-52

20

50

7-12

1

Comparing Food ProductionTerrestrial

Food is harvested from low trophic levels.

More efficient fixing of solar energy by photosynthesis.

AquaticFood is harvested

from higher trophic levels mostly because of human taste.

Energy conversions are more efficient along the food chain.

Meat Consumption (1961-2002)

0.0020000000.0040000000.0060000000.0080000000.00

100000000.00120000000.00140000000.00160000000.00

2002

1998

1994

1990

1986

1982

1978

1974

1970

1966

1962

Year

Mea

t Com

sum

ptio

n (m

etric

to

ns)

Developed Countries

Developing Countries

Cereal Consumption

0

50000

100000

150000

200000

250000

300000

350000

400000

2002

1998

1994

1990

1986

1982

1978

1974

1970

1966

1962

Year

Cere

al C

onsu

mpt

ion

(thou

sand

met

ric to

ns)

Mexico

United States

Ethiopia

Germany

Major environmental effects of food production

Biodiversity LossLoss 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 PollutionGreenhouse 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 HealthNitrates 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 Crop Production

Genetic engineering

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

Try new foodsIncrease cultivation of less widely known plants to supplement or replace staple foods.

Insects – microlivestock – could be an important potential source of protein.

Irrigate &Cultivate

More Land

In use

Not usable

Arid land6%

Tropicalforest

8%

Cultivated

10%

Grazed

11%Forests,

aridlands

14%

51%

Ice, snow, desertsmountains