Chapter 13 Food Resources
Food in the World • 30,000 plant species with parts people can eat • 15 plants and 8 animals supply 90% of our food • Wheat, rice, and corn are half the calories people eat • 66% of people eat mainly rice, wheat, and corn (grains) • The top third of the economic chain eats primarily meat. www.iia.msu.edu/absp/ drought_00.html
Plantation agriculture Industrialized agriculture Nomadic herding Shifting cultivation Intensive traditional agriculture No agriculture World Food Production Fig. 13-2 p. 279
Types of Food Production • Industrialized agriculture • Traditional agriculture www.orknet.co.uk/welsby/ farming.htm
Industrialized Agriculture • Industrialized agriculture-Use large amounts of fossil fuel energy, water, commercial fertilizers and pesticides to produce huge quantities of single crops or livestock animals for sale. • www.alaskajournal.com/.../ foc_20030804021. www.alaskajournal.com/.../ foc_20030804021.
Traditional Agriculture • Traditional agriculture-practiced by 2.7 people on earth • Traditional subsistence agriculture-produce enough food to stay alive • Traditional Intensive agriculture-farmers increase inputs of human and draft labor, fertilizer and water to get a higher yield per area of cultivated land to produce enough food for families, and their income members.aol.com/ porkchopsplace/
The Green Revolution • To eliminate hunger by improving crop performance • Movement to increase yields by using: • New crop cultivars • Irrigation • Fertilizers • Pesticides • Mechanization Results: • Did not eliminate famine • Population still increasing • Increase cost of production • An increased negative environmental impact • Didn’t work for everyone
Green Revolution • Involves 3 steps • 1. Developing and planting monocultures of selectively bred or genetically engineered high yield varieties of key crops • 2. Lavishing fertilizer, pesticides, and water on crops to produce high yields • 3. Often increasing the intensity and frequency of cropping
Positive effects : Reduced pressure to convert more natural land to cropland Prevented some deforestation and habitat conversion Negative effects: Pollution and reduced biodiversity Erosion, salinization and desertification Increased susceptibility to crop diseases Today, soil quality is declining, resulting in lower yields. The green revolution had costs and benefits From 1900 to 2000, cultivated area increased 33%, while energy inputs increased 80 times!
Producing Food by Green-Revolution Techniques (1950-1970) • High-input monoculture • Selectively bred or genetically-engineered crops • High inputs of fertilizer • Extensive use of pesticides • High inputs of water • Increased intensity and frequency of cropping
Second green revolution (developing countries) First green revolution (developed countries) Major International agricultural research centers and seed banks Green Revolutions Fig. 13-6 p. 282
Golden Rice -Grains of Hope or an Illusion? Figure 13-1 • Vitamin A deficiencies cause blindness • Golden rice is a new genetically engineered strain of rice containing beta-carotene. • Can inexpensively supply vitamin A to malnourished.
BUT… • Critics contend that there are quicker and cheaper ways to supply vitamin A. • Scientists call for more evidence that the beta-carotene will be converted to vitamin A by the body.
The green revolution http://www.youtube.com/watch?v=cEBtO25xW-o&feature=related http://www.youtube.com/watch?v=LRPibWf3wN8&feature=related
Food Production in the U.S. • Since 1940, food production in the U.S. has more than doubled crop production • 9% of population is involved in the U.S. agricultural system. • Generates 18% of countries GNP
Eating animal products has significant impacts As wealth and commerce increase, so does consumption of meat, milk, and eggs. Global meat production has increased fivefold. Per capita meat consumption has doubled. .
Feedlot agriculture Feedlots (factory farms): also called Concentrated Animal Feeding Operations (CAFOs) Huge warehouses or pens designed to deliver energy-rich food to animals living at extremely high densities Over ½ of the world’s pork and poultry come from feedlots.
The benefits of feedlots include: Greater production of food Unavoidable in countries with high levels of meat consumption, like the U.S. They take livestock off the land and reduce the impact that they would have on it. Drawbacks of feedlots include: Contributions to water and air pollution Poor waste containment causes outbreaks of disease. Heavy uses of antibiotics to control disease
Livestock Production • Meat products are sources of quality protein. • Between 1950 and 1996, world meat production increased fourfold and per capita meat production rose by 29%. • 14% of U.S. topsoil is associated with livestock grazing. • Cattle belch out 12-15% of all the methane released into the atmosphere • Some say if Americans cut their grain intake by 16%, this would save enough grain to provide a subsistence diet for nearly 900 million people.
World Food Problems • Reasons for problems: • Population growth • Increasing affluence • Degradation and loss of cropland • Little growth in irrigation • Decline in global fertilizer
Some people starve, but others eat too much • Undernourishment: people receive too few calories per day • Malnutrition: receiving too few nutrients in food • Every 5 seconds, a child starves to death. • Overnutrition: receiving too many calories each day • In the U.S., people eat junk food and don’t exercise. • Worldwide, more than 300 million people are obese.
