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Nutrition
• Malnutrition: A lack of specific nutrients • Can occur in people who have enough food but not nutritious food
• Undernutrition: A lack of food
NutritionFood Function Source
Proteins/Amino acids
Growth and repair of tissue
Meat, beans, fish
Carbohydrates Energy Vegetables, grains
Fats Energy Oils, animals
Minerals/Vitamins Many Fruits, vegetables, Suppliments
Nutrition
•Cereal crops: Grains used for food
Cereal crop Location grown Importance
Wheat Temperate regions (USA, Europe, Canada, Russia)
Bread, pasta
Economies depend on wheat trade
Some types have protein
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NutritionCereal crop Location grown Importance
Maize/Corn Tropical and subtropical (USA, China, Eastern Europe/Western Asia)
Animal feed
Fuel
Nutritionally poor- lacks amino acids
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NutritionCereal crop Location grown Importance
Rice China
East Asia
Major source of food for East Asia
Requires little post harvest processing
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NutritionCereal crop Location grown Importance
Sorghum Arid regions
(Africa, Middle East, Central America)
Food
Animal feed
Industrial Uses
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Nutrition
• Currently:• 6 million people die of starvation each year• 845 million are undernourshed mainly due to a lack of proteins, fats, minerals/vitamins
https://www.supertracker.usda.gov/foodtracker.aspx
http://cironline.org/reports/map-world-food-statistics-2971
Farming
• Types of Agriculture• Industrialized/ High-Input: Farmers grow crops to sell
• High technology (machines), high input, high yield (amounts of food)
• Traditional/Subsistence: Farmers make only enough food for their families
• Low technology, low input, low yield
FarmingPros Cons
Industrialized High yield (high amount of food)
Foods cost less for consumers
Individual families do not have to farm
High technology (uses machines)- has high costs
High inputs of fuel, water, fertilizer, pesticides
Environmental problems
Farming
• First Green Revolution: 1950-1970• In developed countries • Farmers started to practice industrialized agriculture • Growth of monocultures (only growing 1 type of crop)
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Farming
• Fertilizers• After a harvest, nutrients are removed, chemical cycles are disrupted• Fertilizers replace nutrients (especially nitrogen)
• Organic: Manure, compost• Inorganic: Man-made chemicals
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Farming
• Pesticides: The use of chemicals to kill species that destroy crops• LD50 (Lethal dose 50%): A test that determines how much of a pesticide kills 50% of a population
• Lower numbers means more toxic• Persistence: How long chemical stays in the environment
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Farming
•Pros• Increase crop yield
• Cons• Populations become resistant• Costly• Some have high persistence• Some can affect other species than the targeted pest
Farming
• Second Green Revolution: 1967-Today• In developing and developed countries • Started by Norman Borlaug in Mexico
Farming
• Scientists breed specialized versions of crops that are high yielding for the climate they will be growing in • Farmers in developing nations also start to use industrialized agriculture methods
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Farming
•Gene Revolution: Scientists are creating genetically modified organisms (GMOs)
• Pros: GMOs have a higher yield, are pest resistance, grow in harsh climates (droughts), or have more nutritional value• Cons: Costly, can require specific levels of water/fertilizer
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Farming
• Major problems with Industrial Agriculture• Overuse of fertilizers, water, and pesticides• Preemptive use of pesticides• Soil degradation
Farming
• Sustainable farming: Using farming practices that considers the long term ability of a farm to produce food AND the health of the ecosystem around the farm
• Polycultures (plant different crops) • Organic fertilizers• Efficient use of water• Conserves soil
Farming
• Biomagnification: The concentration of a high-persistent toxic chemicals increases for organisms higher on the food chain
• Chemicals: Pesticides, PCBs, Mercury
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Farming
• Integrated Pest Management (IPM): Alternative to using large amounts of pesticides
Steps:1. Monitor crops for pests2. Use cultivation controls (hot water, vacuum pests, remove by hand, trap)3. Biological controls (introduce natural predators or pathogens)4. Use small amounts of pesticides in a limited area