human food systems: 1. croplands 2. rangelands 3. oceanic fisheries
TRANSCRIPT
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
Recyclingvital
chemicalsRenewable
energyresources
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
Capital
Fossil 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
Labor
Capital
• 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)
0.00
20000000.00
40000000.00
60000000.00
80000000.00
100000000.00
120000000.00
140000000.00
160000000.00
2002
1998
1994
1990
1986
1982
1978
1974
1970
1966
1962
Year
Mea
t C
om
sum
pti
on
(m
etri
c 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
Cer
eal
Co
nsu
mp
tio
n
(th
ou
san
d m
etri
c to
ns)
Mexico
United States
Ethiopia
Germany
Major environmental effects of food production
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 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,arid
lands
14%
51%
Ice, snow, desertsmountains