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3.5 Food Resources. Food Resources. Human food systems: Croplands Rangelands Oceanic fisheries. Solar Capital. Air resources and purification. Climate control. Recycling vital chemicals. Water resources and purification. Renewable energy resources. Soil formation and
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Food Resources Human food systems: Croplands Rangelands Oceanic fisheries
Solar Capital Air resources and purification Climate control Recycling vital chemicals Water resources and purification Renewable energy resources Soil formation and renewal Natural Capital Nonrenewable energy resources Waste removal and detoxification Nonrenewable mineral resources Natural pest and disease control Potentially renewable matter resources Biodiversity and gene pool To feed the increasing world population we must: • Produce and equitably distribute more food than ever before. • Do this in a environmentally sustainable way.
Limitations: • Environmental degradation • Pollution • Lack of water for irrigation • Overgrazing • Overfishing • Loss of ecological services
Land Labor Capital Fossil fuel energy Industrialized agriculture in developed countries 4 Types of agriculture systems: • 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.
Land Labor Capital Fossil fuel energy Intensive traditional agriculture in developing countries • 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.
Land Labor Capital Shifting cultivation in tropical forests in developing countries • 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.
Land Labor Capital Nomadic herding in developing countries • 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.
Plantation agriculture Intensive traditional agriculture Industrialized agriculture Nomadic herding No agriculture Shifting cultivation
Rangelands • About 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
Kilocalories of fossil fuel input per kilocalorie of protein output Food Type Feed lot beef 20-78 Pigs 35 Broiler chicken 22 Rangeland Beef 10 Sheep 10 Vegetables 2-4
Fisheries • The 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 Trawler fishing Fish farming in cage Purse-seine fishing trawl flap sonar trawl lines fish school trawl bag Fish caught by gills Drift-net fishing float buoy Long line fishing lines with hooks
Krill Hake Sardine Anchovy Oyster Clam Shrimp Herring Haddock Mackerel Lobster Octopus Squid Cod Tuna Crab • 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.
Kilocalories of fossil fuel input per kilocalorie of protein output Seafood type Marine Fisheries Shrimp 3-98 18-52 Salmon 20 Cod Ocean Aquaculture Salmon cage culture 50 Salmon ranching 7-12 Seaweed 1
Aquatic Food is harvested from higher trophic levels mostly because of human taste. Energy conversions are more efficient along the food chain. Comparing Food Production Terrestrial • Food is harvested from low trophic levels. • More efficient fixing of solar energy byphotosynthesis.
Soil Erosion Loss of fertility Salinization Waterlogging Desertification Biodiversity Loss Loss and degradation of habitat from clearing grasslands and forests and draining wetland Fish kills from pesticide runoff Killing of wild predators to protect livestock Loss of genetic diversity from replacing thousands of wild crop strains with a few monoculture strains
Water Aquifer depletion Increased runoff and flooding from land cleared to grow crops Sediment pollution from erosion Fish kills from pesticide runoff Surface and groundwater pollution from pesticides and fertilizers Overfertilization of lakes and slow-moving rivers from runoff of nitrates and phosphates from fertilizers, livestock wastes, and food processing wastes Air Pollution Greenhouse gas emissions from fossil Fuel issue Other air pollutants from fossil fuel use Pollution from pesticide sprays
Human Health Nitrates in drinking water Pesticide residues in drinking water, food, and air Contamination of drinking and swimming water with disease organisms from livestock wastes Bacterial contamination of meat
Projected Advantages Projected Disadvantages Need less fertilizer Need less water More resistant to insects, plant disease, frost, and drought Faster growth Can grow in slightly salty soils Less spoilage Better flavor Less use of con- ventional pesticides Tolerate higher levels of herbicide use Irreversible and unpredictable genetic and eco- logical effects Harmful toxins in food from possible plant cell mutations New allergens in food Lower nutrition Increased evolution of pesticide- resistant insects and plant diseases Creation of herbicide- resistant weeds Harm beneficial insects Lower genetic diversity Genetic engineering
Try new foods • Increase cultivation of less widely known plants to supplement or replace staple foods. • Insects – microlivestock – could be an important potential source of protein.
In use Grazed Cultivated Tropical forest Forests, arid lands 11% 10% Arid land 8% 6% 14% 51% Ice, snow, deserts mountains Not usable Irrigate &Cultivate More Land