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This chapter discusses the concepts of food production, including traditional and industrialized methods, as well as the impact on nutritional deficiencies. It covers undernutrition, malnutrition, micronutrient deficiencies, and the problems associated with different types of food production systems.
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Chapter 12 Food Resources
Nutritional Deficiencies • Undernutrition: less than 90% of minimum calories(serious if under 80%) • Malnutrition: deficient in protein + nutrients • Marasmus: low calories and protein (age 0-1) • Kwashiorkor: very low protein (age 1-3)
Macronutrient Deficiencies Vitamin A (carrots) • affects 124 million children: blindness, reduces resistance to diarrhea • gene splicing: beta carotene rich variety of rice (golden rice) Iron (spinach) needed for hemoglobin--> anemia Iodine (seafood) deficiency leads to goiter, enlargement of thyroid
12-2 How Is Food Produced? • Concept 12-2A We have sharply increased crop production using a mix of industrialized and traditional agriculture. • Concept 12-2B We have used industrialized and traditional methods to greatly increase supplies of meat, fish, and shellfish.
Traditional Foods • Three systems produce most of our food • Croplands: 77% • Rangelands, pastures, and feedlots: 16% (using 29% of world’s land area) • Ocean fisheries and aquaculture: 7% • Importance of wheat, rice, and corn • Provide a little less than half of calories and protein • Monoculture problems
Food Production • Has increased tremendously • Technology • Increased use of tractors, farm machinery, and high tech fish equipment • Inorganic fertilizer, pesticides, irrigation, high yield crops • Raising fish, poultry and livestock in factory like conditions (CAFOs)
Changes in Food Supply System Croplands Problems • Environmental degradation • Pollution • Water shortage
Changes in Food Supply System • Rangelands Problems • Overgrazing
Changes in Food Supply System Fisheries Improvements • High tech fishing boats (radar, nets) • Aquaculture ponds Problems - Overfishing
Major Types of Food Production • Crop growth replaces late-successional community with early-successional community (usually monoculture)
Major Types of Food Production • Industrialized (high-input) agriculture • 25% of all cropland • plantation agriculture • common in tropical developing countries • produces cash crops e.g. sugarcane, coffee, bananas
Major Types of Food Production • Greenhouse food production • Used in arid areas • Requires diversion of water • Hydroponics (no soil) uses recycled water, so more efficient
Spain Greenhouses • Between 1974 and 2000, Spain built 118 dams as part of 22 water diversion projects to support greenhouse agriculture
2nd Major type of Food Production • Traditional agriculture • feeds 42% of world • Traditional subsistence • uses humans and draft animals to feed family • Shifting agriculture, nomadic livestock herding • Traditional intensive agriculture increased input: labor, water, fertilizer
More Traditional Ag • Polyculture • Several crops on same plot • Polyculture provides habitat for pest predators • Crops mature at different times e.g. Slash and burn agriculture • Leave abandoned plot fallow for 10 – 30 years • Ashes fertilize
Agriculture and Environmental Problems • Soil erosion • Desertification • Salinization and waterlogging • Water shortages • Loss of wild species • Global warming
Science Focus: Soil Is the Baseof Life on Land • Soil composition • Soil formation • Layers (horizons) of mature soils • O horizon: leaf litter • A horizon: topsoil • B horizon: subsoil • C horizon: parent material often is bedrock • Soil erosion • Hundreds of years to produce an inch of soil
First Green Revolution • Developed countries, 1950-1970 • Greatly improved production • 3 steps 1. Use high yield crops (monoculture) 2. Use large amounts of fertilizer, pesticides, and water 3. Increase frequency of planting (multicropping)
2nd green revolution • Began in 1967 • Dwarf varieties for tropics • Fast growth • High input: water, chemicals, oil • Conserves forest, grassland, etc
Impact of 2 Green Revolutions • Overall food production tripled (1950-1996) • per capita food prod up by 31% (1961 to 1985) • World Bank: food price in 2000 was 1/3 food price in 1957 (taking inflation into account) • Per capita increased, then decreased since 1985 • lower price?, limits on high input crops b/c of erosion?, etc
Agribusiness in U.S. 1. 650,000 farmers (2% of population) a) 9% of population is part of ag system, from growing to market 2. Biggest industry in US (18% of GNP)