Diseases of Malnutrition and Undernutrition • Anemia • Goiter • Marasmus • Kwashiorkor • Rickets • Scurvy
Famine vs. Food Shortage Political situations causes famine Present day examples – famine in the Darfur region of Sudan
Good News! • Between 1970 and 1995, worldwide proportion of people suffering from undernourishment went from 36% to 14%. • Number of malnourished people fell from 940 million in 1970 to 850 million in 1995. • We produce more than enough food to meet the basic nutritional needs of every person on earth today
Environmental Effects of Food Production See Fig. 13-13 p. 288 • Biodiversity loss – habitat loss, fish kills, poaching of predators, loss of genetic diversity b/c of monocultures • Soil – erosion, fertility loss, salinization, waterlogging, desertification • Air pollution – emissons fr. Fossil fuels, pollution from pesiticide sprays • Water – aquifer depletion, runoff, sedimentation, fish kills, pollution from pesticides, overfertilization of lakes • Human health – nitrates, pesticides & disease organisms in drinking water, bacterial contam of meat
Increasing World Crop Production • Crossbreeding and artificial selection • Genetic engineering (gene splicing) • Genetically modified organisms (GMOs) • Continued Green Revolution techniques • Introducing new foods – ex. Winged bean p. 292 • Working more land – is cultivating marginal land likely to be sustainable? See Fig. 13-16 p. 291
Food security Food security: the guarantee of adequate and reliable food supply to all people at all times We have reduced hunger by half since 1970. Through fossil fuels, irrigation, fertilizers, pesticides, more agricultural land, more productive crops, and livestock Monoculture: the uniform planting of a single crop Industrialized agriculture requires that vast fields are planted with single types of crops. Since 1985, world grain production per person has fallen by 9%.
Environmental Effects of Producing Food • Agriculture has a greater harmful impact on air, soil, water, and biodiversity resources than any other human activity.
Interplanting • Polyvarietal cultivation-Where plot is planted with several varieties of the same crop • Intercropping-two or more different crops grown at same time on a plot • Agroforestry- Crops and trees are planted together • Polyculture-Many different plants mature at various times, and are planted together.
Cultivation of Land • 36% of the world’s land is devoted to raising crops. • Some think that cultivating more land is a possible solution to the food crisis.
Food Growth in Urban Areas • Urban gardens provide 15% of world’s food. • If people grew more food in their backyards, they could live more sustainable and save money.
Fishing • 3rd major food producing system consists of fisheries • 99% of fish caught in ocean is from the coastal waters • Between 1950 and 1996, fish catch increased 4.9 fold
Problems With Fishing • Overfishing-Taking of so many fish that too little breeding stock is left to maintain numbers • Commercial extinction-reduction of a species to the point at which it’s no longer profitable to hunt for them
Aquaculture • Aquaculture-where fish and shellfish are raised for food • Supplies 20% of world’s commercial food harvest • Increased 3.3 fold between 1984 and 1996
Aquaculture in ENC Catfish farming
Aquaculture – The Blue Revolution Wild fish populations are plummeting. Technology and increased demand Aquaculture: raising aquatic organisms for food in a controlled environment (“fish farm”) Aquatic species are raised in open-water pens or land-based ponds. The fastest-growing type of food production Provides a third of the world’s fish Most widespread in Asia
The benefits and drawbacks of aquaculture Benefits: A reliable protein source Sustainable Increases food security Reduces fishing pressure on wild fish stocks Energy efficient Drawbacks: Diseases can occur, requiring expensive antibiotics Reduces food security Large amounts of waste Growing grain to feed fish is inefficient Farmed fish may escape and introduce disease into the wild
Major Environmental Effects of Food Production Biodiversity Loss • Loss and degradation of habitat from clearing grasslands and forests and draining wetlands • Fish kills from pesticide runoff • Killing of wild predators to protect live stock • Loss of genetic diversity from replacing thousands of wild crop strains with a few monoculture strains • 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
Gov. assistance to farmers and consumers • Keep food prices low • Give farmers subsidies to keep them in business and to encourage them to increase food production • Eliminate most or all price controls and subsidies • Continue Agricultural research
Sustainable Agricultural • Sustainable Agricultural-Method of growing crops and raising livestock based on organic fertilizers, soil conservation, water conservation, biological control of pests, and minimal use of nonrenewable fossil fuel energy
Figure 13-36 Page 308 Increase Decrease High-yield polyculture Organic fertilizers Biological pest control Integrated pest management Irrigation efficiency Perennial crops Crop rotation Use of more water- efficient crops Soil conservation Subsidies for more sustainable farming and fishing Soil erosion Soil salinization Aquifer depletion Overgrazing Overfishing Loss of biodiversity Loss of prime cropland Food waste Subsidies for unsustainable farming and fishing Population growth Poverty Components of more sustainable, low-throughput agriculture