Agribusiness in U.S. 3. In US, 2% income on food vs 40-70% developing - rise in corn prices hurt developing countries - 2% above includes external costs of subsidies, taxpayer cleanup
Agribusiness in U.S. 4. Overall: 1 unit food energy = 10 units fossil fuel in growing, harvesting, transporting to store, refrigerating, cooking Food travels an average of 1300 mi from field to plate
Video • http://www.youtube.com/watch?v=AEINuCL-5wc&feature=related • file:///Volumes/Miller_3B_PL/Media/LITE/PowerPoint_Lectures/chapter12/videos_animations/transgenic_plants.html
Meat Production and Consumption Increased • Animals for meat raised in • Pastures • Feedlots and CAFOs • Meat production increased fourfold between 1961 and 2007 • Demand is expected to go higher
Fish and Shellfish Production Have Increased Dramatically • Aquaculture (blue revolution) • Worlds fastest-growing type of food production • In 2006, aquaculture produced 43% of all fish consumed • Dominated by operations that raise herbivorous species (catfish, tilapia, carp) • Polyaquaculture farm waste to fertilize ponds for phytoplankton food
Aquaculture • Fish and shellfish • China produces 62% of output • Fish farming: raising fish under controlled conditions • Fish ranching: hold, release anadromous fish, catch when they return to spawn
Aquaculture • China has developed fish polyculture • 4 species of carp feed at different trophic levels • Aquaculture produces • 90% oysters, 40% salmon, 50% shrimp, prawn • 65% of freshwater fish worldwide • Catfish is leading US aquaculture product
Aquaculture • Pros: little space, saves conventional fisheries • Cons: large output of waste, disease spreads, Mangroves are cleared to raise shrimp (Indonesia)
140 120 100 80 Wild catch Catch (millions of metric tons) 60 40 20 Aquaculture 0 1950 1960 1970 1980 1990 2000 2010 Year Total World Fish Catch Fig. 12-8a, p. 285
Environmental Problems of Food Production • Erosion • Wind and water • Reduces fertility, sedimentation • Desertification • definition
Irrigation • 20% of world’s cropland is irrigated • Salinization • Waterlogging • Sometimes results from attempt to counteract salinization
Pros and Cons of GMFs • Pros • Cons
Food Distribution Problems • Poverty • 80% of all malnourished children live in countries with enough food to feed them • Political corruption • Inadequate storage facilities
Rangeland and Pastures • Rangeland (40% managed by BLM) • Pasture (managed or enclosed) • Overgrazing (metabolic reserve) • Compaction • Nomadic herding • Riparian zones • Feedlots
Sustainability • Sustainable yield is hard to establish • Overfishing may lead to commercial extinction, e.g. orange roughy • 11 of 15 most important fisheries are overfished (cod off Cape Cod, salmon in Washington and Oregon) • Over 100 international fishery disputes • Global warming: degrade coral reef • Ozone depletion: increased UV penetration
Pests • Compete with humans for food • Invade lawns and gardens • Destroy wood in houses • Spread disease • Are a nuisance • May be controlled by natural enemies
Pesticides • Types of Pesticides • Pros and Cons of Pesticide Use • Pesticide Legislation • Pesticide Alternatives
Pesticides: Types • Chemicals that kill undesirable organisms • Insecticides • Herbicides • Fungicides • Rodenticides
First Generation Pesticides • Derived from plants (coevolution) • Plant extracts • Nicotine, pyrethrum (from the head of a chrysanthemum), and rotenone (from root of rainforest legume) • Sulfur, lead, arsenic, mercury
Second Generation Pesticides • Primarily synthetic organic compounds • Broad-spectrum agents • Narrow-spectrum agents • Persistence in the environment
The Case for Pesticides • Save human lives • Increase food supplies and lower costs • Work better and faster than alternatives • Health risks may be insignificant compared to benefits • Newer pesticides are becoming safer • New pesticides are used at lower rates
The Case Against Pesticides • Genetic resistance • The pesticide treadmill • Can kill non-target and natural control species • Can cause an increase in other pest species • Pesticides do not stay put • Can harm wildlife • Potential human health threats
Characteristics of an Ideal Pesticide • Affects only target pests • Harms no other species • No genetic resistance • Breaks down quickly in the environment • More cost-effective than doing nothing
Pesticide Regulation in the United States • Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) • EPA Evaluation of chemicals • Tolerance levels • Inadequate and poorly enforced • Food Quality Protection Act